Honghai Tian, Ying Hai, Yiying Jin, Huimin Yin and Nan Li
National
Center for Environmental Analysis and Measurement
Persistent
organic pollutants (POPs), worldwide environmental compounds derived from
natural and anthropogenic sources, are characterized by their persistent,
fat-seeking, and endocrine-disrupting effects. Among those, the unintended
by-products (dioxins, furans) are recognized as the most toxic man-made
chemicals. These compounds are derived primarily from combustion processes
(e.g., incineration of municipal waste). They are also produced during the
burning of fuels, the production and use of chloro
organic chemicals (e.g., PCBs, pentachlorophenol, chlorinated aromatic
chemicals), and the chlorine bleaching of pulp and paper. Many countries have
recently compiled national inventories of PCDD/Fs emissions to air from
regulated, industrial sources in order to gain a better understanding of the
quantities released per annum and to develop strategies to reduce emissions.
Incineration
is not the dominant way to disposal of MSW at present in China. However, more
and more cities with rapid development of economy are planning to build MSW
incineration facilities. According to the latest result of investigation on MSW
treatment, nearly three percent of MSW, approximately four million tons, was
treated in over 40 incineration plants in 2001. As one of the potential dioxins
sources, MSW incineration has been concerned more and more seriously by public.
The State Environmental Protection Administration (SEPA) of China has made
efforts on this matter by issuing environmental protection standards to
restrict dioxins emission from both MSW and hazardous waste incineration
facilities.
An initiative survey
was conducted on dioxins emission from MSW incinerators in China. Over 20
incinerators were selected for dioxins monitoring and half of monitoring data
exceed the emission limit of national standard. Dioxins emission to air was
estimated to be 72ng TEQ annually from the existing MSW incinerators in China,
which is far lower than estimation following UNEP recommended factors.