Organochlorine pesticide (OCP) and polybrominated diphenyl ether (PBDE) concentrations were measured in thirty popular brands of imported canned fish (mackerel, sardines, and tuna) in Nigeria to ...ascertain potential threats to humans arising from their consumption. The Σ20 OCP concentrations in mackerel ranged from 0.47 to 7.36 ng g−1, while those of tuna and sardines varied from 1.06 to 2.19 and 0.11 to 12.7 ng g−1, respectively. The Σ39 PBDE concentrations in mackerel varied from 0.06 to 4.21 ng g−1, while those of tuna and sardines ranged from 0.19 to 3.18 and 0.04 to 8.26 ng g−1, respectively. The estimated daily intake (EDI) of OCPs and PBDEs from ingestion of the canned fish by adults and children were in the magnitude of 0.03 to 17.6 ng kg−1 bw day−1 and 9.9 × 10−3 to 11.5 ng kg−1 bw day−1 respectively. The hazard index (HI) and total cancer risk (TCR) values for OCPs and PBDEs from ingestion of the canned fish were less than 1 and 10−6, respectively. The dietary intakes of OCPs and PBDEs from these brands of canned fish by adults and children result in no adverse non-cancer and cancer risks.
The concentrations, sources, and risk of twenty organochlorine pesticides (OCPs) in soils and dusts from a typical urban setting in the Niger Delta of Nigeria were examined. The Σ20 OCP ...concentrations (ng g−1) varied from 4.49 to 150 with an average value of 32.6 for soil, 4.67 to 21.5 with an average of 11.7 for indoor dust, and 1.6 to 96.7 with an average value of 23.5 for outdoor dust. The Σ20 OCP concentrations in these media were in the order: soil > outdoor dust > indoor dust, which was in contrast with the order of the detection frequency, i.e., indoor dust (95 to 100 %) > soil (60 to 90 %) > outdoor dust (30 to 80 %). The concentrations of the different OCP classes in these media followed the order: aldrin + dieldrin + endrin and its isomers (Drins) > chlordanes > dichlorodiphenyltrichloroethane (DDTs) > hexachlorocyclohexane (HCHs) > endosulfans for outdoor dust and soil, while that of the indoor dust followed the order: Drins > chlordanes > endosulfans > DDTs > HCHs. The cancer risk values for human exposure to OCPs in these sites exceeded 10−6 which indicates possible carcinogenic risks. The sources of OCPs in these media reflected both past use and recent inputs.
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•OCPs in dust and soils from Port Harcourt city were investigated.•OCP concentrations in soils were higher than those of outdoor and indoor dusts.•Drins and chlordanes were the dominant OCPs in these media.•Exposure to OCPs in these media pose a risk to humans.•OCPs in these media originated from predominantly aged used sources.
•The sheep organs were contaminated with potentially toxic metals.•The metals in the organs was in the order of liver > kidney > muscles.•The metals were in the order of Fe>Mn>Zn>Cu>Ni>Cr>Co>Pb>Cd in ...the organs.•The HI and TCR values indicated no non-cancer and cancer risks.
The concentrations and risks of metals (Cd, Pb, Cr, Ni, Cu, Co, Mn, Zn and Fe) in organs of sheep from Southern Nigeria were investigated in this study.
A total of 105 sheep organs (kidney, liver and muscles) were collected from abattoirs in five widely distributed areas (Asaba, Benin, Onitsha, Sapele and Warri) in southern Nigeria. The organs were digested using a mixture of nitric and perchloric acids and thereafter the metal concentrations in the digested sample solutions were determined using an atomic absorption spectrophotometer.
The mean concentrations of metals (mg kg−1) were as follows: Cd: 0.05–0.37, Pb 0.86 to 1.99, Cr: 2.20–3.03, Ni: 1.87–3.54, Cu: 17.4–24.3, Co: 1.45–4.30, Mn 192–410, Zn: 41.8–117 and Fe: 423–1068. The concentrations of the metals in the organs were in the order of Fe > Mn > Zn > Cu > Ni > Cr > Co > Pb > Cd while the ability of the sheep organs to accumulate the studied metals followed the order of liver > kidney > muscles. The estimated daily intake values suggested that except for Mn, the intake of metals from the ingestion of these sheep organs was below their respective PTDI. The hazard index and total cancer risk values show that there are no possible risks of non-cancer and cancer risks associated with the consumption of the sheep's organs.
Although there are no health risks associated with the metals in the sheep organs from southern Nigeria, there is, however, a need for continuous monitoring of contaminants in sheep and other animal organs.
Dust is ubiquitous and humans are unavoidably in constant contact with it. Therefore, exposure to metal-laden dust from workplaces can be a serious threat to human health.
The objective of this study ...was to assess the concentrations of nine metals, namely, Cd, Pb, Cr, Ni Cu, Co, Mn, Zn and Fe, in dust from automobile mechanic workshops (AMWs) in urban and semi-urban areas of Delta State, Nigeria.
The dust samples were digested in aqua-regia and their metal content was determined by atomic absorption spectrometry.
The concentrations of metals (mg kg-1) in dust from the AMWs ranged from 0.12 to 4.20 for Cd, 11.3 to 3900 for Pb, 9.05 to 45.3 for Cr, 0.35 to 345 for Ni, 170 to 56,400 for Cu, 1.05 to 31.4 for Co, 51.3 to 310 for Mn, 143 to 634 for Zn, and 70,900 to 258,000 for Fe. The pollution indices indicated that Cd, Cu, Pb and Zn were the prominent contaminants in dust from the AMWs. Children's exposure to metal-laden dust from the AMWs could elicit adverse non-carcinogenic health effects. The carcinogenic risk values obtained for human exposure to metals in dust from the AMWs were above the safe level indicating possible induction of cancer or cancer-related illnesses. The sources of metals in dust from the AMWs are related to automobile emissions and discharges from vehicular components.
The activities in AMWs are potent sources of metals to the environment, especially Cd, Cu, Pb and Zn. Therefore, this study recommends regulatory control of activities conducted in AMWs so as to minimize widespread metal contamination and the consequent impact of metals in the affected dust on humans and the environment.
