Most homes have more than one source that contributes to indoor air pollution. In addition, some of the products used in home construction, like standard paints and wood finishes and processed wood products such as cabinetry and flooring, give off volatile organic compounds (VOCs) that have a larger environmental impact because they create ground-level ozone pollution which is the primary component of smog. Below is a chart listing the most common chemicals and their sources, and health affects:

 gas boiler and furnaces  carbon monoxide, nitrogen dioxide and nitric oxide
 gas hot water heater  carbon monoxide, nitrogen dioxide and nitric oxide
 gas clothes dryer  carbon monoxide, nitrogen dioxide and nitric oxide
 gas stove and/or oven  carbon monoxide, nitrogen dioxide and nitric oxide
 unvented gas space heater/fireplace, kerosene heaters  carbon monoxide, nitrogen dioxide, nitric oxide and formaldehyde
 chimney flue (blocked, leaking, improperly sized or disconnected)  carbon monoxide
 gas powered equipment (i.e. generators)  carbon monoxide
 automobiles  carbon monoxide, benzene
 tobacco smoke  4,000 compounds including carbon monoxide, benzene, nitrogen dioxide (NO2) and nitric oxide (NO), formaldehyde, particulate matter
 wood burning fireplaces  particulate matter, carbon monoxide
 humidifiers, cooling coils or condensation pans  mold, mildew, bacteria
 unvented bathrooms  mold, mildew, bacteria
 Textiles: Draperies, bedding, carpeting, upholstery, permanent  dust and dust mites, animal dander, pest droppings and body parts, formaldehyde
 Textiles: permanent press clothing  formaldehyde
 paint (including painted furniture and old painted toys)  formaldehyde; benzene; old paint can contain lead
 paint strippers  methyl chloride, benzene, formaldehyde
 solvents, adhesive removers  methylene chloride
 aerosol sprays  methylene chloride
 household cleaners and disinfectants  click on "Resource Room" on the  CHEC’s (Children’s Health Environmental Coalition) HealtheHouse website
 herbicides  click on "Resource Room" on the CHEC’s (Children’s Health Environmental Coalition) HealtheHouse website
 rodenticides  click on "Resource Room" on the  CHEC’s (Children’s Health Environmental Coalition) HealtheHouse website
 moth balls  naphthalene, benzene
 hobby supplies  lead
 dry-cleaned clothing  perchloroethylene
 adhesive removers  methyl chloride
 insulation  asbestos, formaldehyde
 drop ceiling tiles  asbestos
 floor tiles  asbestos
 leaded crystal  lead
 soil, rock  radon
 plywood (softwoods)  formaldehyde
 composite wood particleboard furniture and cabinetry  formaldehyde
 flooring with particleboard backing  formaldehyde
 glues  formaldehyde
 adhesives  formaldehyde
 hardwood plywood paneling  formaldehyde
 medium density fiberboard (furniture)  formaldehyde
 bathrooms  biological pollutants
 kitchens  biological pollutants
 rodents  biological pollutants
 animals, pets  biological pollutants
 any poorly ventilated area with a source of water, moisture or steam  biological pollutants
 polyvinyl chloride (PVC) plastic, which is "vinyl". Plastics marked with a recycling symbol "3"  dioxins (in its production and incineration)
 fiberglass insulation  may contain formaldehyde; old insulation may contain asbestos
 composite or pressed-wood products; medium-density particle board  formadehyde
 softwood plywood and hardwood plywood paneling (used in decorative wall covering, cabinets and furniture)  formaldehyde
Copyright ©2008 Eden Industries, LLC d/b/a ECOBROWNSTONE™. All rights reserved.

