Concentration and health risk assessment of trichloromethane in drinking water for rural primary and middle school students in Tianjin / 中国学校卫生

ABSTRACT

Objective@#To evaluate the distribution characteristics and health risk of trichloromethane (TCM) in the drinking water supply of primary and middle schools in rural areas of Tianjin, so as to provide a scientific basis for improving drinking water safety in rural schools.@*Methods@#A total of 60 water samples from 30 rural primary and middle schools in 10 agricultural districts of Tianjin were collected from April to June (dry season) and July to October (wet season) in 2023 with direct selection method. The content of TCM was detected according to the Standard Methods for the Examination of Drinking Water, and a risk assessment method recommended by the United States Environmental Protection Agency was used to evaluate the health risk of TCM through oral exposure.@*Results@#The concentration of TCM in drinking water was no detection to 54.00 μg/L, with an average of (13.44±14.88) μg/L, and the value was higher during the wet season [12.90(1.40,32.28)μg/L] than the dry season [2.40(1.40,18.13)μg/L] (Z=-2.09, P<0.05). The concentration of TCM for primary and middle schools were [3.38(1.40,20.75) μg/L] and [5.30(1.40,28.23)μg/L] respectively, and there was no statistically significant difference between different types of schools (Z=0.50, P>0.05). The carcinogenic risk through oral exposure ranged from 3.84×10-7 to 2.05×10-5, while the noncarcinogenic risk ranged from (0.00-0.16), all within the acceptable range. Children aged 6 to 9 years old were at the highest risk.@*Conclusions@#TCM has been detected in the drinking water of rural primary and middle schools to a certain extent in Tianjin, and attention should be paid to the potential health risks of oral exposure. The monitoring and management of disinfection byproducts in drinking water should be strengthened to further reduce the risk of exposure to children.