back to article The return of Killer Chlorine

After many mind-sapping years of trawling through the morass of health scare stories, I formulated a number of laws, one of which was the Law of Beneficial Developments: The intensity of the scaremongering attack on any new development is proportional to the level of benefit that it endows. Unbelievably, the Chlorine Scare has …


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  1. Linbox
    Thumb Up

    Great addition to the staff

    I've been reading Numberwatch for many years and it's been a valuable addition to my reading mix. Like the always brilliant Lewis Page, John Brignell is a welcome addition to the staff of El. Reg.

  2. Anonymous Coward
    Anonymous Coward

    Lovin' the time of cholera?

    No doubt certain more radical environmentalist can regard calmly the rise in mortality that we could expect from giving up chlorination, but it might be stressful for the rest of us.

  3. Roddy MacKenzie
    Paris Hilton

    Headline: Dihydrogen Monoxide found in all cancer cells

    Ban this dangerous substance before more innocents die.

    For further detail, visit the campaign site at

    This warning brought to you by the Minstri uv Ejukashun an Sines

  4. Steve

    I'm puzzled

    If (as an analogy) you perform a random poll of 2000 adults and ask a question to which only 4 respond in a specific way, the claim that you survey'd 2000 people is still valid.

    Why are you arguing that the study size was only 80, if it was in reality 400,000 of which only 80 were not healthy (in the specified way)?

  5. Anonymous Coward
    Anonymous Coward

    Simple solution

    Offer every household a choice of chlorinated or non-chlorinated water.

    After a while, the non-chlorinated argument will just sort of go away...

  6. Jon Kale

    Would the author care to explain...

    why p=0.05 is described as an "abysmal standard of significance". While I concur with his loathing of data combing ('cos, as we all know, correlation doesn't imply causation), there's nothing wrong with stating your thesis, setting up your study and then seeing if the observed numbers match the prediction with small p; traditionally, we call this process "science" (although any true Popperian would agree that only if the thesis is disprovable does it have any value).

    Anyone got the appropriate papers to hand and can tell me what Doll's significance was? I assume we're all adult enough to have got over the "no, smoking doesn't cause cancer, it's - erm - something else that smokers do and non-smokers don't" theory so beloved of Forest in the late 70s and 80s...

  7. Iwann
    Thumb Up

    RE: Great addition to the staff

    Second that, welcome.

  8. Steven Jones


    Nice to read an analysis by somebody who is clearly an expert in this area. I sometimes think that the misuse of statistical techniques is the true curse of our times. The use by politicans and sociologists is bad enough (a closely overlapped group for anybody who has read the History Man), but the apperance of professional epidemologists is a modern pestilence. Of course there have been some stunning success stories (like the off-quoted one linking smoking with lung cancer). However, the attempt to use such techniques to find incredibly rare events is fundamentally prone to errors due to all sorts of real-world issues, factors they don't take into account, interpetation of results, data source errors. Even if the real risk changes in absolutely numbers is tiny, they can be dressed up into alarmist talk like 200% increases. So my chance might go from one in a million, to three in a million. Big deal - there are lots more real world risks that I can influence (like not riding a motorbike).

    Of course the real truth here is that epidimologists have to find something, or they can't justify their academic salaries. If they can't generate scare stories, get in the media and wake up a few journalists or politicians in need of a cheap story then people might ask why they exist.

    For those who want to read more about the malign effects of epidimology on medicine and "lifestyle" campaigns, then I'd recommend reading The Rise and Fall of Modern Medicine. It's not infallible but it puts a lot of this into perspective.

    It's not as if this stuff can just be ignored. Channel 4 news recently ran a story supported by a "nutritionalist" describing a wekeend fried brekfast as "binging on fat" on the basis that this one meal could cause you to exceed your entire day's saturated fat allowance. This stuff is all based on government guideline numbers, often produced under political pressure, with next to no scientific evidence to support the numbers (admitted as such by those who came up with the guideline amounts on daily alcohol units). A dose of common sense is required here, but the opportunity to politicise policy decision making based on this soprt of junk is open-ended.

    As for Peru, then I can personaly testify as to the effects of having rampant bacteria in your dietary intake having sucumbed twice to some such pestilence in the space of a three week trip. A bit of chorinated drinking water would have been the least of my troubles.

    And don't start me on the subject of Greenpeace junk science...

  9. Anonymous Coward
    Gates Horns

    So DDT wasn't bad?

    I didn't know that.

  10. Graham Wood


    Imagine that the question were 'Are spurs supporters more likely to commit murder than Arsenal supporters?'.

    Now, go find 1 million people - and ask if they are Spurs or Arsenal supporters, and say you get 10 of each.

    Then you ask if they are murderers - and you get two Spurs supporter and one Arsenal supporter.

    Now, does that mean that you have a sample size of 1,000,000 people to say that Spurs supporters are twice as likely to commit murder than Arsenal supporters?


    When you're looking at the affects of <x> on <y>, your sample size is the people that <y> applies to, not everyone that you could have asked.

  11. Terry Kellum

    Public Health Hazards!

    Chlorine is nothing! There is a more insidious killer that is lurking in every home in the free world! Dihydrogen Monoxide threatens our wives and children each and every day of the week! Look it up!

    We need immediate legislation to remove this poisonous substance from sale everywhere!!!!!!!

  12. Darkside
    Thumb Up

    Junk science is everywhere!

    The US government spends vast sums on "research" designed to find harmful effects of cannabis, dammit, no matter how long it takes.

    Meanwhile in the UK, bicycle helmets are a scam: they actually make most cyclists less safe, but there's money in selling them and they shift the blame for accidents onto the person who got hurt.

    A welcome addition to the Reg, indeed, Sir.

  13. Damian Jauregui
    Paris Hilton

    My favourite stats+ignorance=news

    My favourite has to be the one I came across whilst doing Knowledge Management for a agro-chemical business. An attack on an already unpopular weed killer, still on sale in many countries today...

    The headline read "Four Killed By Chemical X In South America!"

    What the article didn't bother to print was the full story...

    One day a helicopter was spraying chemical X across an illegal cannabis plantation in south america, it was known to kill cannabis plants almost instantly which is why the US and the local government were using it.

    First the gardener guy appeared, shouting the odds, then two locals appeared and started shooting up at the helicopter. The helicopter crashed on all three of them and the pilot was killed in the crash too.

    Hence the headline "Four Killed By Chemical X In South America!"

    Not exactly the fault of the chemical company...

    Paris, cause you would, wouldn't you...

  14. David Harper

    The original study is shows no correlation

    I'm looking at the paper from the journal Environmental Health which is the basis of the Torygraph news article.

    Out of almost 400,000 births, only 43 suffered from anencephalus, so we're dealing with a very tiny sample to start with.

    If we look more closely, we find there is zero correlation between the number of cases and the level of trihalomethanes in the mothers' drinking water.

    The same is true of cleft palate and the other birth defects in the study.

    The authors are clearly not statisticians, and Roger Highfield no longer deserves the title of science correspondent.

  15. peter birch

    don't forget....

    when apples appear on trees the weather starts getting colder. kill all apple trees and have summer all year round!

    Was there an IT angle to this?

  16. err0r

    RE: So DDT wasn't bad?

    No, it wasn't.

    DDT should still be used to spray the insides of human dwellings in mosquito prone areas, as it has been proved to be a life saver and perfectly safe for the environment when not used to excess in areas where it is likely to quickly end up in aquatic systems.

  17. Anonymous Coward

    Measure of exposure.

    "Then there is the measure of exposure itself. How much of the dreaded fluid did the pregnant women drink? How did the boffins distinguish between a thirsty mother in a low dosage area and a non-thirsty mother in a high dosage area?"

    And did they account for regular attendance at aqua-natal classes or other pool-based activities...?

  18. Tony

    @I'm puzzled


    that depends on what question you are asking and whether a negative answer has any bearing on your study.

    Lets say you ask the 2000 people in your example 'how long did you have to wait for your hip operation on the NHS' and 2 said 'a year', one said 5 months and the other 1997 said 'I havent had a hip operation'.

    It is true that you asked 2000 people, but only the answers of the three that matched the critera for your question are relevant, so your sample would be 3, not 2000.

  19. Anonymous Coward
    Anonymous Coward


    it was used to battle maleria, but due to residential resistance it's no longer as effective.1 million deaths a year due to maleria - jee I bet that those 60 million dead people were pleased that rich folk didn't have to worry so much about little timmy eating some ddt on his crops.

