Factors influencing atmospheric concentrations of polybrominated diphenyl ethers in Japan

We used polybrominated diphenyl ether (PBDE) data in air at 38 sites across Japan (2009–2012), which were measured by the Japan Ministry of Environment (JMOE), to elucidate the time trend and seasonality of atmospheric PBDEs. In order to address few (7% for BDE-47) to many (63% for BDE-153 and 183) non-detect data, Tobit model, also called a censored regression model was used. The model revealed that the concentrations of PBDE congeners were influenced by a combination of year, temperature, rainfall rate, and population density. Greater declines were observed for BDE-47, -99, -153 and -183 (−21, −25, −17, −23%/year, p