Shrimps can be used as indicators of the quality of aquatic systems exposed to a variety of pollutants. Chlorpyrifos is one of the most common pesticides found in environmental samples. In order to evaluate the effects of chlorpyrifos, adult organisms of Litopenaeus vannamei were exposed to two sublethal concentrations of the pesticide (0.7 and 1.3 μg/L) for four days. The LC 50 (96-hours) value was determined and Lipid oxidation levels (LPO) and the activities of catalase (CAT), glutathion peroxidase (GPx), glutathion-S-transferase (GST) were assessed on the muscle, hepatopancreas and gills from the exposed organisms. In addition, inhibition of acetylcholinesterase (AChE) was determined in the brain. LC 50 (96hours) was 2.10 μg/L of chlorpyrifos. Catalase activity and LPO were elevated in the three tissues, whereas a decrease of AChE activities in the brain and an increase of GST activity in the hepatopancreas were observed.

This study evaluates the water quality for human consumption in the municipalities of Sincerín and Gambote. It was measured through physico-chemical (color, turbidity, conductivity, pH, dissolved oxygen, hardness, and heavy metals) and microbiological (total coliforms, Escherichia coli) parameters before and after a partial form of water treatment was used (alum and chlorine addition in Gambote and Sincerín municipalities, respectively).  This investigation was done in accordance with the maximum permissible values established by the Resolution 2115 of 2007 of the Ministry of Environment, Housing, and Territorial Development of Colombia (MAVD in Spanish). Additionally, the IRCA (Water Quality Risk Index) was calculated to determine the degree of risk of disease occurrence. The results indicated concentrations higher than the recommended values for: (a) hardness (in Sincerín); (b) iron (Fe), turbidity (only before being treated), E. coli (in Gambote); and (c) mercury (Hg), and total coliforms. The water supplies of the municipalities presented unsafe IRCA. Therefore, it is expected that the results of this study could be used for proposing strategies for improving these conditions by means of the design and implementation of an adequate treatment system.