Chelan-Douglas Health District staff provide consultation to the public regarding environmental hazards.  If you need information on an environmental hazard or would like to request a consultation please call us at (509) 886-6400.


Arsenic occurs naturally in the earth’s crust. Most arsenic in drinking water comes from natural rock formations.  As water flows through these formations, it can dissolve arsenic and carry it into underground aquifers, streams, or rivers that may become drinking water supplies. Arsenic also can come from human activities, such as mining or smelting ores that contain arsenic. In North Central Washington, arsenic can also find its way to well water from past agricultural practices.

The drinking water standard for arsenic is 10 parts per billion (ppb) for federally regulated (Group A) community and nontransient noncommunity (NTNC) water systems.

A map is available of arsenic detections in Washington public water systems that have exceeded an arsenic level of 10 ppd (black dots) or 50 ppb (red dots) at least once over the sampling history for that source.  The data contained in the above map covers the time period from 1/1/1993 – 07/31/2007. (include thumbnail of map as link)

Additional Resources:


Asbestos is a mineral fiber found in rocks and soil. It was once widely used in building materials and products to strengthen them and provide heat insulation and fire resistance. It is still used in some products today. When it is intact and undisturbed, asbestos-containing materials generally do not pose a health risk. If asbestos-containing materials are damaged, disturbed, or deteriorate over time, there is a health risk because the microscopic fibers can be inhaled into the lungs.

Being exposed to asbestos doesn’t mean you’ll develop health problems. Many factors need to be considered, including:

  • How long and how frequently you were exposed.
  • How long it’s been since your exposure started.
  • How much you were exposed.
  • If you smoke (cigarette smoking with asbestos exposure increases your chances of getting lung cancer).
  • The size and type of asbestos you were exposed to.
  • Other pre-existing lung conditions.

A doctor can help you determine whether you are at risk for health problems from asbestos exposure.

Most people don’t show any signs or symptoms of asbestos-related disease for 10-20 years or more after exposure. When symptoms do appear, they can be similar to those of other health problems. Only a doctor can tell if your symptoms are asbestos-related.

While most products made today don’t contain asbestos, there are many which still might. Testing may be the only way to know if a product contains asbestos. The following are examples of where asbestos hazards may be found in the home.

  • Some roofing materials contain asbestos.
  • Some siding shingles are made of cement asbestos board (CAB).
  • Houses built between 1930 and the 1970s may have asbestos as insulation in the walls or in the attic.
  • Attic and wall insulation produced using vermiculite ore, particularly ore that originated from a Libby, Montana mine and sold under the name “Zonolite Attic Insulation” may contain asbestos fibers. Vermiculite was mined in Libby between 1923 and 1990. This insulation was used in millions of homes and businesses nationwide, and in over 50,000 homes in Washington State. For more information, see EPA’s vermiculite insulation.
  • Asbestos may be present in textured paint, popcorn ceilings, sheetrock taping compound, and in patching compounds used on wall and ceiling joints. Their use was banned in 1977.
  • Artificial ashes and embers sold for use in gas-fired fireplaces may contain asbestos.
  • Older products such as stove-top pads may have some asbestos compounds.
  • Walls and floors around wood burning stoves may be protected with asbestos paper, millboard, or CAB.
  • Some vinyl floor tiles and adhesives and the backing on vinyl sheet flooring (linoleum) contain asbestos.
  • Hot water and steam pipes in older houses may be coated with an asbestos material or covered with an asbestos blanket or tape.
  • Oil and coal furnaces and door gaskets may have asbestos insulation.

If the asbestos material is in good shape and won’t be disturbed, it’s likely that nothing needs to be done. Monitor the material for deterioration and prevent the material from getting damaged or disturbed. If asbestos material is more than slightly damaged, or if you are going to make changes in your home that might disturb it, you should consider hiring a professional to repair or remove the material.

Repair usually involves either sealing or covering asbestos material.

