*Article* **Low-Level Groundwater Atrazine in High Atrazine Usage Nebraska Counties: Likely Effects of Excessive Groundwater Abstraction**

**Moses New-Aaron 1,\*, Olufemi Abimbola 2,\*, Raheleh Mohammadi 3, Oluwaseun Famojuro 3, Zaeema Naveed 4, Azar Abadi 1, Jesse E. Bell 1, Shannon Bartelt-Hunt <sup>5</sup> and Eleanor G. Rogan <sup>1</sup>**


**Citation:** New-Aaron, M.; Abimbola, O.; Mohammadi, R.; Famojuro, O.; Naveed, Z.; Abadi, A.; Bell, J.E.; Bartelt-Hunt, S.; Rogan, E.G. Low-Level Groundwater Atrazine in High Atrazine Usage Nebraska Counties: Likely Effects of Excessive Groundwater Abstraction. *Int. J. Environ. Res. Public Health* **2021**, *18*, 13241. https://doi.org/10.3390/ ijerph182413241

Academic Editors: Alban Kuriqi and Luis Garrote

Received: 17 November 2021 Accepted: 13 December 2021 Published: 15 December 2021

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**Copyright:** © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

**Abstract:** Recent studies observed a correlation between estrogen-related cancers and groundwater atrazine in eastern Nebraska counties. However, the mechanisms of human exposure to atrazine are unclear because low groundwater atrazine concentration was observed in counties with high cancer incidence despite having the highest atrazine usage. We studied groundwater atrazine fate in high atrazine usage Nebraska counties. Data were collected from Quality Assessed Agrichemical Contaminant Nebraska Groundwater, Parameter–Elevation Regressions on Independent Slopes Model (PRISM), and water use databases. Descriptive statistics and cluster analysis were performed. Domestic wells (59%) were the predominant well type. Groundwater atrazine was affected by well depth. Clusters consisting of wells with low atrazine were characterized by excessive groundwater abstraction, reduced precipitation, high population, discharge areas, and metropolitan counties. Hence, low groundwater atrazine may be due to excessive groundwater abstraction accompanied by atrazine. Human exposure to atrazine in abstracted groundwater may be higher than the estimated amount in groundwater.

**Keywords:** groundwater; atrazine; abstraction; cancers; climate; Nebraska
