Exposure to particle-bound polyaromatic hydrocarbons in the Al-Mansoria residential area during the Kuwait oil fires: A qualitative appraisal of the adsorption role

Abstract

High ambient levels of inhalable particulate matter (PM 10) were detected in residential areas during the oil well burning in Kuwait (February–November 1991). Because inhalation exposures to PM 10 were significant (data on PAH quantification are scarce), it became possible to describe the exposure to PM 10-associated PAHs of alternative courses of events, such as PAH-particle interaction mechanisms. Depending on particle adsorption characteristics (affinity and site availability), it is concluded that, contrary to what is currently believed, low levels of ambient PM 10 levels did not indicate low PAH exposures in Al-Mansoria residential area during May 10–31, 1991. Due to the frequent presence of dust particles in the ambient air caused by the heavy dust fallout in Al-Mansoria (average > 65 tons/km 2) during May, 1991, the predicted patterns can be explained by two hypothesized mechanisms. The first is a two-step process: loss of PAHs from low affinity sites and reabsorption onto stronger affinity ones leading to low surface coverage at high PM 10 concentrations. The second involves dilution of PAH-containing soot with aeolian particles. Both events can lead to low ambient PAHs at high PM 10 levels or high ambient PAHs at low PM 10 levels.