Effect Measure

On a couple of occasions (here, here) we’ve taken note of the scientific controversy regarding the plasticizer, bisphenol-A (BPA). I shouldn’t really put it this way, because as the leading BPA researcher, Fred vom Saal of the Univeristy of Missouri said in the Washington Post over the weekend, there is no meaningful controversy any longer. Now that NIH’s National Toxicology Program has finally presented its draft report on BPA expressing concern over possible carcinogenic and developmental effects, vom Saal’s statement seems pertinent:

“The scientific community basically said, ‘This argument is over,’ ” he said. “It ended a long time ago. There’s only been an illusion of a controversy created by a well-financed public relations outfit. The idea that the FDA tells people this is safe is offensive.” (Washington Post)

Whether there remains a controversy in some people’s minds (e.g., some people in the Bush administration, including its FDA puppets), for the rest of the world the train has left the station. I reported here many months ago how my daughter, who is no scientist but knows how to use the internet, stopped using plastic baby bottles and went ahead and ordered (hard to find) glass ones. She had done it without asking me, even though this is an area of my scientific expertise. She had already made up her mind and whatever I had to say, especially my habitual over-nuanced explanations, wouldn’t have made a difference. Now in the wake of the NTP report and Canada’s decision to begin the process that might lead to the banning the importation, sale and advertising of polycarbonate baby bottles which contain bisphenol A, retailer Walmart will pull BPA containing baby bottles and Nalgene, maker of BPA containing water bottles, has announced intentions of abandoning BPA containing plastic bottles. The market is speaking. Loudly.

The facts on the ground aside, the BPA story is another illustration of how the Bush administration and the Clinton administration before it have been in bed with industry:

Despite more than 100 published studies by government scientists and university laboratories that have raised health concerns about a chemical compound that is central to the multibillion-dollar plastics industry, the Food and Drug Administration has deemed it safe largely because of two studies, both funded by an industry trade group.

The agency says it has relied on research backed by the American Plastics Council because it had input on its design, monitored its progress and reviewed the raw data.

The compound, bisphenol A (BPA), has been linked to breast and prostate cancer, behavioral disorders and reproductive health problems in laboratory animals.

As David Michaels has documented in his new book, Doubt is their Product, the plastics industry strategy of manufacturing scientific confusion is a time tested and effective way to delay or even prevent regulation of mass exposures to questionable chemicals. It is a strategy that also affects the public view of science:

The Orwellian strategy of dismissing research conducted by the scientific community as “junk science” and elevating science conducted by product defense specialists to “sound science” status also creates confusion about the very nature of scientific inquiry and undermines the public’s confidence in science’s ability to address public health and environmental concerns. (Doubt is Their Produce site)

Skeptical? Michaels has not only written a stunning exposé of this practice, using thousands of pages of documents, but he has put many of the documents themselves up on the web for anyone to see (here; scroll down)

Want more? The WaPo article (by all means read it; it’s long and juicy) discusses the role of the Weinberg Group, a consulting company specializing in manufacturing scientific confusion for well-heeled clients. Congress is just now beginning an investigation of their effect on regulation. The Weinberg Group has been notorious in scientific circles for years as hired guns (they even bragged about it on their website), so when an investigative journalist for Environmental Science and Technology (ES&T) wrote an exposé using documents disclosed in an EPA docket it came as no surprise to those familiar with the field. But it was an unpleasant surprise for ES&T, the official journal of the American Chemical Society, one of the least enlightened big professional organizations around (see here, here, here and here). They fired the journalist, Paul Thacker, alleging his story on The Weinberg Group was a “hatchet job.” You can read his account of the affair here and decide for yourself.

In fact I urge those readers whose first tendency will be to defend the Bush administration (you know who you are) to actually read the original documents and then defend them. For my part I prefer to defend science.

But maybe that’s just me. And my daughter. And my grandson, 11 months old.


  1. #1 floormaster squeeze
    April 28, 2008

    I sort of feel cheated on this. While I got rid of older Lexan containers I still use some of the newer ones. It is amazing to me how little useful information (particularly unmediated clear stuff) was available for so long.