    And as with most of these things it's the poor people that die becouse they don't have a choice, not the rich ones who can afford quality health care, hygene, medicine, vacination and food (and the ones who spear head resistance to these things.)

  20. Anonymous Coward
    Anonymous Coward

    Re: Public Health Hazards!

    >What are some uses of Dihydrogen Monoxide?

    They should update this to include interrogation techniques in Gitmo.

  21. Ross Ryles
    Thumb Down

    Statistical Standards

    "The abysmal standard of significance in modern epidemiology is a one in 20 chance of the result having occurred by accident. But if you look at ten different diseases, this standard means that the probability of at least one crossing a given threshold of risk level becomes 40 per cent, which should be adjusted for, but isn’t."

    Very true. Unfortunately this is far beyond the general populations understanding of statistics. More worryingly, it seems to be beyond many scientists understanding of statistics!

  22. Anonymous Coward
    Paris Hilton

    And Next ...

    Could some good professor please turn their attention to road accident statistics?

    I (and also Jeremy Clarkson, apparently) am sick to death of every road accident where "speed was a factor" being used as another reason to lower speed limits. Of course speed was a factor - it's always a factor - if the car was stationary, there'd be no accident .. and there'd be no point, either! The essential factor, so often not mentioned, is that the driver made a serious error of judgement ... so education and driver skill improvement should be the appropriate response, not lowered limits, speed cameras and harsher penalties.

    And then there's the road design, sign posting, fatigue, mobile phones, etc., etc., etc.

    OK, sorry I'm off topic, but there haven't been any driving/traffic stories that I've seen recently and I needed to vent.

  23. Anonymous Coward
    Black Helicopters


    That would be the lethal strain of cannabis then.

  24. Dr Stephen Jones

    Roger Highfield ...

    ... is the new editor of New Scientist.

    "Roger is a formidable force in science journalism. He has immense knowledge and wisdom and is brimming with new ideas," said Jeremy Webb, New Scientist's editor-in-chief. The magazine is right at the centre of all these efforts and we need a strong, creative editor to lead it."

    I think the chlorine article demonstrates what Webb means by "creative" - makestuffup.

    My subscription lapsed a few years ago - I won't be renewing it.

  25. JimC


    Yes it was bad... but not so bad as nothing!

  26. Alan
    Black Helicopters

    Chris W

    Nice catch, that is indeed a addition to the uses/dangers of Dihydrogen Monoxide

  27. James Bassett

    @ Darkside - Junk Science

    So, in a rant on "Junk Science" you make the claim "bicycle helmets are a scam: they actually make most cyclists less safe".


    I think you may have difficulty showing, scientifically, quite how a plastic helmet physically makes someone a poorer cyclist. Call me MR Presumptuous, but I would hypothesise that the causality is a purely psychological one and not the fault of the poor, defenceless helmet.

    But thank you for giving me a good laugh on an, otherwise, entirely dull Thursday afternoon. Junk Science indeed.

  28. Mark
    Paris Hilton

    @Darkside Re:Bicycle Helmets

    I know my cycle helmets have saved my life (or at least prevented a nasty cracked head) twice during bicycle accidents. The first time was on a cycle path when someone stepped out in front of me and in avoiding them I came off and totally trashed my helmet, the second was when the new chain on the bike snapped as I accelerated away from traffic lights and I went over the handlebars.

    I personally think you would find it quite hard to prove cycling without a helmet is safer than cycling with one!

    One thing I can't get over is why not wear a helmet? It isn't exactly onerous to remember to put it on before you go out? But the thing that gets me the most is where you see parents cycling with their kids, the kids with helmets and the parents without... I mean do the parents think they are immune to accidents?

    Because even Paris knows a helmet when she sees one...

  29. Steven Jones

    @Jon kale

    The reason why 0.05 is an abismal standard of significance is that if you do a data trawl looking for correlations at maybe 100 different possible causes then a one in twenty level of significance is virtually certain to show a few positive examples. That's how many epidemologist work - rather than starting of with a potential causative model which they want to test, they effectively use the same analysis on a whole range of ills. Even if this particular study wasn't looking at 100 different illnesses, then at any one time there are probably thousands of such studies being worked on. It's inevitable that some wil show a correlation so the result is the same. Large numbers of false positives.

    The best that can be said about a one in twenty test for significance is that it may be sufficient to trigger of a further set of studies to see if some form of causative link (or at least non-randomly occuring correlation) is present. This can be very difficult to do, especially on very rare illnesses. Certainly this sort of study is not sufficient for an alarmist headline which states that exposure to chlorinated water doubles the risk.

    There have been many occasions where corrations have been desmonstrated with no conceivable causative mechanism, simply by tramping through huge numbers of possibilities (as a method of debunking this sort of approach I should add). That doesn't stop the generation of stupid "hidden message" type books about how predictions of past events can be found, retrospectively I should add, in the Bible, works of Shakespeare, you name it. This fallacy doesn't just apply to cases like this - false genetic and fingerprint matches have been found the same way (and cases goine to court). People have been jailed due to misapplication of statistics, sometimes by so-called experts whose methodologies have been shown to be wrong (and anyone reasonably conversant with statistics - which mostly does not include lawyers) could have seen the error.

    What I also note from some of the responses to this article is that a considerable number of people have got no real sense of how statistics work, but that doesn't stop them having an opinion. That includes sarcasm and ridiculopus comparisons to the lung cancer/smoking study. The correlation factors here are just many orders of magnitude different.

    I dare say that the average Register reader is more numerate than the average member of the population. The truth is that most people can't do statistics (and the inability is virtually universal among politicans and national newspaper journalists). What they tend to do is get blinded by numbers thrown around by "experts" as somehow definitive when they are not. Well I say that, but most people I know are now so confused with the conflicting messages that they just don't take any seriously. The problem is that fanatics who do, more dealers in faith than logic.

  30. Anonymous Coward

    more Chlorine scare!

    I'm tracking the EC plans to allow the so called (and rightly scary) "American Chlorine Chicken" into the EU market. This hybrid monster seems to be some sort of beast that is raised purely in terms of good economics, then bathed in Chlorine dioxide to annihilate the inevitable nasties that crowd its surfaces, then posted off to Europe by a slow boat. Once in the EU will probably be stamped as, "countryside nature's best" or similar, sprayed with limonene to dampen the nerve gas olfactory remnants and sold to customers at the price of Bourg-en-Bresse bantams?

    More info available by searching the francophone web with "Poulets américains au chlore"

    for the record, I've converted my swimming pool at home to use 14 tons of water with around a hundred kilos of dissolved NaCl. Galvanically electrolysing with 14amps for three hours each night. Pool doesn;t smell of Cl2, tastes mildly of salt, and hasn't suffered death by algael bloom as it has in previous years using mega 'double' & 'triple' Cl expensive stock pool chemicals. Just don't use Iodised salt!

    100kilos of salt can be had for around 8 quid (for the whole season!)

    Mine's the smock with the bleached, tattered holes in it

  31. Fred

    @ James

    What I remember seeing was:

    - a Cyclist wearing a helmet appears more "professional" to the driver.

    - the driver then gives the cyclist less room during an overtake.

    - less room = more chance of contact between large 1+ tonne object and small <120kg cyclist

    There is also probably an element of "... i'm wearing a helmet so I'm safer from damage, and can take more chances..." effect on the cyclist side.

  32. Fred
    IT Angle

    @ Peter - It angle (or close)

    see this article - some bored "researcher" determined they needed some extra exposure in the media -

    so Cell phones are (again) a cancer danger -


    YET - MRI is not even though the electromagnetic fields involved are 1000s (or more) times as strong.

  33. alphaxion

    how about;...

    a commentary on those dreadful "how clean is your kitchen/room/small intestine" where you see these cretins taking swabs from dirty kitchens and then exclaiming "my lord, you have ecoli growing on your plates! and you have children.. you filthy man (cause it's *always* a man), buy loads of cleaning products and sterelise your environment!".

    Yet, I can't help but notice they never mention that the person is yet to fall ill to these bugs and, in fact is likely be in posession of a healthier immune system and a reduced incidence of allergies.

