Accumulation of microcystin toxin in irrigation water and alfalfa (Medicago sativa) forage plant, and assessing the potential risk to animal health.

ABSTRACT

Microcystin (MC) toxin produced by cyanobacteria has become a significant concern for societies worldwide. The risk of MC in drinking water has been assessed to human health. Nonetheless, its risk to animal health has not been thoroughly evaluated. This study investigated MCs in irrigation water and alfalfa plant from nearby farmlands. Both irrigation water and alfalfa shoots contained greater MC concentrations (1.8-17.4 µg L-1 and 0.053-0.128 µg g-1) during summer than winter (2.4 µg L-1 and 0.017 µg g-1). These MC concentrations showed a correlation with the predominance of cyanobacteria in the sites, triggering the potential risk of these microorganisms in irrigation waters. Accordingly, there would be a high risk (risk quotient, RQ > 1) during summer and a moderate risk (0.1cattle and sheep that drink polluted irrigation water or eat contaminated alfalfa plants. Therefore, the study suggests that cyanotoxins in forage plants and irrigation water sources should be regularly monitored to protect animals from consuming contaminated food and water.