Risk assessment and regulation

Zoonotic microorganisms present perhaps the greatest past, present, and future risks to the safety of ambient water and drinking-water. Their worldwide distribution varies and is affected by climate and numerous natural and anthropogenic factors, and some microorganisms are emerging or re-emerging as disease risks. Some of the most significant risk factors include transboundary movements of people, food, and animals and increased intensive food and animal production, waste disposal, and cellular mutations, which ensure that the prevalence venues of these zoonotic microorganisms will continue to expand. Virtually every surface water source and many groundwaters are or will be vulnerable to one or more types of these ubiquitous microorganisms. Analytical methodologies continue to improve our capabilities to detect and identify zoonotic microorganisms with greater specificity and rapidity and to trace them to their sources. Risk assessment is a useful tool that helps practitioners and regulators to determine the extent and magnitude of