Potential health risks of Polycyclic Aromatic Hydrocarbons (PAHs) associated with sediment and selected sea foods from a Ramsar site

摘要

Persistent organic pollutants such as polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the environment. It is important to assess risk of PAHs exposure. Sixteen United States Environmental Protection Agency (USEPA) priority PAHs were determined in sediments and edible biota at a Ramsar site - Chilika lagoon, the largest brackish water lagoon in Asia. High Performance Liquid Chromatography was used to identify and quantify PAHs. Statistical tools were used for source apportionment and health risk assessment. Mean total PAH level in the sediments was 13674 ng/g dry weight, higher than other reported studies from the region. High molecular weight species dominated total PAH profile indicating pyrolytic origin. Diagnostic ratios and principal component analysis indicated diesel and coal/wood combustion as sources of PAHs in the sediments. Assessment of sediment associated individual PAHs effect on aquatic organisms of the lagoon revealed all the compounds, except Naphthalene and Anthracene, to be present above the lower range of concentrations related to toxicity. Risk quotient of PAHs revealed that Acenaphthene, Fluorene and Dibenz[a,h]anthracene require priority management concerns. PAH levels in crabs and prawns were 394.4 and 153.0 ng/g d.w. BaPeq concentrations were 42.9 and 15.2 ng/g d.w. in crabs and prawns respectively. Carcinogenic PAHs accounted for 33% of the PAHs concentrations in edible biota but consumption can be considered safe with respect to lifetime excess cancer risk guideline values. Low biota sediment accumulation factors in biota from the lagoon suggest that the studied PAHs have low bioavailability. The results of the study are useful for risk assessement due to dietary exposure of sea foods from the lagoon, which is consumed in domestic markets and also used for export to developed countries.