Department of Environmental Management and Toxicology, Federal University Oye Ekiti, Oye, Ekiti, Nigeria.
Department of Environmental Management and Toxicology, University of Agriculture and Environmental Sciences, Umuagwo, Nigeria.
Biol Trace Elem Res. 2024 Jul;202(7):3333-3348. doi: 10.1007/s12011-023-03903-w. Epub 2023 Oct 17.
Conversion of dumpsites to farm lands in several communities is a usual practice in Nigeria. Wastes accumulate heavy metals in a variety of forms. This study assessed the concentration, degrees of contamination, and attendant health risk of heavy metals (HMs), using two major indigenous vegetables (Amaranthus viridis and Talinum triangulare) grown on five major dumpsites in Lagos state. After wet digestion, the mean concentrations of the HMs in the vegetable samples were evaluated using atomic absorption spectrophotometer (AAS). Daily intake of metals (DIM), target hazard quotient (THQ), and hazard index (HI) biomathematics were employed in the assessment of non-carcinogenic health risk. Incremental lifetime cancer risk (ILCR) assessment was used to assess carcinogenicity. The obtained result shows that the concentrations of HMs fell within the following ranges: (0.37 to 0.59), (0.07 to 1.36), (0.30 to 1.92), (0.00 to 0.03), and (0.00 to 0.04) mg/kg; for zinc (Zn), lead (Pb), Iron (Fe), cadmium (Cd), and chromium (Cr), respectively, with low to moderate variability. At Ikorodu dumping site, the Pb concentration was above the World Health Organization (WHO) permissible range and has the highest contamination factor. DIM for Pb was also above threshold values (> 1) in both adults and children, while the THQ values for Fe, Pb, and Cd were above 1 (> 1) in both adults and children. HI values for the vegetables exceeded WHO normal range (> 1), except Abule-Egba dumps' samples (70% HI greater than 1 in adults and 90% HI greater than 1 in children). Additionally, the ILCR values of above 50% of the samples were above the WHO (10) limits, with the highest value in children (Cd, 1.064 × 10) indicating high risk of carcinogenicity over a life time of exposure. Thus, the results revealed great health risk from consumption of vegetables from the four major dumping sites, with children being at greater risk.
尼日利亚的几个社区通常会将垃圾场改造成农田。废物以各种形式积累重金属。本研究使用在拉各斯州五个主要垃圾场种植的两种主要本地蔬菜（苋菜和三尖杉）评估了重金属（HM）的浓度、污染程度和伴随的健康风险。使用原子吸收分光光度计（AAS）对蔬菜样品中的金属进行湿消化后，评估了主要元素的平均浓度。使用每日金属摄入量（DIM）、目标危害系数（THQ）和危害指数（HI）生物数学评估非致癌健康风险。使用增量终生癌症风险（ILCR）评估评估致癌性。结果表明，重金属浓度范围如下：（0.37 至 0.59）、（0.07 至 1.36）、（0.30 至 1.92）、（0.00 至 0.03）和（0.00 至 0.04）mg/kg；分别为锌（Zn）、铅（Pb）、铁（Fe）、镉（Cd）和铬（Cr），变异性低至中等。在伊科罗杜垃圾场，Pb 浓度高于世界卫生组织（WHO）允许范围，且污染系数最高。成人和儿童的 Pb DIM 均高于阈值 (>1)，而成人和儿童的 Fe、Pb 和 Cd 的 THQ 值均高于 1 (>1)。除了阿布卢埃格巴垃圾场的样本（70%的 HI 在成人中大于 1，90%的 HI 在儿童中大于 1）外，蔬菜的 HI 值均超过了 WHO 正常范围 (>1)。此外，超过 50%的样本的 ILCR 值超过了 WHO（10）限值，儿童的最高值（Cd，1.064×10）表明在一生中暴露于致癌物质的风险较高。因此，结果表明，从四个主要垃圾场的蔬菜中摄入这些蔬菜会带来很大的健康风险，儿童的风险更高。
