Toxicity Assessment of Atrazine and Related Triazine Compounds in the Microtox Assay, and Computational Modeling for Their Structure-Activity Relationship
Open Access
- 12 October 2000
- journal article
- research article
- Published by MDPI AG in International Journal of Molecular Sciences
- Vol. 1 (4), 63-74
- https://doi.org/10.3390/ijms1040063
Abstract
The triazines are a group of chemically similar herbicides including atrazine, cyanazine, and propazine, primarily used to control broadleaf weeds. About 64 to 80 million lbs of atrazine alone are used each year in the United States, making it one of the two most widely used pesticides in the country. All triazines are somewhat persistent in water and mobile in soil. They are among the most frequently detected pesticides in groundwater. They are considered as possible human carcinogens (Group C) based on an increase in mammary gland tumors in female laboratory animals. In this research, we performed the Microtox Assay to investigate the acute toxicity of a significant number of triazines including atrazine, atraton, ametryne, bladex, prometryne, and propazine, and some of their degradation products including atrazine desethyl, atrazine deisopropyl, and didealkyled triazine. Tests were carried out as described by Azur Environmental [1]. The procedure measured the relative acute toxicity of triazines, producing data for the calculation of triazine concentrations effecting 50% reduction in bioluminescence (EC50s). Quantitative structure-activity relationships (QSAR) were examined based on the molecular properties obtained from quantum mechanical predictions performed for each compound. Toxicity tests yielded EC50 values of 39.87, 273.20, 226.80, 36.96, 81.86, 82.68, 12.74, 11.80, and 78.50 mg/L for atrazine, propazine, prometryne, atraton, atrazine desethyl, atrazine deisopropyl, didealkylated triazine, ametryne, and bladex, respectively; indicating that ametryne was the most toxic chemical while propazine was the least toxic. QSAR evaluation resulted in a coefficient of determination (r2) of 0.86, indicating a good value of toxicity prediction based on the chemical structures/properties of tested triazines.Keywords
This publication has 32 references indexed in Scilit:
- Relation of Usage to the Occurrence of Cotton and Rice Herbicides in Three Streams of the Mississippi DeltaEnvironmental Science & Technology, 1998
- The Environmental Occurrence of Herbicides: The Importance of Degradates in Ground WaterArchives of Environmental Contamination and Toxicology, 1998
- Occurrence of Selected Herbicides and Herbicide Degradation Products in Iowa's Ground Water, 1995Groundwater, 1997
- Formation and Transport of Deethylatrazine and Deisopropylatrazine in Surface WaterEnvironmental Science & Technology, 1994
- Groundwater as a nonpoint source of atrazine and deethylatrazine in a river during base flow conditionsWater Resources Research, 1993
- A reconnaissance study of herbicides and their metabolites in surface water of the midwestern United States using immunoassay and gas chromatography/mass spectrometryEnvironmental Science & Technology, 1992
- Herbicide transport in rivers: importance of hydrology and geochemistry in nonpoint-source contaminationEnvironmental Science & Technology, 1992
- An Extended Version of a Novel Method for the Estimation of Partition CoefficientsJournal of Pharmaceutical Sciences, 1992
- Herbicides in surface waters of the midwestern United States: the effect of spring flushEnvironmental Science & Technology, 1991
- A new method for the estimation of partition coefficientJournal of the American Chemical Society, 1989