Polycyclic Aromatic Hydrocarbons Levels in Drinking Water Sources in Rural Areas in a City of Jiangsu Province

Objective To investigate the levels of polycyclic aromatic hydrocarbons(PAHs) in sources of drinking water in rural areas with high cancer incidence in Huai'an City of Jiangsu Province.

Methods A total of 28 villages were selected from 14 towns in Xuyi County, Jinhu County, and Chuzhou District in Huai'an in 2010. Samples(n=159) of surface water, shallow groundwater, and deep groundwater were collected during wet season and dry season for detecting PAHs. The relationship between PAHs concentrations in samples and upper gastrointestinal cancer mortality of local residents was analyzed.

Results The mean concentration of PAHs was(2 700.09±5 756.08) ng/L, and it was higher in wet season than in dry season (4 914.68±7 247.71) ng/L, (219.74±147.80) ng/L; t=5.95, P=0.00. The concentration was highest in surface water, followed by shallow groundwater and deep groundwater, with statistical differences(F=6.15, P=0.00). Besides, the difference in PAHs concentrations was significant among three areas(F=17.40, P=0.00). According to the Drinking Water Health Standards(GB 5749-2006), the rate of sample with disqualified PAHs level was 26.42%. Specifically, in wet season the rate was 50.00%, while in dry season all samples were qualified in terms of PAHs level. In wet season, the disqualification rate was highest in surface water samples, followed by shallow groundwater and deep groundwater(χ²=7.75, P=0.02). The difference in disqualification rate was significant among three areas(χ²=46.80, P=0.00). No statistical correlation was found between PAHs level and upper gastrointestinal cancer mortality(P>0.05).

Conclusion Higher PAHs levels are detected in drinking water sources in rural areas with high cancer incidence of Huai'an City. The findings do not indicate a correlation between PAHs and upper gastrointestinal cancer mortality.