Occurrence and risk evaluation of organophosphorus pesticides in typical water bodies of Beijing, China

Human activities, particularly in large cities, can lead to pollution caused by micropollutants such as pesticides in water bodies, which have been recognized as serious threats to the environment and human health. The pollution level of six organophosphorus pesticides, three herbicides, and one bactericide in groundwater and the Wenyu River, and their fates in three sewage treatment plants (STPs) and a hospital were investigated in this study. The concentrations of the ten detected pesticides ranged from not detected (ND) to 323.44 ng L(-1)in different water samples from Beijing; metalaxyl was detected to have the highest concentration (89.58 ng L-1), and the detection frequencies of atrazine and metalaxyl were 100%. The maximum concentrations of pesticides in the Wenyu River, STPs, and the hospital were 1-2 orders of magnitude higher than those in the groundwater. Good removal efficiencies by the treatment processes were observed for ametryn (100%), while the removal efficiencies for atrazine and omethoate were the lowest in the three STPs (- 9.6% and 12.67%, respectively). Finally, risk quotient (RQ) values of each contaminant were estimated from the maximum values determined for typical urban to assess the ecology and health effects. In the case of environmental toxicity, the highest RQ values (> 1) were obtained for dichlorvos and omethoate. In the case of health toxicity, the RQ values show that the pesticides found in groundwater pose no potential health risks to humans at current concentrations.

Automated summary

Human activities in large cities can lead to pollution caused by micropollutants such as pesticides in water bodies, which pose serious threats to the environment and human health. A study in Beijing investigated the pollution levels of pesticides in groundwater and the Wenyu River, as well as their fates in sewage treatment plants and a hospital. The study found high detection frequencies for atrazine and metalaxyl, with low removal efficiencies for some pesticides in the treatment plants. The risk quotient values show that the pesticides in groundwater do not pose potential health risks to humans at current concentrations.