    Of course, there's always limits to this - IE total squalor - but the abuse of bleach and cleaning products in the home (and their constant pitching of them through programs such as those mentioned above) is a massiively ignored issue because everyone is obsessed with cleaning rather than living in a slightly dirty environment (IE given a big clean only once a month or so and simply maintained with little wipedowns in between) and promoting the use of their bodies own defense mechanisms and the reinforcement they get through contact with outside particles.

  34. Sweep

    @ James Bassett

    The fault would not lie with the helmet, but rather with motorists who are (supposedly) more likely to give a cyclist adequate space if they are not wearing a helmet. From what i remember this wasn't from a scientific study as such but from the experiences of one cyclist. I could be wrong though.

  35. David

    @ James Bassett

    Nice strawman you've got there. Where did it say anything about 'physically makes someone a poorer cyclist'? Causality is no less real for being psychological.

    Actually, though, a helmet can physically make a cyclist less safe (though it would be a stretch to say 'most cyclists'). Damaged or weakened helmets (of which there are a substantial number on the road) can concentrate an impact to a greater degree than it would have been with no protection, and so cause more severe injuries.

  36. Dave

    Blame God

    Christine Houghton said: "Since its creation, chlorine has been a chemical catastrophe. It is either chlorine or us."

    Chlorine is an element, comes as a gas in its native form. It was formed along with all the other elements when the universe was created.

    I expect this sort of rubbish from creationists, but this is by inference insulting the sky fairy.


  37. Stewart Haywood

    @Evil Graham

    A good extension would be call the un-chlorinated water "God Water" and the chlorinated water "Darwin Water". This would fix a number of problems.

  38. Dave

    @James Bassett

    The usual form of the bicycle helmet argument is that because helmets are needed, people perceive cycling as dangerous and so do it less and discourage their children from doing it. This puts more cars on the road as a result, which increases the hazard for those who do still cycle, so therefore the helmets do make cycling more hazardous. There's also less exercise done because less people cycle, so a few more people will die for reasons associated with that.

    Therefore, cycle helmets are a bad thing for normal road use.

    (simple, isn't it?)

  39. Phil Hare
    Thumb Up

    @"And next..."


  40. Stef

    @ Darkside - Junk Science

    Well, I for one am still here due to junk science.

    If it wasn't for my cycle helmet It would have been my bare head smacking into the side of the kerb (at a fairly respectable 15mph if witnesses are to be believed). One cracked cycle helmet, one living stef.

    Keep up with the junk science, and with the helmets too!

  41. Werner McGoole
    Thumb Down

    Can't really see the point of this article

    I mean, it's not as if anyone is really going to go out and ban chlorine in our water supply on the strength of one weak study is it? The most likely (and probably most appropriate) reaction is just to ignore it. The literature isn't short of papers making somewhat extravagant claims based on weak evidence in any discipline, so where's the news angle? A weak study is not unusual, it's not important and it's only marginally interesting. By making a fuss about it you only increase the likelihood that some idiot will be convinced by it.

  42. Anonymous Coward

    @Dave - Leave me out of this

    "Sky fairy" eh? How about I open up a can of pestilence on your ass?

  43. Stevie
    Thumb Down

    Gotta Love the Ecoloons

    One invited to a barbecue was pontificating the current salmonella in tomatoes and lettuce scare (his attention was drawn by the lack of tomatoes and lettuce in our burger customising kit that day). He wondered aloud why it was that we had these problems with fresh tomatoes and not with the ketchup we had supplied.

    I looked up from the grill and said (with a secret glee) "Don'cha know? Ketchup is treated with gamma radiation when it's bottled to kill off all lurking biologicals"

    When this was confirmed by a couple of our other guests, Mr Green (47), product of his US upbringing and former fan of Messrs Heinz's product made a big show of rejecting the ketchup.

    I then asked him if he was feeling well.

    He said he was.

    I sprang the trap. "Well, they've been zapping the ketchup since the 1950s. A lifetime of eating irradiated ketchup can't have done you much harm, can they?" and loaded up my own sandwich.


    Anyone rejecting sane water treatment should be made to live well-away from the rest of us. I don't want to catch any one of the plagues these loons will re-introduce to the population because of some half-arsed new-age "knowledge" they picked up in a newspaper or website.

    Did you know we have whooping cough, *whooping cough* for christ sake, in some neighbourhoods of New York? The fools that live there think that because an enlightened immunisation plan has all-but eradicated the disease in the wealthy west there is no need to vaccinate. Idiots. Worse. Dangerous idiots.

    I despair of the human race sometimes.

  44. Peter W

    I'm missing something, obviously

    but isn't this kind of investigation valuable, even if the sample sizes are small, as it can flag up important issues?

    This particular one doesn't seem to fall into the "important" category mind, but I'm sure all the thalidomide babies would have appreciated searches like this a bit sooner....

    the mistake that's made is to put too much emphasis on %age increases rather than absolute increases (1 extra death per mil is pretty much irrelevant even if that's a 500% increase, if elsewhere it's saving 10 per mil).

  45. Chris G

    Real science

    Is increasingly being pushed aside in favour of correlating statistics, particularly in medical `research´? The reasons probably being that it is a cheap way of doing it and it's not even a requirement to actually see a patient. I subscribe to amongst others an online mag called Science Daily.

    Literally every day in it there are new so called discoveries to show that one thing or another can cause this or that disease/condition, all this research is carried out by statistical analysis of records with seemingly no empirical science to back it up. So, hundreds of published papers are relatively meaningless, they serve only as indicators of trends in numbers of patients suffering from similar things, mathematically. I guess the thing is driven by the current trend in the sciences that you are a nobody unless you have published a decent number of papers.

    Oh and as far as wearing a cycle helmet is concerned.

    I will wear one when they start to design them to look cool and not make the wearer look like a complete twat!

  46. Andy Taylor

    Clean and safe

    I used to work in the water industry* and the whole point about using Chlorine to treat tap water is this: Chlorine is added to the water near the end of the treatment process to kill the nasties and then most of it is removed again before the water leaves the treatment plant. What is left keeps the water safe all the way to your tap. If you're worried about it, why not filter the water before you drink it or even just leave it in a jug for an hour or two for the remaining Chorine to escape?

    *It was 6 months before someone told me what the windsock at the treatment plant was for - in the event of a Chlorine gas leak, you run in the opposite direction to where the sock is pointing!

  47. Herby

    Lies, Damned lies, and Statistics!

    All evil. We (the public) are easily duped by these numbers (aren't they all made up anyway!). Most of this is due to the "dumbing down" of our education.

    I grew up in the 50's and given all that has been discovered as being "bad" it is a wonder I made it at all. Fortunately we had nice clean chlorinated water and it had fluoride as well, so I have descent teeth.

    Now for the silly fact of the day: If you grow up in a house with lots of people (who just happen to share a bathroom) you have a stronger immune system. No, you don't have to be slobs, but the variety of germs that everyone brings to the bathroom induces a good immune system. If you are "too clean" your immune system doesn't get "trained", and you have things like asthma later in life.

    If you start out life in a bubble, you are destined to live all of it that way.

    Remember: Life is a terminal disease!

  48. RRRoamer

    RE: So DDT wasn't bad?

    DDT wasn't bad. The gross over application of DDT was bad. And even then it wasn't nearly as bad as the environmentalists and the media would have you think. That stuff is VERY effective in what it does and it really doesn't take much to work wonders.

    It's kind of strange to see the exact same FUD that was applied to DDT being used today against CO2.

    Something never change.

  49. Anonymous Coward

    so we're all gonna die again

    Just stay in bed, kids. If you get up you might die. Next up: Breathing causes greenhouse gases, so don't do it! Think of the children!

  50. Anonymous Coward

    @Blame God

    Chlorine was nor produced when the universe was created, it was formed after this event, see

    for example

  51. Anonymous Coward
    Anonymous Coward

    DDT's problems

    Was DDT hazardous to our health? I can't answer that, however it does have side-effects in nature. One example was weakening bird's egg shells, causing them to break under the weight of the brooding parent bird. Pelicans, sea eagles, and other avian top predators disappeared along the California coast because of DDT. They have reappeared since DDT was banned.

    In addition it seems that some pests had begun to eat the stuff, an example of evolution (sorry, I had to use the word) in action.

  52. Mike Hocker

    @AC more Chlorine scare

    Clever about that electrochlorinator for the pool. Of course, it's still chlorine being used to kill the nasties... plus the 9-10KW-hr of energy every night (not just the 8 quid for the NaCl). But not having to diddle with the chemicals is an advantage.

