Colorless, odorless, and tasteless metals in drinking water across the United States are associated with an increased risk of heart disease, a large new study has found.
Researchers at Columbia University examined the health records of 100,000 Californians over a 23-year period and compared them with estimated exposure to arsenic in drinking water.
Researchers found that people exposed to high levels of toxic metals for more than 10 years were 42 percent more likely to develop heart disease, even after controlling for factors such as high blood pressure, smoking status, and exercise habits. did.
Drinking water that contains less than the EPA limit of 10 parts per billion can increase your risk of heart disease by 5 to 20 percent over time.
Study author Dr. Tiffany Sanchez, an environmental and molecular epidemiologist, said this suggests that current policies regarding the amount of arsenic allowed in drinking water may need to be reconsidered. Ta.
“Our results are novel and encourage new discussions about current policy and regulatory standards,” Dr. Sanchez said.
This map from the U.S. Geological Survey estimates areas in the country with high concentrations of naturally occurring arsenic in private drinking wells.
“This study is one of the first to comprehensively describe the risks at exposure levels below current regulatory limits,” Dr. Sanchez said.
It is unclear how arsenic causes heart disease, but old research on animals It has been shown that it can cause inflammation that affects the shape of blood vessels branching from the heart.
Changes in the shape of these blood vessels can affect blood flow and damage organs over time.
Arsenic is a naturally occurring heavy metal found in the Earth’s crust and can enter the air, water, and soil.
It is most concentrated in groundwater in New England, the upper Midwest, and parts of the West. California is one of those states.
According to , the most common way people are exposed to metals is through drinking water. National Institute of Environmental Health Sciences.
People who use private drinking wells and do not regularly test for arsenic are at a much higher risk than those who get their water from a community tap.
The Environmental Protection Agency estimates that these utilities provide drinking water to 90 percent of Americans.
Exposure to large amounts over long periods of time to this tasteless, colorless, and odorless substance can damage the cardiovascular, immune, and endocrine systems. It can also accumulate in the liver, kidneys, prostate, and bladder.
Still, researchers aren’t sure how much long-term arsenic exposure can cause heart disease.
New research published in journals Environmental hygiene perspective Researchers at Columbia University’s Mailman School of Public Health aimed to narrow down that measurement.
This included an analysis of 98,250 participants in the California Teacher Study, which collected data from more than 100,000 teachers, nurses and other school staff from 1995 to 2018.
It tracked their lifestyle habits, location, and health outcomes over time.
The Colombian researchers excluded people over the age of 85 and people with previous heart disease. They then compared the health data from teachers to a map showing the amount of arsenic in drinking water across California.
They looked at both ischemic heart disease and cardiovascular disease.
Ischemic heart disease, also known as coronary artery disease, is associated with reduced blood flow to the heart due to plaque buildup and blood clots. According to the NIH, this is the leading cause of heart attacks.
Cardiovascular disease is an umbrella term that includes stroke, heart disease, heart failure, and peripheral artery disease.
After examining 6,119 cases of ischemic heart disease and 9,936 cases of cardiovascular disease, a pattern emerged linking arsenic exposure and coronary artery disease. There was no evidence of an association with cardiovascular disease such as stroke.
The study found that arsenic in water was specifically associated with coronary artery disease, but not with other cardiovascular diseases such as stroke. CAD is the main cause of heart attacks
The current EPA limit for the allowable amount of arsenic in drinking water is parts per billion (ppb) of water.
About 48 percent of the participants were exposed to less than 1 ppb of arsenic, and the researchers found no increased risk of developing heart disease. However, people were exposed to radiation ranging from 1 part per billion to 1 part per billion.
Exposure to 1 to 5 ppb of the environment increases the chance of developing ischemic heart disease by 5 to 6 percent.
Exposure to 5 to 10 ppb of arsenic increases the risk of developing ischemic heart disease by 20%.
Finally, exposure to levels above the EPA limit increases the likelihood of developing ischemic heart disease by 42%.
In addition to the amount of arsenic, the researchers investigated whether the amount of time a person was exposed to the arsenic water also mattered. They found that the longer someone was exposed, the higher the risk.
After 10 years of exposure, the risk was about 18 to 20 percent higher than for people exposed to arsenic in drinking water for short periods of time.
Although unique in their scope, these findings are not the first to link arsenic exposure to heart disease.
Ischemic heart disease, also known as coronary heart disease or coronary artery disease, occurs when blood flow to the heart is reduced due to blockages in blood vessels. This can be caused by plaque buildup, blood clots, or narrowing of blood vessels
2018 survey A study of Native Americans across the United States found that people with high levels of arsenic in their urine were 1.5 times more likely to have high blood pressure and thickened heart muscle.
Both of these factors are signs that the heart is under stress and can lead to heart disease and irregular heart rhythms.
Still, Dr. Sanchez said more research is needed before doctors can conclude that arsenic causes heart disease, and doctors are unsure how the increased risk seen in the study is caused by the metal. He said he was not sure.
Narrowing of blood vessels and plaque buildup is usually caused by poor dietary choices, which results in the accumulation of cholesterol and fat in the bloodstream, clogging the tubes of the cardiovascular system.
It is unclear how arsenic contributes to this.
Dr. Sánchez therefore concluded that their findings are a starting point for further research: “The data and methods developed in this study can be used to enhance and inform future research. We believe it can be extended to assess other drinking water exposures and health effects.” ”
