By Richard Mesquita, AquaMD

A one-time oral dose of 60,000 ppb of arsenic will kill you. That's no more than 1/50 the weight of a penny, which shows how dangerous arsenic really is.

It's unlikely you won't be exposed to that much arsenic at one time. However, there's a very good chance you will be exposed to much higher levels over just a few years, merely through the water you drink, food you eat and air you breathe. Why? Unfortunately, the arsenic to which you are exposed is typically colorless, odorless and tasteless. So if arsenic is in your water, you won't notice it by sight, smell or taste.

How does arsenic get into your drinking water?

Arsenic occurs naturally in some soil and rock. When water comes in contact with arsenic in soil or rocks, it's absorbed naturally.

Industrial processes such as mining, smelting and coal-fired electric power plants contribute to the presence of arsenic in your water. Arsenic can either be discharged directly into rivers and streams or pumped into the air.

When arsenic is pumped into the air, it travels with the wind before settling back into lakes and rivers. Or if arsenic settles on the ground, it's carried into the underground water supply by rain or melting snow.

Arsenic is also used in agricultural pesticides and chemicals used to preserve wood. The residue from these applications can be washed into rivers, lakes and underground water supplies.

So, it shouldn't be surprising to you that arsenic is very common in ground water across the United States.

What are the possible health effects of ingesting even low levels of arsenic? The likely links to disease:

1. Skin cancer
2. Nervous system damage
3. Diabetes
4. Circulatory diseases
5. High blood pressure
6. Reduced intelligence in children

Studies have also linked long-term arsenic exposure to an increased risk of cancer of the bladder, lungs, liver and other organs. Arsenic can also damage chromosomes, which house the genetic material inside the cells of the body.

It's believed the side effects from arsenic exposure in drinking water typically take years to develop. Much of it depends on the concentration of arsenic to which you are exposed. Most arsenic leaves your body within three days of exposure. But the arsenic that remains is stored in the brain, bones and tissue and continues to do serious damage.

How much arsenic in my water is considered safe?

The EPA (Environmental Protection Agency) has reduced the safe drinking water standard for arsenic in your water to 10 parts per billion (ppb). That standard -- a dramatic decrease from the current standard of 50 ppb -- goes into effect in January 2006. The agency reduced the level it currently allows in water because newer scientific studies found the old standard did not protect people exposed to arsenic for many years.

While the new standard is lower, it's certainly not enough to eliminate all the risk of cancer and other side effects. Your exposure to arsenic in past years could cause problems to your health later in life. That's why the EPA set a goal of zero as to the amount of arsenic that should be in your water.

But their goal is not enforceable.

You might feel a little safer knowing arsenic is not easily absorbed through the skin and doesn't evaporate from water. But don't get too comfortable... If arsenic is in your water, you will primarily be exposed to it from the water you drink, and not to bathe, wash dishes or clean your clothes.

Find out if arsenic or other harmful contaminants are in your water supply. If they are, get the appropriate water purification system to treat your specific problem. Then, see your health practitioner about removing the contaminants that are already in your body.