 Crumbling, damaged, or disturbed insulation, fireproofing, acoustical materials such as drop ceilings, and floor tiles.  No immediate symptoms, but long-term risk of chest and abdominal cancers (mesothelioma) and lung diseases (asbestosis). Smokers are at higher risk of developing asbestos-induced lung cancer.
 carbon monoxide (CO)  combustion sources: gas stoves and ovens; gas furnaces and boilers; cracked chimney flues; wood stoves and fireplaces; gas water heaters and clothes dryers; unvented gas and kerosene heaters and "fireplaces"; gas powered equipment such as generators; automobile exhaust; tobacco smoke  reduces oxygen flow to the brain. In low concentrations causes fatigue, can cause chest pain in people with heart disease. At higher concentrations causes impaired vision and coordination; headaches; dizziness; confusion; nausea. Can cause flu-like symptoms that clear up after leaving the contaminated area. Fatal at very high concentrations. 
 benzene  tobacco smoke, stored fuels and paint supplies, and automobile emissions in attached garages, mothballs  a known carcinogen
 lead  deteriorating lead-based paint which can produce lead dust and further contaminate soil, drinking water, food; old painted toys and furniture; liquids stored in lead crystal vessels, hobbies such as leaded glazes for use in pottery and stained glass and refinishing furniture  Lead affects practically all systems within the body. At high levels (at or above 80 micrograms per deciliter of blood) can cause convulsions, coma, and even death. Lower levels adversely affect the central nervous system, kidney, and blood cells. Blood lead levels as low as 10 micrograms per deciliter can impair mental and physical development. In fetuses and young children can delay physical and mental development, lower IQ levels, lead to shortened attention spans, and increased behavioral problems.
 radon  uranium in soil and rock lung cancer
 formaldehyde (urea-formaldehyde resin)  building materials such as insulation and certain softwood plywoods; pressed or composite wood furniture using adhesives with urea-formaldehyde resins; tobacco smoke; the use of un-vented, fuel-burning appliances like gas stoves, gas fireplaces or kerosene space heaters; "permanent press" clothing, draperies and upholstery; glues and adhesives; paint; particleboard (used as sub-flooring and shelving and in cabinetry and furniture); hardwood plywood paneling (used for decorative wall covering and used in cabinets and furniture); medium density fiberboard (used for drawer fronts, cabinets, and furniture tops) which is the highest formaldehyde-emitting pressed wood product.  eye, nose, and throat irritation; wheezing and coughing; fatigue; skin rash; severe allergic reactions. May cause cancer.
 biological pollutants: mold, mildew, viruses, bacteria, animal dander, cat saliva, dust, mites, pest droppings and body parts (cockroaches, rat and mice urine), pollen  humid or wet/moist areas, plants, people, animals  hypersensitivity pneumonitis, allergic rhinitis, asthma. Can promote spread of infectious respiratory diseases. Molds and mildews release disease-causing toxins. Symptoms include sneezing, watery eyes, coughing, shortness of breath, dizziness, lethargy, fever, and digestive problems.
 tobacco smoke (Environmental Tobacco Smoke or Secondhand Smoke)  smoke from the burning end of a cigarette, cigar or pipe and smoke exhaled by a smoker  pneumonia and bronchitis, lung cancer, cough, excess phlegm, and wheezing, ear infections and reduced lung function, increased severity of asthma attacks, possible onset of chest pain
 particulate matter  Fireplaces, wood stoves, and kerosene heaters, and secondhand smoke  Eye, nose, and throat irritation; respiratory infections and bronchitis; lung cancer
 methylene chloride  paint strippers, adhesive removers, and aerosol spray paints  causes cancer in animals; is converted to carbon monoxide in the body
 naphthalene  moth balls  neurotoxin, may cause cancer
 Perchloroethylene  dry cleaning fluids  causes cancer in animals
 nitrogen dioxide (NO2) and nitric oxide (NO).  tobacco smoke, unvented combustion appliances, e.g. gas stoves, vented appliances with defective installations, welding  Eye, nose, and throat irritation, possible bronchitis and impaired lung function, increased respiratory infections in young children; extremely high-dose exposure (as in a building fire) may result in pulmonary edema and diffuse lung injury.
Copyright ©2008 Eden Industries, LLC d/b/a ECOBROWNSTONE™. All rights reserved.

Let’s look further at some of the biggest offenders. Due to the important nature of this topic, we have not limited ourselves to construction- and renovation-related substances.

Environmental tobacco smoke (ETS), or Secondhand Smoke is the mixture of smoke that comes from the burning end of a cigarette, pipe, or cigar, and smoke exhaled by the smoker. According to the EPA, it is a complex mixture of over 4,000 compounds, more than 40 of which are known to cause cancer in humans or animals and many of which are strong eye, nose and throat irritants. In a study conducted in the early 1990s the EPA concluded that ETS is responsible for approximately 3,000 lung cancer deaths each year in nonsmoking adults and impairs the respiratory health of hundreds of thousands of children. For more information visit the EPA website.  

Radon The American Lung Association, the American Medical Association and the Center for Disease Control agree that radon causes, on average, 14,000 deaths from lung cancer every year. Radon gas enters homes through dirt floors, cracks in concrete walls and floors, floor drains, and sumps, and can be a problem in any home, however some areas of the countgry are more at risk than others. Consult the EPA’s Radon Zone Map , to find out if your home is in a risk area -- New York City and Boston are in a low potential zone, Chicago is in a moderate potential zone. In addition, for an in depth discussion of radon we recommend you refer to the EPA website “A Citizen's Guide to Radon: The Guide to Protecting Yourself and Your Family from Radon”.
You can test for radon by obtaining an inexpensive, do-it-yourself radon test kit through the mail and in hardware stores. Look for kits that are state certified or have met the requirements of some national radon proficiency program. Alternatively you can hire a contractor to do the testing for you, and you can obtain a list of state certified radon contractors from your state’s radon office, state radon office (in New York state can be contacted at 1-800-458-1158 ext. 27556 or 518-402-7556 or email, and see also the New York State Departmentof Health Radon information resources, or you can also contact either the National Environmental Health Association's (NEHA) National Radon Proficiency Program (NRPP)  or the National Radon Safety Board (NRSB) for a list of proficient radon measurement and/or mitigation contractors.

Formaldehyde – Due to its prevalence in the manufacturing of building materials, furniture, cabinetry and fabrics and its nature as a byproduct of certain combustion processes, formaldehyde has become ubiquitous. The rate at which products like pressed wood or textiles release formaldehyde can change over time and will generally decrease as products age. When the products are new, high indoor temperatures or humidity can cause increased emissions.

Lead The EPA and other federal agencies initiated policies starting in the 1980’s to phase out lead in gasoline, to ban or limit lead used in consumer products, including residential paint, to reduce lead in drinking water and in industrial air pollution. Lead is equally dangerous whether it is inhaled or ingested, and lead dust, from sources like deteriorating lead paint for example, can be ingested in both those manners.

Children are more prone to ingesting lead due to dust settling on toys and floors where they crawl and play, and childrens’ proclivity for putting objects and hands into their mouths. Children's growing bodies absorb more lead, and their brains and nervous systems are more sensitive to the damaging effects of lead. If not detected early, children with high levels of lead in their bodies can suffer from damage to the brain and nervous system, behavior and learning problems (such as hyperactivity), slowed growth, hearing problems and headaches. 

Adults who are exposed to lead can suffer from difficulties during pregnancy, reproductive problems in both men and women, high blood pressure, digestive problems, nerve disorders, memory and concentration problems, and muscle and joint pain.

For more information visit the EPA website