SPATIAL VARIATION OF BENO-A-PYRENE, NICKEL AND LEAD CONFINED IN PM10 AS WELL MODELLING AND HEALTH RISK ASSESSMENT

Abstract

Exposure to fine particulate matter from ambient air is a leading environmental contributor to disease burden across the world. Polycyclic aromatic hydrocarbons (PAHs) are the common environmental pollutants. PAHs are persistent organic pollutants and strive carcinogenic and mutagenic effects. Aerosol samples in the particulate phase were collected simultaneously for the first time in Numaligarh at an industrial and a traffic dominated site for two year to investigate the gas–particle partitioning of polycyclic aromatic hydrocarbon (PAH) and heavy metal. The samples were collected using a high volume sampler on PTFE filter papers. Benzo-a-pyrene was analyzed using gas chromatograph-mass spectrometry. The ground level concentration (GLC) of pollutants from stationary sources is computed    using   dispersion model AERMOD, which are mathematical relations between the source strength and concentration   and involves parameters related transport and diffusion. Increases in GLC (Ground Level Concentration) are very minimal. Maximum Predicted Summer Season 24 hour Average increase in GLC is 2.05 μgm^-3 and that of winter is 1.58 μgm^-3. Although PAH represented a high proportion of risk as carcinogenic whose Cancer Risk (CR) values were calculated (0.03 CR value), and they were very less than the permissible limit (CR > 0.25). However, the risk of exposure to mixtures is difficult to estimate, and risk assessment by whole mixture potency evaluations has been done in this study.