Interventions to reduce cadmium exposure in low- and middle-income countries during pregnancy and childhood: A systematic review.

Background: Exposure to the toxic metal cadmium is widespread globally and especially prevalent in low- and middle-income countries (LMICs). Early life (from pregnancy through childhood) is a vulnerable window for exposure. Therefore, interventions in low- and middle-income countries to prevent or reduce early life exposure to cadmium may be relevant for improving public health.

Methods: We systematically reviewed five databases (Scopus, Web of Science, Global Health Medicus, Greenfile, and PubMed). A synthesis without meta-analysis (narrative synthesis) was used for data analysis due to the wide heterogeneity of included studies. Study quality and risk of bias were assessed using modified GRADE criteria.

Results: 4098 articles were returned by the search and a total of 26 studies from 21 LMICs were included in this review, ranging from policies to clinical treatment, rehabilitation and clean-up methods for agricultural soil, interventions for nutrition and cooking, and anti-pollution strategies at the household level. The interventions targeted children, pregnant and postpartum women, and/or women of childbearing age. While several studies provided some evidence of effectiveness, none appeared to offer a realistic solution for cadmium pollution at scale. Agricultural and food preparation studies were relatively frequent, particularly related to rice. Studies on air filtration during pregnancy indicated some effectiveness in reducing indoor cadmium exposures.

Conclusions: Cadmium pollution is a persistent and widespread threat to children's health with few identified solutions. Long-lasting damage to children's health starting in the earliest years should motivate investment in higher-quality interventions, innovations, and further research.

Registration: PROSPERO (CRD42021235435).