Temporal distribution of fine particulates (PM 2.5, PM 10 ), potentially toxic metals, PAHs and Metal-bound carcinogenic risk in the population of Lucknow City, India (original) (raw)

Ubiquitous fine particulates can readily be bound to toxic metals and polycyclic aromatic hydrocarbons and are considered to be a great threat to human health. The purpose of this study was to assess the magnitude of air pollution risks to public health by determining four crucial parameters-inhalable particulates, metals in particulates and PAHs which are associated with PM 10 in the air environment of Lucknow, India during 2007-09. The values of PM 10 and PM 2.5 ranged between 102.3-240.5 and 28.0-196.9 µg/m 3 whilst the average PM 10 was 1.7 times and PM 2.5 was 1.5 times higher than their respective NAAQS of 100 and 60 µg/m 3 respectively. The estimated relative death rate and hospital admissions for each increase in the PM 10 levels of 10 µg/m 3 ranged from 1.5-8% and from 3.9-8.0% (as per APHEA2 1990) respectively in persons > 65 yrs. Among the locations; AQ S-1 , AQ S-2, and AQ S-3 (with diversified activities and heavy traffic) recorded higher concentrations of both the particulate fractions than the AQ S-4 (residential area with low traffic). The average concentrations of Fe, Pb, Ni, Cu, Cr, Cd in PM 10 were 219.4, 40.6, 35.1, 27.3, 22.2 and 16.2 ng/m 3 and that in PM 2.5 were 54.3, 33.9, 38.5, 29.4, 8.4, and 1.17 ng/m 3 respectively. Regression analysis revealed that correlation of metals with PM 2.5 was stronger than PM 10. The ratio of metals adsorbed on surface of particles (PM 2.5 :PM 10) reveals that PM 2.5 has more affinity for Ni, Cu and Pb and PM 10 for Cd, Fe and Cr. Health risk due to carcinogenic metals bound to respirable particulates was predicted by estimating excess cancer risk (ECR). The highest ECR value was estimated for Cr, 266.70 × 10 −6 , which was associated with PM10 and 100.92 × 10 −6 which was associated with PM 2.5 , whereas lead has the lowest ECR value. Amongst PAHs, benzo(a)pyrene (51.96±19.71 ng/m 3) was maximum in PM 10 samples. Maximum concentrations of PM 10 , PM 2.5 , metals and PAHs were detected during winter, and the lowest was during monsoon. The higher prevalence of diseases among the population may be due to high concentration of particulates coated with toxic metals and PAHs present in air environment.