  2. #2 hardindr
    April 28, 2008


    What do you think re this (NPR report), and this. What are your thoughts?

  3. #3 gribley
    April 29, 2008

    Are you asking Revere to weigh in on the whole thread of confused comments, or just the ones about carcinogenicity of BPA? It’s an odd point to make, since carcinogenicity is not the endpoint of concern. The draft report is here.

  4. #4 hardindr
    April 29, 2008


    Just about the carcinogenicity of BPA, and whether the Revere(s) thought BPA should be banned/fazed out. I would also be interested in their comments on what he thought of the scientist who oversaw the report and declined to say that BPA should be banned/fazed out.

    I looked at the conclusions of the draft report. They used the words “some concern”, “minimal concern” and “negligible concern” to describe the risks BPA poses to humans. I also looked at the charts on pages 39-41. They show clear evidence for problems with laboratory mice, but much less evidence for a danger to humans.

  5. #5 hardindr
    April 29, 2008

    Sorry I wasn’t clearer.

  6. #6 gribley
    April 29, 2008

    Well, I am not one of the Reveres, but I’ll chime in anyway. Again, carcinogenicity is not the endpoint of interest. The NTP has “some concern” about certain exposures to fetuses, infants, and children, and that’s enough to give me pause. In fact, having seen some of vom Saal’s data, I would say that I have more than “some” concern about those exposures.

    The evidence is not perfect, but the problem is that epidemiology is an extremely weak tool for this sort of exposure (and I know at least one of the Reveres will back me up on this). (For example, how would you quantify how much BPA you were exposed to in utero?) If we did have strong evidence of danger to humans, it would mean that the regulatory process had completely failed (as with lead, cigarettes, etc). Having animal data for which we can draw connections to effects in humans is pretty powerful.

    Whether one person says that it should be phased out or not isn’t really a good answer to a complex question. The effects of BPA are of most concern in certain populations and times of exposure, and especially for in utero exposure. It might make perfect sense for non-pregnant adults to use products that incorporate BPA in some cases, for example. Maybe the scientist quoted in the NPR interview thinks that calling for an outright ban for all uses is not supported by the evidence, but that it should be phased out for certain uses when susceptible populations are at risk. That would probably be a good representation of my own views.

  7. #7 hardindr
    April 29, 2008


    Thank you for your thoughts on this complex problem.

  8. #8 revere
    April 29, 2008

    hardindr: I am in total agreement with gribley on this. vom Saal’s data are quite worrisome but they involve endocrine disruption effects. I discussed the biological issues behind this in a previous post (first link in the post). Regarding carcinogenicity, one would have to worry about the co-carcinogenic effect in endocrine sensitive tumors like breast and prostate. I wouldn’t rule out primary effects on other tissues but the main question is the endocrine effects which occur at astonishingly low levels (which is consistent with their hormone mimicking activity). I will also affirm I agree with gribley on the extreme insensitivity of epidemiology (and I’m an epidemiologist). There is also very little epi evidence about BPA. The studies are just too hard to do and you have to wait too long for the late effects of fetal exposure (which are the ones at issue here).

    Given the massive population exposure you wouldn’t have to have much in the way of risk to accrue bodies or damaged children/later adults.

  9. #9 hardindr
    April 29, 2008


    Thanks for your comments, too.

  10. #10 ryan
    April 30, 2008

    Toxicology isn’t one of my areas. I wondered if you might comment on the dose-response/levels of BPA if you know that info. It seems that the major argument against regulation is the observation that normal exposures are far below dangerous levels.

    Even the Canada report contends that there is no danger to average Canadians. What are your thoughts?

    Is your concern just with the developmental effects?

    (OK, I’m too lazy to read the lit while I study).

