The tap water consumed by up to 40 million Americans may be increasing their risk of a fast-growing cancer, a study suggests.
Researchers at Texas A and M University compared kidney cancer rates in 240 Texas counties with arsenic levels in water from public and private water systems.
They found that people with high levels of the toxic mineral in their water had a 22 percent increased risk of cancer. Even low levels that the FDA considers safe were associated with a 6 percent increased risk.
Arsenic is a toxic substance found in rocks and enters groundwater when they erode. It can also be used in pesticides and then washed into groundwater by rain.
In the body, it can be absorbed into the blood and travel to cells, damaging their DNA and increasing the risk of cancer.
The results come as kidney cancer rates continue to rise in the United States.
In 2010, it was behind 54,000 cases in the United States each year. But in 2021, it was behind 68,000 cases and was the ninth most common cancer in the country.
Rates are rising about 1.2 percent each year, the data show, along with increases in other cancers, including breast and colon cancer in young people. This year was the first on record that the American Cancer Society said 2 million people would be diagnosed with the disease.
The map above, published in 2017, shows estimated arsenic levels in private well water across the US.
The map above shows arsenic levels in public drinking water by county in the US. It is dated between 2006 and 2011.
The increase came at the same time that smoking rates, which also increase the risk of kidney cancer, continued to decline.
Experts have previously suggested that the increase may be due to rising obesity rates or better imaging tests.
Other products also contain arsenic at low levels, such as apple juice, apples, pears and grapes, and even white wine, according to some studies.
Dr. Taehyun Roh, a Texas A and M epidemiologist who led the latest study, said: “Some public water systems are poorly managed and could expose customers to arsenic, but the 40 million people in the United States who depend on of private wells are particularly vulnerable. .’
Of the 40 million, estimates suggest that up to 2.7 million are using private wells that contain more than 10 ppb (parts per billion) of arsenic.
Wells in Nevada, Washington and California are most likely to contain the chemical.
Millions of people who use public water systems are also exposed to high levels of arsenic, and a previous Consumer Reports study found that eight percent of the samples it tested nationwide had arsenic levels above 10 ppb.
But the study found that even 5 ppb was linked to increased cancer risk.
The FDA says the safe limit for arsenic is levels no higher than 10 ppb.
The above shows kidney cancer cases per year in the US, according to the CDC.
And this shows the rate of kidney cancer cases per year in the United States, which explains the changes in population size. There is a drop in 2020 and 2021 during the Covid pandemic, when people avoided the hospital.
In the study, published in the journal Environmental pollutionResearchers analyzed data from 28,896 kidney cancer cases among people in their 20s recorded between 2016 and 2020 in Texas.
The data was adjusted for cancer risk factors, such as obesity, smoking and diabetes, and other variables such as pesticide density, income and heart disease rates.
The results also showed that every time the level of arsenic in the water doubled, the risk of cancer increased by four percent.
Dr Roh added: ‘This study suggests that even low levels of arsenic exposure in drinking water may be associated with an increased risk of kidney cancer.
“This is consistent with previous research indicating an association between this exposure and lung, bladder and skin cancer.”
The kidneys are responsible for filtering the blood for waste products and toxic substances, including arsenic.
Scientists say exposure to arsenic over long periods, such as through drinking water, can cause damage to build up in the kidneys and lead to cancer.
Early kidney cancer often does not cause any symptoms, but in more advanced stages it can trigger warning signs such as blood in the urine, lower back pain on one side, and loss of appetite.
Nearly two in three patients are diagnosed with kidney cancer at stage one or two, when the tumor has not spread throughout the body. And almost one in five are diagnosed at stage three, when the cancer has spread to nearby tissue.
Overall, 77 percent of people diagnosed with kidney cancer live more than five years after their diagnosis, a rate that has improved over time even as cases have increased.
It comes amid warnings about other substances to avoid in tap water, including PFAS.