Significantly Elevated Urinary OH-PAHs and Oxidative Damage Concentrations Attributable to PM2.5 Exposure: A Panel Study of Preaging Females in Chiang Mai, Thailand

Exposure to ambient particulate matter with an aerodynamic diameter ≤ 2.5 µm (PM2.5) has been associated with oxidative damage. This study investigated the PM2.5-bound polycyclic aromatic hydrocarbon (PAH) exposure levels during elevated PM2.5 levels and the oxidative damage among a preaging females in Chiang Mai, Thailand. The 64 female participants, aged between 50 and 65 years old, were followed for 5 weeks consecutively during the non-haze rainy season as the baseline and haze episodes. The morning void urine sample was collected weekly and analyzed for 8 species of hydroxylated-polycyclic aromatic hydrocarbons (OH-PAHs) and malondialdehyde (MDA). The results showed that the high increase in PM2.5 levels was positively associated with OH-PAH levels. In addition, for every 1 µg/gCre increase in individual urinary OH-PAH concentrations, the MDA concentration increased from 0.073 to 2.071 µg/gCre. Therefore, the present study suggested that detected urinary OH-PAHs were attributable to PM2.5-bound PAH exposure, particularly from inhalation. These study results provide useful information for policy makers and public health agencies to mitigate the chain effects of PM2.5 exposure from haze pollution. Keywords: Air pollution, Hydroxylated-PAHs, Oxidative stress, Urinary biomarkers