Arsenic is highly toxic and potentially lethal to humans. It may kill a person exposed to high levels in just a few days. Even at lower levels, it may cause severe and life-threatening symptoms. And long-term exposure has been linked to several cancers.
And yet, arsenic is found just about everywhere — in the food we eat, the air we breathe and the water we drink. For the most part, however, the arsenic found in our environment is often a less-toxic organic variety. And normally we are exposed to levels of arsenic much smaller than those used to kill a victim in an old-time murder mystery. Indeed, most people are exposed to levels of arsenic so small they may never feel any ill effects.
In the Southwest, however, arsenic levels teeter on the edge of being dangerous, especially to those in rural areas who rely on wells for drinking water. Arizona, New Mexico, Nevada, Utah and parts of California have some of highest levels of arsenic found in water in the country, prompting health agencies to urge those who rely on well water to take steps to limit their exposure.
The more you know about the risks of arsenic exposure and how to detect and reduce levels in your drinking water may help reduce your risk for developing cancer and other illnesses caused by the mineral.
In this article, we’ll explore:
- What Is Arsenic?
- How Does Arsenic Get in Water?
- Why Are Arsenic Levels Higher in Arizona?
- Arsenic and Cancer Risk
- How to Know if Your Drinking Water Is Safe
If you or a loved one has been diagnosed with lung cancer and are looking for a second opinion, call us 24/7 at 877-524-4673.
What Is Arsenic?
Arsenic is a ubiquitous, natural, semi-metallic mineral found in the Earth’s crust. It’s often a product of geologic or volcanic activity from eons past.
The two types of arsenic are listed below.
Organic arsenic: This type of arsenic contains carbon and may be found naturally in some foods. Organic arsenic compounds are considered less toxic and not linked to cancer, but they still may be dangerous in high levels.
Inorganic arsenic: This form of the mineral does not contain carbon and is very toxic. Inorganic arsenic may be a byproduct of industrial activity, such as manufacturing building materials or pressure-treating wood. Inorganic arsenic may be lethal in high doses and has been linked to an increased risk for developing cancer and other illnesses.
How Does Arsenic Get in Water?
Arsenic may leach or dissolve into water from rocks that surround rivers, lakes and aquifers, huge underground pools often tapped for drinking water.
The mineral may also get into water from agricultural or industrial waste discharged into rivers, lakes or below-ground wells.
The World Health Organization estimates that about 140 million people in at least 70 countries are drinking water containing arsenic above recommended levels.
A report from the U.S. Geological Survey (USGS) and the Centers for Disease Control and Prevention (CDC) estimates that more than 2 million Americans may be getting drinking water from private wells with high levels of naturally occurring arsenic, presumed to be from natural sources. Many of those wells are in the West or Southwest.
Why Are Arsenic Levels Higher in Arizona?
Centuries of geologic and volcanic activity have produced rock formations in the Southwest with high levels of arsenic. Mining, a common industry in the Southwest, may also expose rocks with high levels of arsenic and mining waste and byproducts may contain high levels of arsenic.
Current weather conditions in the Southwest may concentrate levels of arsenic in water. How?
With less rainfall, aquifers may sit stagnant for long periods without a recharge of fresh water. This keeps the remaining aquifer supply exposed longer to arsenic-bearing rock.
In hot and arid conditions, arsenic levels become concentrated as above-ground water supplies evaporate.
A University of Arizona report on arsenic levels in drinking water cites a USGS survey of aquifers in the Southwest and “found that about 19% of the drinking water wells sampled exceeded the maximum contaminant level (MCL) for arsenic of 10 [micrograms per liter] established by the U.S. Environmental Protection Agency (EPA).”
Arsenic and Cancer Risk
At high levels, arsenic may alter our DNA, disrupt cell signaling and affect gene expression. These changes may harm cells’ ability to regulate growth and division or for DNA to repair itself — all potential precursor conditions for tumor development.
Humans are exposed to arsenic by ingesting or inhaling it, and it may also be absorbed through the skin. Exposure to high levels of arsenic may increase the risk for developing:
”Exposure from a chemical that's carcinogenic and is filtered by the kidney ends up in the bladder and will increase your bladder cancer risk,” says Farshid Sadeghi, M.D., medical director of the Genitourinary Cancer Center and a urologic oncologist at City of Hope® Cancer Center Phoenix. “But of course, we should also focus on the number one risk for bladder cancer: smoking.”
How to Know if Your Drinking Water Is Safe
Testing is the only way to determine the levels of arsenic in your drinking water. You may test the water yourself with a DIY kit found online or at a local hardware store. Or you may hire a company that tests water and installs water-purification systems.
Be aware that at-home water treatment systems may not be adequate to remove arsenic when levels are extremely high. The University of Arizona Superfund Research Program recommends specific actions if your water supply has arsenic levels at these parts per billion (PPB) levels, as follows.
10 PPB: No action needed. Your water is safe for cooking and drinking.
10 to 200 PPB: Consider installing a water treatment system or getting your cooking and drinking water from another source, such as a public supply or bottled water.
Over 200 PPB: Do not use your water for drinking or cooking. Consult an expert on whether a home treatment system will reduce your arsenic to acceptable levels. Bathe or wash clothes in the water only if it is below 500 PPB.
“About 44 million people in the lower 48 states use water from domestic wells,” USGS hydrologist Joe Ayotte, a lead author of the study referenced above says in his report. “While we’re confident our research will help well owners understand if they live in an area of higher risk for arsenic, the only way for them to be certain of what’s in their water is to have it tested.”
If you or a loved one has been diagnosed with lung cancer and are looking for a second opinion, call us 24/7 at 877-524-4673.