Drinking water that is contaminated with arsenic, even at low levels, can increase the risk of heart damage among younger individuals, according to the findings of a new study.
Researchers from Spain and the U.S. report that consuming low levels of arsenic appears to increase the likelihood a person’s heart grows disproportionately and affects how the heart functions. The findings were published May 1, in the journal Circulation: Cardiovascular Imaging.
The study involved 1,337 young adult participants without diabetes or cardiovascular disease who were recruited from the Strong Heart Family Study. This included participants who were North American Indians living in Oklahoma, Arizona, North and South Dakota who rely mostly on well water.
Researchers measured inorganic and methylated arsenic concentrations in participant’s urine. They then measured the size and functioning of the left ventricle of the heart. The left ventricle is the part of the heart that conducts the main pumping of blood through the body.
Increased arsenic exposure was associated with an enlarged left ventricle. Subjects who consumed low-to-moderate levels of arsenic developed heart damage after only five years of exposure, and when urinary arsenic levels doubled, the likelihood of damage to the left ventricle increased by 47%.
Even low-level exposure of arsenic was associated with disproportionate growth of the heart without other risk factors being present. In fact, the higher the arsenic content in the urine the greater the damage to the heart a person experienced, indicating a dose-specific response, which is often considered a strong sign of causation.
Participants who had risk factors present, like pre-hypertension or high blood pressure, had a 58% greater risk of experiencing thickening or damage to the heart walls.
When the heart walls thicken in the left ventricle, it causes the heart to work harder to pump blood through the body. This can lead to sudden cardiac arrest, stroke, and heart failure.
Inorganic arsenic is naturally occurring in the Earth. It is also commonly found in groundwater. However, it is harmful to humans and has been linked to cancer, kidney damage, hypertension, cardiovascular disease and diabetes.
People who use private wells can be exposed to untreated groundwater which contains arsenic, especially since private wells are not currently regulated for arsenic.
U.S. Environmental Protection Agency standards call for arsenic levels at less than 10 micrograms per liter in regular water sources. However, some research indicates concentrations much lower can cause human health issues.
Arsenic is one of the most abundant environmental contaminants in the world, affecting more than 200 million people worldwide in more than 70 countries. In the U.S., 44 million people use private wells, with roughly 2 million of those people drinking from wells that have high concentrations of arsenic.