Laniyan Temitope Ayodeji, Adewumi Adeniyi JohnPaul
Department of Environmental Health Sciences, Faculty of Public Health, College of Medicine, University of Ibadan, Ibadan, Nigeria.
Department of Geological Sciences, Achievers University, Owo, Ondo State, Nigeria.
J Health Pollut. 2020 Feb 28;10(25):200306. doi: 10.5696/2156-9614-10.25.200306. eCollection 2020 Mar.
Exposure to heavy metals emanating from cement production and other anthropogenic activities can pose ecological risks.
A detailed investigation was carried out to assess the contamination and ecological risk of heavy metals associated with dust released during cement production.
Sixty samples, including 30 soils and 30 plants, were collected around Lafarge Cement Production Company. Control samples of soil and plants were collected in areas where human activities are limited. Samples were dried, sieved (for soil; 65 μm), packaged and analyzed using inductively coupled plasma mass spectrometry at Acme Laboratory in Canada.
The average concentration of heavy metals in soils of the area are: copper (Cu): 41.63 mg/kg; lead (Pb): 35.43 mg/kg; zinc (Zn): 213.64 mg/kg; chromium (Cr): 35.60 mg/kg; cobalt (Co): 3.84 mg/kg and nickel (Ni): 5.13 mg/kg. Concentrations of Cr in soils were above the recommended standards, while other metals were below recommended limits. The average concentrations of heavy metals in plants were: Cu: 26.32 mg/kg; Pb: 15.46 mg/kg; Zn: 213.94 mg/kg; Cr: 30.62 mg/kg; Co: 0.45 mg/kg and Ni: 3.77 mg/kg. Levels of heavy metals in plants were all above international limits. Geo-accumulation of metals in soils ranged between -0.15 and 6.32, while the contamination factor ranged between 0.53 and 119.59. Ecological risk index of heavy metals in soils ranged between 49.71 and 749.
All metals in soils of the study area except for Cr were below the allowable limits, while the levels of metals in plants were above the permissible limits. Levels of heavy metals reported in this study were higher than those from similar cement production areas. Soils around the Ewekoro cement production area were low to extremely contaminated by toxic metals. Cement production, processing, transportation in conjunction with the abandoned railway track in the area greatly contribute to the high degree of contamination observed in the area. Metal transfers from soil to plant are a common phenomenon. The metals pose low to considerable ecological risk.
Anthropogenic sources, especially cement processing activities, release heavy metals which leads to progressive pollution of the environment and poses high ecological risk.
The authors declare no competing financial interests.
接触水泥生产及其他人为活动产生的重金属会带来生态风险。
开展详细调查以评估水泥生产过程中释放的粉尘所关联的重金属污染及生态风险。
在拉法基水泥生产公司周边采集了60个样本，包括30份土壤样本和30份植物样本。在人类活动受限的区域采集了土壤和植物的对照样本。样本经干燥、过筛（土壤过65μm筛）、包装后，送加拿大埃克梅实验室使用电感耦合等离子体质谱仪进行分析。
该区域土壤中重金属的平均浓度为：铜（Cu）：41.63毫克/千克；铅（Pb）：35.43毫克/千克；锌（Zn）：213.64毫克/千克；铬（Cr）：35.60毫克/千克；钴（Co）：3.84毫克/千克；镍（Ni）：5.13毫克/千克。土壤中铬的浓度高于推荐标准，而其他金属低于推荐限值。植物中重金属的平均浓度为：铜：26.32毫克/千克；铅：15.46毫克/千克；锌：213.94毫克/千克；铬：30.62毫克/千克；钴：0.45毫克/千克；镍：3.77毫克/千克。植物中的重金属含量均高于国际限值。土壤中金属的地累积指数在-0.15至6.32之间，污染因子在0.53至119.59之间。土壤中重金属的生态风险指数在49.71至749之间。
研究区域土壤中除铬以外的所有金属均低于允许限值，而植物中的金属含量高于允许限值。本研究报告的重金属含量高于类似水泥生产区域。埃韦科罗水泥生产区域周边的土壤受到有毒金属的低度至高度污染。该区域的水泥生产、加工、运输以及废弃的铁轨极大地导致了该区域观察到的高度污染。金属从土壤向植物的转移是常见现象。这些金属构成了低度至相当程度的生态风险。
人为来源，尤其是水泥加工活动，释放重金属，导致环境逐渐污染并带来高生态风险。
作者声明不存在相互竞争的财务利益。
