Doctors warn that fast-growing cancer is linked to tap water consumed by 40 million Americans
Tap water consumed by as many as 40 million Americans may increase the risk of a fast-growing cancer, a study suggests.
Researchers from Texas A and M University compared kidney cancer rates in 240 Texas counties to arsenic levels in water in public and private water systems.
They found that people with high levels of the toxic mineral in their water had a 22 percent higher 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 that enter groundwater as 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 enter cells, causing damage to DNA and increasing the risk of cancer.
The results come as kidney cancer rates continue to rise in the US.
In 2010, there were 54,000 cases annually in the US. But in 2021 it was behind 68,000 cases – and was the ninth most common cancer in the country.
Rates are rising by around 1.2 per cent each year, data shows, alongside rises in other cancers including breast and bowel cancer in young people. This year was the first year the American Cancer Society said 2 million people would be diagnosed with the disease.
The above map, published in 2017, shows estimated arsenic levels in water from private wells in the US.
The above map shows arsenic levels in public drinking water by county in the US. It dates from 2006 to 2011
The increase occurred at the same time that the number of smokers, which also increases the risk of kidney cancer, continued to decline.
Experts have previously suggested that the uptick may have to do with rising obesity rates or better imaging tests.
Other products also contain low levels of arsenic, including 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 research, said: “Some public water systems are poorly managed and can expose customers to arsenic, but the 40 million people in the United States who rely on private water sources are especially vulnerable . .’
Estimates indicate that out of 40 million people use private wells containing more than 10 ppb (parts per billion) of arsenic.
It is highly likely that wells in Nevada, Washington and California contain the chemical.
Millions of people who use public water systems are also exposed to high levels of arsenic. An earlier Consumer Reports study found that eight percent of samples tested from across the country had arsenic levels above 10 ppb.
But the study found that even 5 ppb was linked to an increased risk of cancer.
The FDA says the safe limit for arsenic is levels no higher than 10 ppb.
The above shows cases of kidney cancer per year in the US, according to the CDC
And this shows the number of kidney cancer cases per year in the US, which is responsible for shifts in population size. There is a dip in 2020 and 2021 during the Covid pandemic as people left hospital
In the study, published in the journal Environmental pollutionresearchers analyzed data from 28,896 cases of kidney cancer among 20-year-olds, 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 cardiovascular disease.
The results also showed that every time the arsenic level in water doubled, the risk of cancer increased by four percent.
Dr. Roh added: ‘This study suggests that even low exposure to arsenic in drinking water may be associated with an increased risk of kidney cancer.
‘This is consistent with previous research indicating a link between this exposure and lung, bladder and skin cancer.’
The kidneys are responsible for filtering the blood for waste products and toxins, including arsenic.
Scientists say exposure to arsenic over long periods of time, such as through drinking water, can cause damage that builds up in the kidneys, leading to cancer.
Early kidney cancer often causes no symptoms, but in more advanced stages it can cause warning signs such as blood in the urine, lower back pain on one side and loss of appetite.
In almost two out of three patients, kidney cancer is diagnosed at stage one or two, when the tumor has not yet spread in the body. And almost one in five are diagnosed at stage three, when the cancer has spread to nearby tissues.
Overall, 77 percent of those diagnosed with kidney cancer live more than five years after their diagnosis – a rate that has improved over time, even as the number of cases has risen.
It comes amid warnings about other substances in tap water that should be avoided, including PFAS.