    As for chlorine dioxide, it's claimed to be pretty effective. I use it to kill fungus in my horse's feet (White Lightning(r), for white line).

    I'm sure some epidemiologist in the pay of Brussels can prove that chlorine dioxide soaked chickens is bad for someone, something, everything, or maybe the Earth As We Know It though, since it isn't a francophone invention!

  53. RW
    Dead Vulture

    Comments at large

    First of all, my thanks to El Reg for publishing this article. I used to "do statistics" for a living, so know something whereof John Brignell wrote.

    Statistics is a fucking minefield. It's very easy to draw improper and unwarranted conclusions. In particular, any conclusion based on statistics has to be reviewed for making sense in the context of everything else we know. In the present instance, unless there is a reasonable suspected mechanism whereby chlorine causes anencephaly, simply coming up with a correlation at a 5% significance level is about as useful as saying "the sky is blue."

    DDT: the stuff saved millions of lives at the end of World War II. The generous use of DDT powder in refugee camps prevented the outbreak of a louse-transmitted epidemic of typhus which otherwise would have been the normal result of such huge population movements.

    The villain in the DDT drama is agricultural overuse. This is, however, understandable given the tenor of the times, which led to such now-frightening slogans as "better living through chemistry" and "spray your garden once a week to eliminate insect damage." We have to thank Rachel Carson for waking us up to the fact that there was a distinct downside to the use of "chemicals" instead of them being marvelous, wonderful miracle substances with only an upside. There is no free lunch, you might say.

    Attentive readers of everyday news articles may noticed how much more careful the regulation of "chemicals" is these days. That is a direct outcome from the publication of "Silent Spring" and is a good thing.

    Speaking personally, my cut on this is that many of us suffer from what I like to call "the silver bullet syndrome." We look for simple solutions to our complex problems, and expect all our woes to go away if we do such and so . . . if only we can discover "such and so."

    An amazing range of human follies can be explained by reference to this syndrome: transgendered people who are sure that sex reassignment surgery will make their lives Truly Wonderful -- and then discover when they get home from the hospital that their boss is as big an asshole as ever, that the neighbors are the same lowlifes they always were, and so on.

    Another example: the anti-circumcision fanatics who, convinced that the lose of their foreskins as newborns is the cause of all their miseries, go to great lengths to have said appendage "restored" and then discover they still can't get a date.

    And finally: the nutrition nuts who are sure that if they take special herbs and "nutritional supplements", disease will be kept at bay. We had a gal here who was carted off to hospital with something like 75% loss of liver function. Upon investigation, it turned out she was taking a witch's brew o some 20 different herbs and "supplements". These had interacted and destroyed a big chunk of her liver. Afterwards, the newspaper interviewed her and she was still blissfully unaware of her folly: "Oh, I take X to prevent disease Y, and I take Z to prevent disease Q, and I take <something else> to prevent <some other condition>." I was sorry the reporter didn't have the gumption to lift the curtain, point out to the street, and say "see all those people? They take none of these, but neither do they have the conditions you fear."

    It seems to me that when the media come up with these hysterical reports of such-and-so causing evil results, it's the same mindset: a stupid, uninformed attitude that ignores the inherent complexity of life -- esp when we look at it at the molecular level.

    A better approach to the question whether chlorinated water causes anencephaly would have a been a cross cultural comparison of chlorination levels and the incidence of anencephaly. A simple minded study such as the one rightfully dissed by John Bignell is nothing more than an exercise suitable for beginning students of statistics.

    it's shameful this crap ever sees the light of day.

    Dead vulture from too much chlorine, perhaps?

  54. Schultz

    @Mark: Bicycle Helmets

    Hot, and annoying to carry around all day, that's why. But I also fail to see how the helmet kills people.

  55. Jeff Deacon

    DHMO, DDT, and MRI

    Firstly, I too would like to welcome John Brignell to the team. Another sane author when other publications seem to pride themselves on their insanity.

    I am sad that others have beaten me to the truth about DHMO. It is so closely linked with all sorts of harm that it really must be taken seriously by the UN :p)

    To add to the serious point raised above about DDT. In the best of all possible worlds it is a problem because it accumulates in the fat of animals and birds high up the predatory food chain. But we don't live in the best of all possible worlds, and as others have already indicated its absence is causing humans to die of malaria and other insect borne diseases, let alone starvation because of insect damage to food crops. What is needed is a rational cost - benefit analysis. And that is the very thing that our limited attention span media are incapable of doing. Yes, there is a downside to DDT, but it has an very great upside too. But all we hear are the scares based on the wishful thinking that if only we do as we are told, then the world will be perfect in a few short years. Perfect mess maybe!

    Fred made reference to the safety of MRI scans. Of course they are, but that didn't worry the EU when they were drawing up the Physical Agents Directive. Had its implementation not been delayed, most MRI scans would be illegal and would have ceased by now!

  56. Anonymous Coward
    Anonymous Coward

    basic chemistry

    Chlorine in solution takes many forms - chloride, (per)chlorate, (hypo)chlorite - which have quite different chemical and biological effects. Not quite as simple as saying 'it's salt' and leaving it at that. Salt (chloride) doesn't kill bacteria and it is of course what is washing around inside all our cells. The thing that does the disinfection is hypochlorite, a strong oxidiser.

    So what happens to hypochlorite inside the body? It would be nice to know if there is a fundamental reason why it should effectively disrupt bacteria but - at the same low concentration - not interfere with the internal workings of humans. Anyone know? I guess it doesn't survive the stomach environment, but there's more to us than stomach.

    Of course the claims here are not directly about chlorine, but in fact specific organic compounds 'THM's' designated as byproducts of chlorination. This is a much less obvious question. Above a certain level these are unlikely to be safe, the question is whether the concentration in your water is well below this level (as you might assume) or not. Arguments like 'we've already been doing it for decades so it must be safe' (not to mention 'It's only salt'... aagh) aren't quite enough. Trace organic compounds in water (e.g. hormone mimics) do change significantly over the decades...

  57. Anonymous Coward

    @more Chlorine scare!

    Around here it'd be kind of pricey to run 14A of current for several hours through the pool. (Actually, since I'm in the US, it'd be 28A to have the same effect)

    I hope you don't have the system on a timer. I'd hate to be in the pool and have the system come on because someone forgot to set the time correctly. Ouch!

  58. Eddie Edwards
    Dead Vulture

    And another thing

    The author is being incredibly disingenuous when he states that "chlorine is essential to life on earth". Scientifically, that's a stupid statement.

    Chlorine is an element. As an element, it is part of molecules which are essential to life, but then so are sodium and potassium but I wouldn't want to add them to drinking water in their elemental form.

    Chlorine in water and swimming pools is there in a form which is deadly to most life and that is precisely the reason it is there. Let us not be coy, the chlorine is in the water for its toxic properties, not as a nutrient.

    This is exactly the kind of BS the author purports to be against. Its pro-chlorine propaganda, appealing to our emotions as an "essential part of life of Earth" and then performing a classic bait-and-switch which in fact refers to its toxic propreties and conveniently sweeps aside the possibility (which any intelligent person might infer) that if it's toxic to microorganisms maybe it might have some sort of an effect on us.

    I infer that the author would prefer that the Times not report on the results of basic research in a dispassionate way, and that we should all just accept things without question or debate. I expected better from El Reg.

  59. Anonymous Coward
    Anonymous Coward

    As soon as

    one of you experts demonstrates that they know the difference between

    ionic and organic chlorine, then this idiocy can cease.

    The reg is getting some real winners for columnists these days.

  60. Steve Lubman


    The California Brown Pelican was almost wiped out - IIRC as a result of their eggs becoming so weak that they would collapse under the roosting birds. DDT was implicated.

    Since the ban, the Pelican has done a good job of coming back.

    I believe other species of birds (such as eagles) were similarly harmed by DDT.

    Surely there is a different method to combat mosquitoes. Why insist on continuing to use something that has harmful side effects elsewhere on the food chain? That would be extremely foolish don't you think?

  61. Fred
    Paris Hilton

    @ Jeff -- MRI

    Well, being that I am in the US (not UK) I was unaware of that side issue.

    But as a humorous (further afield) story...

    I live in a city with has 2 very large universities. One is CMU you get to guess where I live now : ), and a number of smaller ones. Plus a massive health care system, spun off from one of the big Universities.

