Arsenic cancer risk still high decades later in Chile region

People exposed to very high levels of arsenic in Chilean drinking water back in the 1950s and 60s are still showing a higher-than-normal risk of bladder cancer - years after the arsenic problem was brought under control, a new study shows.

The findings are not surprising, researchers say, since the cancer would take decades to emerge.

But the results underscore the importance of continuing to screen high-risk people for bladder cancer, according to lead researcher Dr. Fernando Coz, a professor of urology at the Universidad de Los Andes in Santiago de Chile.

The study, reported in the Journal of Urology, focused on people in the Antofagasta region of Chile. In the 1950s and 60s, drinking water in the region became contaminated with high levels of arsenic.

Arsenic is semi-metallic element found in rock, soil, water and air. It is also released into the environment through industrial activities, and can be found in products like paints, dyes and fertilizers. High exposure has been linked to several cancers, including tumors of the bladder, liver and lungs.

In Antofagasta, a combination of factors led to a huge increase in drinking-water arsenic by the late-1950s: naturally high arsenic levels in the environment, heavy mining and a move to make two rivers the area's main drinking-water sources.

Bladder cancer Risk factors It's not clear what causes bladder cancer, but doctors have identified factors that may increase your risk of bladder cancer. Risk factors include:

Increasing age. Your risk of bladder cancer increases as you age. Bladder cancer can occur at any age, but it's rarely found in people younger than 40.
Being white. Whites have a greater risk of bladder cancer than do people of other races.
Being a man. Men are more likely to develop bladder cancer than women are.
Smoking. Smoking cigarettes, cigars or pipes may increase your risk of bladder cancer by causing harmful chemicals to accumulate in your urine. When you smoke, your body processes the chemicals in the smoke and excretes some of them in your urine. These harmful chemicals may damage the lining of your bladder, which can increase your risk of cancer.
Exposure to certain chemicals. Your kidneys play a key role in filtering harmful chemicals from your bloodstream and moving them into your bladder. Because of this, it's thought that being around certain chemicals may increase your risk of bladder cancer. Chemicals linked to bladder cancer risk include arsenic and chemicals used in the manufacture of dyes, rubber, leather, textiles and paint products. Smokers who are exposed to toxic chemicals may have an even higher risk of bladder cancer.
Previous cancer treatment. Treatment with the anti-cancer drug cyclophosphamide (Cytoxan) increases your risk of bladder cancer. People who received radiation treatments aimed at the pelvis for a previous cancer may have an elevated risk of developing bladder cancer.. Chronic or repeated urinary infections or inflammations (cystitis), such as may happen with long-term use of a urinary catheter, may increase your risk of a squamous cell bladder cancer. In some areas of the world, squamous cell carcinoma is linked to chronic bladder inflammation caused by the parasitic infection known as schistosomiasis.. If you've had bladder cancer, you're more likely to get it again. If one or more of your immediate relatives have a history of bladder cancer, you may have an increased risk of the disease, although it's rare for bladder cancer to run in families. A family history of hereditary nonpolyposis colorectal cancer (HNPCC), also called Lynch syndrome, can increase your risk of cancer in your urinary system, as well as in your colon, uterus, ovaries and other organs.