Abstract

Airborne particulate matter (PM10) contains a large number of genotoxic and carcinogenic substances. Ambient air is reported to be mutagenic in many areas worldwide. Particulate matter has been linked to premature mortality, lung cancer, respiratory and cardiovascular health problems. In the present study, we investigated the genotoxicity of the ambient air PM10 extractable organic matter (EOM) collected at Arafat and Muzdalifa in Makkah, Saudi Arabia. The amounts of sixteen polycyclic aromatic hydrocarbons (PAHs) in the EOM were quantified. The PM10 averages in Arafat and Muzdalifa were 158 and 444.5 μg/m³, respectively which exceeded the U.S. maximum daily of 150 μg/m³. The reference site PM10 was 6.1μg/m³. The EOM averages in Arafat, Muzdalifa and the reference site were respectively 46.4, 151.6 and 6.15 µg/m³ and the PAH averages in the EOM were 2.8, 5.0 and 0.19 ng/m³. The EOM samples were mutagenic in the salmonella TA98 test and damaged human blood cells DNA in the comet assay in a dose related response. The bacterial revertants and the comet tail moment means were higher in Muzdalifa than in Arafat. Regression analyses of both showed a positive relation between each and the EOM concentrations tested (P < 0.001). For routine ambient air genotoxicity monitoring, the use of salmonella TA98 and the comet tests are recommendable. This study provides information for the first time on the PM10 air pollutants and its genotoxic activity in Arafat and Muzdalifa.

Key words: Ambient air PM10, polycyclic aromatic, hydrocarbons, salmonella mutagenicity, comet tests.