    Anyway - as some of you may be aware MRI (Magnetic Resonance Imaging) was not always called MRI. It was originally called (and in speech I still do refer to it this way) NMR (Nuclear Magnetic Resonance) - sometimes an I was added (Imaging).

    As NMR was being brought to market, there was a building built in which a company/research center was placed. The center had prominent signage -

    "NMR Laboratory Research Center" -- or some such.

    When passing through the community in which this center was housed one day - I find the roadway blocked by protesters. OK - protesters can be good.

    Well these protesters obviously had absolutely ** NO ** clue - As they were protesting : The NMR center.

    Why? you might ask would they protest a new imaging technic which can help lots of people.

    They were protesting - all Carrying signs that said (or to this effect) :

    "No NUKES!"

    "Close the Nuclear Research Center"

    Paris - because EVEN SHE knows better

    This protest (or other ones like it) is most likely the reason for the name Change to MRI from NMR.

  62. Robert Synnott

    I'm shocked that it hasn't been said, but...

    They're after our precious bodily fluids!

    Unless that was flourine. Hmm.

  63. J

    @"And another thing" and "As soon as"

    Exactly my feelings, even if the general points of the original article are right.

  64. Joseph Jones


    You don't know, you're guessing. Fall off your bike (without helmet), assume the position while in-flight and walk away having narrowly avoided a nasty crack on the head. Doesn't prove that bike helmets are useless any more than your anecdote proves they're great.

    Helmets are big and cause nasty cricked necks and suchlike in low-speed collisions instead of allowing narrow escapes and increased caution in future.

    My 2p.

  65. James Pickett


    And did you know that most children who get complications or die from whooping cough are too young to have been vaccinated, and that the vaccine is responsible for more compensation payouts than any other? Not surprising, when you learn that the antigen it contains is also used to induce fits in laboratory rats...

    Agree about the chorine though.

  66. John H Woods Silver badge

    @Peter W

    You are absolutely right about %ages. Increases in tiny risks should NEVER EVER be expressed as percentages. Any scientist who does this is pretty much guilty of fraud --- misleading consumers (the public) for gain (research grant money).

  67. Dodgy Geezer Silver badge
    Thumb Up

    And another welcome...

    "Great addition to the staff "

    By Linbox

    Professor Brignell - It's wonderful to see you educating a wider audience! May I add my welcome to the others above. I hope we can see more items from you in the future - they are sorely needed...

  68. Anonymous Coward
    Black Helicopters

    A commie plot!

    Mandrake. Mandrake, have you never wondered why I drink only distilled water, or rain water, and only pure-grain alcohol? . . . Have you ever heard of a thing called fluoridation. Fluoridation of water? . . . Do you realize that fluoridation is the most monstrously conceived and dangerous Communist plot we have ever had to face?

    Do you realize that in addition to fluoridating water, why, there are studies underway to fluoridate salt, flour, fruit juices, soup, sugar, milk, ice cream? Ice cream, Mandrake? Children's ice cream!...You know when fluoridation began?...1946. 1946, Mandrake. How does that coincide with your post-war Commie conspiracy, huh? It's incredibly obvious, isn't it? A foreign substance is introduced into our precious bodily fluids without the knowledge of the individual, and certainly without any choice. That's the way your hard-core Commie works.

    I first became aware of it, Mandrake, during the physical act of love...Yes, a profound sense of fatigue, a feeling of emptiness followed. Luckily I-I was able to interpret these feelings correctly. Loss of essence. I can assure you it has not recurred, Mandrake. Women, er, women sense my power, and they seek the life essence. I do not avoid women, Mandrake...but I do deny them my essence.

  69. Brett Leach

    Re: DDT

    Who remembers seeing the promotional clip of a swimming pool full of kids being sprayed with DDT to demonstrate how safe it was? That it could be sprayed safely across every square inch of the countryside.

    THIS method of application is why it proved to be the environmental disaster it turned out to be.

    Applied to surfaces inside a building, it is an amazingly effective mosquito repellent which will NOT contaminate the wider environment to any significant degree.

  70. heystoopid
    Paris Hilton


    Hmmmm , explains much why that popular brand of Frog Radon water is sold in such large volumes world wide .

    But then again , given given the annual road toll from motor vehicles equates for every time a pedestrian goes walking , strolling or running across the road a one chance in eighty of being struck by a lazy mostly incompetent nut behind the wheel with over one point two million killed annually (any gun in any fools hands kills approximately four million which makes it more lethal then a car ) and is also one of the largest listed causes of death for those road users under the age of 28 , perhaps we should totally ban this lethal weapon called a car for the masses absolutely and think of the trillions in cost savings , the massive reduction in air pollution and huge numbers of lives saved annually !

    However the ultimate killer of the lot is cancer with one in five ultimately being killed by one's own body and the most fatal for males has the smallest research budget of the lot , so go figure mens business indeed !

    Funny numbers indeed , now why was I afraid of the DC Chimps Yanker self wanking terrorist plots of the imaginary improbable what if , I appear to have quite forgotten the reason yet again as his numbers just do not add up ?

    Still we live in a world run by numbers that we can never escape from as PH well knows !

  71. Lukin Brewer

    DDT and circumcision

    In my experience, any rational debate or cost/benefit analysis will be skewed, invalidated or altogether defenestrated if someone stands to lose or gain much money or political power from the subject at hand. Need I mention ID cards or nuclear energy?

    The manufacturers of DDT weren't going to stop people from overusing their product at full trade price, no matter how worried they were about it (in those days, probably not much). They didn't want to have a nice scientific debate with Rachel Carson, demonstrating evidence indicating that their product could be used safely, they wanted her to shut up and go away and never threaten their profits again. They launched lawsuits and personal attacks, including the inevitable accusation that she was a communist (i.e. please God, let McCarthy and the HUAC dig up something on her and get rid of her for us).

    As it goes, Carson was firmly against total bans, arguing that pesticides should always be available for use against disease vectors; but apart from that, they should be used with the greatest moderation possible until such time as their effects can be fully understood and safe usage determined. Some pro-DDT advocates now go further than that, arguing that DDT should be banned from agricultural use worldwide, so that disease vectors cannot become resistant to it.

    It's funny that the subject of circumcision should come up, as once again money and power are involved. BTW, while there presumably *are* anti-circumcision "fanatics" out there, blaming all their misfortunes on their missing foreskin, I am not one of them - I am whole and intact, having my original foreskin, appendix, tonsils, adenoids and all four wisdom teeth in their proper places :-)=) <- see!

    Circumcision was invented by the Jews (and a number of African tribes) for reasons lost in the mists of time. It was pushed by Christian ministers early in the history of the US as a way to prevent boys from distracting themselves from God with manual relief. It is now used by US obstetricians as a way to earn a three figure sum for 5 minutes' work. The "health benefits", such as they are, can be duplicated by washing properly. Penn (and Teller) put it best in their "Bullshit" series: "The first rule of medicine is 'do no harm'... [so] put down the knife, step away from the baby, and DO NO HARM."

  72. Anonymous Coward
    Anonymous Coward

    @"As Soon As" AC

    Ionic chlorine would be chlorine with extra/missing electrons

    Organic chlorine refers to compounds that contain both Carbon and Chlorine. Carbon Tetrachloride and the like.

    Even assuming the new age bullcrap of "organic" meaning "'natural' and fresh as a daisy picked from Gaia's flowery bosom" Organic and Ionic chlorine would not be mutually exclusive.

  73. Boris the Cockroach Silver badge

    Ban everything

    I say ban it all bleach , clorine, DDT, everything that kills disease, the lot

    A few years of 40% infant mortality, coupled with a life expectancy of 45 yrs should concentrate people's minds as to why these things were developed in the first place.


    mmmmmmmm black death

  74. Ronny Cook

    @James Pickett

    Do you know that the main idea behind vaccination is to protect the population, so that there's no pool of people to *infect* those too young for vaccination? An immunisation rate above a certain level restricts the spread of a disease. In a population that is otherwise 100% vaccinated, you are probably better off *not* vaccinating your child. However if enough people do this the disease (in this case whooping cough) has the opportunity to spead and the number of children killed vastly exceeds the number affected by side effects from vaccination.

