9 Assumptions We Make About Chemicals

File:Biohazard symbol.svgAll things considered, I’m not a particularly paranoid person. Not all of my food is organic, there’s fluoride in my toothpaste, I breathe in way too much clay dust, support vaccination, and at a time when everyone is shunning the evils of gluten, I’ve taken up baking bread. (Chewy, crusty bread that crackles when taken out of the oven…) However, given inevitable gaps in scientific knowledge and human fallibility, I and many other environmentally concerned people support the precautionary principle.

But given how many headlines from my Twitter feed scream about carcinogens, infertility, asthma, and other diseases, I have to wonder: are we being rational in how we look at chemicals and evaluate our risk from them? Or is this some kind of knee-jerk reaction?

I recently read (and reviewed) an eye-opening book on toxicology called The Dose Makes the Poison by Patricia Frank and M. Alice Ottoboni. It’s no page turner, but it offers a perspective on toxins that squarely contradicts the more usual alarmist headlines that show up in my environmental Twitter feed. Its conclusion: public perception of chemicals and risk have very little correlation with what the scientific data show. Although I do feel like the book downplays potential risk, especially from combined chemical exposure, it also exposes the press and public’s tendency to consider chemicals in a black/white dichotomy.

I felt very defensive while reading this book, but after that first reaction, have come to recognize that it made valid points and shook up some assumptions I didn’t even know I was making. Are you looking for some food for thought? Here are some of the myths the book takes pains to point out and disprove.

  1. Natural = safe. In fact, many of the most toxic substances on this planet are entirely natural. From death cap mushrooms and oleanders to hemlock, arsenic to radon, nature’s pharmacy is much, much bigger than man’s. And frequently bad for us. Humans have been poisoning themselves (accidentally) and others (not accidentally) for our entire history as a species, long before we were able to create synthetics.
  2. Chemicals are bad. Even if you’re only talking about synthetic chemicals, this is a pretty broad generalization. Manmade chemicals include pesticides, poisons, and life-saving medicines.
  3. Substances are inherently safe or unsafe. You can die from drinking too much water, eating too much spinach, drinking too much coffee, or taking too much Tylenol. Hell, the chemical acrylamide, produced by frying, baking, or roasting starches, is carcinogenic. Granted, you’d have to drink or eat a lot of these substances, but the point is: there’s a threshold after which they stop being harmless or therapeutic and become dangerous. With relatively few exceptions, chemicals have measurable thresholds. It’s the dose that makes the poison. 
  4. Correlation equals causation. In one case study, a new hospital was experiencing a spike in the rate of newborn jaundice. Everyone suspected the culprit was pesticides sprayed on the farms outside. However, nearby hospitals exposed to similar levels of the same pesticides didn’t have increased jaundice cases. Eventually, they figured out that babies at the new hospital, which had fewer windows, were less exposed to light. Phototherapy is now effectively used to treat jaundice.  It’s both easy and tempting to jump to conclusions, but correlation does not always equal causation, certainly not to the extent the press makes it seem. The next time you read an article about how x substance causes x disease, it might be worth considering whether the article is really about a correlation, not a proven cause.
  5. Banning a chemical is the safest way to go. Well…sometimes. And then sometimes it just makes manufacturers switch to a less well tested substitute, and we’re faced with choosing between the known risk (e.g. BPA) and the unknown one that we have much less information on (BPS). Joy.
  6. Anyone who doesn’t condemn synthetic chemicals is an industry apologist. Dismissing anyone who disagrees with your beliefs as incompetent or corrupt is a devastatingly effective way to stop making rational evaluations. There are certainly industry apologists. However, there are also studies — lots of them — that simply don’t yield conclusive results, show that a chemical used at its recommended level is safe, or that its benefits outweigh its risks (as with many medicines).
  7. Studies can give us definite yes or no answers about how safe chemicals are. Sometimes, but not very often.  Toxicological testing often requires so much time and resources  in order to draw statistically valid conclusions that the amount of funding provided just isn’t enough. So we end up with plenty of studies that suggest possible conclusions without being statistically valid, yet are interpreted by the press to be a definite conclusion.
  8. Looking at one source can give us definitive answers about how much risk we face. It’s hard to get a balanced perspective by looking at just one website or one study, even if you haven’t leaped to any of the above conclusions. Did you know that 79% of the Society of Toxicologists surveyed consider the EWG (home of the Skin Deep database) to overstate the health risks of chemicals? I didn’t either. But knowing that will help me evaluate how much risk I think my shampoo is putting me in. I recommend also checking out Personal Care Truth for another perspective on cosmetics safety.
  9. Organic farming does not involve pesticides. Some small farms do use crop rotation and other pesticide-free ways to manage pests, but most larger scale organic farms use pesticides. The main difference is that they are required to use organic pesticides rather than synthetic ones. (Mostly.) However, there’s some evidence to suggest that organic pesticides are not necessarily safer for humans or ecosystems than their conventional counterparts, and some biodegrade into other chemicals that are harmful. Dammit, why can’t things be straightforward for once?

