Study On Health Risk Assessment Of Volatile Substances Emitted From Urban Wastewater Pump Stations

Wastewater pump stations are important part of urban drainage system, recentlythe number and size of wastewater pump stations were increasing, some urbanwastewater pump stations located in residential area, commercial sites or other sensitiveareas with high population density. The volatile substances from wastewater pumpstations draw more attention on their influence of human health. Therefore, it becomesimportant to evaluate the impacts of volatile substances on air equality and humanhealth.Firstly, the paper introduced the sampling and analysis methods of urbanwastewater pump stations, and the concentration of volatile substances in the stationswas analyzed. The results showed that fifteen kinds of chemicals were detected, andsulfide and BTEX were the two main volatile categories; hydrogen sulfide was thehighest concentration of the volatile substances. In addition the concentration of volatilesubstances in station A was higher than that in station B, and the order of volatilesubstances concentration in different position was: wellhead of volatile substances＞wellhead of the valve＞pumping station. The concentration of odors in stations wasunder the standard value.Then, a health risk assessment method recommended by USEPA was applied toevaluate the potential health effects of each volatile substance according to theircarcinogenicities in deterministic and uncertainty ways. Deterministic assessmentshowed that the non-carcinogenic risk of hydrogen sulfides was highest (>1); thecarcinogenic risks of benzene and naphthalene was higher than the most acceptablelevel10-6. Uncertainty assessment showed that the main non-carcinogenic risk wasfrom hydrogen sulfide and the main carcinogenic substances were benzene andnaphthalene, these results was accorded with the deterministic assessment.Finally, the sensitive feature analysis was adopted to assess the impact of themodel parameters on model outputs, and the results could provide the guide to establishthe risk prevention measures for operators and residents in urban wastewater pumpstations.