STATISTICAL APPROACH FOR ASSESSING AQUATIC ATRAZINE CONCENTRATIONS AND POTENTIAL IMPACTS ON AMPHIBIANS

Abstract

Aquatic contaminant assessments using water quality data can be challenged if sampling frequency is less than daily, if sampling only happens during certain months of the year, and if sampling lacks appropriate adjustments for averaging partial or insufficient data. Random or long-interval data collection will miss temporary spikes in contaminant concentrations. This leads to underestimates of harmful chemical concentrations, which in turn affects risk assessment, hazard assessment, and further conclusions made from quantitative data. A year-round, once daily sampling scheme paired with temporal adjustment factors is proposed to accurately assess the impact on amphibians. The daily sampling technique has potential additional uses for assessing the impact of other environmental contaminants on amphibians, which are particularly susceptible to aquatic chemical contaminants due to their permeable skin and aquatic developmental phases of life. In this paper, the herbicide atrazine and its presence in fresh waterways is explored in relation to current standardized aquatic sampling techniques, as well as the need to make changes in sampling that could be applied in the field, directly impacting assessments relating to amphibians.