A rapid systematic scoping review of research on the impacts of water contaminated by chemicals on very young children

Abstract

Low-income countries are struggling with the health impacts of both surface and groundwater chemical contamination. Although the impact of biological contaminants on children's health is acknowledged, the long-term effects of these and emerging contaminants on young children may be underestimated. To map the existing evidence on health impacts of water contaminated with chemicals on young children (<5 years), we conducted a scoping review to select and organize relevant literature. Of the 98 studies in the review, 24 revealed that the hazard ratio of arsenic, nitrates, cadmium, and fluoride (all of which are on the World Health Organisation's list of 10 chemicals of public health concern) was higher in very young children than in older age groups. Anthropogenic activities (textile manufacturing, waste disposal, and intensified agriculture) are leading contributors to the release of chemicals to groundwater used for drinking. Three major pathways for chemical contamination exposure in young children were confirmed: maternal transmission during pregnancy and breastfeeding, and early school years. Children exhibited acute and chronic disruptions to their neurological, skeletal, reproductive, and endocrine systems, as well as cumulative carcinogenic risks, amongst other life-altering consequences. The lack of research on emerging contaminants' effects on young children in low-income countries is worrisome, as their increased use may compound the issues caused by the existing problem of "legacy chemicals." Precautionary principle should regulate the operation of industries producing these chemicals in a robust manner. Evidence from major producers and exporters in high-income countries is sufficient to warrant action, even without waiting for direct harm to be observed in low-income countries. Literature recommends prioritising prevention of contamination over demand side treatment or finding alternative water sources, especially in water-scarce areas affected by climate change. Local and transnational efforts are required to enforce safer industry practices and prevent further water quality deterioration in low-income countries.

Keywords: Breastfeeding; Chemical toxicity; Child health; Maternal; Neurological development; Pregnancy.