“…Concentrations of the other HCH isomers, a-HCH, g-HCH, and d-HCH, ranged from 0.01 to 0.07 ng/g (mean 0.02 ng/g), 0.01 to 0.09 ng/g (mean 0.03 ng/g), n.d. to 0.08 ng/g (mean 0.03 ng/g), respectively (Table 1). Compared to other regions of China and other countries, HCH contamination in the surface soils along the Bahe River was lower than in such areas within China as Shanghai (2.4 ng/g; Jiang et al, 2009), Harbin (7.1 ng/g; Wang et al, 2009), Hong Kong (6.2 ng/g; Zhang et al, 2006), Beijing (31.1 ng/g; Shi et al, 2013), and the Pearl River Delta (3.4 ng/g; Yu et al, 2013), as well as areas within other countries such as India (825 ng/g; Mishra et al, 2012) and Vietnam (7.4 ng/g; Toan et al, 2009). However, the concentration was slightly higher than the values observed in Dashiwei Tiankeng (0.11 ng/g; Wang et al, 2013).…”