Citation: Shakya, A.; Dodson, M.; Artiola, J.F.; Ramirez-Andreotta, M.; Root, R.A.; Ding, X.; Chorover, J.; Maier, R.M. Arsenic in Drinking Water and Diabetes. Water 2023, 15, 1751. https://doi.org/10.3390/ w15091751 Academic Editors: Richard K. Kwok and Danielle J. Carlin Received: 1 April 2023 Revised: 26 April 2023 Accepted: 27 April 2023 Published: 2 May 2023 Copyright: © 2023 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/). water Review Arsenic in Drinking Water and Diabetes Aryatara Shakya 1 , Matthew Dodson 1 , Janick F. Artiola 2 , Monica Ramirez-Andreotta 2 , Robert A. Root 2 , Xinxin Ding 1 , Jon Chorover 2 and Raina M. Maier 2, * 1 Department Pharmacology & Toxicology, University of Arizona, Tucson, AZ 85721, USA; aryatarashakya@arizona.edu (A.S.); dodson@pharmacy.arizona.edu (M.D.); xding@pharmacy.arizona.edu (X.D.) 2 Department Environmental Science, University of Arizona, Tucson, AZ 85721, USA; artiola@gmail.com (J.F.A.); mdramire@arizona.edu (M.R.-A.); robroot.az@gmail.com (R.A.R.); chorover@arizona.edu (J.C.) * Correspondence: rmaier@ag.arizona.edu Abstract: Arsenic is ubiquitous in soil and water environments and is consistently at the top of the Agency for Toxic Substances Disease Registry (ATSDR) substance priority list. It has been shown to induce toxicity even at low levels of exposure. One of the major routes of exposure to arsenic is through drinking water. This review presents current information related to the distribution of arsenic in the environment, the resultant impacts on human health, especially related to diabetes, which is one of the most prevalent chronic diseases, regulation of arsenic in drinking water, and approaches for treatment of arsenic in drinking water for both public utilities and private wells. Taken together, this information points out the existing challenges to understanding both the complex health impacts of arsenic and to implementing the treatment strategies needed to effectively reduce arsenic exposure at different scales. Keywords: arsenic; diabetes; drinking water treatment; arsenic exposure 1. Introduction—Water Quality and Importance Safe and affordable drinking water is a prerequisite for prosperity and sustainable development. The 2021 World Economic Forum report [1] lists natural resources crises, which includes water, as the fifth-highest existential threat globally. According to the 2017 WHO and UNICEF reports, more than 785 million people that year did not have access to basic water services [2]. While substantial progress has been made worldwide to provide access to clean drinking water, many regions have limited surface-water supplies and rely on groundwater resources. This has led to an increased risk of developing health issues in many parts of the world [3]. Metal(loid)s such as zinc (Zn), selenium (Se), copper (Cu), molybdenum (Mo), chromium (Cr), manganese (Mn), nickel (Ni), cobalt (Co), iron (Fe), magnesium (Mg), and arsenic (As) rank among the top priority metals that act as environmental toxicants in drinking water worldwide [4–10]. This review focuses in particular on As, a ubiquitous element that has been at the top of the Agency for Toxic Substances Disease Registry (ATSDR) substance priority list since 1997 [11], as it has been shown to induce toxicity even at low levels of exposure, thus representing a continuously growing public health concern. Exacerbating the issue is the fact that exposure are not equal. Environmental racism and injustices result in people of color and low-income community members living in closer proximity to sources of environmental pollution (e.g., [12,13]). As a case in point, on 31 May 2022, the Biden–Harris Administration established a Department of Health and Human Services Office of Environmental Justice. As stated in the press release by HHS Secretary Xavier Becerra: “The blunt truth is that many communities across our nation—particularly low-income communities and communities of color—continue to bear Water 2023, 15, 1751. https://doi.org/10.3390/w15091751 https://www.mdpi.com/journal/water