  11. #11 revere
    April 30, 2008

    ryan: You wouldn’t have time to read the literature even if you weren’t studying. The NTP report surveyed over 700 recent articles. There is a lot of consistency that there are demonstrable biological effects of BPA in experimental systems at levels that are below those to which the human population is exposed. What we don’t know is what the downstream effects of these exposures are. One of the concerns has to do with later effects (say on adolescents or adults) or fetal exposures, something for which there is evidence (again) in experimental systems. The literature on this goes back a long way. I gave some of the reasoning for being concerned from the public health perspective in earlier post here.

    It is very difficult to do epidemiology on this for many reasons (potentially long latency, difficulty in doing exposure assessment, uncertainty about endpoints, lots of noise, etc.) so we are forced to use judgment and (I hope) prudence. With very large denominators the risk doesn’t have to be large to accrue substantial disease burdens. Is BPA an absolute necessity in our lives? Obviously not. If we can take off our shoes at the airport at huge cost to the taxpayer we can forego polycarbonate water bottles at a cost only to chemical companies.

  12. #12 kathleen
    May 3, 2008

    I’ve been following the vomSaal et al. literature for a while on this topic, and find it quite credible (and alarming).

    The most striking thing to me is how very difficult it is to avoid exposure to bpa. The major source for people is not just the polycarbonate bottles, but also canned foods, as most cans are lined with bpa-containing plastic, and the stuff leaches into food quite significantly. One of the highest measured was chicken soup. (The one exception I found was Eden’s canned beans, for which they line the cans with balsam-based material.)

    I also contacted the manufacturer of PUR water filtration systems, since that’s what I use, to ask what kind of plastic they use in their pitchers and filters. Since PUR was sold to P&G, I was not surprised when I received no reply. To avoid chloramine, lead, etc. I need to filter, but if I filter I add bpa? Seems one cannot win.

    Add this to the nanoparticles they’re adding to pants (thanks, LLBean!), perfluorination that’s added to coat dental floss of all things, and endless etc., and it becomes a full-time task to TRY to avoid all the garbage that’s being fed to us.

    I also highly recommend “Doubt is Their Product” and thank the Reveres for focusing on these important issues.

  13. #13 Marilynn
    May 15, 2008

    Recently I had a baby, and purchased 9 Nuk bottles. Then I watched a report on the news about BPA. That scared me, so I checked all my baby bottles and found that all nine of the NUK bottles had BPA. I called the Gerber Company and spoke with a customer service rep. She is taking the bottles back and sending me coupons for some BPA free bottles. They paid for the shipping. Well while waiting for the new bottles, I bought 3 Doctor Browns plastic bottles and 3 Soothie bottles made by The First Years. I bought them cause there was no code at the bottom at all, thinking that there was no BPA in them. Well I was wrong… It has it. I called the companies, The First Years told me that they wont take it back and they wont assist me in getting any BPA free bottles. That all there bottles have BPA in it. I told the woman that it was missleading that there was no recycle number on there, cause it made me think that it was BPA free. She told me that they dont have to and that it is my problem basicly. When I spoke with Handi-Craft which is in St. Louis, MO. and told them about the bottles and asked what are they doing about it. I was told that if you buy some more DR BROWNS bottles that are BPA free then I need to send to them the UPC code off the bottles and they will send me coupons for products for the amount spent. HUMMM that is not right. I was told to speak with Scott Rhodes and see what he will do.. I called to speak with him and got no one. I dont know about you but there is no one you can trust anymore. This is very upsetting. I wonder if there is a link between ADHD and ADD, since BPA does inhibit developemental stages in babies. I think that people need to stand up to these companies and make them change things.

  14. #14 stillwaggon
    August 16, 2008

    A friend of mine in the environmental health field recently mentioned in an email:

    “Unfortunately, certain chemicals in plastics have led to very high levels in children born prematurely who are on IVs from the bags. I heard about the latter at a conference where researchers presented the findings.”

    As if preemies don’t have enough strokes against them.

  15. #15 revere
    August 16, 2008

    stillwaggon: I think IV bags now are OK. It was true a few years ago but I think they eliminated the di-2-ethylhexyl phthalate (DEHP) that was fingered as the problem in bags made of polyvinyl chloride (PVC).

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