Is Exposure To Environmental Toxins A Risk Factor For Heart Disease?

The American Heart Association says YES. Plus, Heavy Metals Found In These Store-Bought Drinks.

Photo by Cathal Mac an Bheatha on Unsplash

The science is clear. Chronic exposure to low levels of lead, cadmium, and arsenic in our air, water, soil, and food is associated with an increased risk of cardiovascular disease, according to a new American Heart Association statement made on Monday.

These metals have no function in the human body. Yet, they are found in groundwater, water pipes, paint, fertilizer, plastics, electronics, gasoline, pesticides, batteries, foods and other commonly used household items.

“Large population studies indicate that even low-level exposure to contaminant metals is near-universal and contributes to the burden of cardiovascular disease, especially heart attacks, stroke, disease of the arteries to the legs and premature death from cardiac causes,” said Gervasio A. Lamas, M.D., FAHA, chair of the statement writing group and chairman of medicine and chief of the Columbia University Division of Cardiology at Mount Sinai Medical Center in Miami Beach, Florida.

This new statement is a big deal when you consider that cardiovascular disease (CVD) is the No. 1 cause of death in the world, leading to at least 18 million lives lost each year.

Here’s some background from the study:

Decades of study have identified modifiable risk factors for atherosclerosis, including tobacco smoke, dyslipidemia, hypertension, diabetes, obesity, and a sedentary lifestyle. However, the known risk factors do not present a complete risk profile.

A group of experts on environmental health, metals, toxicology, epidemiology, atherosclerosis, cardiology, clinical trials, and public health reviewed the evidence linking chronic exposure to low and low‐moderate levels of lead, cadmium, and arsenic to coronary and peripheral artery atherosclerosis, including stroke. They excluded the acute consequences of high‐level exposures, such as industrial, accidental, or suicidal, which affect a few thousand individuals annually in the United States.

I’m struck by the idea that exposure to low or moderate levels of these toxic metals can increase your risk of heart disease.

Are you kidding me?! And of course, it’s not really making headlines.

For a deep dive into this topic, look up environmental cardiology. For years, scientists and researchers have suspected that pollution might contribute to heart disease, and now we are getting a much clearer picture.

“These metals interfere with essential biological functions and affect most populations on a global scale,” said vice chair of the statement writing group Ana Navas-Acien, M.D., Ph.D., a professor of environmental health sciences at Columbia University’s Mailman School of Public Health and the director of the Columbia University Northern Plains Superfund Research Program in New York City. “After exposure, lead, and cadmium accumulate in the body and remain in bones and organs for decades. In the U.S. alone, one large study suggested that more than 450,000 deaths annually could be attributed to lead exposure.”

Let’s take a closer look at each of these metals, where they come from, and how they are regulated.

Lead

Do you know the MCL for lead is in U.S. drinking water?

[MCL = Maximum Contaminant Level or the highest level of a contaminant that is allowed in drinking water. MCLs are enforceable standards set by the U.S. EPA]

You know lead—a nervous-system toxin that according to our own regulatory agency (the EPA) has no safe level of exposure. Lead in drinking water can cause everything from stomach pains to permanent brain damage.

About 10 million American households connect to water through lead pipes and service lines, risking exposure to this hazardous heavy metal every day.

It’s a trick question. We don’t have an MCL, and that’s a big problem. We have a TT—a “treatment technique” regulation better known as the Lead and Copper Rule, or as of 2021, the Lead and Copper Rule Revisions. It’s meant to monitor levels but ultimately relies on meticulous reporting.

The treatment technique for the rule requires systems to monitor drinking water at customer taps. If lead concentrations exceed an action level in more than 10 percent of customer taps sampled, the system must undertake a number of additional actions to control corrosion.

Unlike an MCL, an action level is not an enforceable standard, but is instead a screening tool for determining whether treatment technique actions are required. Failure to implement the required actions is enforceable.

To fill gaps in federal legislation some states have implemented stricter rules for lead, particularly in schools, where water fountains provide a a significant amount of children’s daily water intake.

In 2016, New York became the first state in the country to pass legislation that required all of its school districts to test their water systems for lead and develop remediation plans when necessary. New York schools are now required to report their lead test results to the state.

Since then, California, Illinois, Indiana, Maine, Maryland, Minnesota, Montana, New Hampshire, New Jersey, North Carolina, Oregon, Rhode Island, Tennessee, Vermont, Virginia, and Washington have launched voluntary testing programs at schools. For more info check out this 2021 report from the National Association of State Boards of Education.

