University of Iowa, College of Public Health, Iowa City, IA, USA; University of Iowa, Center for Health Effects of Environmental Contamination, Iowa City, IA, USA.
Iowa Department of Natural Resources, Des Moines, IA, USA.
Chemosphere. 2021 Oct;281:130856. doi: 10.1016/j.chemosphere.2021.130856. Epub 2021 May 13.
A statewide assessment of neonicotinoids in groundwater was conducted among a sample of public water supply wells in Iowa from October 2017 to August 2018. Samples from all the state's major aquifer groups were initially collected from 118 wells in 69 counties. Subsets of 55 untreated samples and 45 paired pre- and post-treatment samples were then collected in summer 2018, post-planting season for primarily corn and soybeans, to assess seasonal differences and the efficacy of treatment. Samples prepared using solid phase extraction were analyzed using LC/MS/MS for six neonicotinoids: acetamiprid, clothianidin, dinotefuran, imidacloprid, thiacloprid, thiamethoxam, and a sulfoximine (i.e., sulfoxaflor). Clothianidin was the most frequently detected (34%, max: 13.4 ng/L), followed by thiamethoxam (14.4%, max: 20.6 ng/L), imidacloprid (13%, max: 2.3 ng/L), and dinotefuran (0.1%, max: 1.4 ng/L). Alluvial aquifers (unadjusted odds ratio (UOR) = 14.1; 95% CI (5.4-36.9), p=<0.0001), wells with confining layers <15 m (UOR = 13.5, 95% CI (4.8-38.4), p=<0.0001), and less than 19.4 m in depth (UOR = 20.0; 95% CI (6.5-58.0), p=<0.0001) had the greatest risk for contamination. In vulnerable aquifers, neonicotinoids were detected in 62% of winter and 46% of summer samples, with winter samples over 3 times (UOR = 3.2; 95% CI (1.2-8.8), p = 0.02) more likely to have at least two neonicotinoids detected. In 55 public water supply systems, the median concentrations of clothianidin (p = 0.6), imidacloprid (p = 0.7), and thiamethoxam (p = 0.7) were unchanged following treatment. These results suggest that neonicotinoid contamination may be present year-round in treated drinking water from vulnerable groundwater sources and represent a source of human exposure.
对爱荷华州公共供水井的样本进行了全州范围内的地下水新烟碱类物质评估，采样时间为 2017 年 10 月至 2018 年 8 月。最初从 69 个县的 118 口井中采集了所有主要含水层组的样本。2018 年夏季，在主要种植玉米和大豆的种植季后，又采集了 55 个未处理样本和 45 个预处理和后处理样本的子集，以评估季节性差异和处理效果。使用固相萃取法制备的样本，采用 LC/MS/MS 分析了六种新烟碱类物质：乙虫腈、噻虫胺、噻虫嗪、吡虫啉、噻虫啉、噻虫脒和一种亚砜亚胺（即噻虫啉）。噻虫嗪的检出率最高（34%，最大值：13.4ng/L），其次是噻虫啉（14.4%，最大值：20.6ng/L）、吡虫啉（13%，最大值：2.3ng/L）和噻虫嗪（0.1%，最大值：1.4ng/L）。冲积含水层（未调整的优势比（UOR）=14.1；95%置信区间（5.4-36.9），p<0.0001）、隔水层<15 米（UOR=13.5，95%置信区间（4.8-38.4），p<0.0001）和深度<19.4 米（UOR=20.0；95%置信区间（6.5-58.0），p<0.0001）的井具有最大的污染风险。在脆弱的含水层中，冬季样本中有 62%和夏季样本中有 46%检测到新烟碱类物质，冬季样本中至少有两种新烟碱类物质检测到的可能性是夏季样本的三倍以上（UOR=3.2；95%置信区间（1.2-8.8），p=0.02）。在 55 个公共供水系统中，经过处理后，棉铃虫（p=0.6）、吡虫啉（p=0.7）和噻虫嗪（p=0.7）的浓度中位数没有变化。这些结果表明，脆弱地下水源处理饮用水中的新烟碱类物质污染可能全年存在，这代表了人类暴露的一个来源。