  • Sealing (encapsulation) involves treating the material with a sealant that either binds the asbestos fibers together or coats the material so fibers are not released. Pipe, furnace and boiler insulation can sometimes be repaired this way. This should be done only by a professional trained to handle asbestos safely.
  • Covering (enclosure) involves placing something over or around the material that contains asbestos to prevent release of fibers. Exposed insulated piping may be covered with a protective wrap or jacket.

Removal may be required when remodeling or making major changes to your home, or when asbestos material is damaged and cannot be repaired. Removal is usually more expensive than repair.

Naturally occurring asbestos mineral fibers are found in certain types of rocks and soil. They can be released into the air by human activities such as construction, grading, quarrying, and surface mining. If naturally occurring asbestos is not disturbed and fibers are not released into the air, then it is not a health risk.  Reported asbestos occurrences and potential zones of ultramafic rock are mapped by the Department of Natural Resources. View the map, potential zones of naturally occurring asbestos [].

More information on asbestos in Washington State can be found on the Washington State Department of Health webpage


Formaldehyde is a colorless, flammable gas with a pungent odor. It is used in the production of pressed wood products (urea resins in plywood wall paneling, particleboard, and fiberboard), fertilizer, permanent press products and other textiles, paper, and glues. It is also produced during the burning of organic materials and is a part of tobacco smoke.

Exposure to formaldehyde can cause eye, nose, throat, and skin irritation. It can also cause wheezing and coughing, headache, nausea, and severe allergic reactions. People with asthma or other respiratory problems may be more sensitive to the effects of inhaling formaldehyde. There is evidence that some people can develop a sensitivity to formaldehyde after routinely being exposed to low levels of it over a period of time (these people developed asthma symptoms and skin reactions). Formaldehyde has also been show to cause cancer in animals and is listed as a probable human carcinogen, meaning that it may cause cancer in people.

Exposure to formaldehyde can happen through:

  • Environmental air pollution, smog.
  • Cigarette smoke and other tobacco products.
  • Gas cookers and open fireplaces.
  • Working in industries which use formaldehyde (such as factories or laboratories).
  • Off gassing from manufactured wood products used in new mobile homes.
  • Household sources, such as fiberglass, carpets, permanent press fabrics, paper products, and some cleaners.

Formaldehyde exposure can be reduced by doing the following:

  • Use “exterior-grade” pressed wood products (they don’t emit as much formaldehyde gas  because they contain phenol resins, not urea resins).
  • Formaldehyde levels are usually higher indoors than outdoors. Increase ventilation by opening windows and using fans to bring fresh are indoors, especially after bringing new sources of formaldehyde into the home.
  • Use air conditioning and dehumidifiers to maintain moderate temperature and reduce humidity levels.
  • Seal unfinished manufactured wood surfaces.
  • Wash permanent press clothing before wearing.
  • Don’t use unvented heaters indoors.
  • Don’t smoke indoors.

More information on formaldehyde in can be found on the Washington State Department of Health webpage


Lead is a naturally occurring metal element found in small amounts in the earth’s crust. Lead can be found in the air, soil, water, and inside our homes. Lead exposure can happen from Lead-based paint and lead-contaminated dust are the main sources of lead poisoning. Houses built before 1978 are likely to contain lead-based paint.

Other sources could include contaminated soil, drinking water, children’s toys and jewelry, workplace and hobby hazards, imported candy, and traditional home remedies and cosmetics.

Babies And Children May Be Exposed To Lead By:

  • Inhaling lead dust from lead-based paint or lead-contaminated soil.
  • Putting their hands and other objects, which may be contaminated with lead dust, into their mouths.
  • Eating and drinking food or water containing lead.
  • Using dishes or glasses that contain lead.
  • Playing with toys that contain lead paint.

Learn more about common sources of lead.

Lead can affect almost every organ and system in your body. Children six years old and younger are the most susceptible to the effects of lead. Their growing bodies absorb more lead than adults do and their brains and nervous systems are more sensitive to the damaging effects of lead.

