2015 - 2018年武汉市农村饮水硝酸盐和氟化物浓度水平及健康风险评价

目的 了解武汉市农村饮用水中硝酸盐和氟化物浓度水平，并评估其对成人及儿童身体的潜在健康危害。方法 对2015 - 2018年武汉市蔡甸区、汉南区、黄陂区和新洲区858份农村饮用水中硝酸盐和氟化物的浓度进行调查，采用非参数统计秩和检验比较组间浓度差异，并利用美国环保局（EPA）推荐的风险评估模型进行健康风险评价。结果 4个地区农村饮水中硝酸盐的中位数浓度范围为0.025～1.300 mg/L，超标率为0.12%（1/858）；氟化物的中位数浓度范围为0.05～0.24 mg/L，均在国家标准限值范围内。不同年度、季节硝酸盐浓度差异有统计学意义（H = 40.914，P＜0.001；U = 3.241，P = 0.001），氟化物浓度差异无统计学意义（H = 7.297，P = 0.063；U = 0.667，P = 0.505）。不同水样类型、水源类型、城区之间水质中硝酸盐和氟化物浓度差异均有统计学意义（U = 2.321、2.711，P = 0.020、0.007；H = 377.392、361.906，P均为＜0.001；H = 500.696、610.275，均P＜0.001）。硝酸盐对成人和儿童的健康风险值分别为1.03×10-10/a和1.23×10-10/a，氟化物对成人和儿童的健康风险值分别为8.77×10-10/a和1.05×10-9/a，均低于美国环保局和国际放射防护委员会(ICRP)推荐的最大可接受风险度(1×10-4/a和5×10-5/a)。结论 武汉市农村饮水中的硝酸盐和氟化物不会对武汉市民身体健康造成较大威胁。

Concentrations and human health risk assessment of nitrate and fluoride in rural drinking water of Wuhan from 2015 to 2018

To understand the concentration levels of fluoride and nitrate in rural drinking water of Wuhan,and to evaluate their health risks to the adults and children.Methods The fluoride and nitrate concentrations in 858 rural drinking water samples from Caidian,Hannan,Huangpi and Xinzhou in Wuhan from 2015 to 2018 were investigated.The concentration differences between/among groups were compared using nonparametric statistical rank sum test,and the health risk assessment was carried out by adopting the risk assessment model recommended by EPA.Results The median concentration of nitrate in four districts ranged from 0.025 to 1.300 mg/L,with the over standard rate of 0.12%(1/858).The median concentration of fluoride in rural drinking water in four districts of Wuhan ranged from 0.05 to 0.24 mg/L,lower than the limit of national standard.Significant differences were found in nitrate concentrations among different years and between different seasons(H=40.914,P<0.001;U=3.241,P=0.001),but no significant difference in fluoride concentrations(H=7.297,P=0.063;U=0.667,P=0.505).There were significant differences in nitrate and fluoride concentrations between/among different water types,different water sources and different urban areas(U=2.321 and 2.711,P=0.020 and 0.007;H=377.392and 361.906,P<0.001;H=500.696 and 610.275,P<0.001).The health risks of drinking water to adult and children caused by nitrate were 1.03×10-10/annual and 1.23×10-10/annual,respectively.The health risks of rural drinking water to adult and children caused by fluoride were 8.77×10-10/annual and 1.05×10-10/annual,respectively.All of them were lower than the maximum acceptable risk levels(1×10-4/a and 5×10-5/a)recommended by EPA and ICRP.Conclusion The concentrations of fluoride and nitrate in rural drinking water in Wuhan do not have serious impact on the health of Wuhan residents.