NEW YORK, New York, December 17, 2020 (ENS) – Community water systems that fail to comply with the federal arsenic standard are most likely to occur in the Southwest, serving Hispanic communities, rural populations of around 1,000, and those who rely on groundwater, finds a new study from the Columbia University Mailman School of Public Health.
Arsenic is a toxic human carcinogen and water contaminant present in many aquifers in the United States. The Mailman School researchers found that 38 percent of water systems serving Hispanic communities exceeded the safe maximum arsenic contaminant level, posing concerns about environmental justice.
“Systematic studies of inequalities in public drinking water exposures have been lacking until now. These findings identify communities in immediate need of additional protective public health measures,” said co-author Dr. Anne Nigra, a postdoctoral research fellow focusing on environmental health sciences.
The Mailman School analysis was based on data from public water systems obtained from two of the largest U.S. Environmental Protection Agency, EPA, databases.
Data for this study were collected from 46 states as well as Washington, DC and Native American Tribes. The data represents 95 percent of all public water systems and 92 percent of the entire population served by public water systems across the country.
The researchers studied some 13 million records from 2006-2011; they included 139,000 water systems that serve 290 million people every year.
Arsenic occurs naturally in soil and minerals and may enter the air, water, and land from wind-blown dust and may get into drinking water from runoff and leaching, according to the U.S. Agency for Toxic Substances.
Ingesting very high levels of arsenic can result in death, the agency says. Exposure to lower levels can cause nausea and vomiting, decreased production of red and white blood cells, abnormal heart rhythm, damage to blood vessels, and a sensation of pins and needles in hands and feet.
Breathing high levels of inorganic arsenic can give people a sore throat or irritated lungs.
The U. S. Department of Health and Human Services and the Environmental Protection Agency have determined that inorganic arsenic is a known human carcinogen. The International Agency for Research on Cancer has determined that inorganic arsenic is carcinogenic to humans.
Several other studies have shown that ingestion of inorganic arsenic can increase the risk of skin cancer and cancer in the liver, bladder, and lungs. Inhalation of inorganic arsenic can cause an increased risk of lung cancer.
Earlier research from the same Columbia research team showed that slashing the maximum contaminant level for arsenic from 50 to 10 micrograms per liter prevented up to 900 cancer cases per year.
For the latest study, the Mailman School researchers started by comparing the water system arsenic concentrations from 2006-2008 and then compared them with arsenic concentrations from 2009-2011.
Then they estimated an average arsenic concentration over three years for 36,406 local water supplies and throughout 2,740 countries.
Between 2006 and 2011, the researchers found that arsenic concentrations in the average community water system declined by 10 percent nationwide, by 11.4 percent for the Southwest, and by 37 percent for New England.
“Our findings will help address environmental justice concerns and inform public health interventions and regulatory action needed to eliminate exposure inequalities,” Dr. Nigra said.
“We urge continued state and federal funding for infrastructure and technical assistance support for small public water systems in order to reduce inequalities and further protect numerous communities in the U.S. affected by elevated drinking water arsenic exposure.”
— By Georgia Seidman