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then deposited over a wide area of earth surface (Wu et al., 2009). It's essential to control
pollutant emission to minimize the environmental and health impact. A lot of relevant
researches on dioxin determination, formation and emission control have been conducted in
last decades. Unfortunately, all of this work still can not completely eliminate the public
concern. Incinerators construction and operation is opposed by public and environmental
protection organizations for PCDD/Fs exposure risk. Public protests happened a couple of
times in last two years, and the constructions of several plants were halted in China.
In order to clarify dioxin exposure risk, surveys and monitoring programs have been carried
out via detecting PCDD/Fs concentration in environmental media including soil, water, air,
food and bio-tissues. On one hand, there are remarkable influences of waste incinerators on
the environment. Kim et al. (2005) measured PCDD/Fs concentrations in ambient air, soil,
pine needles and human blood in order to assess the relationships between incinerator
sources and environment. It was observed the incinerator operation had directly influenced
the observed PCDD/F congener profiles of soil and pine needles. Further, the difference
between the levels of PCDD/Fs in the blood of office and plant workers demonstrates that
human exposure to PCDD/Fs occurs as a result of the operation of the incinerator. By the
Korea national monitoring of PCDD/Fs in the environmental media around incinerators
(Kim et al., 2008), the average PCDD/Fs levels in soils decreased with increasing distance
from the incinerator. From the PCDD/Fs level gradient away plant, a distance of 500 m is
suggested as being under the influence of an incinerator. After introduction of technical
improvement in MSWI, a reduction of 40% was observed in the median PCDD/Fs level in
soil around the facility (Domingo et al., 2002). On the other hand, no significant impact of a
waste incinerator on the neighborhood was reported too. In the research of a 10-year
surveillance program of a hazardous waste incinerator (HWI) (Vilavert et al., 2011), the
median value of PCDD/Fs in soil samples decreased 44% (from 0.75 to 0.42 ng I-TEQ Kg -1 )
between 1999 and 2009 year survey. In order to establish the temporal variation after 6 years
regular operation, the concentrations of PCDD/Fs in blood and urine of 19 workers
employed at a HWI were measured in 1999 and 2005 (Mari et al., 2007). The analyzed results
indicate that the workers at the HWI are not occupationally exposed to PCDD/Fs in their
workplaces. In our previous research (Xu et al., 2009), the overall PCDD/F levels in the soil
collected from the vicinity of the MSWI increased significantly, i.e., 39% for I-TEQ (median
value) between 2006 and 2007, though the impact of MSWI on this study area is limited by
congener-specific factor analysis. By the above review of the environmental impact of
incinerators, this topic is still not resolved. The main potential reason is the different
operation condition and pollutant emission level.
PCDD/Fs emission factor of MWI is much higher than the value of MSWI (UNEP
Chemicals, 2005), so it is presumed that MWI has worse environmental influence than
MSWI. In this study, PCDD/Fs level in soil in the vicinity of a MWI was monitored since
April 2007, before this plant started operation (May 2007), and continued this determination
every year after operation (2008-2010). This studied MWI is a typical central incinerator in
China, with a capacity of 20 ton/day. The detailed sampling/analysis methods and
experimental results are introduced along with discussion in this chapter.
2. Method and material
2.1 Study region and MWI
This studied MWI locates in the north of Zhejiang province, China. The designed capacity is
20 tons waste per day. The combustion technology is a rotary kiln combined with a
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