Health Risks Associated With Consumption of Untreated Water From Household Roof Catchment Systems1

ABSTRACT:Rainwater harvesting is receiving increased attention worldwide as an alternative source of drinking water. Although collected rainwater is typically consumed without any type of disinfection, the microbial quality of this type of water source can be poor. Around the world, consumers of collected and stored rainwater may be at considerable risk to a variety of infectious diseases. This review presents studies attributing specific risks of diseases to the consumption of contaminated rainwater. Diseases attributed to the consumption of untreated rainwater include bacterial diarrheas due toSalmonellaandCampylobacter, bacterial pneumonia due toLegionella, botulism due toClostridium, tissue helminths, and protozoal diarrheas fromGiardiaandCryptosporidium.Simple indicator systems such as fecal coliform measurements may prove to be inadequate for determining microbial risks associated with consumption of water from rainwater catchment systems.