title: Dietary exposure of Nigerians to mutagens and estrogen-like chemicals.
abstract: Food and drinking water are poorly delineated sources of human exposure to chemical food mutagens and endocrine-disrupting chemicals. In this study, we investigated the presence of mutagens and chemicals exhibiting estrogenic activity in the daily diet of Nigerians, using in vitro assays. Commercially processed foods or snacks and various brands of pure water sachets were extracted by solid-phase extraction and liquid-liquid extraction, respectively. Mutagenicity was determined by the conventional Ames test and two complementary assays on two strains of Salmonella (TA 100 and TA 98), while the estrogenic activity was assessed by a yeast bioluminescent assay, using two recombinant yeast strains (Saccharomyces cerevisiae BMAEREluc/ERα and S. cerevisiae BMA64/luc). A third of the food varieties investigated (chin-chin, hamburger, suya and bean cake) were mutagenic in all three assays, either in the presence or absence of S9 mix. Of the packed water samples, five out of the sixteen investigated (31%), were found to be estrogenic, with estradiol and bisphenol A equivalents ranging from 0.79 to 44.0 ng/L and 124.2 to 1,000.8 ng/L, respectively. Hence, although the current situation in Nigeria does not appear to be substantially worse than, e.g., in Europe, regular monitoring is warranted in the future.
authors.affiliation: Food and Environmental Toxicology Unit, Department of Food and Environmental Hygiene, Faculty of Veterinary Medicine, University of Helsinki, P.O.Box 66, 00014 Helsinki, Finland. matthew.omoruyi@helsinki.fi.
authors.forename: Iyekhoetin Matthew
authors.initials: IM
authors.lastname: Omoruyi
authors.affiliation: Department of Basic Sciences, Faculty of Basic and Applied Sciences, Benson Idahosa University, P.M.B. 1100, Benin City, Edo State, Nigeria. dahamioje@biu.edu.ng.
authors.forename: Derek
authors.initials: D
authors.lastname: Ahamioje
authors.affiliation: Food and Environmental Toxicology Unit, Department of Food and Environmental Hygiene, Faculty of Veterinary Medicine, University of Helsinki, P.O.Box 66, 00014 Helsinki, Finland. raimo.pohjanvirta@helsinki.fi.
authors.forename: Raimo
authors.initials: R
authors.lastname: Pohjanvirta
mesh_terms: D004032:Diet / Q000009:adverse effects*; D052244:Endocrine Disruptors / Q000633:toxicity*; D005502:Food; D056945:Hep G2 Cells; D006801:Humans; D008163:Luminescent Measurements; D009152:Mutagenicity Tests; D009153:Mutagens / Q000633:toxicity*; D009549:Nigeria; D030781:Organisms, Genetically Modified; D012441:Saccharomyces cerevisiae / Q000187:drug effects*; D012475:Salmonella / Q000187:drug effects*; D014867:Water
chemical_list: D052244:Endocrine Disruptors; D009153:Mutagens; D014867:Water