Even low levels of lead in children’s blood can create permanent damage, including decreased IQ and hyperactivity. While pediatricians monitor blood lead levels in children in many states, we have no equivalent monitoring established for lead (or any other metal) in adult patients.

Our water treatment systems are antiquated and regularly in violation of the laws we’ve established, containing highly concentrated levels of arsenic, lead, bacteria, and more.

In many recent water crises, contamination occurred when lead leached into the drinking water as it traveled through the distribution pipes.

Plus, we have the problem that many water treatment systems now use chloramine to treat the water—a combination of chlorine and ammonia.

Research has shown that chloramine causes deterioration of the municipal infrastructure thanks to changes in the water chemistry. In water systems that still use lead pipes or lead components, this reaction causes the lead and other heavy metals to leach into drinking water and out of faucets and shower heads.

Instead of spending the money to fix old pipes and update our systems, money-crunched municipalities are adding chemicals like ammonia to drinking water as a quick fix, which only causes more issues.

Cadmium

Cadmium can be found in batteries, pigments, plastic, ceramics and glassware, and construction products. Industrially produced fertilizers use phosphate rock that naturally contains cadmium.

While low levels of cadmium can appear in groundwater, it’s not often found in drinking water. Still, the EPA does maintain an MCL of 5 parts per billion (ppb), and the agency states that the potential health effects from long-term exposure above that MCL are kidney damage.

One new study found it in some common store-bought drinks. Yuck!

Tulane University researchers tested 60 popular beverages for toxic metals and found that five drinks contained amounts above federal drinking water standards.

The study, published in the Journal of Food Composition and Analysis, found them in a cranberry juice brand, a mixed carrot and fruit juice, and an oat milk purchased from supermarkets/retail stores.

“Chronic exposures to cadmium, arsenic, and lead are carcinogenic, and have neurological effects,” study author Tewodros Godebo said. “The health effects of cadmium are mainly on renal and bone damage including reduced bone strength.”

I’ve been saying it for years. The more we test, the more we find. I think these results help us understand the prevalence of these metals in our world.

Arsenic

Arsenic was one of the first chemicals recognized to cause cancer, as early as 1879.

About 90 percent of the arsenic used by U.S. industry is for wood preservative purposes, but it can also be found in paints, drugs, dyes, soaps, metals and semi-conductors. Agricultural applications, mining, and smelting also contribute to arsenic releases.

Arsenic can be released into groundwater as a result of human activities, such as mining, and from its various uses in industry, in animal feed, as a wood preservative, and as a pesticide, according to the USGS.

In drinking-water supplies, arsenic poses a problem because it is toxic at low levels.

Thankfully, it does have an MCL. In 2001, the EPA adopted a lower standard for arsenic in drinking water that applies to both community water systems and non-transient non-community water systems. The arsenic standard is 10 ppb, which replaced the old standard of 50 ppb.

Exposure to arsenic has been linked to a number of cancers including cancer of the bladder, lungs, skin, kidney, nasal passages, liver, and prostate.

What Can We Do About Toxic Metals In The Environment?

Monitoring environmental metal levels and testing for metal in individuals are key steps to implement appropriate public health initiatives, the writing group suggests.

As mentioned, lead levels in children are monitored by health professionals using blood tests and future research is needed to establish if testing may be an effective strategy for adults to help identify and protect people at risk of cardiovascular disease.

Obviously, continuing to strengthen our drinking water regulations and enforcing them is another huge step that will benefit everyone.

You can also request a Consumer Confidence Report from the EPA that will detail what’s in the water when it leaves your local treatment plant, although the report does not account for what the water might encounter as it travels through the distribution pipe network. For independent water testing, we recommend My Tap Score. Those interested in testing a private well can get more info here.

And remember if your area has an issue with lead or another contaminant, a water filter is a small bandage on a wound that needs surgery—the larger problem with the pipes or water supply still must be addressed. Just ask the people of Flint!

I am hopeful that doctors and scientists will continue to understand the impact of heavy metals on our body and continue to research the impacts, screening techniques, and how to better treat patients with exposure.

“Cardiovascular health may be improved with a multi-pronged approach that recognizes environmental cardiology and includes environmental monitoring and bio-monitoring of contaminant metals; controlling for sources of exposure; and developing clinical interventions that remove metals or weaken their effects on the body,” Lamas said in a statement.

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Keep the conversation going in the comments below! What did you learn about heavy metals?