Association between Atrazine Utilization and Biologic Response of Rice Field Crab Esanthelphusa nani in Paddy Fields of Nan Province, Thailand

作者：Maneein Rachata; Khonsue Wichase; Varanusupakul Pakorn; Noppadon Kitana^*

来源：Research Journal of Chemistry and Environment, 2011, 15(2): 1018-1023.

• GC-MS
• HPLC
• herbicide
• agriculture
• hepatopancreas
• glutathione S-transferase

Now-a-days, agrochemicals (especially atrazine, glyphosate and paraquat herbicides) have been widely used with increasing intensity in Nan Province, Thailand. Sonic herbicides can directly pose adverse effects on animal such as inducing abnormal reproduction. However, for other herbicides, though the direct/acute effects on animals are minimal, these xenobiotic contaminants must be eliminated from animal body by biotransformation processes and it may chronically cause adverse effects to animals. Therefore it is crucial to monitor herbicide contamination and potential health hazards to non-target organisms living in the herbicide utilization areas. Collection of soil, water and sediment from agricultural area were performed on July and October 2010 for analysis of the herbicide contamination.
The results of GC-MS (atrazine) and HPLC (glyphosate and paraquat) analyses showed that detectable level of atrazine (<0.1 mg/kg) can be found in sediment of Nan River in July or the beginning of crop cultivation. Since it is important to monitor the health of living organisms in the area, a rice field crab Esanthelphusa nani has been selected as a sentinel species because it lives in paddy fields with direct exposure to herbicide contaminated soil and water. In this study, crabs were collected from two study sites: reference site where no herbicides were used and the contaminated site where herbicides were used routinely Crabs were subjected to morphometric and gravimetric analyses and the result showed that body weight of male crabs in the reference site is significantly higher than those from the contaminated site (ANCOVA, p<0.01). This could indicate association between atrazine contamination and the weight loss of male crab population in the contaminated area. Hepatopancreas of the crab were further determined for activity of glutathione S-transferase (GST), a crucial enzyme in biotransformation processes of xenobiotic contaminants. Comparison of the biologic response of crab, in term of hepatopancreas GST activity, to different levels of herbicide contamination will be presented. The results from this sentinel study could be used for assessing a potential impact of herbicide contamination on non-target organisms in agricultural environment.

• 出版日期2011-6