Altitudinal distribution of polybrominated diphenyl ethers (PBDEs) in the soil along Central Tibetan Plateau, China

The distribution of PBDEs in the mountains of the Central Tibetan Plateau (CTP) was determined by sampling soil along an elevation transect. The analysis of soil extracts was performed by gas chromatography and high-resolution mass spectrometry, through which 42 congeners were detected. The samples were also characterized with respect to the soil organic carbon (SOC) and mineral contents. The logarithmic concentration for three of the fractions and the ΣPBDEs increased significantly and exponentially with altitude. The slope value of the linear regression between the logarithm of the clay-normalized three fractional concentrations and the altitude is in the following order: light > intermediate < heavy. The coefficient of determination between the logarithm of normalized concentration and the altitude indicates that in the CTP, the clay normalization exhibits a better correlation to altitude than does the SOC normalization. The exponential equation between the concentration and altitude was modified by accounting for the localized soil properties. The exponential equation between the concentration and altitude was modified by accounting for the localized soil properties.

Highlights► A total of 42 congeners of PBDEs and minerals were detected in the surface soil of the CTP. ► The fractional concentrations of PBDEs were applied to regress against altitude. ► The clay-normalized concentration correlates better with altitude than does the SOC.