Which of the following is less likely to occur in areas with effective water treatment policies?

Waterborne illnesses are significantly reduced in areas with effective water treatment policies. These policies typically involve rigorous water quality testing, proper filtration, disinfection processes, and the implementation of regulations that ensure safe drinking water. By removing pathogens and contaminants from the water supply, communities can prevent the spread of diseases that are transmitted through contaminated water, such as cholera, dysentery, and giardiasis.

Effective water treatment ensures that there is adequate removal of bacteria, viruses, and protozoa, drastically lowering the incidence of waterborne illnesses.

Conversely, in such areas, the likelihood of emergency disinfection, heavy metal contamination, and pathogen outbreaks can still exist due to other environmental factors, contamination from industrial discharges, or failures in the treatment systems, but such risks are mitigated compared to poorly managed water sources.