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Toxicology in the Age of Twitter
By: Steve Herman
Posted: March 8, 2011, from the March 2011 issue of GCI Magazine.
page 4 of 5
The Times Beach case was clear, but regulating lower levels of dioxin has proven a greater challenge.6 A committee of the National Academy of Sciences that reviewed the EPA’s assessment of dioxin determined that there is a threshold below which the risk of cancer disappears. But in May 2010, EPA rejected the threshold approach to cancer risk. European regulators and the World Health Organization (WHO) decided a decade ago that dioxin did have a safe threshold, and they accept exposure levels much higher than the EPA’s proposed standard.
So if the EPA and the WHO can’t agree on a safe threshold for dioxin, is it unreasonable that consumers are confused by all the allegations of dioxin contamination in cosmetics and fragrances? Similar problems exist with parabens and phthalates—bad science driving out good science from the debate.
Since most websites about consumer goods have either a pro or anti industry bias, an objective alternative is the toxicologist. Toxicologists, dealing with the subject in general rather than specific product types, should be a reliable baseline for everyone. One useful resource is the Society of Toxicology.7 A lot of the web material on its site is directed at teachers and students K–12, making it a wonderful guide for non-scientists.
Data can be gathered on the potential harm of chemicals in a straightforward way. Converting that raw data to safety criteria is a very different matter. The LD50 value is a standard measurement of acute toxicity. An LD50 represents the individual dose required to kill 50% of a test subject group; the lower the LD50 dose, the more toxic. The acceptable LD50 for establishing a safe use level involves informed judgment. In real science, expert panels publish results in peer-reviewed journals. In the Age of Twitter, anyone can gain an instant audience for fallacious claims. As the information is repeated again and again in different outlets, it takes on the aura of truth.
The “Risk in the Mass Media,” an excellent symposium conducted by the University of New Hampshire School of Law, contains the following perceptive comment:8 “Due to the media’s handling of the dioxin reassessment controversy—in particular, many reporters’ scanty treatment of various risk estimates and related scientific uncertainties—the public is not sure what to believe about how harmful this chemical is.”9 The symposium was held in 1996. The only thing that has changed in the intervening years is the ease of spreading misinformation.