Research indicates that people spend approximately 80 ~ 90 percent of their time indoors, where they are exposed to polluted indoor air that may cause irritation of the eyes, nose, and throat, headaches, dizziness, fatigue, and even lung cancer or other malignancies. Recent study reveals that bacteria, molds and house dust mites bred inside carpets and air conditioners can be airborne by dust particles, paints, varnishes, harmful chemical fibers and pressed wood products, which are most commonly used in household decoration, may emit formaldehyde, benzene and other hazardous and carcinogenic organic chemicals -- all these as well as unwholesome matters produced in the metabolism of human bodies and ammonia inside toilets have made the air within homes and other buildings more seriously polluted than the outdoor air.
People may experience one or more of the following reactions when exposed to indoor air pollution:
- Some common signs and symptoms are:
- Wheezing and difficulty breathing
Caused by bacteria and viruses, such as influenza, measles, chicken pox, and tuberculosis. Most infectious diseases pass from person to person through physical contact. Crowded conditions with poor air circulation can promote this spread. Some bacteria and viruses thrive in buildings and circulate through indoor ventilation systems.
Some fungi are known to produce toxic substances as a by-product of their metabolism, which can cause a variety of adverse health effects. Short-term symptoms can include dermatitis, respiratory irritation, headaches and fatigue. Long-term health effects can include cancer, damage to the central nervous system, and suppression of the immune system.
The U.S. Environmental Protection Agency ranks poor indoor air quality among the top five environmental risks to public health. Poor indoor air quality can cause or contribute to the development of chronic respiratory diseases such as asthma and hypersensitivity pneumonitis. In addition, it can cause headaches, dry eyes, nasal congestion, nausea and fatigue. People who already have respiratory diseases are at greater risk.