A cement factory nearby communities raise pollution concerns. This study assessed air pollution levels for respirable particulate matter (PM2.5 and PM10) and heavy metals (lead, chromium, nickel, cadmium, zinc and cop...A cement factory nearby communities raise pollution concerns. This study assessed air pollution levels for respirable particulate matter (PM2.5 and PM10) and heavy metals (lead, chromium, nickel, cadmium, zinc and copper) adjacent to a cement factory in Ewekoro and neighbouring communities (Papalantoro, Lapeleko and Itori) in Ogun State, Nigeria. Respirable particulate matter (PM2.5 and PM10) and heavy metals were measured using an ARA N-FRM cassette sampler. Each location sampled was monitored for eight continuous hours daily for 12 days. The PM2.5, PM10 and heavy metals results were compared with different standards, including those of the World Health Organization (WHO), Nigeria’s National Environmental Standard and Regulation Enforcement Agency (NESREA) and Canadian Ambient Air Quality Standards (CAAQS). The PM levels fell within 11 - 19 μg/m3 of the air management level of CAAQS, which signifies continuous actions are needed to improve air quality in the areas monitored but below the NESREA standard. The mean Cd, Cr and Ni concentrations in the cement factory area and the impacted neighbourhoods are higher than the WHO/EU permissible limits, while Zn and Cu were below the WHO/EU permissible limit. A risk assessment hazard quotient (HQ) for Cr was above the WHO/EU safe level (=1) in adults and children throµgh ingestion, inhalation and dermal contact at all the monitoring sites. The HQ for Ni and Cd was higher than the safe level in the cement factory area and Papalantoro, while Zn was at safe levels.展开更多
Radiocarbon content in biogenic samples is widely used to study the variation of atmospheric CO<sub>2</sub> due to anthropogenic activities. A total of 20 samples of several types of tree leaves, were anal...Radiocarbon content in biogenic samples is widely used to study the variation of atmospheric CO<sub>2</sub> due to anthropogenic activities. A total of 20 samples of several types of tree leaves, were analyzed for this study. Sampling was carried out at the end of the rainy season in 2017 from the surrounding of the SOCOCIM cement factory in Rufisque town. Rufisque is located on the peninsula of Cape Verde, 25 km east of Dakar, where it is the 《south gate》 of the agglomeration. Reference samples of five different species were collected during the same period (2017) from a clean zone. The <sup>14</sup>C method was used for the determination of Δ<sup>14</sup>C values. The data show that the <sup>14</sup>C concentration in the studied sites was significantly lower than the clean area, due to the release of anthropogenic CO<sub>2</sub>. To estimate the Suess effect, the fossil fuel fraction was determined based on equations of mass balance for CO<sub>2</sub> concentration, stable isotopic composition of carbon, and <sup>14</sup>C concentration. The results show that selected locations are affected differently according to their distance from the factory and the wind direction.展开更多
文摘A cement factory nearby communities raise pollution concerns. This study assessed air pollution levels for respirable particulate matter (PM2.5 and PM10) and heavy metals (lead, chromium, nickel, cadmium, zinc and copper) adjacent to a cement factory in Ewekoro and neighbouring communities (Papalantoro, Lapeleko and Itori) in Ogun State, Nigeria. Respirable particulate matter (PM2.5 and PM10) and heavy metals were measured using an ARA N-FRM cassette sampler. Each location sampled was monitored for eight continuous hours daily for 12 days. The PM2.5, PM10 and heavy metals results were compared with different standards, including those of the World Health Organization (WHO), Nigeria’s National Environmental Standard and Regulation Enforcement Agency (NESREA) and Canadian Ambient Air Quality Standards (CAAQS). The PM levels fell within 11 - 19 μg/m3 of the air management level of CAAQS, which signifies continuous actions are needed to improve air quality in the areas monitored but below the NESREA standard. The mean Cd, Cr and Ni concentrations in the cement factory area and the impacted neighbourhoods are higher than the WHO/EU permissible limits, while Zn and Cu were below the WHO/EU permissible limit. A risk assessment hazard quotient (HQ) for Cr was above the WHO/EU safe level (=1) in adults and children throµgh ingestion, inhalation and dermal contact at all the monitoring sites. The HQ for Ni and Cd was higher than the safe level in the cement factory area and Papalantoro, while Zn was at safe levels.
文摘Radiocarbon content in biogenic samples is widely used to study the variation of atmospheric CO<sub>2</sub> due to anthropogenic activities. A total of 20 samples of several types of tree leaves, were analyzed for this study. Sampling was carried out at the end of the rainy season in 2017 from the surrounding of the SOCOCIM cement factory in Rufisque town. Rufisque is located on the peninsula of Cape Verde, 25 km east of Dakar, where it is the 《south gate》 of the agglomeration. Reference samples of five different species were collected during the same period (2017) from a clean zone. The <sup>14</sup>C method was used for the determination of Δ<sup>14</sup>C values. The data show that the <sup>14</sup>C concentration in the studied sites was significantly lower than the clean area, due to the release of anthropogenic CO<sub>2</sub>. To estimate the Suess effect, the fossil fuel fraction was determined based on equations of mass balance for CO<sub>2</sub> concentration, stable isotopic composition of carbon, and <sup>14</sup>C concentration. The results show that selected locations are affected differently according to their distance from the factory and the wind direction.