    You may also be interested to know that rats != people. I can't speak for whether the antigen also induces fits in humans; personally I would guess not, in the quantities used in the vaccine. But enough of *anything* is a poison. Try drinking a hundred litres of water. Make sure to change your will so we know what happens.

    Contariwise, there are very few substances that are poisonous in arbitrarily small quantities. Enough chlorine *will* kill you, and it's not very much, relatively speaking. But the fatal quantities are much higher than is used in drinking water.

    Personally I'm perfectly happy with chlorinated, flourinated water.


  75. Anonymous Coward


    I was under the impression that the whole DDT = thin egg shells had been debunked as more rubbish science (but was still "widely known" due to the fact that the media only report scare stories). The link was more to do with lead in petrol and other heavy metal pollution with a decrease in population also due to fishermen, farmers etc killing the birds.

    Here we go:

    And yes, I know the link is to so lots of people probably will flame me for it but the point is that it gives a nice list of papers into the issue.

  76. Mat Ballard

    TriHalo Methanes CAN be a problem

    While the original work on the toxicity of TriHalo Methanes (THMs are a byproduct of the chlorination or ozonation of water) was not the greatest, it is not the only work on the subject, and the general consensus in the water treatment industry is that high concentrations of THMs in drinking water are undesirable. As a consequence, there are legislative limits to their concentration in many countries.

    The issue is quite similar to radioactivity: what happens when you expose a large population to very low doses of a probably toxic material over a long period of time, and what do you do about it ? The practical engineer does a cost analysis of the benefits and the risks, and then builds in sufficient safeguards to minimize the overall costs to society. Unfortunately, there are always a few lunatics at both ends of the spectrum who ignore either the risks (Chernobyl) or the benefits (chlorination in Peru).

  77. Andy Dent

    Bike Helmets, Compulsion and Benefits to Society

    As an Aussie with compulsory bike helmet laws and an argumentative brother in the UK, I actually went and looked up the BMA article when he raised the issue.

    The BMA studied the effects of introducing compulsory helmet laws into Perth, Western Australia. Yes, we were the source of stats for our former colonial masters' quacks.

    As an overall health isssue - the general population suffered because wearing helmets was a factor discouraging a large number of adults from riding who failed to take up an alternative form of exercise. This is a good example of how individual traumatic incidents total up to cost less than the overall health cost of a decreasingly fit population.

    However, bike helmets here are light-weight and relatively cheap due to being compulsory. I'm not sure where the arguments about them contributing to accidents come from but am reminded of all those cases of people who would have been saved by being thrown from the car, that were cited when seatbelts were being made compulsory.

  78. Bruce Sinton

    Back to Cycle Helmets

    I flew over the handlebar of my cycle when I was fairly young, didn't have helmets then. Low speed crash , no fractured skull.

    Flew off (not sure of which direction) of my cycle when I was 22 . High speed crash , was wearing a good helmet, no fractured skull.Protective jacket and gloves saved me from much ripping of flesh.

    That cycle had a 500cc motor attached and got me up about 100mph when a thing called speed wobble happened.

    I think even for low speed crashes they do keep your flesh of your head looking neat and tidy.

    I am now like all of you now, very conservative and responsible.

  79. Maty

    quick test

    Okay - there's this rare disease - affects less than one in 100,000 but its fatal if untreated. There's a test, which is 90% accurate, and a cure which is an injection that cures you if you have the disease, but kills you if you don't.

    Do you take the shot?

    (Apparently most doctors got this one wrong, so think about it for a moment ..!)

  80. Anonymous Coward
    Anonymous Coward

    @Andy Dent

    In which case, presumably, bicycle helmets are only harmful when they are compulsory?

  81. alphaxion
    Thumb Up


    The doctor would just prescribe antibiotics and tell you to call them if symptoms persist ;)

    It's like when I discovered I have epilepsy. I underwent blood workings, EEG and MRI scans and simply got "*shrug* we don't know what causes it... but here's some pills".

    When I returned for my repeat prescription the doctor said "this dosage shouldn't have any affect" and promptly doubled it.. as a consequence I rarely take the pills (but I do still take them, just not to the frequency they prescribe) and the side effects (buggering up my memory) have ceased their progression.

  82. Anonymous Coward
    Anonymous Coward

    Re: quick test

    I have a similar sort of thing with my wife. She's obsessed with the thought of having breast cancer and has a more than healthy number of scans. There's no family history and I've explained the dangers backed up by leaflets from clinics. Sooner or later all this excess radiation will cause a tumor and she'll turn around and say she was right to have been so vigilant.

  83. Jon Kale

    @Steven jones

    You've (very carefully) missed my point, tho', so I'll restate it more clearly and see if it gets through this time:

    1. Basic scientific method is to construct a verifiable hypothesis based on some theory of causality, construct an experiment or experiments to test the hypothesis and then determine whether the results are consistent with the hypothesis.

    2. Epidemiological studies, when done properly (note that I'm not referring to the type of junk science which infests the MSM - the Mail, the BBC, the Reg et al) follow a similar process: the hypothesis is stated and then the generally retrospective data is analysed to see whether the hypothesis is valid: this is the point at which you attempt to make allowances for any confounding factors and then see if the results are significant: p<0.05 is generally taken to suggest that they are.

    3. This process should not be confused with data trawling: the latter has value in suggesting correlations which may be explored further, but simply assuming that any correlation is necessarily related to some undetermined causative effect is fallacious (although, again, a greatly popular pastime in the MSM).

    Note, by the way, that I happen to share your view of this particular piece of woo: I'm simply suggesting that the blanket statement that p<=0.05 is "an abysmal standard of significance" is, *generally*, crap and that even the most-studied and best-understood results in public health don't have p that much lower - unfortunately that's the nature of large-scale population studies.

    Understand now? Or are you philosophically (or otherwise) opposed to epidemiology on other grounds, in which case I'm probably wasting my time...

    [mine's the white one with small flecks of rat pre-frontal cortex on it...]

  84. Mark

    Cycle Helmets

    <<Different Mark

    As far as I remember a cycle helmet is unlikely to save your life if you hit your head at the sort of speed that will kill you. A car drives into your head at 30 miles an hour plus then it will offer very little protection. It is not a motorcycle helmet. It will however limit the damage at collision speeds up to about 20 miles an hour - but collisions at speeds below that are unlikely going to kill you anyway. Not pleasant but probably won't kill you.

    Theres also an argument that helmets provide a false sense of security to the cyclist making them more likely to be involved in accidents.

    Gonna have a quick Google for the research now.

  85. Bad Beaver

    I have a serious objection

    to chlorinated drinking water: It tastes like taking a sip from the pool. Terrible. Then again, I live in an area with an excellent water supply system where no chlorine is needed. Elsewhere: better bad taste than bad germs, I guess. If it was really harmful, there would be NUMBERS to indicate that. Nevertheless, hint to Montreal: TONE IT DOWN!

    Who came up with the helmet thing? Helmets a beneficiary! To the people who make them that is. They might prevent slight damage to your precious head but they will not magically keep your skull from splitting in a skull-splitting situation. The fact that they break easily does not mean that the minor nudge you just experienced would have hurt you in some serious way. Yet each and every moron believes that "whoa, it once saved me" and I say "who cares". They can do as they wish as long as no one _makes me_ wear one.

  86. Mark

    Cycle Helmets - links

    - Cycle Helmets only protect in collisions up to 12 miles an hour

    - Plus some vague stuff about helmet wearing increasing at the same time as number of head injurys increasing

    As far as I can see from the other the links Google throws up theres a raging debate with safety campaigners saying its silly not to wear one even if theres only a small chance it will save you from serious injury and then counter argument from cycling organisations and some science types saying theres no evidence it helps and some statistics actually showing theres a negative effect.

    No sign of any serious science though.


    Personally for street riding I don't wear one and for serious offroading I do. Basically because in a high speed collision on road theres not much chance of it helping and offroad its more likely to be a low speed fall where it will help alot.

  87. Anonymous Coward
    Anonymous Coward

    Maty - mostly in an attempt to see what you think is "right"...

    90% accurate, so if it tells me I have it, there's a 90% chance that I really do. So I take the cure.

    If it tells me I haven't, there's only a 10% x 1 in 100k that I really do have it, so I'll not take it thanks.

    Mind you, I'd be a bit concerned about how they worked out 90% accuracy with 100% fatal side effects...

  88. Anonymous Coward
    Anonymous Coward

    You can tell a scare story is nonsense when...

