Assessment of polycyclic aromatic hydrocarbons in .Fish, meat and the effect of cooking on their Concentrations in meat as sources of human exposure in Winam gulf region of Lake Victoria

Abstract

Polycyclic Aromatic Hydrocarbons are of concern m environmental chemistry because they are known or suspected carcinogens and/or toxicants. Fish is a major indicator of the existence of PARs in aquatic environment and source of ~osure to humans. Charcoal-roasted meat can also be a major human exposure to the PARs. However, the contribution of fish and meat to human exposure to PARs in the region is not known. The study set out to determine the concentration of the PARs in the fish and meat; and to establish the effect of roasting on PAR concentration in the meat and then compare the levels with the standards allowed internationally in these foods. Samples of fish (Rastrineobola argentea, Lates niloticus and Oreochromis niloticusy were obtained from three beaches: Dunga Beach (South West of Kisumu City and South of Kisumu Bay; 4 km from the City Center), 'Usoma and Usare Beach (West and on the opposite side of Kisumu City across Kisumu Bay about 3 km from each other) in Kisumu Bay (006'S, 34°45'E). Samples of meat were from Highway Inn (on Kisumu-Kakamega Highway) for goat meat and beef, Apok Inn for beef (on Kisumu- Nairobi Highway) and pork from Kisumu Hotel (City Center) in Kisumu City. Extraction of PARs was done using liquid-liquid partition after saponification with alcoholic potassium hydroxide; clean-up using open column chromatography with organic solvents on silica gel stationary phases and final analysis done using GC-MS. Twelve PARs were detected in O. niloticus (TPAR 3.934 •.g•./kg); L. niloticus had eleven PARs (TPAR 3.166 •.g•.lk:g). In both cases, the highest and lowest PARs concentrations were Pyrene and Indeno(l,2,3-cd)pyrene respectively, R argentea had two PARs (TPAR 0.035 •.g•.lkg). Overall mean total PARs was 3.047 ug/kg. Raw beef