The concentration of environmental estrogens in surface water in China: a systematic review, meta-analysis and health risk assessments

Environmental estrogens (EEs) have been recognized as emerging organic pollutants in surface waters, posing significant ecological and human health risks. Following the PRISMA guidelines, we conducted a systematic review and meta-analysis of EEs (estrone (E1), 17β-estradiol (E2), estriol (E3) and 17α-ethinylestradiol (EE2)) in Chinese surface water, synthesizing English and Chinese literature. The meta-analysis estimated the concentrations (ng/L) of each EE in water as follows: E1 = 4.48 (95% CI: 2.15, 6.81), E2 = 5.76 (95% CI: 1.34, 10.17), E3 = 7.72 (95% CI: 2.88, 12.57), and EE2 = 6.11 (95% CI: 1.44, 10.78). Spatial patterns showed higher levels in eastern and central China, while studies conducted post-2020 reported lower concentrations, which corresponded to reduced discharges during the COVID-19 lockdown. Age-grouped health risk assessment indicated that current levels of EEs in surface waters have not yet exceeded the lower limit threshold for potential health risks. However, the potential risks to sensitive groups such as children cannot be overlooked. The substantial heterogeneity across studies reflects variations in geographical location, seasonality, and methodology. This study provides the most comprehensive assessment of EEs in Chinese surface water, highlighting their widespread occurrence, potential risks to vulnerable populations, and evidence gaps in western and rural areas. These findings provide a scientific basis for strengthening water quality standards, prioritizing pollutant management, and guiding future monitoring efforts in China.