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This study assessed heavy metal contaminations of soils in cultivated fields (or farms) and water samples from rivers, boreholes, and dug-out wells in Nandom District in semi-arid northwestern Ghana. Other parameters of water from the three sources were also measured and then compared to the permissible limits in the literature. The results showed that soils in farms across the study communities significantly (P ≤ 0.05) had higher levels of chromium (Cr = 0.456 ± 0.132 mgkg-1), iron (Fe = 214.8 ± 1.52 mgkg-1), lead (Pb = 0.854 ± 0.03 mgkg-1), nickel (Ni = 2.813 ± 0.4 mgkg-1), and arsenic (As = 1.753 ± 0.42 mgkg-1) when compared to permissible limits set by World Health Organization (WHO) and Food and Agricultural Organization (FAO) for food crops. Water from the study sites significantly (P ≤ 0.0001) had lower levels of heavy metals than the permissible limits set by FAO for irrigation of growing crops. Thus, the water sources appear to be safe for irrigation in the study area. Nonetheless, these sources of water in Nandom District had significantly higher levels of total suspended solids, turbidity, and coliforms that were above the maximum limits indicated in the guidelines of WHO and the Government of Ghana for drinking water. Therefore, treatments of water for drinking are required to minimize any potential threats to public health.
Assuntos
Arsênio , Água Potável , Poluentes Ambientais , Metais Pesados , Poluentes do Solo , Solo , Poluentes do Solo/análise , Recursos Hídricos , Níquel , Gana , Chumbo , Monitoramento Ambiental/métodos , Metais Pesados/análise , Produtos Agrícolas , Cromo , Ferro , Medição de RiscoRESUMO
The Korle lagoon is known to have high concentration of heavy metals. The use of land for agriculture and water for irrigation within the Korle Lagoon's catchment constitutes a potential health risk. Due to this, the study assessed the concentration of heavy metals in some vegetables (Amaranth, Spinach, Eggplant, Lettuce, Cauliflower, and Onion) and their corresponding soil from a farm within the Korle Lagoon's catchment. The estimated daily intake (EDI), hazard quotient (HQ), and lifetime cancer risk (LCR) was used to assess their health risks. Among the vegetables tested, heavy metals in lettuce exceeded their recommended guideline level. Additionally, the concentrations of Fe (265.94-3599.60 mg/kg) and Zn (76.77-294.70 mg/kg) in all vegetables were above the recommended guideline level. Also, Zn (227.30-534.57 mg/kg) and Pb (101.53-407.58 mg/kg), in soil were above the recommended guideline level for soil. The results also showed not only the severity of heavy metal pollution of soil in the study area, but also risks that were deemed carcinogenic and noncarcinogenic to both adults and children as a result of consumption of vegetables from the study area. The hazard index for adults (0.46-41.156) and children (3.880-384.122), were high for all vegetables tested and are associated with cancer risk due to high Cr and Pb levels. The risk assessment showed that children may suffer more carcinogenic and noncarcinogenic health risk than adults. The study concluded that vegetables grown within the Korle lagoon's catchment is not suitable for consumption due to the associated adverse health effect.
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Coastal lagoons near shores of the marine environment are transitional zones that accumulate litter in transit to the oceans. In view of this, it is important that the dynamics of lagoon litter accumulation are well understood to inform waste control and sustainable management of the coastal environment. The present study assessed the spatio-temporal distribution of lagoon litter along the eastern coast of Ghana, taking a critical look at the abundance and diversity of lagoon litter. Five coastal lagoons were studied: the Kpeshie, Mukwei and Sakumo II lagoons (in urban locations) and the Gao and Keta lagoons (in non-urban locations). Site specific litter abundance (number of items) along the banks of the lagoons ranged between 842 and 8,243 items/month at a deposition rate of 0.71 items/m2/month. Plastic litter was by far the most abundant and diverse litter fraction. Generally, lagoons at urbanised areas of the coast were found to accumulate more litter than those located at non-urbanized areas. Other key factors that affected the accumulation of lagoon litter included proximity to communities, rainfall and the use of lagoons for recreational and religious activities. The results provided baseline data for lagoon waste management in the coastal environment in Ghana and other West African countries that share similar coastal characteristics.
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Wastewater treatment plants receive sewage containing high concentrations of bacteria and antibiotics. We assessed bacterial counts and their antibiotic resistance patterns in water from (a) influents and effluents of the Legon sewage treatment plant (STP) in Accra, Ghana and (b) upstream, outfall, and downstream in the recipient Onyasia stream. We conducted a cross-sectional study of quality-controlled water testing (January-June 2018). In STP effluents, mean bacterial counts (colony-forming units/100 mL) had reduced E. coli (99.9% reduction; 102,266,667 to 710), A. hydrophila (98.8%; 376,333 to 9603), and P. aeruginosa (99.5%; 5,666,667 to 1550). Antibiotic resistance was significantly reduced for tetracycline, ciprofloxacin, cefuroxime, and ceftazidime and increased for gentamicin, amoxicillin/clavulanate, and imipenem. The highest levels were for amoxicillin/clavulanate (50-97%) and aztreonam (33%). Bacterial counts increased by 98.8% downstream compared to the sewage outfall and were predominated by E. coli, implying intense fecal contamination from other sources. There was a progressive increase in antibiotic resistance from upstream, to outfall, to downstream. The highest resistance was for amoxicillin/clavulanate (80-83%), cefuroxime (47-73%), aztreonam (53%), and ciprofloxacin (40%). The STP is efficient in reducing bacterial counts and thus reducing environmental contamination. The recipient stream is contaminated with antibiotic-resistant bacteria listed as critically important for human use, which needs addressing.
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This paper assesses the level of interest, awareness, and adoption of ISO 14001 and Forest Stewardship Council (FSC) certification schemes among logging companies in Cameroon. Eleven logging companies located in Douala in the Littoral Region of Cameroon were assessed through a structured interview using an administered questionnaire which was mostly analyzed qualitatively thereafter. The findings indicated that none of the companies was certified for ISO 14001; however 63.64% of them were already FSC-certified. Four companies (36.36%) were neither FSC- nor ISO 14001 EMS-certified. Among the factors found to influence the adoption rate was the level of awareness about ISO 14001 and FSC certification schemes. The main drivers for pursuing FSC certification were easy penetration into international markets, tax holiday benefits, and enhancement of corporate image of the logging companies through corporate social responsibility fulfillments. Poor domestic market for certified products was found to be the major impediment to get certified. To make logging activities more environmentally friendly and socially acceptable, logging companies should be encouraged to get certified through the ISO 14001 EMS scheme which is almost nonexistent so far. This requires awareness creation about the scheme, encouraging domestic markets for certified products and creating policy incentives.