The Development Of Water Criteria Of Sulfonamides Based On QSAR And IEC

Water pollution caused by pharmaceuticals has been recognized as an environmental threat, and received increasing attention over the past years. Sulfonamides are a category of widely used pharmaceuticals. This study determined the luminescent bacteria toxicities of sulfonamides. The Quantitative Structure-Activity Relationship(QSAR) model was developed to estimate the toxicity of other target sulfonamides, in order to solve the insufficient toxicity data problem of reference species for the Interspecies Correlation Estimation(ICE). Based on the toxicity test and QSAR & ICE models, sufficient species toxicity data are estimated, and then Water Quality Criteria were calculated. This study can also support development of the Species Sensitivity Distributions(SSDs) with greater statistical significance and ecological meaning.The toxicities of sulfonamides to photobacterium phosphoreum depend on the value of Elumo and logKow and can be predicted with the QSAR model of this study; The main mechanism of toxication of sulfonamides is electrophilic attack to biological receptors by the water phase migration to biological phase. Toxicities of sulfonamides to different species have a good correlation so that ICE model can be used to estimate toxicities of other target sulfonamides in order to get sufficient toxicity data.Based on QSAR-ICE-ACR model, water quality criteria of sulfonamides were calculated by using methods of Toxicity Percentile Rank(TPR) and Species Sensitivity Distributions(SSDs). In contrast of the two methods’ results, the value of HC5 is higher than FAV and four of sulfonamides have a similar ratio of 1.17~1.66. Combined with the exposure concentrations of sulfonamides in the water environment of China and other countries, this study has given a preliminary risk assessment of sulfonamides in China. Among the sulfonamides of this study, Sulfadiazine, Sulfamethoxazole and Sulfaquinoxaline have a high risk to the water ecosystem.