What's on Tap? Arsenic in Your Drinking Water

What's the first thing that comes to mind when you hear the word "arsenic"? The word may conjure up images the Cary Grant film, Arsenic and Old Lace or Agatha Christie novels. Perhaps you've heard epic tales about how the deadly poison was once a popular among aristocrats centuries ago. What you may not realize is how it's still very much a health concern for us in this century. Today's concern is with the presence of arsenic in water and food, and limiting exposure to the toxic chemical.


A chemical element that occurs in different minerals, there are two forms of arsenic:

  1. Inorganic arsenic. Formed when arsenic combines with carbon and hydrogen, these compounds are common in industrial uses like building products and in arsenic-contaminated water. This form of arsenic tends to be more toxic and has been linked to cancer.
  2. Organic arsenic. When arsenic is combined with elements like oxygen, chlorine and sulfur, the end result is organic arsenic. Much less toxic than inorganic arsenic, it's not linked to cancer. These compounds are found in some foods, especially fish and shellfish.

Despite its dangers, arsenic serves a number of very useful applications ranging from tanning animal hides to wood preservatives, insecticides to alloy.


A natural component of the Earth's crust, arsenic deposits are common around the globe. When the deposits leach into water supplies, drinking water can become contaminated. Natural occurrences of high arsenic levels are especially common in groundwater in Bangladesh, Chile, China, India, Mexico and the United States of America. But human intervention also causes the spread of arsenic in the air, water and land. Released during industrial mining, copper smelting, coal burning and spraying plants with insecticide, thousands of pounds of arsenic enter the environment each year by industrial and agricultural activities like these in the U.S. alone.


The International Agency for Research on Cancer (part of the World Health Organization) has classified arsenic, arsenic compounds and arsenic in drinking-water as carcinogenic to humans which means its greatest threat to public health originates with contaminated groundwater. Drinking water, crops irrigated with contaminated water and food prepared with contaminated water are the main sources of exposure. In addition, elevated levels in foods can be the result of consuming products treated with insecticides made of arsenic. Fruits like apples are especially at risk, even tobacco plants have proven to be heavily contaminated. Long-term exposure through drinking contaminated water, eating of food prepared with contaminated water and eating food irrigated with arsenic-rich water can lead to chronic arsenic poisoning. The most common effects of exposure are skin lesions and skin cancer, but it can cause irreversible damage. Cancer of the bladder, lungs, skin, kidney, nasal passages, liver and prostate are some of the illnesses linked to arsenic. Non-cancer effects can include thickening and discoloration of the skin, stomach pain, nausea, vomiting, diarrhea, numbness in hands and feet, partial paralysis, and blindness. Developmental effects, cardiovascular disease, neurotoxicity and diabetes have also been associated with long-term exposure.


If you're concerned about the quality of the water in your home, there are a few ways to learn about its safety:

  1. Test the water yourself. Using an at-home kit, you can take a water sample and then mail it to a lab for analysis. An important note: Not all test kits are the same. Make sure the kit you purchase will test for the contaminants you are concerned about.
  2. Request a water quality report. All public water systems in the U.S. are required to keep arsenic levels below 10 parts per billion (ppb) and to routinely test contaminant levels. They are also required to provide customers with an annual Consumer Confidence Report that details the water quality in your community, just ask for a copy.
  3. Test well water at least once per year. In addition to testing the water yourself, your state certification officer can recommend
  4. Call the EPA's Safe Drinking Water Hotline for more information about drinking water safety in your area: 1-800-426-4791.


Arsenic regulation is managed by several government agencies, the EPA and FDA being the most prominent. The EPA has classified Arsenic as a known human carcinogen and has set the arsenic standard for drinking water at 10 ppb to protect consumers served by public water systems from the effects of long-term, chronic exposure to arsenic. In response to concerns over the presence of arsenic level in apple juice, the EPA and FDA have agreed on a limit of 10 ppb. Currently, there no federal limits on most foods.


Arsenic is a naturally occurring element, so it's impossible to entirely avoid exposure, but there are simple ways to reduce exposure. The best action? Prevention through water filtration. Unlike some water contaminants, boiling water does not reduce or remove arsenic. The most effective water filter to reduce the risks associated with arsenic is a reverse osmosis system. With its ability to treat water containing up to 0.160 mg/L of arsenic, and its removal rate of approximately 90%, it's an effective way to keep your water safe.


There are a variety of water filter options for removing arsenic from drinking water:





Regular replacement of the filter and/or cartridge is critical to maintaining their effectiveness and reducing bacterial contamination. An overused or out-of-date filter can become dangerous because the filter will no longer trap contaminants, allowing them to leach back into your water. For the safety of you and your loved ones, it's important not to put off replacement too long. There are four effective ways of knowing when it's time to replace your water filter:

  1. Follow the manufacturer's recommendations. Their specified replacement timing will err on the side of caution so you can be assured that your water quality will always be safe.
  2. Measure usage. Install a filter measurement meter or filter monitor that connects to the incoming water line that feeds the filter system and measures the number of gallons that pass through. Then using the manufacturer's recommended usage limit, program the monitor to alert you when you've reached the allowed number of gallons. You'll know exactly when it's time to replace the filter.
  3. Read your water bill. If your home is supplied with municipal water, your water bill will tell you exactly how much water is used monthly. Compare your actual usage to the manufacturer's recommendation and plan the replacement accordingly.
  4. Monitor manually. If you have non-municipal water, the most cost effective method is to monitor your filter manually either with your palate or a water testing kit. Start with routine water tests that look for lead, microorganisms and other contaminants to verify whether your filters are still removing them. For drinking water systems, simply fill a glass with water and check the flavor yourself. You'll be able to see or taste when the filter is exhausted and no longer purifying your water because the water flavor will be unpleasant.


For answers to arsenic-related questions, recommendations on the best filter for your home or general drinking water questions, contact us.