People spend about 90% of their time indoors and most of that time is spent in their homes. It is important to keep the air inside your home as healthy and fresh as possible. Your home's building materials, furnishings, and products, in addition to the activities that are carried on in your home, can have an effect on the quality of the air inside. While office buildings, schools, hospitals, and other buildings can have indoor air quality problems that can give rise to health effects or discomfort for occupants, this fact sheet focuses on some simple steps you can take to improve your home indoor environment.
There are many things in homes that can contaminate the air you breathe. Gases and particles may be released from the materials used to construct your home, as well as the furniture, cleaning products, and other items in your home. Radon gas can seep in from the soil. Products you burn in your home, like tobacco, candles, and fuels for furnaces and stoves, give off gases and particles.
To conserve energy, many newer and remodeled homes are well-insulated and tightly built. Less fresh air can get in and the stale, contaminated air can not escape. The levels of contaminants inside a home can build-up until they are many times greater than the levels in outdoor air.
Indoor air issues have plagued mankind since there have been dwellings. Prehistoric records show that openings in caves were made to let out the smoke from fires. Changes in construction methods and materials, and a better understanding of the effects of indoor air contaminants, have increased awareness of indoor air quality issues in the past 50 years.
In the mid-1940s, after World War II, the population was on the rise and people wanted a better standard of living. The construction industry responded by developing new building materials - plywood, particleboard, foam insulation, and floor tile. Plywood, particleboard, and foam insulation are made with adhesives and solutions that were not commonly found inside the home previously -- such as formaldehyde, a chemical suspected of causing cancer in some individuals. Some floor tiles and their adhesives were made with asbestos, a material which can cause cancer.
The development of new materials was not restricted to the building trade. Foam padding began to appear in furniture. Permanent press and stain-resistant finishes were applied to fabrics to protect them and make their care easier. At the same time, products to make housework easier began appearing on store shelves. Soon homes were filled with cleaners, insecticides, and other products constructed of manmade materials.
The effects of these materials and the contaminants they can release into the indoor air were compounded when the energy crisis hit in the mid-1970s. To conserve energy, homes were more tightly constructed and better insulated. Energy-efficient homes do not let much fresh air in or contaminated air out, unless they have an air exchanger. And most homes do not have such air exchange devices. Tightly-built homes also keep moisture in, which promotes the growth of fungi and other microorganisms.
Indoor air contaminants that pose the greatest health care risks are:
Radon is a naturally occurring gas that results from the radioactive decay of the element radium in rocks, soils, and some building materials. It can enter through cracks in a building's foundation, via well water, and from radium-containing masonry. Radon sticks to particles in the air, and, when inhaled, lodges deep in the lungs. When the radon undergoes its natural process of radioactive decay, it damages the lung tissue. This can increase the risk of developing cancer. The United States Environmental Protection Agency (EPA) has reported that exposure to radon is the second leading cause of lung cancer in the US - only cigarette smoking causes more lung cancer deaths. Radon is odorless and colorless. The only way to determine radon levels in your home is to have it tested.
Volatile organic compounds (VOCs) are made of carbon along with hydrogen, oxygen, and other elements. VOCs are found in some glues, paints, solvents, and other natural and manmade products commonly used indoors. Not all VOCs are harmful. When you smell a flower, it is the VOCs that the flower is producing that you sense. However, there is still a lot we do not know about exposure to many VOCs and the potential health effects. It is prudent to minimize your exposure to VOCs.
One VOC, formaldehyde is strongly suspected of causing cancer in some individuals. Formaldehyde is a common component of composite wood products such as particleboard, fiberboard, plywood, foam insulation, glues, fabrics, and other building supplies. It can irritate the eyes and nose and may cause respiratory ailments. Other sources of VOCs are tobacco smoke; dry-cleaned clothes; stored household cleaners and paints; pesticides and air fresheners; chemicals in carpeting and fabric finish; molds, fungi, and mildew; and even some drinking water.
The VOCs that are emitted from paint, caulking, new furniture and other building and cleaning materials can be diluted by making sure that sufficient outdoor air is being used to ventilate the area where the products are being used. Ventilation can help to bring the level of VOCs down quickly, as the rate at which VOCs are produced from these building materials generally decreases over time.
Smoke from cigarettes, pipes, and cigars contain many pollutants including gases, particulate matter, VOCs, and products of incomplete burning. According to the EPA, exposure to environmental tobacco smoke (ETS) - commonly known as secondhand smoke - 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.
Prior to the 1960s, asbestos was used in insulation, fireproofing, wallboard, and ceiling and floor tiles. It was often mixed with a cement-like material and sprayed or plastered on ceilings or other surfaces. Now these materials may be crumbling and releasing asbestos. The tiny asbestos fibers are small enough to float in the air. They can then be inhaled and lodge deep in the lung tissue. Exposure to asbestos fibers can cause lung cancer and asbestosis, a chronic scarring of the lungs that hinders breathing.
Homes constructed in the 1960s and earlier have the potential for asbestos-containing floor tiles. Such resilient floor tiles are typically 9-inches square and are adhered to the subfloor with a black mastic. Both the tiles and the mastic can contain asbestos. Care should be taken when any such tiles are removed to prevent particles from getting into the air.
The fuels burnt in furnaces, heaters, fireplaces, and stoves can release contaminants into the air in your home. These fuels include kerosene, natural gas, wood, and oil. Kerosene, natural gas, and oil can give off harmful gases such as nitrogen dioxide, sulfur dioxide, carbon monoxide, formaldehyde, and other VOCs. Wood burned in fireplaces gives off very fine particles. These indoor air contaminants can pose a risk to your health.
Fungi and bacteria can breed in humidifiers and heating, ventilating, and air conditioning (HVAC) systems if this equipment is not properly cleaned and maintained. These systems can also bring biological contaminants indoors and circulate them throughout your home. Contaminants such as pollen, fungi, animal dander; bacteria, viruses, dust mites, and the chemicals or by-products released by these contaminants can cause allergic reactions, colds, influenza and other health effects.
There are things you can do to reduce the levels of air contaminants in your home. Most of these things are simple and involve you making decisions about the furnishings, products, and activities that you allow in your home.
The most important action you can take when using household cleaning products is READ THE LABEL AND FOLLOW THE MANUFACTURERS' DIRECTIONS. Misuse and overuse of household products can lead to overexposure to potentially harmful materials. Common household products can be used safely by most individuals. However, here are some alternatives that you may want to consider: