Marian Stanley doesn't have a problem with research that looks into the health effects of chemicals - many of which are used as the building blocks of plastic products. In fact, she welcomes it. But she does think it is time for people to put that research into perspective.
``It is distressing to see science by press release or news conference,'' said Stanley, who is manager of the Phthalates Esters Panel at the American Chemistry Council in Arlington, Va. ``We are not saying, `Don't do the research,' or, `Don't publish the research' - but don't scare people to death, either,'' said Stanley in a phone interview July 27.
``These studies have their limitations, yet some of the anti-chemical groups are presenting them as the gospel truth'' and using them to suggest that entire series of compounds, such as phthalates, should be banned.
Health Care Without Harm petitioned the Food and Drug Administration on July 24 to require labeling on PVC bags and tubes that contain the plasticizer di(2-ethylhexyl) phthalate. In March, the European Union said companies must label any products containing phthalates that come into contact with the human body.
In reviewing five leading human studies on phthalates, Stanley found that most did not have a control group that would have enabled researchers to make comparisons about the effects of the exposure.
In addition, she said the studies drew conclusions that needed more research to verify their findings. ``The most these studies can do is to suggest a link between the effect and the chemical exposure that should be pursued in follow-up studies.''
For example, Stanley said a 5-year-old study done at Harvard University by Susan Duty and Russ Hauser claimed to show a correlation between phthalate exposure and DNA damage in sperm, but the study had no control group and used people from a fertility clinic.
``You can't correlate their findings and say it is causing more infertility,'' she said. ``You need further research,'' she added, noting that the authors conceded the study sample was small and the results preliminary.
What's more, the study labeled diethyl phthalate as problematic, which Stanley said is ``biologically implausible, because DEP does not show the same toxicological effects in rodents that other phthalates do.''
``We are trying to show that while these studies are important, they have their limitations and can't be used to ban a whole series of compounds,'' she said. It is also incorrect scientifically, she said, ``to try and extrapolate the research from one study to every single type of phthalate.''
``These studies are so overinterpreted and overanalyzed that they are creating a fear in the population,'' Stanley said. ``Let's be rational. Let's put this in perspective. Let's look at the real risks and not overextend conclusions.''