Environmental Toxicants and the Prevalence of Type 2 Diabetes in Texas

摘要

Diabetes mellitus is a chronic disease that is characterized by fasting hyperglycemia and affects approximately 422 million people worldwide. According to the 2012 data from the Centers for Disease Control and Prevention, 29.1 million people in the United States have diabetes, making it the 7 th leading cause of death. In 2013, 11% of the Texas population had diabetes with type 2 diabetes being the most prevalent. In certain regions in Texas diabetes prevalence rates are higher than the state average and some of these regions overlap with a high human activity of coal mining, oil fracking, and cotton farming. The primary objective of this capstone project was to review available literature and determine if environmental toxicants arsenic and glyphosate may contribute to higher prevalence rates of diabetes in certain health service regions in Texas. This study had the specific aims of reviewing the available literature to a) determine if coal mining or oil fracking could increase arsenic into nearby drinking sources and increase type 2 diabetes prevalence in Texas health service regions 1, 4, 5, 7, 8, 9, and 11, and b) determine if glyphosate used in cotton farming may increase the prevalence of type 2 diabetes in Texas health service regions 1, 2, 8, 9, and 11. A literature review was conducted using databases Ovid Medline, Scopus, PubMed, and search engine Google Scholar. The following keywords were used in combination or alone: diabetes mellitus, arsenic, aquifer, coal mining, oil, glyphosate, cotton, farming, and Texas.;No data was found on coal mining and its relationship with diabetes prevalence in Texas, but through separate data on arsenic levels in major aquifers and diabetes prevalence in Texas, comparisons with the Texas health service regions were made. However, the information available is from 2011 (the most current information from the 5-year update has yet to be made accessible), and can leave any conclusions made from it to be speculative. From the information available, a high Hispanic demographic in Texas health service regions 8 and 11 may explain the high diabetes prevalence rates in these areas that are within areas with high arsenic exposure, however health service regions 4 and 5 do not have a significantly lower diabetes prevalence despite having a lower Hispanic demographic and arsenic levels in comparison. Studies completed in different locations around the world provide evidence for a possible connection between arsenic exposure from oil fracking or coal mining and diabetes prevalence rates, but more studies are needed in Texas.;Glyphosate is one of the most used pesticides for overall herbicide use and cotton is one of the crops with most pesticide use. In 2015, cotton was planted in Texas health service regions 1, 2, 8, 9, and 11 with the majority of planted cotton being centralized in health service region 9, which has the second to highest diabetes prevalence rate of 14.5%. Health service region 2 has the highest diabetes prevalence in the state despite having less planted cotton acreage than health service region 9. Health service region 9 has the second highest prevalence rate and the highest cotton production, but glyphosate alone cannot be the sole proponent causing the diabetes prevalence due to the lack of a similar pattern in health service region 2. Even though it may not be the sole factor of an increased diabetes prevalence, glyphosate has been linked to oxidative stress seen in proliferating diabetes. Human studies with glyphosate exposure related to diabetes is rare, however relevant studies from the class of organophosphorus pesticides were used to provide evidence of a possible connection between pesticide exposure and an increase in diabetes prevalence. Organophosphates in human studies have provided a baseline for the hypothesis of glyphosate increasing the prevalence of diabetes, but the lack of specific data on glyphosate and diabetes prevalence rates warrants further research.;Taken together, it appears that more information is needed to determine if an increase in arsenic exposure from coal mining or oil fracking is associated with an increased diabetes prevalence in Texas health service regions 1, 4, 5, 7, 8, 9, and 11. Studies on glyphosate exposure from cotton farming would assist in the determining if the pesticide is associated with increased prevalence of type 2 diabetes in Texas health service regions 1, 2, 8, 9 and 11. Further research is needed on both subjects to test the possible connection to diabetes and its potential role in increasing diabetes prevalence in Texas.