    ... it contains the phrase "studies have shown".

  89. Bad Beaver
    Thumb Up

    @ Mark

    Helmet on road = no use, helmet off road = useful.

    Just like that.

  90. Mark
    Dead Vulture

    @Joseph Jones et Al Re:Cycle Helmets

    The first Mark again...

    You seem to have rather missed my point. Statistics can be used prove anything you like - you have to be really careful what they actually show. I mean look at the info about helmets only helping in accidents below 12mph. What does this actually mean? Is this the limit speed at which helmets have a beneficial effect and above this speed they reduce survivability or is it above this limit there is just no discernible benefit? There is a big difference between the two!

    You also have to look at accident rates between helmet wearers and non helmet wearers and try to explain any difference. Also all the stats I have seen quoted so far look at rate per number of cyclists, why not rate per number of miles travelled or time spent cycling? If helmet wearers cycle twice as far on average or for twice as long as non helmet wearers then of course there will be more accidents per cyclist. What about unreported accidents? I know I reported neither of my accidents but I'm sure I would have had to have some treatment if I had not been wearing a helmet so it would have entered statistics somewhere. This would skew the statistics to make it seem like helmets have no effect when in fact they are having an effect.

    The real question each person must ask is "Do I think I am safer with or without a helmet?". In my case I believe that helmets have prevented an injury being more serious on two occasions. I am not quoting statistics at you, just my personal experience. I can't talk about everyone but I don't think wearing a helmet makes me a worse cyclist, perhaps there is a chance car drivers will go closer to me but I'm not sure. I know I don't treat cyclists with or without helmets any differently when I'm driving (I always give them the maximum possible clearance and won't overtake them if there isn't space for me to give them at least 1m clearance).

    As to those who say helmets make me look like an idiot and are hot and annoying to carry around. Go buy a decent helmet then not a crap £10 job that looks better and has ventilation it will also protect you better and remember you can always do what I do and lock it to the bike when I'm out. Put a plastic bag around it and run a cable lock through one of the holes - sorted!

    The dead vulture because he forgot his flying helmet....

  91. conan

    I love my helmet

    I regularly bang my head on the frame of the bike sheds at work. Sure, my helmet won't stop me dying on the road, but it stops me hurting my head in the morning, which is worth £20 to me.

  92. Sparkypatrick

    DDT and helmets

    The problem with DDT is that it is a cumulative toxin, which will persist in the soil for 2 - 15 years. This means that it will inevitably build up through the foood chain. It also gives it plenty of time to work its way into the water table. Here the problem is magnified, as it persists significantly longer and is extremely damaging to aquatic life.

    Although it is very effective against mosquitos that carry malaria, one WHO study linked it to an outbreak of bubonic plague in Malaysia! It's not effective against cockroaches, which accumulate it in their bodies. They are eaten by geckoes, which are poisoned and die. Cats eat the geckoes and are also poisoned and die. With no cats to control the rats, their population multiplies and they spread the plague.

    There is no doubt that malaria is a serious health problem, but DDT is like cracking nuts with a sledgehammer: even if you are really careful, you may end up choking on bits of shell.

    The use of cycle helmets coincides with the perceived increased risk of death or injury from more carss on the road. Some people respond by wearing a helmet, some by abandoning the bicycle. It's fear that stops people cycling, not having to wear a helmet.

    I bet penguins don't like DDT.

  93. Anonymous Coward

    @ Bad Beaver

    Having used to sell said cycle helmets and having read a lot of the studies about 5 years ago from what I remember a Cycle Helmet will not save your life, although it may look it after the impact! but it can save one hell of a headache irregardless of what the manufacturers will tell you.

    When riding on or off road, the impact to the head is usually a fall from riding height to the floor, and having tried a similar bail at about 15-20 mph with and without a helmet, I can recomend the helmet! Strictly anecdotal of course, but enought to make me stick a nice light one on my head when I'm out.

    Of course, the helmet goes on after the decent gloves and glasses, bugs in the eye can make crashing much more likely and when you do come off, it's usually the grating of the palms on tarmac that really gets me!

    Don't forget that in some very rare cases a helmet can increase the risk of a lethal rotational injury to the brain, so if there is any tabloid reading and wants a scandal: HELMETS CAN KILL!

    I don't get the people who buy the 'piss-pot' style for commuting, why make your life deliberately hot and uncomfortable?

  94. Tom
    Thumb Down

    @AC to Marty

    Wrong answer, based on the wording of his question, and which you should have suspected.

    At most 1 out of 100,000 people will have the disease. The 90% accuracy rate gives a 10% failure rate. Failure in this case also includes false positives, not just false negatives. Testing 100,000 people generates 9,999 or 10,000 false positives that you just killed. Like all those dead people in Peru.

  95. Stevie

    @ Anonymous Basic Chemist

    <<Salt (chloride) doesn't kill bacteria and it is of course what is washing around inside all our cells. >>

    Er, yes it does. Otherwise, salt curing wouldn't work and doctors wouldn't recommend gargling with salt water to help rid yourself of a sore throat.

  96. John Dougald McCallum

    Scare story's

    This sort of reminds me of the sacharine panic in the '80s it traspired that a person would need to drink 1800 litres of soft drink each day to even get near the levels that the"scientists" fed to the lab rats.Numties!

  97. Martin Silver badge

    bicycle helmets are only harmful when they are compulsory

    Exactly - you make helmets compulsary and most people won't wear them and will drive, more cars = more dead cyclists.

  98. Anonymous Coward

    Helmets - do you feel lucky

    I had 2 notable crashes on bikes:

    1st: cycling North from Castlebay on Barra (Outer Hebrides), when on coming minibus caused friend in front to brake, me looking at scenery, wildlife, etc, reacted too late and over the handlebars I went. Broken A-C joint and bike helmet in 2 parts held together by the staps, with a nice jagged rock pressed about 1/2" into one half. Painful shoulder (understatement) but no other injuries.

    2nd: cycling in a bike race in Hamburg, Germany in a peloton of about100 riders, maybe at 40kph, some wheels touch in front, and down go the riders, I pick the gap I am to put the bike into but that develops into the person I am riding/falling over, a person a few riders behind me in a similar situation, his bike and pedal do a nice gouge up my back and into my helmet ripping it clean off, I have another destroyed helmet with a pedal embedded in it, that helmet was replaced by the manufacturer, who at that time wanted the damaged helmets as part of their R and D cycle, not sure if that is done today.

    A 3rd incident worthy of note, a very close friend working on scaffolding a building site fell 2 metres (7 feet), eyewitnesses said he landed OK a little shocked and went to stand up a plank off the scaffolding also falling caught him squarely on the back of the head, he died instantly, his hard hat had fallen off during the fall, if the hat had remained on I am sure he would have climbed back up and carried on his job. He was 24 yo.

    Helmets do work, and with my children, no helmet - no bike.

  99. Ed

    Hydrogen Hydroxide, and other responses.

    I am saddened to see that nobody has pointed out that Dihydrogen Monoxide is more properly known as Hydrogen Hydroxide, and, is, in fact, quite beneficial when used properly:

    Personally, I always put my bike helmet on before putting on the riding gloves, as the riding gloves impaired my dexterity a bit. But otherwise - the helmet saved me from a number of nasty bumps. It never saved my life - I never allowed myself to get into any situations in which my life was threatened in that manner. It was always very obvious to me, with the number of ventilation holes in it, that the bike helmet was not up to real impacts.

    If people had been responsible in their use of DDT, none of its environmental effects would have been anywhere near the levels they were. For reference, I had an uncle who swore by DDT. He had one bucket of the stuff, which he had bought a couple years before it was banned. That bucket lasted him for many, many years (I seem to recall it finally ran out sometime around 1995.)

    And, finally, to say something on-topic, the form of chlorine in tap water may be its most lethal form, but it's also the form found in your stomach. And, last I checked, my stomach has a higher concentration. If that's the case, I have a difficult time understanding how the chlorine in the tap water is going to hurt me. In any event, it tastes a bit nasty, and that's fixed by a little filtering. Of course, the statistics do play out: the number of people saved by chlorinated water is greater than the total number of people who suffer from any of the complications that have been adversely associated with its use (even including those people who would have those complications regardless, and even including those complications which are not, actually, related). If my previous statement is accurate, anyone who contests the use of chlorinated water on safety grounds is a moron.

