Critical issues and alternatives for the establishment of chemical water quality criteria for livestock

Abstract

Good water quality for livestock is essential for animal health, supply of safe food and food production economy. Few countries have established water quality criteria for livestock for chemical contaminants. For those that have them, the values are quite variable among each other for the same substance due to differences in the approach for the acceptable daily intakes and algorithms for the calculation. In several countries, including Brazil, these standards are based on international or other countries’ data, which differ among protected species, exposure scenarios, and levels of protection. The objective of this work was to discuss critical issues to establish chemical water quality criteria for livestock in Brazil. A discussion about the difficulties involved and the alternatives when sufficient data are not available is presented. Using the Canadian framework for reference, we provide recommendations on a revised framework and alternatives regarding the use of chronic studies as mandatory, defaulting to human health drinking water quality guidelines/criteria for livestock, the use of additional safety factors, and alternatives in the absence of toxicological data.