CAMBRIDGE, Mass. (Jan. 7, 2013) — Available evidence shows no correlation between styrene — even among workers exposed to high levels of the substance — and increased fatality from any type of cancer, according to an analysis performed by Gradient Corp., a Cambridge-based environmental and risk science consulting firm.
The Gradient study contradicts the June 2011 findings of the National Toxicology Program (NTP) of the U.S. Department of Health and Human Services, which listed styrene as an anticipated carcinogen in its 12th Report on Carcinogens.
Since that time, the U.S. styrene industry, led by the Styrene Information and Research Center (SIRC), has decried the NTP ruling as based on a biased and faulty review of existing data. The European Union decided not to list styrene as a carcinogen after a full review of the database on the chemical, the SIRC said.
Gradient analysts Lorenz Rhomberg, Julie Goodman and Robyn Prueitt performed the analysis, which has been published in the January/February 2013 issue of Human and Ecological Risk Assessment, a peer-reviewed scientific journal.
According to the Gradient analysis, the only consistent increased incidence of any medical problem associated with styrene exposure was lung tumors, mostly benign, among one strain of lab mice.
"The only plausible mechanism for styrene-induced carcinogenesis…is not relevant to humans," it said.
In a press release, Gradient said the SIRC provided financial support for the analysis, but the report's conclusions were the sole and independent responsibility of the authors.
Styrene is an important chemical in the rubber and other industries, used to make styrene-butadiene rubber and latex among other products.