Highlights of the statement:
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DALLAS, June 12, 2023
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 scientific statement from the American Heart Association published today in the Journal of the American Heart Association , an open access, peer-reviewed professional journal of the American Heart Association.
This scientific statement reviews evidence linking chronic exposure to low or moderate levels of three metal contaminants (lead, cadmium, and arsenic) with cardiovascular disease, including coronary artery disease , stroke, and peripheral artery disease . Highlights clinical and public health consequences. Currently, traditional risk factors for cardiovascular disease do not include environmental toxicants. The field of environmental cardiology identifies exposure to contaminants, including metals, as modifiable cardiovascular disease risks.
“Large-scale population studies indicate that even low-level exposure to metal contaminants is nearly universal and contributes to the burden of cardiovascular disease, especially heart attacks, strokes, leg artery disease, and premature death from chronic causes. cardiac diseases,” said Gervasio. A. Lamas, MD, FAHA, director of the statement writing group and Director of Medicine and Chief of the Division of Cardiology at Columbia University at Sinai Medical Center in Miami Beach, Florida.
“These metals interfere with essential biological functions and affect the majority of populations on a global scale,” said the Vice Chair of the statement writing group, Ana Navas-Acien, M.D., Ph.D., Professor of Life Sciences. Environmental Health at the Mailman School of Public Health at Columbia University and Director of the Northern Plains Superfund Research Program at Columbia University in New York City. “After exposure, lead and cadmium accumulate in the body and remain in bones and organs for decades. In the US alone, one major study suggested that more than 450,000 deaths annually could be attributed to lead exposure.”
Where are people exposed to metal contaminants?
Most often, exposure to metal contaminants occurs involuntarily, during activities of daily living.
Lead can be found in a variety of items, such as paint in older homes (lead-based paint was banned in the U.S. in 1978), tobacco products, secondhand smoke, contaminated food ( water underground and some pottery, ceramics, and kitchen utensils are sources of lead contamination in food), water pipes, spices, cosmetics, electronic devices, and industrial emissions. Smoking is a source of both lead and cadmium.
Cadmium is found in nickel-cadmium batteries, pigments, plastic, ceramics and glassware , and construction products. Fertilizers produced on an industrial scale use phosphate rock that is naturally high in cadmium, which subsequently contaminates tubers and green leafy plants (including tobacco).
Exposure to arsenic occurs primarily through groundwater, affecting drinking water, soil, and food grown on contaminated land. In particular, arsenic accumulates in rice to a greater extent than in other food crops.
While exposure and risk occur in diverse populations, regardless of socioeconomic status, some people experience increased exposure to toxic metals, according to the statement. The risk of exposure is higher for those people who live in areas closer to main roads, industrial sources and hazardous waste landfills; They reside in older houses; or in areas where environmental regulations are poorly enforced and responses to community complaints are inadequate.
“This is a global problem in which lower-income communities are disproportionately exposed to toxic metals through contaminated air, water and soil,” Navas-Acien stated. “Addressing metal exposure in these populations may provide a strategy to reduce disparities in cardiovascular disease and promote environmental justice.”
What are the cardiovascular risks of contaminating metals?
The scientific statement describes global epidemiological research confirming that lead, cadmium and arsenic are associated with premature death, due in large part to the increased risk of cardiovascular disease. The overall investigation includes the following:
- A 2021 American Heart Association scientific statement recognized exposure to toxic metals as an unconventional risk factor for peripheral artery disease.
- A 2018 review published in the professional journal British Medical Journal evaluated 37 studies representing nearly 350,000 people from more than a dozen countries. The review reported that higher levels of arsenic in urine and levels of lead and cadmium in blood were associated with a 15% to 85% higher risk of stroke and heart disease.
- A study in China found that higher blood lead levels were associated with plaque in the carotid arteries in people with type 2 diabetes. Another study found that cadmium and arsenic were associated with a higher rate of heart disease and ischemic stroke.
- In Spain, a study carried out among the general population determined that cadmium in urine was associated with higher rates of newly diagnosed cardiovascular diseases.
What can be done with metals present in the environment?
Monitoring metal levels in the environment and testing people for metals are key steps in implementing appropriate public health initiatives, the writing group suggests. Lead levels in children with symptoms of exposure are monitored by health professionals through blood tests. However, there are no monitoring guidelines or established exposure limits for metal contaminants in adults other than those required for specific types of work. Future research is needed to establish whether these tests could be an effective strategy to identify and protect people at risk of cardiovascular disease.
The authors of the statement point to reducing exposure to metals in tobacco, protecting community water systems and wells, and minimizing metal contamination in air, food, and soil as examples of public health measures that can reduce exposure to metals.
“Cardiovascular health can be improved with a diversified approach that recognizes environmental cardiology and includes environmental and biological monitoring of contaminating metals; control of sources of exposure; and the development of clinical interventions that eliminate metals or weaken their effects in the body,” said Lamas, who is also Professor of Medicine at Irving Medical Center at Columbia University in New York City.
While there is currently no standard medical therapy to counteract the vascular effect of contaminating metals, there is ongoing research to address the potential for treating people if exposed. Some research evaluates the effect of chelating agents , which are medications that can remove contaminating metals, especially lead and cadmium, from the body. The chelating agent binds to the metals so they can be excreted. Additionally, the statement suggests that research is needed to analyze nutritional supplements that could reduce the effects of contaminating metals and accelerate excretion. Supplements that have shown potential, based on small-scale trials, include folate and N-acetylcysteine .
This scientific statement was prepared by the volunteer writing group on behalf of the Council on Epidemiology and Prevention; the Cardiovascular and Stroke Nursing Council; the Cardiometabolic Health and Lifestyle Council; the Peripheral Vascular Disease Council; and the Kidney Council on Cardiovascular Diseases of the American Heart Association. The American Heart Association’s scientific statements promote greater awareness of cardiovascular disease and stroke and help facilitate making informed health care decisions. Scientific statements describe what is currently known about a topic and what areas need more research. While scientific statements inform guideline development, they do not make treatment recommendations. The American Heart Association guidelines provide the Association’s official clinical practice recommendations.
Additional members of the statement Drafting committee are Aruni Bhatnagar, Ph.D., FAHA; Miranda R. Jones, M.H.S., Ph.D.; Koren K. Mann, Ph.D.; Khurram Nasir, MD, MPH, FAHA; Maria Tellez-Plaza, MD, Ph.D. and Francisco Ujueta, MD, MS Public data for the authors can be found in the article.
