This work was carried out in collaboration between all authors. Author STG designed the study, performed the statistical analysis, wrote the protocol and first draft of the manuscript as well as proof read the final report. Author MG supervised the irrigation, monitored the growth for any sign of toxicity up to harvesting period and managed the analyses involved. Authors MG and LBI both managed the literature searches. All authors read and approved the final manuscript.

The purpose of this study was to investigate the concentrations of PAHs in water samples from Dadin Kowa Dam, Nigeria and to evaluate the risk associated with the ingestion of the water from the Dam. The concentrations of PAHs varied with the sample site and season; and the levels of PAHs at all site are found to be significantly below the maximum allowable concentrations (MACs) of 0.005 to 3.0 mg/l. The carcinogenic risks were higher than 10−6 threshold values, and the water from Dadin Kowa Dam is considered to pose significant health effects to children and adult. However, the carcinogenicity risks rating decrease in the order of children > adult. The study further demonstrated that Dadin Kowa Dam requires a substantial PAHs pollution control program.