I’ve read that the human bias is to believe that we are in peril, which back in the good old days was less likely to get us killed than dismissing a potential threat. I also think we have a lot more information at our disposal now and should use it to make rational, well-considered judgments instead of just reacting. Life would be so much simpler if buying organic was always better for the planet, or if all synthetic chemicals were dangerous. Instead, it’s about a whole bunch of case-by-case decisions, like having to judge people as individuals instead of lumping them into stereotypes. No one said it was going to be easy.

What’s your attitude towards chemicals? Have you found yourself falling into any of these assumptions?

24 responses to this post.

  1. Thank you, Jennifer, for another thoughtful and enlightening essay. I’ve always known that “man made” or synthetic substances are not inherently evil just because they are not from mother nature. Still, it’s disturbing to see people die of cancers at an early age who seemingly avoid primary culprits such as cigarettes. I can’t help but wonder if long-term exposure to the myriad of inhaled and ingested modern-day chemicals might be a factor in those cases. But I am increasingly embracing the concept that a 100% plant-based diet may offer the stronget mitigating measure to early-death syndromes including cancers.


    • Hi Donn,

      You’ve never struck me as the hysterical type. 🙂 I agree that we just don’t know enough about longterm exposure to minute doses, or about how chemicals interact over time — I think the precautionary principle should guide our chemical discovery process, and it clearly doesn’t right now. However, with the EPA’s newest announcement regarding limiting mercury and other toxic emissions, I’m hopeful that we’re at least starting to head in that direction. I think diet is an important part of the equation. Instead of coming up with drugs to treat obesity, diabetes, and other first world diseases, I think we would do well to spend that money on better preventative health care, education, and support for programs that keep us healthy.


  2. This is so important! People are so easily swayed by fear and comforted by easy solutions. I have a love-hate relationship with bans… when science concludes that a given chemical is hazardous to us, I want to see it gone… but you’re so right, industry replaces it with a slightly different, untested chemical that is probably just as dangerous. I also have a big issue with what you mentioned in #7 about the media interpreting study results the wrong way. It’s such a shame how little understanding there is of science and the scientific method within the general public. If only people were better educated, nobody would be jumping to false conclusions.

    I just don’t know what to do about people’s tendency to be afraid when headlines sound scary, and put their guard down the moment they hear about a ban, as though that solves everything!


    • Hi Andrea,

      I know, it’s totally frustrating how we’re not nearly as rational creatures as we believe ourselves to be. The ban aspect is difficult. Again, I think it would work within a system that favored the precautionary principle, but not so much in our current safe-until-proven-otherwise system. I *am* uncomplicatedly delighted about the EPA emissions limits that went through yesterday. Setting strict limits may be better, at least as a first step, than an outright ban that sends the industry scrambling for a replacement.

      I’m not a scientist, but I don’t think it would be that hard to educate people about how to evaluate risk as long as they weren’t constantly being bombarded with alarming headlines. I suspect that I am also less involved in the issues because I don’t have kids. I’m a fairly paranoid pet owner, and I think a lot of the alarm comes from people who are very concerned about their children’s health. That’s very understandable.


  3. A fantastic post Jennifer! I agree, catastrophic, all or nothing thinking isn’t helpful in finding a rational solution.

    Links and correlations can be a scary thing and decreasing chemicals in our lives in a balanced way really seems to be the best step.

    Thanks again!


    • Thanks, EcoYogini!

