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Folarin BT, Poma G, Yin S, Altamirano JC, Oluseyi T, Badru G, Covaci A. Assessment of legacy and alternative halogenated organic pollutants in outdoor dust and soil from e-waste sites in Nigeria: Concentrations, patterns, and implications for human exposure. Environ Pollut 2024; 342:123032. [PMID: 38036088 DOI: 10.1016/j.envpol.2023.123032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 11/10/2023] [Accepted: 11/21/2023] [Indexed: 12/02/2023]
Abstract
E-waste is often processed informally, particularly in developing countries, resulting in the release of harmful chemicals into the environment. This study investigated the co-occurrence of selected persistent organic pollutants (POPs), including legacy and alternative halogenated flame retardants (10 polybrominated diphenyl ethers (PBDEs), decabromodiphenyl ethane (DBDPE), syn and anti-dechlorane plus (DP)), 32 polychlorinated biphenyls (PCBs) and 12 organochlorine pesticides (OCPs), in 20 outdoor dust and 49 soil samples from 7 e-waste sites in Nigeria. This study provides the first report on alternative flame retardants (DBDPE and DP) in Nigeria. The total concentration range of the selected classes of compounds was in the order: ∑10PBDEs (44-12300 ng/g) > DBDPE (4.9-3032 ng/g) > ∑2DP (0.7-278 ng/g) > ∑32PCBs (4.9-148 ng/g) > ∑12OCPs (1.9-25 ng/g) for dust, and DBDPE (4.9-9647 ng/g) > ∑10PBDEs (90.3-7548 ng/g) > ∑32PCBs (6.1-5025 ng/g) > ∑12OCPs (1.9-250 ng/g) > ∑2DP (2.1-142 ng/g) for soil. PBDEs were the major contributors to POP pollution at e-waste dismantling sites, while PCBs were the most significant contributors at e-waste dumpsites. DBDPE was found to be significantly associated with pollution at both e-waste dismantling and dumpsites. Estimated daily intake (EDI) via dust and soil ingestion and dermal adsorption routes ranged from 1.3 to 2.8 ng/kg bw/day and 0.2-2.9 ng/kg bw/day, respectively. In the worst-case scenario, EDI ranged from 2.9 to 10 ng/kg bw/day and 0.8-5.8 ng/kg bw/day for dust and soil, respectively. The obtained intake levels posed no non-carcinogenic risk, but could increase the incidence of cancer at some of the studied e-waste sites, with values exceeding the USEPA cancer risk lower limit (1.0 × 10-6). Overall, our results suggest that e-waste sites act as emission point sources of POPs.
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Affiliation(s)
- Bilikis T Folarin
- Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium; Department of Chemistry, University of Lagos, Lagos State, Nigeria; Chemistry Department, Chrisland University, Ogun State, 23409, Nigeria
| | - Giulia Poma
- Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Shanshan Yin
- Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium; Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy (IRA), Zhejiang Shuren University, Hangzhou, 310015, China.
| | - Jorgelina C Altamirano
- Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium; Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales (IANIGLA), CONICET-UNCuyo-Government of Mendoza, P.O. Box. 331, (5500), Mendoza, Argentina; Universidad Nacional de Cuyo, Facultad de Ciencias Exactas y Naturales, (5500), Mendoza, Argentina
| | - Temilola Oluseyi
- Department of Chemistry, University of Lagos, Lagos State, Nigeria
| | - Gbolahan Badru
- Department of Geographical and Environmental Education, Lagos State University of Education, Oto-Ijanikin, Lagos State, Nigeria
| | - Adrian Covaci
- Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
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Folarin BT, Abdallah M, Oluseyi TO, Harrad S, Olayinka KO. Concentrations and Toxic Implications of Dioxin-Like Polychlorinated Biphenyls in Soil Samples from Electrical Power Stations in Lagos, Nigeria. Environ Toxicol Chem 2022; 41:800-809. [PMID: 34918382 DOI: 10.1002/etc.5277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 11/09/2021] [Accepted: 12/15/2021] [Indexed: 06/14/2023]
Abstract
Dioxin-like polychlorinated biphenyls (dl-PCBs) are ubiquitous chemicals which mediate toxicity in a way similar to polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans. In silico modeling was used to predict the absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties of eight dioxin-like PCBs in soil samples of 12 power stations in Lagos, Nigeria. Concentrations of Σdl-PCB8 in soil samples ranged from 490 to 61,000 pg g-1 , with mean concentrations of 17,000 pg g-1 . The corresponding toxic equivalent (TEQ) concentrations of Ʃdl-PCB8 ranged from 0.01 to 450 pg TEQ g-1 , with a mean value of 42 pg TEQ g-1 . Mean TEQ concentrations for Ʃdl-PCB8 in soil samples from all but one of the sites exceeded the Canadian guideline value of 4 pg TEQ g-1 and the US and German guideline values of 5-10 pg TEQ g-1 . However, the TEQ concentrations obtained were all below the US action level of 1000 pg TEQ g-1 . The ADMET predictions revealed that all studied dl-PCBs are inhibitors of three major isoforms (1A2, 2C9, and 2C19) of cytochrome P450 enzyme. Acute oral toxicity (median lethal dose) predictions revealed that all target dl-PCBs were class III compounds. Hepatotoxicity and carcinogenicity were positive, signifying that the studied compounds all have a tendency to elicit these effects. Occupational daily TEQ exposure via soil ingestion was estimated for an average adult worker weighing 70 kg. The maximum exposure obtained was 0.14 pg TEQ kg-1 body weight day-1 , which is half of the European Food Safety Authority (EFSA) tolerable daily intake (TDI) for dioxin-like compounds. This raises concern over the possible exceedance of the EFSA TDI for these workers if other dietary and nondietary exposure pathways and dioxin-like compounds are considered. Environ Toxicol Chem 2022;41:800-809. © 2021 SETAC.
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Affiliation(s)
- Bilikis T Folarin
- Department of Chemistry, University of Lagos, Lagos, Nigeria
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, United Kingdom
- Department of Chemistry, College of Natural and Applied Sciences, Chrisland University, Abeokuta, Nigeria
| | - Mohamed Abdallah
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, United Kingdom
| | | | - Stuart Harrad
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, United Kingdom
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