Profiles and risk assessment of legacy and current use pesticides in urban rivers in Beijing, China.

Pesticides in the environment can pose serious risks to aquatic ecosystems. This study focused on the existence of 27 pesticides, including 13 pesticides regulated by the Stockholm Convention as persistent organic pollutants (POPs) and 14 commonly used pesticides in three urban rivers in Beijing that receive effluents from three municipal wastewater treatment plants (MWTPs). Among the 27 pesticides, 12 were detected at least once over a period of 4 seasons. Atrazine, aldrin and dieldrin were universally found in the three rivers, with the highest concentrations being 311, 163 and 23.3 ng/L, respectively. HCHs, DDTs, heptachlor and endosulfan, which are POPs, were detected at lower concentrations (ND-16.7 ng/L). Most of the insecticides and some of the herbicides in the rivers originated from MWTP effluents. The risk assessment results showed that aldrin posed medium risk (0.1 ≤ RQ < 1) to fish, and atrazine exhibited medium risk to both fish and algae. Despite the implementation of the Stockholm Convention and the upgrades of MWTPs emitting ozone, high loads of aldrin, atrazine and dieldrin were discharged to the rivers. Efforts should be devoted to identifying POP pesticide sources and upgrading MWTPs with other technologies to ensure the ecological safety of rivers.

Occurrence and exposure assessment of bisphenol analogues in source water and drinking water in China.

Bisphenol analogues (BPs) are widely used in the production of epoxy resins and polycarbonate plastics. In recent years, the demand and production capacity of BPs are growing rapidly in China. However, knowledge on the occurrence of BPs other than bisphenol A (BPA) in the aquatic environment, especially in source and drinking water, is still limited. In this study, occurrence of 16 BPs, which have been used in various industrial applications, was investigated in source and drinking water from twenty drinking water treatment plants (DWTPs) across China. In source water, BPA, bisphenol AF (BPAF), bisphenol B (BPB), bisphenol E (BPE), bisphenol F (BPF), and bisphenol S (BPS) were detected at the following concentration ranges: BPA (n.d.-34.9 ng/L), BPAF (n.d.-10.8 ng/L), BPB (n.d.-14.3 ng/L), BPE (n.d.-6.2 ng/L), BPF (n.d.-12.6 ng/L), and BPS (n.d.-5.2 ng/L). In drinking water BPA, BPAF, BPB, BPE, BPF, and BPS were detected as follows: BPA (n.d. - 6.5 ng/L), BPAF (n.d.-4.7 ng/L), BPB (n.d.-3.2 ng/L), BPE (n.d.-0.6 ng/L), BPF (n.d.-0.9 ng/L), and BPS (n.d.-1.6 ng/L). In addition, to assess the exposure of BPs through drinking water consumption, the estimated daily intake of each detected BPs was calculated. The estimated daily intake (EDIs) was below 0.25 ng/kg bw/day for each detected BPs, much lower than the tentative oral reference dose (RfD) values for BPA (4 µg/kg bw/day) recommended by the European Food Safety Authority.