Search

Pollution from organochlorine (OCP) and organophosphorus (OPP) pesticides in groundwater is a key issue for water resource protection. Sixteen kinds of OCP and six kinds of OPP pesticides were detected in 18 groundwater samples determined by GC-MS. Results showed that seven kinds of OPCs and two kinds of OPPs were found in the groundwater in Beijing. Among the OCPs, there were mainly hexachlorobenzene (HCB), hemochromatosis (HCH), and dichlorodiphenyltrichloroethane (DDT), with maximum values of, respectively, 82.4, 193, and 158 ng·L -1 . Among the OPPs, there were o, o -dimethyl- o -2,2-dichlorovinylphosphate and o,o -dimethyl methylcarbamoylmethyl phosphorodithioate, with maximum values of 7.1 ng·L -1 and 17.7 ng·L -1 , respectively. The OCPs and OPPs were found in the sewage irrigation areas. The results of a probabilistic risk assessment showed that the non-carcinogenic and carcinogenic risks of OCPs and OPPs within the drinking water in Beijing had been controlled, that risks from OCPs were higher, and that women were more sensitive to the toxicity of the pesticides. The monitoring of HCH and DDT in the groundwater should be implemented.

Based on the GC-MS technique, we conducted a survey to investigate the concentration, distributions, and emission sources of sulfonamides (SAs), fluoroquinolones (FQs), tetracycline (TCs), β -lactam, and macrolides in groundwater in Beijing. Results indicated that SAs, FQs, and TCs were the main types of antibiotic in groundwater, and the detection ratios of trimethoprim, ciprofloxacin, and norfloxacin were above 70%. Concentration of antibiotics in sites from sewage irrigation areas were significantly higher than those from the drinking source area or the south-to-north water recharge areas. The highest concentration of sulfadimidine (236 ng·L -1 ) and sulfadiazine (96.8 ng·L -1 ) in groundwater were both found in the sewage irrigation area. An ecological risk analysis showed a low risk for antibiotic in groundwater at drinking source sites, while groundwater at sewage irrigation sites fell into the high risk group. It is important to strengthen the ciprofloxacin monitoring and ensure underground water safety.