Volume 16, No. 11, November 2016, Pages 2907-2919 PDF(819 KB)
Incremental Lifetime Cancer Risk of PM2.5 Bound Polycyclic Aromatic Hydrocarbons (PAHs) before and after the Wildland Fire Episode
NIDA Center for Research & Development of Disaster Prevention & Management, School of Social and Environmental Development, National Institute of Development Administration (NIDA), Bangkok 10240, Thailand
- Wildland fire did not contribute significantly to the enhancement of PAHs.
- The excess cancer risks in Northern Thailand were greatly lesser than other cities.
- The average ILCR values were falls into the ‘‘acceptable level’’ range.
In Northern Thailand, wildland fire during cold period releases large amounts of smoke and fine particles into the atmosphere. The fine particles include several persistent organic compounds such as PAHs. In this study, PM2.5-bound PAH concentrations in the air of nine administrative provinces, namely Chiang-Mai, Chiang-Rai, Nan, Phayao, Mae Hong Son, Phrae, Lampang, Lamphun, Uttaradit (N Thailand) were determined during the wildland fire and non-wildland fire seasons. The monitoring strategy comprised two campaigns in each season. PM2.5 was collected using MiniVolTM portable air samplers (Airmetrics) with quartz fibre filters. Both PAHs and their B[a]PEquivalent concentrations of other urban cities around the world were significantly higher than those of northern provinces for both seasons. The average cancer risks observed at nine administrative provinces were 8.525 × 10–4 ± 3.493 × 10–3 and 2.558 × 10–3 ± 6.986 × 10–3 for ingestion rate of 50 and 100 mg day–1, respectively. The excess cancer risks of world cities for ingestion rate of 50 and 100 mg day–1 were much higher than those of Northern Thailand for 851 and 567 times in that order. Dust ingestion was exceedingly critical to non-dietary PAH exposure in comparison with PM2.5 inhalation. These results are in good agreement with those of previous studies, underlining the significance of indoor air quality on long-term adverse respiratory diseases in Asian cities.
Wildland fire; PAHs; Northern Thailand; PM2.5; Incremental lifetime cancer risk.