Sg. Zemba et al., QUANTITATIVE RISK ASSESSMENT OF STACK EMISSIONS FROM MUNICIPAL WASTE COMBUSTORS, Journal of hazardous materials, 47(1-3), 1996, pp. 229-275
Multi-pathway risk assessment (MRA) is a tool for evaluating the possi
bility of adverse effects to human health that may result from contami
nant releases from municipal solid waste combustors (MWCs) and other s
ources of air pollution. An MRA attempts to model the movement of poll
utants within the environment to various points at which they may be c
ontacted by people, beginning with inhalation of contaminated air and
continuing with indirect pathways such as food chain exposures that en
tail contaminant transfer and accumulation through several media. MRAs
of MWCs date back to the mid-1980s, and are rooted in methods develop
ed to assess the consequences of radionuclide releases from nuclear po
wer generation. A detailed example of a typical MRA is presented that
follows the classic four-stage risk assessment paradigm (Valberg et al
., 1995). MRA methods, however, continue to be enhanced and refined by
recent research. A number of current risk assessment topics are explo
red that are new to traditional MRAs and may serve to re-focus our col
lective efforts. The purpose of and demands on MRAs must be considered
. A philosophical shift toward placing greater realism in MRAs undersc
ores the importance of uncertainties inherent to risk estimates. Tools
such as probabilistic risk assessment techniques must be developed an
d endorsed so that decision-makers may intelligently utilize the infor
mation provided by MRAs.