Environmentalists want you to worry that plastic is causing the uterus of pregnant women to change. Here is the actual science.
The sure-fire way for anti-science groups to frighten the public about the 'new' scary chemical of the month (and raise some money in the process) is to use one of a short list of general-purpose indictments, such as "endocrine disruptor."
If you aren't sure what the term endocrine disruptor even means, you are not alone. And if you do think you understand it, you are almost certainly wrong.
Like "Smurf" and "transgression" it is an entirely subjective term for most people who use it. The U.S. Environmental Protection Agency recently examined 52 chemicals that people might be exposed to during agricultural use to see if they even had any potential interaction with the endocrine system - even benign, much less being a "disruptor" of it - and found that popular environmental claims about products were entirely overblown.
Despite what the EPA has shown over and over, another paper in Environmental Health Perspectives, a publication notorious in science for publishing speculative papers, will be fodder for new fundraising efforts. It is already being gushed about at Environmental Health News, which is considered a vanity press for any number of foundations that are disguising political funding for their war on science.
However, you won't learn much about the actual science used in the paper reading them. Instead, they invoke a friendly mouthpiece who goes on and on about endocrine disruptors. It's a common head-fake technique, but that is why you are wise enough to read the expert opinions at the American Council on Science and Health instead.
The authors used a highly sensitive in vitro DNA amplification technique known as polymerase chain reaction (PCR) to find associations between urine concentrations of eight phenol-containing compounds and 11 metabolites of phthalates (plastic softeners) in 179 women in the Harvard Epigenetic Birth Cohort and the Predictors of Preeclampsia Study and expression of 29 candidate microRNAs in placenta.
In this case, the results were not significant despite belief they must be due to the p<0.05 statistic that people who write about this stuff think is some sort of Holy Grail for legitimacy. There was no link between these changes in expression of genes and baby birth weights or sizes - so, no effect - but since they have to conclude something, anti-science groups just make hints about blanket changes in "epigenetics" and imply it could impact people decades from now. It's a superb scare but follows a specious chain of logic: If certain molecules linked to expression of gene regulation in the placenta change and this change is correlated to Bisphenol A levels and babies are important, then send environmentalists money so they can misunderstand this "science" more effectively.
Perhaps that is why Bisphenol A (BPA), a perennial honey pot for environmental activists, is also invoked plenty by the authors of the study. BPA is used in plastic because it is clear and tough. It was invented in 1891 and has been in wide use for almost 60 years. Yet, it has become a fundraising darling for various anti-science groups despite it being found safe numerous times.
Most recently, the EPA spent four years and analyzed 300 articles on BPA and couldn't find a problem, but as we have seen since the 1970s, environmental groups scare first, raise money, and then invoke conspiracy theories when science does not agree, so it is irrelevant to them that BPA is harmless. The same demographic that believes vaccines cause autism and organic food is more nutritious are going to believe that BPA is harmful and no amount of evidence will satisfy them.
So is BPA changing the regulation of gene expression in anyone's placenta? Probably a little, but so is everything else, that is the promise and the peril of the ability to detect anything in 2015 if we try hard enough - correlation is easy, even if it is not meaningful. But we are talking about the same demographic that believes fracking will cause the Earth to deflate so it isn't much of a surprise they are worried about plastic.