Chronic exposure to low levels of lead, cadmium and arsenic through commonly used household items, air, water, soil and food is associated with an increased risk of cardiovascular disease, according to a new American Heart Association scientific statement published today in the Journal of the American Heart Association, an open access, peer-reviewed journal of the American Heart Association.
This scientific statement reviews evidence linking chronic exposure to low or moderate levels of three contaminant metals — lead, cadmium and arsenic — to cardiovascular diseases including coronary artery disease, stroke and peripheral artery disease.
It highlights clinical and public health implications. Traditional risk factors for cardiovascular disease do not currently include environmental toxicants. The field of environmental cardiology identifies exposure to pollutants including contaminant metals as modifiable risks for cardiovascular disease.
Exposure to contaminant metals most often occurs involuntarily, through activities of daily living. Lead may be found in a variety of items such as paint in old homes (lead paint was banned in the U.S. in 1978), tobacco products, second-hand smoke, contaminated foods (ground water and some pottery, ceramics and kitchenware are sources of lead contamination in food), water pipes, spices, cosmetics, electronics and industrial emissions. Cigarette smoking is a source of both lead and cadmium.
Cadmium is found in nickel-cadmium batteries, pigments, plastic, ceramics and glassware, and construction products. Industrially produced fertilizers use phosphate rock that is naturally rich in cadmium, which then contaminates root vegetables and leafy green plants (including tobacco).
Arsenic exposure is primarily through groundwater, which affects drinking water, soil and food grown in contaminated soil. Notably, arsenic builds up in rice more than other food crops.
Monitoring environmental metal levels and testing for metal in individuals are key steps to implement appropriate public health initiatives, the writing group suggests. Lead levels in children with symptoms of exposure are monitored by health professionals using blood tests. However, there are no monitoring guidelines or exposure limits established for contaminant metals in adults other than those required for specific types of work. Future research is needed to establish if such testing may be an effective strategy to identify and protect people at risk of cardiovascular disease.
The statement authors note that decreasing metal exposure in tobacco, protecting community water systems and wells, and minimizing metal contamination in air, food and soil are all examples of public health measures that may reduce exposure to metals.
While there is currently no standard medical therapy to counteract the vascular impact of contaminant metals, there is research in progress to address the potential for treating individuals for exposure. Some research is assessing the effect of chelating agents, which are medications that can remove contaminant metals, especially lead and cadmium, from the body. The chelating agent binds to metals so they can be excreted.
In addition, the statement suggests research is needed to investigate nutritional supplements that may reduce the effects of contaminant metals and accelerate excretion. Supplements that have shown potential based on small trials include folate and N-acetyl cysteine.
Gervasio A. Lamas, Aruni Bhatnagar, Miranda R. Jones, Koren K. Mann, Khurram Nasir, Maria Tellez‐Plaza, Francisco Ujueta, Ana Navas‐Acien. Contaminant Metals as Cardiovascular Risk Factors: A Scientific Statement From the American Heart Association. Journal of the American Heart Association, 2023; DOI: 10.1161/JAHA.123.029852
American Heart Association. (2023, June 12). Chronic exposure to lead, cadmium and arsenic increases risk of cardiovascular disease. ScienceDaily. Retrieved June 13, 2023 from www.sciencedaily.com/releases/2023/06/230612114722.htm
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