By Richard Mesquita, AquaMD

On January 1, the Environmental Protection Agency (EPA) finally implements a stricter standard for the amount of arsenic allowed in public water supplies. From that date forward, they'll require arsenic levels in public water supplies not exceed 10 parts per billion (ppb). The previous standard -- 50 ppb -- had been in place since 1942.

How much scientific research as to the harmful effects of arsenic on humans do you think was available before 1942? Not much ...

Scientists and doctors did know arsenic was toxic (exposure to a one-time dose that's only 1/45 the weight of a dime will kill you), but they weren't sure what would happen if you were exposed to smaller amounts of arsenic over longer periods of time.

After the standard was adopted in 1942, a great deal of research was done, and it was realized that the 50 ppb standard was wrong. In fact, it was in 1962 that the U.S. Public Health Service recommended that water containing more than 10 ppb of arsenic should not be used for domestic supplies.

Despite advice from the U.S. Public Health Service, as well as three recommendations by the Congress in 1974, 1986 and 1996 to lower the amount of arsenic in water supplies, however, the EPA did not act, until now.

Is The New Standard Strict Enough?

Studies say it's not.

The National Academy of Sciences analyzed the relationship of exposure to arsenic in drinking water supplies with kidney and bladder cancer. Even with the revised EPA arsenic standard, they found hundreds of thousands of people risk developing kidney or bladder cancer in their lifetime as a result of exposure to arsenic.

The EPA itself tacitly admits that if you are exposed to any level of arsenic in your water, you risk damaging your health. You see, the EPA's Safe Water Goal for arsenic in public water supplies is zero. That's the level at which exposure to arsenic will not harm you. Unfortunately, that goal is not enforceable.

Research now reveals that inhaling arsenic from water vapor (think showering, bathing, washing dishes, etc.) also has long-term health implications.

When you ingest water that contains arsenic, most of it leaves your body within days. But arsenic that doesn't go away accumulates in your brain, bones and other organs. That's why exposure to arsenic in water puts you at risk of various diseases:

• Skin cancer
• Bladder cancer
• Lung cancer
• Liver cancer
• Kidney cancer
• Nervous system damage

How Does Arsenic Get Into The Water Supply?

The National Resources Defense Council lists these key reasons:

Runoff or leaching of pesticides that contain arsenic.
In some cases, arsenic-based pesticides remain in the areas where they were applied, manufactured or disposed of, and they are continually washed into water supplies.

Heavy groundwater pumping.
Heavy pumping can pull water out of arsenic-contaminated layers of rock. In other cases, over-pumping causes groundwater levels to drop, thus increasing arsenic-bearing rock contact with air and thereby increasing arsenic leaching.

Leaking of arsenic from old industrial waste dumps.
Arsenic is one of the most common contaminants found at Superfund sites.

Leaching of arsenic from mines.
Some mines expose arsenic-bearing rock to the elements. Rainwater then washes the contamination into ground and surface waters.

Is Arsenic in Your Water Supply?

Arsenic-contaminated water is found all across the United States. Interestingly, there was a study done by the EPA in which they asked water companies to report the levels of arsenic found in their public water systems.

Water companies in 25 states reported their findings and in every state, public water systems reported arsenic in their water. But worse was the attitude of water companies in the other 25 states. They never bothered to submit lab results showing how much arsenic was in their water supplies.

According to the World Health Organization, the only way to accurately know if, and how much arsenic is in your water, is to have it analyzed by a laboratory. Find out if arsenic and other contaminants are in your water supply. Once you know what contaminants are there, you can install the right treatment system to remove them.

Because no single filter exists, unfortunately, that removes all contaminants from water, you have to know what is in your water to get the right purification system.

(AquaMD is the water testing division of the American Water Council, a nationally respected provider of water education and testing services. AquaMD has teamed up with Dr. Mercola to provide you both the free home water evaluation and the Dr. Mercola water testing packages at http://www.aquamd.com/mercola/labtests.cfm.)