Indoor air pollution refers to the presence of gaseous and particulate contaminants in the indoor air environment. Contamination of indoor air is particularly hazardous because people spend about 65 to 95 percent of their lives indoors and exposure to some of the contaminants may cause serious health problems. However, for taking effective control measures, it is necessary to identify the sources of air pollutants.
Sources of Indoor Air Pollution
Both natural and man-made sources can deteriorate indoor air quality. Natural sources include soils and water that release radon decay products, volatile organic compounds (VOCs) and fungi. In addition, some animal pets also release certain allergens affecting sensitive individuals. Other than natural sources, many human actions cause emissions of dangerous air pollutants into the indoor environment.
Human-produced air contaminants originate from various types of appliances, combustion sources such as vehicle engines, wood burning and unvented space heating using gas and kerosene. Building materials are also a significant source of particulates in air. Some pollutants are generated by individual behavior, such as tobacco smoking and through use of consumer products.
Effects of Indoor Air pollution
Effects of poor indoor air quality upon humans and animals are dependent upon exposure and the concentration of pollutants. Effects experienced by humans include respiratory illness, decreased lung function and other physiological changes. Particulate matter and formaldehyde cause irritation of eyes and produce changes in pulmonary function. Carbon monoxide, nitrogen oxides, nitrates and methylene chlorides affect heart and brain by causing changes in carboxy hemoglobin.
Lead has been identified to have neurological effects, especially in infants and children. Benzene has been shown to produce a form of leukemia while both radon and asbestos have been proven to cause lung cancer in humans. Studies of effects on animals have shown results similar to those found in humans.
Indoor air contamination can also have corrosive effects on materials. Outdoor pollutants can infiltrate and interact with indoor pollutants to generate new substances that are detrimental to materials; an example is outdoor ozone interacting with indoor volatile organic compounds to produce corrosive compounds affecting electronic equipment. Extensive damage to rubber, paint and dyes, leather and textiles, and ceramics have been demonstrated by indoor air pollutants.
Indoor Air Pollution Control
The first and foremost control measure on indoor air contamination is source removal including water, plants, pets, and certain building materials. Another effective consideration is reduction in source emissions through manufacturing processes, changes in building materials, prevention of water leakage, and source usage recommendations. Similarly, reduction of exposure to humans can be achieved using standard direct methods such as filtration and cleaning, as well as good building and source design.
Government agencies can monitor product manufacturing, promote ventilation in workplaces, use public health education to help people minimize risks and encourage safe indoor air, and enforce regulations (such as banning tobacco smoking in workplaces and public buildings). Finally, individuals can limit their exposures, especially in residences, by several measures, including avoidance of sources that degrade the quality of indoor air.
Clean Indoor Air
The quality of indoor air is badly affected by addition of contaminants from both natural and human-caused sources. Many of these contaminants such as VOCs are harmful for human health and may cause terrible ailments. Some of the pollutants in indoor air are detrimental to objects made of rubber, ceramics and metals and result in material losses. The indoor air pollution can be controlled by removing sources, reducing emissions and minimizing exposures to humans and materials. Both Government regulations and public education are vital for effective results.