In future a new computer model will be available to help assess the public health impact of air pollution from new industrial developments. It combines a geographical information system (GIS) with an existing spreadsheet model to measure the effect of the extra exposure per unit resident population—or enumeration district.
The model is fundamentally different from other approaches, especially in North America, in relying on clear evidence of harm from epidemiological studies of large human populations. As such, it is limited to modelling the effects of a few pollutants, including some airborne pollutants.
In a case study to measure potential health effects of a new energy from waste facility on surrounding residents from PM10 emissions small changes in airborne PM10 concentration—mean 0.02 μg/m3 in an area of 20 km radius and 0.08 μg/m3 in the worst affected areas—were predicted, leading to about 0.03 premature deaths/year in a population of 3.5 million and 0.4 extra hospital admissions for respiratory disease. Long term, 1.8–7.8 premature deaths in the next 30 years were predicted. The predictions were achieved by entering expected PM10 emissions into an air dispersion model to obtain “contours” of extra concentrations from the new source and transferring this output to a GIS, combined with a population database for a 20 km radius, for export into an MS Excel spreadsheet.
Environmental impact assessments, though mandatory in many countries, often fail to measure likely public health effects. Availability of dispersion models and GIS programs on personal computers means that these impacts can now be modelled—at least for pollutants with an epidemiological track record of harm.
▴ Mindell J, et al.Journal of Epidemiology and Community Health 2005;59:1092–1098.
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