Characteristics And Health Risk Assessment Of PCDD/Fs In Ambient Medium Around A Municipal Solid Waste Incinerator In South China

With the development of the municipal solid waste incineration(MSWI) technology, the technology has been the main channel to deal with existing waste. Dioxin(PCDD/Fs) produced from the MSWI will be dangerous to human health. With the new regulation of the municipal solid waste control standards, our nation will further tighten the control standard of the dioxin emission. Against this background, our team have taken commercial waste-to energy plant in south China(named B plant) as an object and monitored the dioxin levels and features of hair from residents and environmental media(air, soil and vegetation). Also human health risk assessment will be carried out with the the dioxin levels and features of hair. The main contents and conclusions of the study are as follows:(1) The level of flue gas dioxin TEQ from B plant is 0.033 I-TEQ/ m3, this level is lower than the new national standard limits(0.1ng I-TEQ/Nm3); the scope of dioxin TEQ in the air of study area is 0.020~0.443 pg I-TEQ/m3, this level is lower than ambient air standard limits(0.6pg I-TEQ/m3) of which is reference to Japan, the scope of dioxin TEQ in top soil of study area is 1.740~8.280 ng I-TEQ/kg, this level is higher than the agricultural soil standards of Netherlands(10 ng I-TEQ/kg) and lower than the Switzerland. The dioxin toxic equivalents is in the range of 0.040~12.445 ng I-TEQ/kg in the vegetation of the study area, this level is higher than the level in suburb of Guangzhou.(2) Study on the dioxin fingerprint characteristics and correlation analysis shows that, MSWI is the primary pollution source of the study area; 2,3,4,7,8-PeCDF is the main contribution to the monomer; the level of dioxin in study area has spatial distribution characteristics, the pollution level in the factory is higher than outside, the dioxin in soil and vegetation has the accumulation, lychee trees is the most accumulative in the study area.With the expose model for exposure assessment(breathing exposure, soil/dust intake and soil/dust skin absorption) of adults and children, the results show that the exposure and cancer risk of residents in study area are well tolerated. Otherwise, the analysis of the level of dioxin in hair reveals that the level of dioxin in hair is higher because of the high pollution occupational exposure and it will accumulate in the body of long-term exposure. The health risk of residents in study area is in the safe range, but the dioxin may threat people's health due to the long-term exposure. It is important to control the emission of the dioxin from the MSWI.