Inter-Method Comparison of US EPA Analytical Methods 507 and 508.1 to Test for Atrazine in Kentucky Drinking Water

摘要

This study examined United States Environmental Protection Agency (US EPA) methods 507 and 508.1; analytical methods used to test drinking water for Atrazine. Additionally, this study examines the seasonal variation of Atrazine in Kentucky drinking water. Atrazine is a triazine herbicide used to control and inhibit the growth of broad leaf and grassy weeds. Atrazine’s ability to be transported to community drinking water supplies makes it a significant public health issue, as it has been linked to myriad negative health endpoints ranging from endocrine disruption to various forms of cancer, including stomach and ovarian cancer. To date, there is little research examining the current methods used to test for Atrazine and its seasonal variation in drinking water. Drinking water samples previously collected by the Kentucky Division of Water and the Kentucky Geological Survey from 117 of 120 counties throughout the state from January 2000 to December 2008 were used for this study. To examine inter-method comparison between methods 507 and 508.1, samples were subjected to the Mann-Whitney U test. Median values of methods 507 and 508.1 were found to be similar (p=0.7421). To examine seasonal variation, data from each year from 2000 to 2008, as well as the entire 2000-2008 period, were analyzed using the Kruskal-Wallis One Way Analysis of Variance. Years 2000, 2002, 2003, 2004, 2007, and 2008 as well as the full 2000-2008 span were found to have significantly different Atrazine concentrations from season to season. Years 2001, 2005, and 2006 were not found to have significantly different concentrations from season to season. The 2000-2008 span was then subjected to the Seasonal Kendal Test for Trend, which determined a significant (p=0.000092) decreasing linear trend of -7.6 x 10-6 mg/L/year of Atrazine in Kentucky. Similar decreasing linear trends were seen throughout the five regions in the state during this time period as well. This study further expands on knowledge of the occurrence and persistence of Atrazine in the environment. Comparative analysis of US EPA analytical methods and the seasonal variation of Atrazine in drinking water provide a background for future research.