Water quality impacts on human health: towards an integrated, solution-oriented global assessment

Poor water quality negatively affects human health. Large-scale knowledge of present and future water quality and associated health impacts remains limited, hindering the development of effective policies and regulations to reduce water quality related health risks. This paper collates current knowledge on global water quality relevant for human health at present and in the future and identifies key knowledge gaps and ways forward. Six relevant water quality constituent groups include (1) microorganisms, (2) organic micropollutants, (3) heavy metals, metalloids and constituents of geogenic origin, (4) nitrate/nitrite, (5) salts/salinity, and (6) plastics. These have a variety of health impacts ranging from gastroenteritis to cancer. An analysis of monitoring data and approaches for past and future water quality and health risk demonstrates that data availability for the assessment of water quality impacts on human health is very limited, while integration of these approaches provides some opportunities to reduce knowledge and data gaps in this field. We call for an integrated, solution-oriented approach that should incorporate interactions between multiple constituents, study compound impacts on health, and focus on synergies and trade-offs of interventions that can improve human health. In addition, this approach should include human health alongside other impacts, such as animal health, aquatic ecosystems and food production. A holistic approach would provide more comprehensive understanding of present and future water quality and consequent human health impacts, which is a prerequisite for intervention strategies, and the realisation of sustainable development goals (SDGs) 6 for clean water and 3 on good health and well-being.