A Review of Particulate Matter and Health: Focus on Developing Countries

The burden of ill human health attributable to particulate air pollution is a critical problem of growing concern. In developing countries it is not uncommon to experience today the same particulate matter levels that characterized the devastating "London fog episodes" of the 1950s which resulted in over 4000 cases of premature mortality and countless cases of exacerbated morbidity related health endpoints. This literature review gives an overview of the situation in developing countries by synthesizing the pertinent information relating to source and concentration of particulate matter, to exposure-response curves, the observed health effects, the plausibility of biological mechanisms, and health related costs. The feasibility of extrapolating data derived from developed countries to estimate health effects for developing countries is briefly considered. There is little doubt that particulate matter causes or contributes to premature mortality and morbidity related health endpoints in developing countries. Only the most easily observed and quantified health effects have been identified to date. There is increasing proof that the most harmful effects of particulate matter are related to the size of the particle, as particles decrease in size, they are hypothesized to either increase in acidity or in their ability to penetrate into the lower airways. Even more than in developed countries, personal exposure to particulate matter in developing countries has been found to be badly represented by ambient monitors. Additionally, it may be much more depending on indoor sources and housing types than in developed countries. Previous studies on costs of particulate air pollution to society in developing countries are rare, and many different approaches have been used. They do not account for loss of welfare, disutility or loss of productivity, which may cause the greatest costs. Thoughts have been given to use the Disability Adjusted Life Year (DALY) to assess health costs for a certain disease and for a given population. DALYs would allow for comparable measures of health costs or or benefits to be quantified and compared across populations and regions of the world.