Created to replace older chemicals thought to pose an environmental threat, new flame retardants have become widespread in the air near the Great Lakes, according to a new report (Environ. Sci. Technol., DOI: 10.1021/es203251f).
Since the 1970s, manufacturers have used retardants to reduce fire risk in consumer products such as upholstered furniture, electronics, and clothing. Commonly used flame retardants called polybrominated diphenylethers (PBDEs) volatilize from those products and escape into the environment, where they may pose health and environmental hazards.
In 2004, the flame-retardant industry began replacing PBDEs with new formulations including Firemaster 550 and Firemaster BZ-54, which contain 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB) and bis(2-ethylhexyl)-tetrabromophthalate (TBPH). But these chemicals could also have environmental risks: Research has suggested that the compounds can build up in fish and damage their DNA.
So Ronald A. Hites of Indiana University, Bloomington, and his colleagues wanted to know if TBB and TBPH had started to accumulate in the environment. The researchers analyzed 507 air samples collected by the Integrated Atmospheric Deposition Network, a U.S.-Canada program that monitors air quality in the Great Lakes region. Hites and his team used gas chromatography/mass spectrometry to measure levels of the two chemicals in samples collected between 2008 and 2010. They detected TBB and TBPH in the vast majority of samples from Chicago and Cleveland, where levels of the compounds doubled approximately every 13 months. They also found the compounds in about half of air samples from four rural sites. At those sites, levels doubled every 19 months.
The flame retardants even reached remote Eagle Harbor in Michigan’s Upper Peninsula, which suggests to Hites that winds transport the chemicals over hundreds of miles. He points out that scientists don’t know much about these chemicals’ environmental fate. They may degrade naturally in the environment, he says, but they also may not.