Forensic Identification of Sources and Ecological Risk Assessment of Polycyclic Aromatic Hydrocarbons in an Aquatic Ecosystem

Roland Uwadiae, Eugene Itua and Adebambo Adesokan

Background and Objective: Polycyclic Aromatic Hydrocarbons (PAHs) are environmental pollutants formed at high temperatures and under pyrolytic conditions during the incomplete combustion of organic matter. This paper reports sources and ecological risk assessment of PAHs in sediment and specimens of Pachymelania aurita in a Nigerian Coastal aquatic ecosystem. Materials and Methods: The study involved six months collection of water, sediment and macrofauna samples from five study locations. Sixteen priority PAHs pollutants described by the USEPA were analyzed to determine variation in concentration and distribution in the study area. The sources of these pollutants in the study area was investigated using the diagnostic ratio method. Ecological risk factors were computed to determine the risk posed by these pollutants and statistical analyses were performed to evaluate the relationship between PAH concentrations in samples and to determine variation in risk parameters. Results: Values of Σ16PAHs were highest in sediment with a range of 4.7-13.0 μg kg^–1. Among the PAHs, chrysene and benz[a]anthracene occurred in relatively higher concentrations in the collected samples. Polycyclic aromatic hydrocarbons in the area may have originated majorly from pyrolytic sources, with some elements of petrogenic input in sediment samples. Hazard Index was highest for sediment samples. Values of BAF were higher than BSAF in all the sampling points. Conclusion: The concentrations of individual and Σ16PAHs at the sampling points were below regulatory limits in most cases, however, the growing anthropogenic activities may result in the aggravation of risk parameters for the study area which may lead to general threat to ecological integrity.

View Fulltext Back