      It’s hard to find a movement without some degree of all or nothing thinking, just because a message like ‘buy organic’ is so much clearer and reassuring than something like, “Certain types of organic farming may, in some regards, have a lower impact on the planet and human health.” Bleah! Talk about unmarketable. I’m on the fence about this one, because we certainly do need numbers to reach any sort of tipping point, but my whole thing is that I want people to think more before responding.


  4. Wonderful post. CatMan, who is very scientifically minded, is forever having to “talk me down” from one freak-out or another, because I tend to get my panic button pushed way too easily. He is forever having to remind me that the “natural” course of many illnesses is death, and things weren’t necessarily all rosy and wonderful in the age before technology when people lived significantly shorter, and arguably harder lives.

    I recently got all freaked out about studies showing that vitamin E was dangerous. (I know vitamin E is not a chemical, but still…) Anyhow, this one study (apparently sponsored by some drug company who’s agenda is to get vitamins regulated like drugs) supposedly showed that women who took vitamin E supplements died sooner than those who didn’t. CatMan finally found some details about the study, and when I read it I was shocked! The data actually showed the exact opposite… the women who took vitamin E lived LONGER… that was, until they “corrected” the data to factor out other healthy lifestyle choices that might make a person live longer, like diet & exercise. Of course, they didn’t bother to “correct” the data for things that might cause a person to die sooner like, say, smoking or having cancer! I guess that one taught me a lesson about taking study results at face value!

    And the organic thing is so totally disheartening isn’t it? Did you know that when GMO crops have a “pesticide” woven into their genetics, the pesticide is Bacillus thuringiensis (Bt) which is actually actually a bacteria that is widely used in organic farming to control insects. I don’t have enough information to argue for or against the use of Bt in any form, but I find it very interesting that there is a collective freak-out about GMO foods with “pesticides built in,” yet people happily consume organic produce every day, much of which is covered with the very same pesticide!

    It all just makes me want to throw my arms into the air and surrender.


    • HI EcoCatLady,

      I also have a problem with idealizing the past. We weren’t more ecologically responsible — we were just less capable of creating a mess on the scale that we do now. There are plenty of modern [chemical] advances that add to our quality of life, including birth control, antibiotics, and medicines. I’m probably not as scientifically minded as CatMan (I don’t have a background in science, although I’m kind of wishing I did), but I think he’s making sense. It’s good to have a grounded partner!

      As for the organic vs conventional/GMO thing…yeah, it’s difficult. Apparently the ideal way is to really talk to the farmers at the market to see what they’re using and the impact of how they’re using it before making a decision, but before that’s a possibility for me, I need to get over 1) my dislike of talking to strangers; and 2) my general lack of knowledge about different conventional and organic pesticides. I have an uncle who is a top scientist at Monsanto, and I’ve often thought about asking him to guest blog, just for some perspective. He has said before that he won’t spend the money on organic produce, and I’d love to hear his reasons, which I think are probably based on a whole lot of scientific knowledge that I don’t have. Might start a flame war, though…


      • I, for one, would LOVE to hear what your uncle has to say on the matter. I’m sure it would spark some… er… um… “conversation” but I think that would be wonderful, especially if he’s willing to respond to comments & questions.

        I am SOOOOO with you on the talking to strangers front. I mean, I can handle chit chat, but when it comes to quizzing some farmer on their techniques, oy vey… my stomach is in a knot just contemplating it. To be honest, I’ve never actually made it out to any of the farmer’s markets in the area. The closest one is a 15 minute drive, plus they all take place at ungodly hours of the morning (from my hopeless night owl perspective.) Plus, when the farmer’s markets are in full swing (spring – fall) I’ve generally got more fresh veggies from the garden than I can eat. Does that take me off the “talking to farmers” hook? 🙂


        • My uncle and I don’t see each other all that often, but I should ask. I’ve always thought he was a person of great integrity and intelligence.

          Growing your own veggies definitely gets you out of having to talk to farmers. Lucky you! I don’t have any outdoor space, so I’m stuck for at least a little longer. I have to admit that I don’t always get to the farmers’ markets around here, either. They’re so full of people. I really don’t do well in crowds, and I think that would make it even harder to ask the right questions. I think I may eventually follow your example and grow my own just to avoid that situation!


        • Hmmm… maybe you could find a good CSA in your area. That way you could ask all of the questions up front (probably through email)… and there would be no crowds to contend with.


