Indoor Air Pollutants: Where To Find Them and What To Do

greenbuildinggreen home improvement

Toxin Sources What to Do


  • Old house paint (especially made before 1950) found on interior and exterior of home; notably, window frames, window and door trim, railings, baseboards, radiators, walls
  • Plumbing pipes and the service connection into homes (before 1950s)
  • Solder used to join water pipes in modern homes
  • Miscellaneous household items (ceramic pottery, lead crystal, hobby materials)
  • Have old paint lab-tested for high lead content, especially before major renovations
  • Leave paint undisturbed if it is not accessible to children and if it is in good condition
  • Do not create any leaded paint dust when young children or pregnant women are living in the house.
  • Replace doors, windows or trim covered with lead paint, or strip and repaint them away from the house.
  • If you want lead paint removed, have it done by a trained contractor. This work will be dusty. Move the family out of the house during the work and clean up thoroughly before moving back in.
  • Have your water tested for lead content. Recommended levels are below 10 parts per billion. If results show high lead levels: 1) Replace old plumbing 2) Install a point-of-use water purification device in your kitchen for drinking and cooking 3) Secure a better source of lead-free water for drinking and cooking.
  • Vinyl-asbestos floor tiles and sheet flooring
  • Patching compounds and textured paints
  • Ceilings
  • Pipe insulation and furnace ducts
  • Wall and ceiling insulation
  • Take precautions when you tear up, remove, cut, scrape or sand any materials you suspect may contain asbestos.
  • If the asbestos material is isolated or doesn’t pose a threat, 1) Leave it alone 2) Seal it with paint or (in small areas)  Cover it with a new surface such as wallboard
  • If it is deteriorating or must be removed, have an experienced contractor do it using precautions to avoid exposure to fibers or spreading them into the house
  • Carpets
  • Upholstered furniture
  • Pets
  • Fireplaces
  • Smoking
  • Heating ducts
  • Doors, windows and air leaks that allow particles to enter from outdoors
  • Exposed, worn or damaged surfaces on building materials such as particleboard or vinyl-asbestos flooring
  • Install a central vacuum system vented to the outside
  • Install a ventilation system with a filter for incoming air.
  • Add an effective air filter to your forced-air heating system.
  • Remove carpets or other sources of dust and allergens
  • Reduce moisture levels causing mold and mildew problems
  • Caulk and weatherstrip thoroughly to prevent outdoor irritants from getting in.

Combustion Gases

  • Carbon Monoxide
  • Formaldehyde
  • Nitrogen Dioxide
  • Sulfur Dioxide
  • Carbon Dioxide
  • Hydrogen Cyanide
  • Nitric Oxide
  • Benzo(a)pyrene
  • Gas or oil furnaces
  • Boilers
  • Hot water heaters
  • Gas fire places
  • Woodburning fireplaces
  • Coal-burning stoves
  • Kitchen ranges
  • Clothes dryers
  • Space heaters
  • Wall heaters
  • Central heating systems
  • Kerosene space heaters
  • Use alternatives such as solar or steam heat
  • Install a balanced ventilation system in the house; beware of negative pressure and downdrafts
  • Ensure that fuel-burning appliances are induced-draft, sealed-combustion units. Small enclosed furnace rooms should have direct air supply from exterior.
  • Seal ductwork with mastic, including cracks or leaks in stovepipe
  • Have a qualified service person check for chimney obstructions like creosote buildup
  • Have your furnace maintained regularly by a competent mechanical contractor—look out for cracked heat exchanger
  • Eliminate wood or gas fireplaces. Or, install tight-fitting doors on fireplaces or install an efficient fireplace insert. Replace older wood stoves with new cleaner-burning devices.
  • Install a quiet range hood, exhausted to the exterior, that is close to the cooking surface. This is especially important for gas stoves.
  • Install a certified carbon monoxide detector or smoke alarm in rooms with a fuel burning appliance that uses a chimney.
  • Make sure stoves are installed and fitted properly.