  100. Bruce Clare
    Black Helicopters

    @John Kale and Mr. Brignell

    I have to wonder whether it was the researcher that caused the sensationalism in the chlorine scare. It looks like the original study was a data trawl designed to turn up items worth investigation. Someone in the researcher's organization (the media department, the Director or the researcher herself?) decided to alert the media that some interesting avenues for investigation had been identified, probably as part of a grant application cycle. It obviously snowballed from there into a meaningless mess of sensationalism. While there is a role for the media in documenting scientific research and making it meaningful to the general public, this study should never have been brought to the public media's attention.

    And Mr. Brignell: while this was an interesting, thought-provoking article pointing out real flaws in the way the media handle statistics and science, I'm sorry to see you conflating the risks (or lack of risk) of ionic chlorine from salt with the Sodium Hypochlorite used in bleach and the TCH compounds that arise in drinking water. Don't fight junk science with junk science.

  101. Avalanche


    I live in the Netherlands, and as people know: lots of people riding bikes here and almost no one wears a helmet. As it is, most accidents involving cyclists are usually side impact from a car, and the helmet would not have helped. On the other hand, here we have a lot cycling paths (either free-laying or a reserved strip on the main road), which probably makes it a whole lot safer then in countries without a developed cycling-culture.

    When I was in school I had to ride 30 km by bike daily (15km to school, and 15km back) and had some 'accidents' (linking of handlebars with the friend next to you, slippery roads, racing cyclists who don't yield). In my experience, you usually are able to break your fall and as a result are more likely to hurt your hands, arms or knees (or maybe your balls) then your head.

    In my opinion the benefits of a bicycle helmet is grossly overrated (as almost all other Dutch seem to think), I only think they can have some benefit for:

    1) kids: inexperience and small posture will make it easier for them to hit their head, and the helmet will probably not save more lives, but prevent them from crying (negative effect in the Netherlands: more likely to be bullied by other kids without helmets)

    2) racing cyclists: racing in a large group of cyclists makes it more likely that you cannot anticipate and break your fall, or that someone in behind you drives over you

  102. Tom

    It's safest to not get vaccinated, as long as every one else is.

    "And did you know that most children who get complications or die from whooping cough are too young to have been vaccinated"

    And where did they get whooping cough from? The people who didn't get vaccinated.

  103. El Draque

    Cycle safely

    Ref. Cycle helmets.

    There was a scientific study, I believe the researcher was based at Bath. He fitted a proximity sensor to his bicyle on his regular trip to work. He rode the bicycle with and without the helmet.

    The cars came closer to him when he wore a helmet.

    He was hit twice during the test, both times when wearing said helmet.

    But: it doesn't mean it's better not to wear one. The risk of an incident may be slightly higher, but the consequences if you land on your head are many times more serious.

  104. JT2008
    Dead Vulture

    Hmmm ...good question, but -

    Christine Houghton said: "Since its creation, chlorine has been a chemical catastrophe. It is either chlorine or us."

    Chlorine. We're all going to die sometime ...

    PS: Even the radioactive isotope version will outlive humanity by a long stretch. Its half-life is 301,000 (± 4,000 years).

  105. James Pickett


    "And where did they get whooping cough from? The people who didn't get vaccinated"

    Or the people who did. My partner has post-polio syndrome, despite never having officially had the disease. Indeed, virtually all cases of polio in the Western world are caused by the vaccine, as it doesn't exist in the wild.

    Curiously, deaths and complications from whooping cough in very young babies increased a while after vaccinations began. This was a bit of a mystery until it became apparent that mothers who had been vaccinated were unable to transfer their immunity (not being the same as that obtained from the actual disease) through breast-feeding. The same is true of measles, so none of this is quite as simple as it looks.

    Also, look up shaken baby syndrome...

  106. MooToTheMax

    Bicycle helments

    I used to cycle 25 miles each day, until I was given a free frlying lesson over an Audi TT.

    Anyway, in ten years of cycling hard, I've fallen off the bike twice, and had the one nasty accident mentioned above, and you know what? Despite not wearing a helmet now, I'd much rather that if my head was going to scrape along the ground, I would like it to be covered.

    Sure, I'm convinced that not wearing a helmet makes me a safer cyclist, but as a driver I don't notice if a cyclist is wearing a helmet or not; I go out of my way to pass considerately regardless.

    So, in short: helmet makes scrapes less painful.

  107. yeah, right.

    bad science

    I haven't seen so much bad science (on all sides of the argument) since the "Intentional Design" people last tried to argue that their hypothesis is actually a theory.

  108. Markus Bleicher

    Fighting junk science with junk journalism

    Reading the as "chlorination was stopped in Peru" referenced article (published by

    the organisation of the US chemical industry), I've now read two articles from

    people claiming to provide some scientific insight, but in fact just tell stories. "From a superior vantage point." And not even they are reported correcty.

    To summarize "I was surprised to learn that some local PAHO officials were encountering pockets of resistance to chlorination from a number of health officials, both in Peru and in other countries" as "chlorination was stopped in Peru"

    without any figures how widespread its adoptions was before and after the

    cholera outbreak is probably just the ususal way, Greenpeace and other people

    looking for attention do it.

    To criticize the anti-industrial attitude of most of the ecological movement and put

    the suffering of human beings at the center of the debate is absolutely reasonable,

    but this kind of industry-hugging unwillingness to really climb on the " superior vantage point" is an insult to reason, even this is not the main point of the article.

    I see: The Register bites the hands feeding IT, not chemistry.

    If you want to read about science, read Science.

  109. CTG

    In defence of 0.05

    I've had several scornful reactions from mathematicians when I have referred to 0.05 as the level of statistical significance commonly used in biology. "What about the law of large numbers?" they cry.

    Well, yes, when you are looking at large numbers, a probability of 0.05 doesn't mean a hell of a lot. But a lot of the time in biology you are not dealing with large numbers. Sample sizes in the tens or hundreds are pretty typical. For those kind of sample sizes there is a whole branch of statistics which specifically deal with small samples - things like Student's t-test and so on. When you are doing that sort of thing, getting p < 0.05 generally does mean something significant.

    Sadly, a lot of people in biology don't really understand what the stats are doing, so 0.05 gets treated as a magic number. Hey, I got p < 0.05, it must be true!

    This is particularly true in epidemiology, which is one branch where sample sizes usually are large. Data trawling looking for correlations at p < 0.05 is just bad science.

    It seems to me that this is another consequence of the dumbing down of science, and the insistence that all science has to be "applied". If you don't teach the theoretical underpinnings of pure science, then applied science is just bullshit.

  110. archie lukas

    Lies, damn lies and statistics

    Good to see someone challenging this plethora of meaningless statistics, 68.25% of which are made up on the spot!

  111. Anonymous Coward

    Oh, my...


    "That would be the lethal strain of cannabis then..."

    For some bizarre reason, my mind parsed this as the 'lethal strain of cannibals.'

  112. Chris Long


    Reminds of a proposed road-safety measure - put an 8-inch steel spike in the centre of all car steering wheels. Drivers might then tend to be a bit more cautious.

    Cycle helmets work in the opposite direction... see (I haven't actually read this yet, I'm just hoping that it supports my position).

  113. Philip

    RE: The Doctor, and the rare disease...

    Right this is a long thread, so this hopefully won't get read....

    There is this disease, that affects all people in equal proportion at a rate of 1 in 100 000. Assuming your a normalish human being, your chances of getting the disease is 1/100 000.

    Now you go to the doctor for a routine check up (ie. the disease doesn't present any symptoms except sudden death) where he does a battery of tests. Guess what, the test comes back positive for sudden death disease.

    "Lucky" for you, there is a cure, that is 100% effective, but which kills you if you don't have the disease. The doctor then tells you the test for the disease is 90% accurate. That is, if it says you don't have it, there is a 10% chance that you actually do, and if it says you don't, there is a 10% chance that actually you do.

    Thus, the question is, what is the probability that you have the disease, given that the test was positive?

    Applying Bayes' Theorem, hopefully correctly, gives:

    (0.90*0.000 01)/(.9*0.000 01 + 0.1*0.999 9)

    = 9 in 111 119 or roughly 0.0081%

    or roughly 1 in 10 000.

    So, no, don't take the "cure", except if your feeling really unlucky, who knows, you could be the 1 in 100 000 person who actually has the disease.'_theorem

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