Aquatic Toxicology and Remediation Laboratory, Department of Life Science and Bioinformatics, Assam University, Silchar, 788011, India.
Environ Sci Pollut Res Int. 2021 Jun;28(22):28133-28145. doi: 10.1007/s11356-021-12608-3. Epub 2021 Feb 2.
To investigate the complex Pb-Cd exposure network in school-going children, a thorough investigation of the probable exposure means (diet, water, and school micro-environments such as paint dust and school courtyard soil) and exposure route (ingestion, inhalation and dermal) was carried out in a periurban area spanning three districts in southern Assam, India. Multivariate statistical analysis was carried out to understand the complex data matrices, and the health risk assessments (carcinogenic and non-carcinogenic) based on US EPA Risk Assessment models were also made. We found the median values to be 0.9-4.0 mg Pb/kg and 0.21-6.2 mg Cd/kg in various food items. Groundwater also had Pb (0.13-0.48 mg/L) and Cd (0.11-0.29 mg/L). Pb levels in paint dust were within the permissible limits, but 50% of the samples had higher than permissible levels of Cd. Approximately 23% of the school courtyard soil had Pb above the global background levels, but all the samples had 4-27 times elevated levels of Cd in them. School micro-environment contributed significantly to the metal load in children due to their typical hand-to-mouth behavior and dietary intake (food and water) via ingestion was the most prominent route of exposure in children. The evaluation of the estimated chronic daily intake and the hazard quotient indicated hazardous exposure over a lifetime to both Pb and Cd, but only Cd posed a prominent cancer risk. It could be concluded that chronic insidious effects of metals would be a noteworthy toxicological threat to children when exposed early on.
为了研究学龄儿童体内复杂的 Pb-Cd 暴露网络，我们对可能的暴露途径（饮食、水以及学校微观环境，如油漆粉尘和校园土壤）和暴露途径（摄入、吸入和皮肤接触）进行了彻底调查，该研究覆盖了印度阿萨姆邦南部三个区的城乡过渡带。我们进行了多变量统计分析以了解复杂的数据矩阵，并根据美国环保署风险评估模型进行了健康风险评估（致癌和非致癌）。我们发现，各种食物中 Pb 的中位数为 0.9-4.0mg/kg，Cd 的中位数为 0.21-6.2mg/kg。地下水也含有 Pb（0.13-0.48mg/L）和 Cd（0.11-0.29mg/L）。油漆粉尘中的 Pb 含量在允许范围内，但 50%的样本中 Cd 含量超过了允许水平。约 23%的校园土壤中的 Pb 含量高于全球背景水平，但所有样本中的 Cd 含量均高出 4-27 倍。由于儿童通常有手口行为，学校微观环境对儿童的金属负荷有显著影响，并且通过摄入饮食摄入是儿童暴露的最主要途径。对估计的慢性日摄入量和危害商数的评估表明，儿童在一生中对 Pb 和 Cd 的暴露都是危险的，但只有 Cd 会带来明显的癌症风险。可以得出结论，金属的慢性隐匿效应将对儿童造成显著的毒理学威胁，尤其是在儿童早期接触时。
