Contaminated drinking-water is a major health hazard in developing countries where infectious diseases caused by pathogens and parasites make up the most common and widespread health risk.
The effects of diseases from pathogenic bacteria are immediate and debilitating, even affecting the taste and appearance of drinking-water (2).
Despite these obvious ill effects and inexpensive water-purification methods, adoption of safe drinking-water practices is not prevalent.
Naturally-occurring arsenic in groundwater of South and South-East Asia has also been jeopardizing the health of millions of people who have been drinking contaminated water for years.
In areas with natural geological contamination, such as Bangladesh, drinking-water from wells containing high levels of inorganic arsenic can cause serious health consequences, such as skin lesions, cancer, and death (4).
Unlike contamination of drinking-water by pathogens, arsenic does not affect the taste or appearance of drinking-water and, moreover, the health effects from ingesting arsenic-contaminated water appear very slowly.
For example, the average latency for appearance of skin lesions may be 23 years from the first exposure (5).
Use of arsenic-contaminated water may be predicated on lack of awareness of the dangers posed by such action.
With taste and appearance not being an issue and with health risks being an abstract notion, it is essential for public-health officials to increase public awareness of risks of arsenic to change the behaviour of people who use this water.
Previous studies attempting to explain and predict health-related behaviours have identified that perceived negative consequence of taking a health action is the most influential variable for predicting actions taken to avoid health risks.
Water sources free of arsenic may be few and far between, taking a practical toll on a person’s time available for work.
Such perceived negative consequences stemming from the lack of arsenic-free groundwater are complicated by the trade-off of health risks from consuming pathogen-contaminated surface water.
Loss of convenience may outweigh the long-term costs associated with obtaining safe drinking-water.
This ambivalence or reduced concern may be mitigated by individual household characteristics, such as the presence of children in the household—it is more likely for a child to contract diseases from arsenic exposure within their lifetime that it is for the contraction of such diseases within a parents’ lifetime (5).
By disseminating knowledge on health risks associated with arsenic exposure, a successful public-awareness campaign could change health behaviours. Accordingly, the demand for safe drinking-water may reflect mitigating factors, such as the presence of children in the household.
Drinking water that is contaminated with arsenic may lead to thickening of the heart’s main pumping chamber in young adults, a structural change that increases the risk for future heart problems, according to new research in Circulation: Cardiovascular Imaging, an American Heart Association journal.
“People drinking water from private wells, which are not regulated, need to be aware that arsenic may increase the risk for cardiovascular disease.
Testing those wells is a critical first step to take action and prevent exposure,” said Gernot Pichler, M.D., Ph.D., M.Sc., lead author of the study and medical specialist for Internal Medicine, Department of Cardiology at Hospital Hietzing/Heart Center Clinic Floridsdorf in Vienna, Austria, scientific collaborator at INCLIVA Health Research Institute in Valencia, Spain, and a visitor scholar in the Department of Environmental Health Sciences at Columbia University in New York City.
People are most frequently exposed to arsenic, a toxic metalloid, through drinking water in areas where groundwater is contaminated, including many American Indian tribal communities and other rural and suburban communities in the United States.
Previously, several studies have shown that arsenic exposure raises the risk of heart disease and its risk factors, including high blood pressure and diabetes.
This is the first study to review the question in young American Indians in Oklahoma, Arizona and North and South Dakota.
Here, researchers reviewed data from the Strong Heart Family Study, a study evaluating cardiovascular risk factors among American Indians.
Arsenic exposure was measured in urine samples from 1,337 adults (average age 30.7 years, 61% female) and the size, shape and function of their hearts were assessed using ultrasound (echocardiography).
None of the participants had diabetes or heart disease at the start of the five-year study.
Overall, arsenic exposure was higher than in the general United States population, but lower than that found in other studies conducted in Mexico and Bangladesh. With a two-fold increase in arsenic in the urine, the researchers found:
- 47% greater chance of thickening of the heart’s main pumping chamber (left ventricle) in the group as a whole; and
- 58% greater chance of thickening of the left ventricle in participants with increased or high blood pressure (blood pressure at least 120/80 mm Hg or using pressure-lowering medication)
“The stronger association in subjects with elevated blood pressure suggests that individuals with pre-clinical heart disease might be more prone to the toxic effects of arsenic on the heart,” Pichler said.
The study is limited by having only one measure of arsenic exposure, and by the lack of long-term follow-up of the participants.
Although this study was performed in tribal populations in the north, central and southwestern United States, the results are likely to be generalizable to millions of people in other rural locations exposed to low or moderate levels of arsenic in their water, according to Pichler.
“The study raises the question of whether the changes in heart structure are reversible if exposure is reduced.
Some changes have occurred in water sources in the study communities, and it will be important to check the potential health impact of reducing arsenic exposure,” Pichler said.
“Observational studies can stimulate future research on genetic, environmental and clinical factors to shed light on the relationship between arsenic and cardiovascular disease,” said editorial author, Rajiv Chowdhury, M.B.B.S., Ph.D., Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, University of Cambridge, United Kingdom “These studies are important since cardiovascular diseaseremains the single leading cause of adult premature death worldwide and millions of individuals globally are exposed to arsenic and other metal contaminants.”
More information:Circulation: Cardiovascular Imaging (2019). www.ahajournals.org/doi/10.116 … RCIMAGING.118.009018
Journal information: Circulation: Cardiovascular Imaging
Provided by American Heart Association