AWWA JAW65069

Perchlorate and nitrate are both goitrogens, i.e., agents that can prevent the thyroid from absorbing iodide. Several environmental studies have focused on perchlorate as the sole waterborne goitrogen of public health concern in drinking water sources; however, any potential goitrogenic health effects of perchlorate cannot be understood in isolation from other waterborne goitrogens. This research set out to determine the overall distribution of perchlorate and nitrate in California drinking water sources and investigate the co-occurrence, if any, of these goitrogens. Data from the California Department of Health Services Division of Drinking Water and Environmental Monitoring database of source water monitoring results were analyzed. The study found that nitrate occurred in significantly higher concentrations than perchlorate (and over a much broader geographic area) and co-occurred with perchlorate. Drinking water sources that contained detectable levels of perchlorate had, on average, much higher concentrations of nitrates compared with other sources. This research provides insight into how water sources can be contaminated by multiple analytes simultaneously and how to determine whether these contaminants share a common source or infiltration route. Includes 19 references, tables, figure.