  5. I love this post. Mostly because it’s so well-researched and I’m kinda on a high after the scientifically backed human menstruation article I read earlier this morning. *le sigh* But I also like this because it points out the short-cuts the media takes when discussing organic food, pesticides and what we can do to help the planet.

    My friend was telling me about how not all food that is labelled organic actually is. But a lot of places rely on buzzwords words like “gluten free” or “natural” to get people – who haven’t done any research – to buy their product.

    It can be overwhelming, all the different information, and is probably what companies rely on because they know few people will have done their research.

    Great post! I loved this.


    • Thanks, Parisian Feline! It is overwhelming, and one problem is that we can find research online to back up our beliefs on virtually anything. I feel like data used to be less plentiful, but also a bit more authoritative. Now anyone (and that includes me! I have no science degree, so take this whole post with that in mind!) can get online and mouth off, cite sources that sound good, and come across as convincingly authoritative. I think it has become harder to identify good sources and possible biases because there’s just so much out there…and of course, we’re always drawn to the ones that we agree with already. Objectivity probably isn’t possible, but we can at least be aware of how and where we’re biased.


  6. Hi Jennifer,

    I applaud your willingness to shove through defensiveness and look at all angles of an argument. That is very admirable. There are no easy answers in this arena! No one knows the long term effects of the mix of synthetic chemicals we inhale, absorb, and eat daily so it’s really impossible to come to any definitive conclusions.

    However, I definitely smell them off-gassing from new electronic equipment, wrapping paper, new clothing, and any number of other items. So I know we are indeed inhaling and absorbing them far more than anyone did 50 or 100 years ago. I think there are enough clues to proceed with caution, but it’s not helpful to become hysterical.

    I’m not at all surprised that 70% of the toxicologists surveyed believe EWG overstates the health risks of chemicals. In my mind, that fits perfectly with the traditional medical model. It’s like doctors saying wholeheartedly for years that gastritis is due to stress and disregarding Barry Marshall’s research on h pylori for at least ten years. That’s not to say EWG is correct necessarily. The problem is we just don’t know.

    I’m personally concerned about the rising rates of asthma and chronic illness in children. The problem is that it’s difficult to link back. And like the study you shared on jaundice, easy to make the wrong conclusions.

    Nevertheless, there’s a lot at stake so I think it’s smart to be concerned, proceed cautiously, and minimize the risk.

    Thanks for challenging us!


    • Hi Sandra,

      You’ve mentioned your chemical sensitivities before, so it’s great to have your perspective on all this. We certainly are exposed to many more synthetic chemicals than we were in the past, and I think we’re in for some interesting times as we start sorting out what long term effects are. At the same time, I think it’s helpful to understand that chemicals are not a black and white issue and to make rational decisions about them. Overall, humans still enjoy better health and longer lives than we ever have in our evolutionary history, which is at least in part due to synthetic chemical medicines.

      It’s true that the sciences have the burden of proof on them, which can make it difficult to draw definite conclusions. However, I have to consider that people who have been highly trained in their fields have access to a lot of data and information that I don’t, and have good reason for making the recommendations they do. Every dentist I’ve ever had contact with has recommended fluoride toothpaste; most doctors support vaccination, the majority of scientists concur that climate change is happening right now. I hesitate to dismiss a position that a majority of people in a field support solely based on my own research as a non-expert. The internet makes it easy to seek out sources that disagree with the majority, but that doesn’t necessarily mean they should carry more weight with us.

      I think the whole point of making rational decisions is being willing to re-evaluate when new data appears, especially if it doesn’t support our beliefs. Judging by how difficult this is for me, I have to conclude that humans aren’t particularly rational creatures, however much we try. 🙂


  7. Posted by DaveD on 12/29/2011 at 12:30

    Great article Jennifer! It’s refreshing to see a rational approach to these topics. I’ll queue up that book to read too.

    A big part of this has to do with good critical thinking habits. As a non-scientist vegan myself I was overwhelmed by the scary information available on teh internets. It took a long time to recognize my own bias and figure out how to tell good information from bad. Vegan Chicago made a “baloney detection guide” to help vegans navigate these treacherous waters and I wrote about it here: http://pythagoreancrank.com/?p=1783 You might find it interesting.

