More than one million Americans have been killed by falling water or other causes related to metal-pond pollution in recent years, according to data compiled by the Environmental Protection Agency and the U.S. Centers for Disease Control and Prevention.
More than half of those fatalities occurred in California, which has one of the nation’s highest rates of drinking water contamination.
“The problem with metal pools is that they don’t require proper environmental monitoring and they don`t make sense,” said Paul M. Keesing, a professor of environmental health at the University of California, San Diego, who has studied the impacts of pollution on the environment.
“You can’t have a large pool and expect that water to stay clean.”
Maintaining clean drinking water is especially important for many Americans who live in areas with a high number of metal-water pollution complaints.
A 2011 study published in the journal Environmental Health Perspectives found that water quality in many parts of the country is worse than it was in the 1970s, and many areas are now at greater risk of contaminating drinking water.
The EPA issued its annual report on water pollution in December, and its latest report on the state of drinking-water quality in 2017 showed that water pollution is the leading cause of death in the United States.
The report said California has the nation�s worst rate of metal contamination, and the state has among the highest levels of drinking and wastewater contamination in the country.
More recently, the EPA has linked metal-pools to more than a dozen deaths.
The agency has also noted that in recent decades, more than 80 percent of metal drinking water wells in California have been closed because of contamination.
The pollution problem has been exacerbated by changes in water-quality regulations.
California adopted stricter rules for groundwater, and now allows metal water to be pumped into surface-level pools at night, a feature that has made some pools unlivable to the public.
A 2015 report from the California Environmental Protection agency found that the amount of contaminants in drinking water in California dropped from about 10,000 parts per billion in 1975 to about 3,000 ppm in 2015.
The decline coincided with the passage of the state�s Water Quality Standards Act, which required more stringent standards for water quality.
The changes have led to more people coming to rely on underground pools, which can often be full of contaminants.
In the past two years, the number of complaints against a California metal-aquarium has quadrupled, according the EPA.
The number of residents filing such complaints in 2017 was up by nearly 40 percent from 2014.
The EPA said the rise is partly due to people visiting the state for the first time, as well as the availability of underground pools that are not as crowded.
But many of the complaints filed by residents are still not serious enough to be reported to the EPA, the agency said.
A spokeswoman for the agency, Andrea Ritter, said the agency has not determined whether the increase is related to the new rules.
In most cases, residents do not complain because they are afraid of being sued by the owners of the pool, said Robert S. Stryker, a lawyer who specializes in pollution cases at the Environmental Law and Policy Center in New York City.
The pool is not owned by the company that is responsible for it, he said.
But the pool has also been accused of being dangerous to animals.
In recent years in California and around the country, people have complained that water from the pool causes skin infections in their pets.
In many cases, those cases have been traced to the pool’s treatment of the water.
One California resident filed a complaint against the city of Sacramento, saying that the city should remove the metal pool and install an air-purification system.
A Sacramento spokesman said he could not comment on pending litigation.
The water in some underground pools can have toxic levels of metals.
In some of the most polluted areas of the world, water has been found to contain concentrations of heavy metals that are 10, 20, or 30 times higher than those in the general water supply, according a review by the International Center for Non-Proliferation Studies, a U.N.-affiliated group that monitors and monitors nuclear-weapons-related activities.
A 2013 study by the Center for Health and Environmental Impact in New Zealand found that more than 90 percent of the underground water in a major city was contaminated with heavy metals.
The U.K. Environmental Protection Authority said the country�s underground water was contaminated at levels 10 times higher in 2015 than in 1998.
The average concentration of heavy metal in underground water worldwide was 3.5 parts per trillion, according in the report.
More than 2.5 million people die from water-related illnesses each year, according an Associated Press analysis of the World Health Organization�s annual report.
Many of those deaths are caused by the buildup of toxins in the bodies of people who drink water contaminated by metal pools.
The U.F.O. has also warned