Status, Influences and Risk Assessment of Hexachlorocyclohexanes in Agricultural Soils Across China

Abstract

Large amounts of hexaclorocyclohexanes (HCHs) were historically applied to Chinese soils. However, there has been limited information on the residue patterns of HCHs in soils at a national scale in China. In this study, surface soil samples were collected from agricultural fields across China, and the concentrations of HCHs and enantiomeric fractions (EFs) of α-HCH were measured. The results showed that the average concentrations of α-HCH, β-HCH, γ-HCH, and total HCHs in Chinese agricultural soils were 0.190, 1.31, 0.236, and 1.74 ng g(-1), respectively. Residues of HCHs likely originated from past usage of technical HCHs. The isomers of α-HCH and γ-HCH tended to accumulate in the sites with lower total HCH concentrations, lower temperature, higher elevation, and less wet precipitation when compared to β-HCH. Enantiomeric analysis showed a preferential degradation of (-)-α-HCH. Human health risks via various exposure routes to HCHs in soils were further estimated. Overall, the mean hazard index (HI) linked to noncarcinogenic risks was below 1, suggesting an absence of noncarcinogenic risks of HCHs in Chinese soils. In addition, the cancer risk values were all below 10(-4), which indicates low or very low risks.

Spatio-vertical characterization of the BTEXS group of VOCs in Chinese agricultural soils

“…The highest correlation coefficient was observed between toluene and total BTEXS (r = 0.920, p < 0.01 in 2013; r = 0.899, p < 0.01 in 2016). Such finding indicated that total concentration could be an essential factor influencing the residue status of individual compound in soils (Niu et al, 2013).…”

“…Accumulation of organic pollutants in the environment, particularly the more volatile ones, could be enhanced at sites with higher elevations and lower temperatures due to global distillation effects (Niu et al, 2013). Relatively high BTEXS levels have been detected at Datong basin, which is located at the loess Plateau of Shanxi, where cold condensation is pronounced due to the mountainous topography.…”

Effects of metals on enantioselective toxicity and biotransformation of cis‐bifenthrin in zebrafish

“…The purity of the separated enantiomers was determined by HPLC under the same conditions described above. The concentration of each enantiomer was analyzed on an Agilent Technologies 7890A gas chromatography system equipped with an electron capture detector and a HP-5 capillary column (30 m  0.25 mm  0.25 mm) [32][33][34].…”

Atomic-scale investigation of the interactions between tetrabromobisphenol A, tetrabromobisphenol S and bovine trypsin by spectroscopies and molecular dynamics simulations

“…The environmental release of TBBPA and TBBPS from existing or discarded products caused their residues in air, water, sediment, soil, food [7][8][9][10][11][12], human serum and breast milk [13,14]. Exposure to TBBPA was reported to cause carcinogenic effects, hepatotoxicity, immune response neurotoxicity, and disruption of endocrine system [15].…”