    Thanks again, cheers!


    • Thanks, Dave! I just took a look at your baloney detection guide and love it. These are definitely questions we should be asking ourselves whenever we come across a new claim. I especially love your last question — does it affirm our pre-existing beliefs? Being aware of our existing biases and ideologies is a huge part of the equation. I’m still looking for the middle ground between intelligent skepticism and open mindedness,


      • I believe critical thinking to be that middle ground. It relies on science which is open-minded by default!

        I’ve learned to recognize that defensive feeling, that you described, as a red flag to double-check my bias. If that feeling crops up I may be wrong about something.


  8. Posted by Perry on 01/09/2012 at 17:16

    Excellent article here. Nice job getting past your initial defensiveness. The key to maintaining an open mind is to work with two key assumptions.

    1. Everything you know may be proven wrong. You have to be open to evidence that shows you are wrong.

    2. There are experts who know more about a subject than you. In matters of science, the experts are the scientists not the activist groups. There is definitely gray areas (e.g. some people have a higher tolerance for risk than other people) but if you go with what the consensus of scientists think, you’re much more likely to be following what is true.

    Sure, science makes mistakes but it has a built-in mechanism for correcting mistakes. This is what makes it a powerful way to figure out what is actually true or not.

    Keep up the good work.


  9. Thank you, Perry. I appreciate your perspective as a chemist, and I agree that as a layperson, I don’t have the knowledge or background to make definitive statements about what chemicals are harmful or safe, and in what quantities. As a consumer, I continue to err on the side of caution, simply because I can and I’ve found products that work effectively for my skin that are low in synthetic chemicals…although I realize that natural chemicals certainly can’t be assumed to be safer by default.

    I’d read more if you ever decided to take on the problems with the EWG database again. 🙂


  10. Posted by Christy on 02/10/2012 at 04:19

    Wow, this is fantastic! I was just in an argument yesterday on facebook with two ladies that were bashing a “natural” children’s bath product company because they use some synthetic chemicals. Their view is exactly black and white about the issue. They even claim that they don’t use any chemically altered substances on their children (they pointed out that they have higher standards than I do for my own children…did you see me roll my eyes?). You know, if you wouldn’t eat it, why put it on your skin?

    One is even a bio chemist. Apparently they don’t realize that saponified oil soaps are changed from their natural state. Take olive oil soap. First, you get the olives. Then, you squeeze out the oil. Then, you CHEMICALLY REACT that olive oil with lye to saponify it! So they are dead wrong. Saponified olive oil is chemically structurally different than regular olive oil. Seriously, do you think that put their “direct from nature” olive oil shampoo on their children’s vegetables? I mean, she said if you wouldn’t eat it, why put it on your children’s skin? I don’t know about you but while I give my kids olive oil, no way would I feed them organic olive oil soap!

    OK, sorry for the rant. 🙂 They just had my fired up. I personally take a more balanced approach to life. I buy my kids organic foods when they are available AND affordable. Otherwise, I buy them conventional food. I use bath products that are half organic ingredients and half green synthetic ingredients because saponified oils, organic or not, do not work well with our hard water. It’s all about balance.

    I do my research online, access risk for our family and then make decisions. So this article was very refreshing to read! 🙂


    • Hi Christy,

      Glad you liked it. 🙂 I’m with you about balance and making rational, thoughtful decisions based on actual evidence rather than ideology. I am a bit surprised about the bio chemist, though. Really? Surely she knows that everything, natural or synthetic, is a chemical? Maybe it’s time to pull out that article on ‘dihydrogen monoxide’ again. I think it’s good to be concerned about what you’re putting on/in yourself and your family, but conclusions should be based on science, not a good/bad dichotomy.

      You might like to read the toxicology book that inspired this post, The Dose Makes the Poison. It is a little hostile toward many aspects of the green movement (organic food, fluoride avoidance, pesticides), but it makes interesting points and has broadened my perspective for sure.


  11. […] nor is organic always synonymous with sustainability. Organic tomatoes imported from Mexico are sucking local water tables dry. The organic strawberries […]


  12. […] sad.) Interestingly, oleanders are also being investigated for therapeutic uses in treating cancer. The dose makes the poison. Viburnum lantana. Image credit: Bosc […]


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