Gh. Eduljee et Aj. Gair, SETTING DIOXIN EMISSION LIMITS FOR MSW-INCINERATORS - A MULTIMEDIA EXPOSURE ASSESSMENT FRAMEWORK, Waste management and research, 15(4), 1997, pp. 335-348
Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzof
urans (PCDFs) are emitted in trace amounts from municipal solid waste
(MSW) incinerators. The exposure to PCDD/Fs experienced by an individu
al is dominated by the food chain pathway, which accounts for over 98%
of the total uptake. Defining a target daily intake (the World Health
Organization TDI of 10 pg I-TEQ kg.bw(-1) day(-1)) exposure assessmen
t algorithms were then applied to arrive at the corresponding PCDD/F l
evels in air, soil, plants, food products, etc., which would allow the
target intake to be met while retaining the balance of intake between
the Various exposure pathways. These concentrations were converted to
an ambient air concentration of PCDD/Fs and ultimately, by defining c
riteria for acceptability, to a guide value for PCDD/F concentration i
n emissions from the MSW incinerator. This strategy was applied to PCD
D/F emissions from MSW incinerators of various sizes against two illus
trative criteria for acceptability: an ''insignificant'' release and a
threshold above which the release may require further assessment for
environmental effects and for control. Using the criteria developed in
this paper, the current PCDD/ F emission limit of 0.1 ng I-TEQ m(-3)
results in an emission that is classed as ''insignificant'' for all pl
ant sizes. However, higher emission concentrations can also be accommo
dated below the threshold for further assessment and control. (C) 1997
ISWA.