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Inhalable desert dust, urban emissions, and potentially biotoxic metals in urban Saharan-Sahelian air

December 1, 2014

Saharan dust incursions and particulates emitted from human activities degrade air quality throughout West Africa, especially in the rapidly expanding urban centers in the region. Particulate matter (PM) that can be inhaled is strongly associated with increased incidence of and mortality from cardiovascular and respiratory diseases and cancer. Air samples collected in the capital of a Saharan–Sahelian country (Bamako, Mali) between September 2012 and July 2013 were found to contain inhalable PM concentrations that exceeded World Health Organization (WHO) and US Environmental Protection Agency (USEPA) PM2.5 and PM10 24-h limits 58 – 98% of days and European Union (EU) PM10 24-h limit 98% of days. Mean concentrations were 1.2-to-4.5 fold greater than existing limits. Inhalable PM was enriched in transition metals, known to produce reactive oxygen species and initiate the inflammatory response, and other potentially bioactive and biotoxic metals/metalloids. Eroded mineral dust composed the bulk of inhalable PM, whereas most enriched metals/metalloids were likely emitted from oil combustion, biomass burning, refuse incineration, vehicle traffic, and mining activities. Human exposure to inhalable PM and associated metals/metalloids over 24-h was estimated. The findings indicate that inhalable PM in the Sahara–Sahel region may present a threat to human health, especially in urban areas with greater inhalable PM and transition metal exposure.

Publication Year 2014
Title Inhalable desert dust, urban emissions, and potentially biotoxic metals in urban Saharan-Sahelian air
DOI 10.1016/j.scitotenv.2014.08.106
Authors Virginia H. Garrison, Michael S. Majewski, Lassana Konde, Ruth E. Wolf, Richard D. Otto, Yutaka Tsuneoka
Publication Type Article
Publication Subtype Journal Article
Series Title Science of the Total Environment
Index ID 70138860
Record Source USGS Publications Warehouse
USGS Organization Southeast Ecological Science Center