4.1.3. Carcinogenic Risk Assessment

The International Agency for Cancer Research classified five elements (i.e., chromium, cadmium, arsenic, nickel, and cobalt) as possible carcinogens (IARC, 2013). Since cadmium and cobalt have no SF, the oral intake and skin contact for chromium, arsenic, and nickel were considered pathways of human contact, with a special focus on arsenic. In Tables 3 and 4, it can be seen that from 2017 to 2018 a total of 114 records of CR, which indicate the carcinogenic risk of adults and children, exceeded the value of 1 <sup>×</sup> <sup>10</sup>−0.6 , demonstrating that the study area was seriously polluted, and that the main pollution factor was As. From 2017 to 2018, the average CR values for adults for As in the study area were 2.94 <sup>×</sup> <sup>10</sup>−0.5, 5.93 <sup>×</sup> <sup>10</sup>−0.5, 5.48 <sup>×</sup> <sup>10</sup>−0.5, and 3.59 <sup>×</sup> <sup>10</sup>−0.5 (Table 5), respectively, while those of children were 6.28 <sup>×</sup> <sup>10</sup>−0.5, 1.27 <sup>×</sup> <sup>10</sup>−0.4, 1.17 <sup>×</sup> <sup>10</sup>−0.4, and 7.67 <sup>×</sup> <sup>10</sup>−0.5 , respectively, which were higher than those of adults (Table 6). Therefore, we mainly analyzed the influence of As ions on children's health risk and the possible ion forms under local hydrogeological conditions (Table 7).



**Table 6.** Non-carcinogenic risk assessment for children.






**Table 7.** Carcinogenic risk assessment for children.



