Quantification of PM_2.5 (particulate matter <2.5 µm) bound heavy metals and their potential health risks were carried out around a cement manufacturing company in Ewekoro, Nigeria. The PM_2.5 samples were collected using Environtech gravimetric sampler. A four-staged sequential extraction procedure was used to fractionate PM_2.5 bound chromium (Cr), lead (Pb), aluminum (Al), copper (Cu), and silver (Ag), and further analyzed using inductively coupled plasma mass spectrometry. Chemical speciation results reveal bioavailable levels of Pb (4.05 µg/m³), Cr (10.75 µg/m³), Al (16.47 µg/m³), Cu (4.38E-01 µg/m³), and Ag (1.22E-02 µg/m³) in the airborne particulates. Pb and Cr levels exceeded the World Health Organization allowable limit of 0.5 and 2.5E-05 µg/m³, respectively. The labile phases showed strong indication of the presence of Cr and Cu metal. Excess cancer risks exposure for adults, outdoor workers and children were higher than the acceptable risk target level of 1E-06. Non-carcinogenic health risk estimated using hazard quotients (HQs) and hazard indices (HIs) showed ingestion route within the safe level of HI <1 implying no adverse effect while inhalation route exceeded the safe level for all receptors. Enforcement of pollution control by authorized agencies, and screening of greenbelts as sinks for air pollutants is strongly recommended.

尼日利亚Ewekoro的一家水泥制造公司对PM _2.5（颗粒物质<2.5 µm）结合的重金属及其潜在的健康风险进行了定量分析。使用Environtech重量采样器收集PM _2.5样品。使用四阶段顺序萃取程序对与PM _2.5结合的铬（Cr），铅（Pb），铝（Al），铜（Cu）和银（Ag）进行分级分离，并使用电感耦合等离子体质谱法进行进一步分析。化学形态学结果显示Pb（4.05 µg / m ³），Cr（10.75 µg / m ³），Al（16.47 µg / m ³），Cu（4.38E-01 µg / m ³）和Ag（1.22）的生物利用度水平E-02 µg / m ³）空气中的微粒。铅和铬的含量分别超过了世界卫生组织的允许极限0.5和2.5E-05 µg / m ³。不稳定相强烈表明存在Cr和Cu。成人，户外工作人员和儿童的过度癌症风险暴露高于可接受的风险目标水平1E-06。使用危险系数（HQs）和危险指数（HIs）估算的非致癌健康风险显示，摄入途径在HI <1的安全水平内，这意味着没有不良影响，而吸入途径对所有受体而言都超过了安全水平。强烈建议由授权机构实施污染控制，并筛选绿带作为空气污染物的汇。