Secondary particulate matter originating from an industrial source and its impact on population health

Epidemiological studies have reported adverse associations between long-term exposure to ambient particulate matter (PM<inf>2.5</inf>) and several health outcomes. One issue in this field is exposure assessment and, in particular, the role of secondary PM<inf>2.5</inf>, often neglected in environmental and health risk assessment. Thus, the aim of this work was to evaluate the long-term environmental and health impact of primary and secondary PM<inf>2.5</inf> concentrations originating from a single industrial source. As a case study, we considered a coal power plant which is a large emitter of both primary PM<inf>2.5</inf> and secondary PM<inf>2.5</inf> precursors. PM<inf>2.5</inf> concentrations were estimated using the Calpuff dispersion model. The health impact was expressed in terms of number of non-accidental deaths potentially attributable to the power plant. Results showed that the estimated secondary PM<inf>2.5</inf> extended over a larger area than that related to primary PM<inf>2.5</inf> with maximum concentration values of the two components well separated in space. Exposure to secondary PM<inf>2.5</inf> increased significantly the estimated number of annual attributable non-accidental deaths. Our study indicates that the impact of secondary PM<inf>2.5</inf> may be relevant also at local scale and ought to be considered when estimating the impact of industrial emissions on population health.