Concentrations, sources and exposure risks associated with particulate matter in the Middle East Area-a review

Rapid economic expansion, industrialization, urbanisation and construction in the Middle East Area (MEA) have led to an increase in the levels of air pollution, resulting in serious effects on human health. For the first time, this article provides a comprehensive synthesis of the currently available published information which deals with atmospheric particulate matter (PM) in MEA. The focus of the article remains on the PM sources, monitoring, health impacts and source apportionment. The key objectives are to identify the levels of PM pollution and the associated exposure risks, to highlight research gaps and to discuss future research directions. The limited number of monitoring studies available for MEA indicates that dust storms augmented by the rapid increase in urban population are the key reasons for the high PM concentration levels. The findings of reviewed monitoring studies suggest that the levels of both annual mean PM10 (20 mu g/m(3)) and PM2.5 (10 mu g/m(3)) concentrations exceed the World Health Organization (WHO) guidelines during most of the non-dust storm episodes, and as expected, the PM pollution levels become even higher during dust storm episodes. For example, 24-h mean PM10 concentrations of over 1,000 mu g/m(3) were noted during a severe dust storm episode in Kuwait. The findings of the epidemiological and toxicological studies in MEA have shown that dust storm events have a significant impact on respiratory admissions and the adverse health effects of PM are particularly in the form of asthma and respiratory and cardiovascular diseases. It is concluded that PM pollution in MEA is a significant problem and quantification of PM emissions and the design of control measures to abate their impacts on public health are of primary importance. Besides, there is a need for more systematic PM data collection for source apportionment and assessment of PM levels that would enable air pollution-related health impact assessments of MEA. Furthermore, this review highlights that the release of airborne PM from major building activities such as building construction is largely unknown and emission inventories for different situations are needed.