Water quality and public health risks associated with roof rainwater harvesting systems for potable supply: Review and perspectives

Knowledge of rainwater quality is critical for safeguarding public health. The review investigated rainwater quality, and public health risks associated with its consumption. Land use practices, roof material, weather patterns and their interactions influence rainwater quality. Contrary to the notion that roof water is safe, data point to physico-chemical and microbial contamination of rainwater via atmospheric deposition, leaching and weathering of roof materials, storage/conveyance utilities and faecal contamination. However, epidemiological studies linking consumption of rainwater to public health risks are scarce especially in developing countries. This reflects the lack of epidemiological research and confounding factors such as high disease burden. To minimize the public health risks, we recommend the implementation of risk assessment framework integrating laboratory analytical results and sanitary inspection risk analysis. Such a framework will enable proper prioritization and targeting of engineering/technological interventions, public education and housekeeping programmes.