Pesticide residues in breast milk and the associated risk assessment: A review focused on China.

This review aims to provide an overview of studies on pesticide residues in breast milk in China and the related health risk to mother and infants. Results showed that the investigations of breast milk covered 22 provincial administrative regions of China. Beijing and some densely populated and economically developed areas have most publications. The study frequency was followed the order of DDTs>HCHs>HCB > ∑Drins,∑Chlordane. While the residue levels were ranked as DDTs, HCHs > ∑Drins>HCB > ∑Chlordane. The highest residue levels of DDTs and HCHs in breast milk were found in 1980s (~10,000 ng/g lipid), then experienced a sharp decrease in 1990s (~1000-2000 ng/g lipid). In 2000s and 2010s, DDTs, and HCHs residue still showed a decreasing trend. Spatially, people located in urban area, coastal areas and southern China tend to have higher pesticide residues as compared to rural area, inland area and northern China, respectively. Other factors such as dietary habit, living environment, the maternal age, the parity, body mass index, lactation period, menstruation characteristics as well as hormonal drug intake and infertility treatment will also affect the pesticide residues in breast milk of Chinese people. According to the estimated daily ingestion (EDI) of breast milk, the average health risk for infants were generally exceeded the acceptable level before 2006, while after that, most EDI values were within the standard. Body burden of pesticides in mother can also be evaluated by using the residue data in breast milk, but no relevant guidelines were available. Other knowledge gap included 1) for some provinces with large consumption of pesticides or located in remote and plateau areas, there are few/no studies available; 2) current study on pesticide residues in breast milk in China were only focused on organochlorine pesticides, research on current used pesticides (such as pyrethroids, organophosphorus, carbamate) were necessary in the future.