Molecular Biomedicine Laboratory, Facultad de Ciencias Químicas, Universidad Juárez del Estado de Durango, Durango, Mexico.
Laboratory of Identification of Persistent Organic Pollutants, EPOMEX, Universidad Autónoma de Campeche, Campeche, Mexico.
Sci Rep. 2020 Oct 16;10(1):17584. doi: 10.1038/s41598-020-74620-w.
This study identified and determined organochloride pesticide (OCs) concentrations in hair samples from children at two elementary schools: one exposed to fumigations in agricultural fields, the other unexposed. Three concentrations of OCs levels in the hair were compared (high, medium, low), and total nuclear abnormalities in buccal cells were determined: micronuclei (MNi), condensed chromatin, karyorrhexis, pyknosis, binucleate cells, karyolysis, lobed nuclei, and apoptosis. No significant differences were found for the presence of MNi between the schoolchildren from the exposed and unexposed schools, but the prevalence of OCs in both schools was over 50%, as well as the frequencies of MNi in the children were over 58%. Findings show a significant difference between the frequency of MNi in the total sample of schoolchildren (exposed school + unexposed school) in relation to the concentration of OCs detected in their hair. The children from exposed school that showed the higher concentrations of OCs in hair had higher levels of genotoxic damage in the buccal cells; compared against children with lower concentrations of OCs. The most frequent nuclear abnormalities in the exposed children were lobed nuclei (79.4%), binucleate cells (66.66%), apoptosis (65.07), and MNi (58.7%). We determined the prevalence ratio (PR) and prevalence odds ratio (POR) for the presence of MNi in buccal cells in relation to the OCs concentrations in the hair samples. Both ratios were high for MNi [PR 3.93, 95% confidence interval (CI) 1.97-7.84, p = 0.0003; and POR 7.97, 95% CI 2.62-24.28, p = 0.0003], indicating a 7.97 times greater risk that the exposed children will present > 0.2% of MNi when OCs concentrations exceed 0.447 μg/g. These indicators may be useful biomarkers of genotoxic damage in children exposed to persistent, highly-toxic compounds. Results suggest the potential risk to which those schoolchildren are exposed on a daily basis due to fumigations in nearby agricultural fields.
本研究在两所小学的儿童头发样本中鉴定和确定了有机氯农药 (OCs) 的浓度：一所小学的儿童暴露于农田熏蒸，另一所小学的儿童未暴露于此。比较了头发中三种 OCs 浓度水平（高、中、低），并测定了口腔细胞中的总核异常：微核 (MNi)、浓缩染色质、核碎裂、固缩、双核细胞、核溶解、分叶核和细胞凋亡。暴露于熏蒸的学校儿童与未暴露于熏蒸的学校儿童之间的 MNi 阳性率无显著差异，但两所学校的 OCs 检出率均超过 50%，儿童的 MNi 频率均超过 58%。研究结果表明，暴露于熏蒸的学校儿童的口腔细胞中 MNi 频率与头发中 OCs 浓度之间存在显著差异。暴露于熏蒸的学校中头发中 OCs 浓度较高的儿童的口腔细胞的遗传毒性损伤水平较高；与 OCs 浓度较低的儿童相比。暴露于熏蒸的儿童中最常见的核异常是分叶核 (79.4%)、双核细胞 (66.66%)、细胞凋亡 (65.07%) 和 MNi (58.7%)。我们确定了口腔细胞中 MNi 存在与头发样本中 OCs 浓度相关的患病率比 (PR) 和患病率比值比 (POR)。MNi 的比值均较高 [PR 3.93，95%置信区间 (CI) 1.97-7.84，p=0.0003；POR 7.97，95%CI 2.62-24.28，p=0.0003]，表明当 OCs 浓度超过 0.447μg/g 时，暴露于熏蒸的儿童出现 MNi 超过 0.2%的风险增加了 7.97 倍。这些指标可能是接触持久性、高毒性化合物的儿童遗传毒性损伤的有用生物标志物。结果表明，由于附近农田的熏蒸，这些学童每天都面临潜在的风险。