Volatile Organic Chemicals (VOCs)

  • Composite wood products, including particleboard, MDF, fiberboard, and interior plywood
  • Furniture, cabinets made from composite wood products
  • Upholstery
  • Carpeting
  • Insulation
  • Paints and finishes
  • Glues, cleaners, waxes, and other household products
  • Choose building materials that don’t contain urea formaldehyde; for example, solid wood instead of particleboard or medium density fiberboard
  • If solid wood is too expensive, use construction-grade (softwood) plywood, which uses more stable phenol formaldehyde glues, rather than finish-grade plywood (hardwood) made with urea formaldehyde glues.
  • Seal all exposed surfaces and edges on materials that are manufactured with high formaldehyde content. Use plastic laminates or multiple coats of low toxicity, water-based, acrylic sealers designed to reduce emissions from wood, to reduce the moisture permeability of surfaces. Improve the ventilation in your house
  • Buy spider plants to put in a room with formaldehyde
  • Herbicide (weed killer, lawns and garden, turf, algae control)
  • Insecticide (mosquito, flea, ant, roach, lice, mite, termite control; lawn treatment; pet products)
  • Fungicide (paints, plastics, wood preservatives, grout, lawn treatment, carpet treatment)
  • Do not treat soil under the building
  • Eliminate standard building products that contain biocides
  • If a pest must be eliminated, first see if its current access to nourishment and habitat can be limited. For example, if you have ants, you might clean up crumbs from the floor and counters and caulk the cracks
  • If a pest must be trapped or killed, consider the most benign methods first. Least toxic chemicals are employed as a last resort.

A well-renovated home will also be pest resistant because it incorporates the following features:

  • Weather tightness
  • Appropriate grading and drainage
  • Provisions made for the prevention of excess moisture buildup from within. These provisions include extraction fans and windows that allow cross-ventilation
  • Dry wood without rot or infestation used in construction
  • Exterior wood appropriately treated for prevailing climatic conditions
  • All openings screened
  • Ground cover, leaves, chip and wood piles, and other  potential insect habitats kept at a distance from the building
  • Avoid carpeting where pesticides can become trapped for years, protected from degradation caused by sunlight and bacteria

Vinyl Chloride

  • Municipal drinking waters
  • Vinyl flooring
  • Adhesives
  • Swimming pools
  • Upholstery
  • Wall coverings
  • Use natural linoleum instead of vinyl flooring
  • Use safer plastic alternatives, like melamine formaldehyde use in countertops

Radioactive Contaminates

  • Floor drains and sumps
  • Joints where basement walls and floor come together
  • Cracks in basement walls and floors
  • Holes in the foundation wall for pipes and wiring
  • Exposed earth or rock surfaces in the basement
  • Well water
  • Environmental Protection Agency and the Surgeon General recommend that all homes test their radon levels below the third floor.
  • Install a sub-slab ventilation system
  • Cover exposed earth with a polyethylene air barrier
  • Seal all cracks and joints in the foundation wall and floor slab with caulking or foam
  • Install a self priming drain or gas trap in floor drains leading to a sump or to drainage tiles
  • Remove radon from well water using activated charcoal filters or aeration units
  • Basement or crawl space
  • Kitchen
  • Bathrooms
  • In, and under, carpet and rugs on cold floors
  • On window frames or below windows
  • In, and on, furniture against outside walls
  • Inside wall cavities where there is dampness or condensation
  • In damp or unventilated storage areas
  • Closets, especially ones adjacent to exterior walls.
  • Around plumbing leaks
  • Near roof or wall leaks
  • Fix basement plumbing and leaks
  • Do not store porous, absorbent materials such as cardboard, newspaper, or books in the basement. Keep the floors and walls clear.
  • In winter, do not turn on the humidifier unless relative humidity falls below 30 percent.
  • Provide better general ventilation, and spot ventilation in damp areas
  • Insulate fresh air ducts and cold water pipes to prevent condensation
  • Use air-vapour barriers to keep wall cavities dry
  • Remove carpets and rugs from cold floors, such as basements
  • Remove obstacles obstructing air flow in damp areas
  • Eliminate piles of newspapers, clothing and other materials in damp areas that can give molds a place to grow
  • Kitchen
  • Bathroom
  • Laundry room
  • Basements and crawl spaces
  • Repair leaks and cracks in basement and eliminate all other sources of moisture
  • Use a hygrometer to monitor humidity levels
  • Provide direct ventilation with an outside exhaust for moisture sources such as stoves, showers, and clothes dryers
  • Do not hang clothes to dry in the basement unless the area is well ventilated, with stale air being exhausted to the outdoors
  • Install a balanced, whole-house ventilation system that controls moisture by bringing in drier outside air, where possible
  • Provide an outside area for drying firewood

From Green Remodeling, Changing the World One Room at a Time, New Society Press