Lead In The Blood Of Children Can Result In:

  • Permanent damage to the brain and nervous system, leading to behavior and learning problems, lower IQ, and hearing problems
  • Slowed growth
  • Anemia

There may be no obvious symptoms of lead poisoning. People exposed to and affected by lead may not act or look sick. Symptoms may be mistaken for other illnesses such as an upset stomach or flu.  However, there is a blood test that shows lead poisoning, which is the only way to find out if someone has lead poisoning.  The test measures the amount of lead in blood and estimates the amount of recent exposure to lead.

A blood test is the only way to find out if someone has lead poisoning. The test measures the amount of lead in blood and estimates the amount of recent exposure to lead. Learn more about testing children for lead poisoning.

Steps you can take to lower the chances of exposure to lead in your home:

  • Keep your home clean and dust-free.
  • Inspect and maintain all painted surfaces. When old paint cracks and peels, it makes dangerous dust.
  • Clean painted areas where friction can generate dust, such as doors, windows, and drawers with a wet sponge or rag.
  • Remodel, repair, and paint old homes safely. Sanding or scraping paint can create lead dust. Make sure your contractor is Lead-Safe Certified.
  • Wash children’s hands, bottles, pacifiers, and toys often.
  • Learn how to reduce lead exposure in drinking water.
  • Eat well-balanced meals with calcium, iron, and vitamin C. Children with healthy diets absorb less lead. EPA’s Fight Lead Poisoning with a Healthy Diet
  • Remove shoes and wash hands after working or playing outdoors to avoid bringing in soil that may contain lead.
  • If you’re exposed to lead at work, don’t bring it home. Use separate work clothes and shoes. Shower before coming home or as soon as you get home. Put dirty work clothes in plastic bag and wash them separately from other clothes.
  • If you have a hobby that exposes you to lead, don’t contaminate your home. Keep children and pregnant women out of the area.
  • Look at toy and jewelry product recalls due to lead. CPSC’s product recalls
  • Avoid using home remedies and cosmetics that contain lead.
  • Avoid using imported pottery, dishware, and ceramics for food and drinks if unsure whether or not it contains lead.
  • Read Lead Publications for more information.

More information on lead can be found on the Washington State Department of Health webpage.


Mold FAQ


Radon gas, the invisible radioactive killer, is the second leading contributor to lung cancer behind smoking tobacco.  Radon is a naturally occurring radioactive gas that is invisible, odorless, and tasteless. It comes from the radioactive decay of radium, an element found in most rocks and soils. Radon can enter a building from the ground underneath it, and concentrate to tens or even hundreds of times the level in outdoor air. Structures can accumulate radon gas.  The only way to know if your home has elevated levels of radon to test it. In recent years new data suggests a greater prevalence of radium in the geology of Chelan and Douglas Counties.

The Washington State Tracking Network (WTN) collects data from national radon testing laboratories. From 1989-2015 there have been only 140 radon tests in Chelan County and 50 in Douglas County. In 2015 three radon tests were conducted in Chelan County and one  in Douglas County.  This lack of testing suggests people are living in homes that are accumulating radon gas and some at levels that are a health risk.

Easy-to-use, inexpensive test kits are available online, and from many home improvement and hardware stores. You can also hire a professional radon tester. A professional tester is often hired when radon detection is part of a real estate transaction. Find lists of professionals from the National Environmental Health Association and the National Radon Safety Board.

Three things that can help reduce radon levels in your house:

  1. Make it harder for radon to get in by caulking and sealing up cracks in your basement or foundation, or by installing a good vapor barrier in your crawl space. The goal is to have a gas-tight barrier between the ground and the inside of your home.
  2. Make it easier for radon to go somewhere other than your house. A radon mitigation system can be installed in a home that has already been built to move radon from under your house to the outside.
  3. Increase air exchange with the outside, to remove the radon.  If you have a crawl space, be sure to keep the vents free of obstructions, so the cross-ventilation can remove radon and other gases.

More information on radon in Washington State can be found on the Washington State Department of Health webpage or contact or call 360-236-3200.

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