Spatial Association of Surface Water Quality and Cancer in the Huaihe River Basin.

Objective To reveal the spatial distribution patterns of key pollutants in the Huaihe River Basin and quantify the risks and burdens of non-gastrointestinal cancers by the grade of pollution,providing targets and data support for enhanced management of water pollution in the Huaihe River Basin. Methods Surface water quality data of the Huaihe River Basin were obtained from the National Surface Water Environmental Quality Monitoring Network(2021).Incidence data of seven cancers were extracted from the 2019 Annual Report of the China Cancer Registry.Random forest and SHapley Additive exPlanations were employed to select key pollutants,and pollution was graded based on the spatial analysis of the Huaihe River Basin.The cancer risks and population attributable fractions were calculated under pollution grades. Results Five key pollutants linked to cancers were identified,including total nitrogen,total phosphorus,chemical oxygen demand,biochemical oxygen demand after 5 days,and arsenic.Pollution was graded into three levels regarding the combined effects of pollutants.Compared with the low pollution areas,high pollution areas showed increased risks of lung cancer(RR=1.26,95%CI:1.06-1.50),breast cancer(female)(RR=1.46,95%CI:1.21-1.77),pancreatic cancer(RR=1.46,95%CI:1.06-2.01),brain cancer(RR=1.44,95%CI:1.05-1.98),and gallbladder cancer(RR=1.60,95%CI:1.03-2.50).The grade of pollution contributed to more than 5% of cases for most cancers above. Conclusions The potential cancer risks and burdens attributed to surface water pollution cannot be overlooked.Addressing this challenge necessitates close collaboration of various stakeholders to strengthen policy development,enhance environmental governance,and implement public health interventions.