Association of environmental metallic and metalloid contaminants with cardiovascular and all-cause mortality: an umbrella review of systematic reviews and meta-analyses

Abstract Aims The aim was to examine the relationship between exposure to environmental metallic and metalloid pollutants and cardiovascular disease (CVD) and all-cause mortality by integrating the information currently available from systematic reviews and meta-analyses. Methods and results PubMed, Embase, and Web of Science for systematic reviews and meta-analyses were thoroughly searched up to 9 October 2024. Systematic reviews and meta-analyses of various kinds that evaluated the relationship between exposure to ambient metallic and metalloid pollutants and CVD and all-cause mortality were included. The methodological quality and the evidence quality were assessed using AMSTAR2 and GRADE, respectively. We identified 25 meta-analyses and 81 health outcomes—76 unique outcomes from observational studies and 5 unique outcomes from RCTs—from 8841 independent publications. Exposure to non-essential metallic and metalloid pollutants, including arsenic, lead, and cadmium as well as essential metallic and metalloid contaminants like copper, has been associated with an elevated risk of CVD events and CVD mortality, according to moderate-quality evidence. According to low-quality evidence, exposure to arsenic, lead, and cadmium increases the risk of CHD, while exposure to lead, cadmium, and copper is strongly associated with an increased risk of stroke and all-cause mortality. Further, zinc and selenium may be protective factors for CVD and all-cause mortality. Conclusion Despite variations in evidence gradients, environmental metallic and metalloid contaminants like arsenic, lead, cadmium, mercury, and copper are linked to CVD events and mortality, whereas zinc and selenium may offer protection. Lay summary Non-essential environmental metallic and metalloid contaminant exposure is associated with a higher risk of CVDs and all-cause mortality, whereas essential metallic and metalloid may confer a protective benefit.Non-essential metallic and metalloid contaminants, such as arsenic, lead, and cadmium, raise the possibility of CVD events, CHD, and all-cause mortality, with lead and cadmium associated with higher risk of stroke.Essential metallic and metalloid contaminants like zinc and selenium can protect against CVD events and CHD, but too much selenium or copper may be harmful.