Pollution indoor

Difficult as it is to avoid air pollution outdoors, it is no easier to avoid indoor pollution. The air quality in homes and in the workplace is affected by human activities, by construction materials, and by other factors in our immediate environment. The common indoor pollutants are radon, carbon monoxide and carbon dioxide, and formaldehyde. 

In a highly publicized case in the mid-1980s, an employee reporting for work at the Limerick Nuclear Power Plant in Pennsylvania set off the plant s radiation monitor. Astonishingly, the source of his contamination turned out not to be the plant, bnt radon in his home  

A lot has been said and written about the potential dangers of radon as an air pollutant. Just what is radon Where does it come from And how does it affect our health  

After cigarette smoking, radon is the leading cause of lung cancer in the United States. It is responsible for perhaps 20,000 deaths per year. 

The long-term test kits use a piece of special polymer film on which an a particle will leave a track. After several months exposure, the film is etched with a sodium hydroxide solution and the number of tracks counted. Knowing the length of exposure enables the technician to calculate the radon concentration. If the radon level is unacceptably high, then the house must be regularly ventilated. This precaution is particularly important in recently built houses, which are well insulated. A more effective way to prevent radon pollution is to reroute the gas before it gets into the house, for example, by installing a ventilation duct to draw air from beneath the basement floor to the outside. 

Air quality in homes and workplaces is affected by human activities, construction material, underground minerals, and outside pollution. The most common indoor pollutants are radon, carbon oxides, nitrogen oxides, tobacco smoke, formaldehyde, and a large variety of organic compounds. Indoor atmospheres can also be contaminated with fine particles such as dust, aerosols (from spray cans), fungal spores, and other microorganisms. 

Water vapor itself is not usually considered a pollutant, but the amounts generated in closed spaces such as in kitchens (that use gas for cooking) can favor the growth of house dust mites, moulds, and fungi, which in many cases lead to allergic reactions. 

Why is radon, a noble gas, a pollutant Although Rn is a member of the noble gas family, 222 Rn is a radioactive gas (half-life = 3.8 days) that decays first into 218Po (half-life = 3 min), ending in 210Pb (half-life = 22.3 years). Radon enters a building from the subjacent ground, either carried by a convective flow of soil gas or dissolved in the ground-water. 

Indoor moderate airborne concentrations of radon daughters can increase considerably in the presence of particles such as those found in cigarette smoke. The size of these particles (now radioactive) allows them to reach the lungs and remain there, increasing the probability of consequences in health. 

The amount of radon that enters a building depends on the geology of the zone, the concentration of the gas, the pathways into the building and its ventilation rate. The US EPA recommended limit indoor radon concentration is 4 pico Curies/L. 

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The concentration of indoor pollutants is a function of removal processes such as dilution, filtration, and destruction. Dilution is a function of the air exchange rate and the ambient air quality. Gases and particulate matter may also be removed from indoor air by deposition on surfaces. Filtration systems are part of many ventilahon systems. As air is circulated by the air-conditioning system it passes through a filter which can remove some of the particulate matter. The removal efficiency depends on particle size. In addition, some reactive gases like NOj and SOj are readily adsorbed on interior surfaces of a building or home. 

Limited to residents in BRA s weatherization program Adopted OSHA standards Indoor air exposures considered in determining drinking water levels Restricts use and sales of pesticides which may cause indoor air pollution Bans on use of some potential indoor pollutants in consumer products Restricts smoking in specified indoor environments Restricts use of asl estos in VA buildings... 

Occupational and environmental exposure to chemicals can take place both indoors and outdoors. Occupational exposure is caused by the chemicals that are used and produced indoors in industrial plants, whereas nonoccupa-tional (and occupational nonindustrial) indoor exposure is mainly caused by products. Toluene in printing plants and styrene in the reinforced plastic industry are typical examples of the two types of industrial occupational exposures. Products containing styrene polymers may release the styrene monomer into indoor air in the nonindustrial environment for a long time. Formaldehyde is another typical indoor pollutant. The source of formaldehyde is the resins used in the production process. During accidents, occupational and environmental exposures may occur simultaneously. Years ago, dioxin was formed as a byproduct of production of phenoxy acid herbicides. An explosion in a factory in... 

Indoor pollution Pollution inside a building due to internally generated pollutants as well as external pollutants entering the building. 

Buildings are ventilated mechanically with the ITVAC systems where it is a controlled process, as well as via air infiltration and through the openable windows and doors where it is largely an uncontrolled process. However, as discussed earlier, mechanical ventilation is one of the most energy-intensive methods of reducing indoor pollutant concentrations primarily because of the need to thermally condition air before it can be circulated inside the occupied spaces. It is estimated that the... 

Assisting as technical aids in making film strips, educational games, and informational packets on hazardous wastes, indoor pollutants, and natural and synthetic toxins. 

Shair, F. H., and K. L. Heitner. Theoretical model for relating indoor pollutant concentrations to those outside. Environ. Sd. Technol. 8 444-451, 1974. 

Enviromnent and health-related problems Bio varnishes , i.e. varnishes based on natural, renewable raw materials, were developed as close-to-nature alternatives (substitutes) i.a. as a reaction to the so-called German wood preservative scandal and indoor pollution due to chemical solvents. Nevertheless, they have until now had a relatively high content of volatile bio-organic solvents, which may cause irritations, allergic and neurotoxic reactions, and contribute to the formation of tropospheric ozone. 

Raiyani C, Shah S, Desai N, et al. 1993. Characterization and problems of indoor pollution due to cooking stove smoke. Atmos Environ Part A Gen Top 27(11) 1643-1655. 

Ryan PB, Spengler JD, Letz R. 1983. The effects of kerosene heaters on indoor pollutant concentrations ... 

Tokiwa H, Nakagawa R, Horikawa K. 1985. Mutagenic/carcinogenic agents in indoor pollutants The dinitropyrenes, generated by kerosene heaters and fuel gas and liquefied petroleum gas burners. Mutat Resl57(l) 39-47. 

Viegi G, Paoletti P, Carrozzi L, et al. 1989a. Adverse health effects of exposure to indoor pollutants in young non-smokers from a general population sample of North Italy. Am Rev Respir Dis 13(4 part 2) A563. 

Sollinger, S., K. Levsen, and G. Wiinsch, Indoor Pollution by Organic Emissions from Textile Floor Coverings Climate Test Chamber Studies under Static Conditions, Atmos. Environ., 28, 2369-2378 (1994). 

Weschler, C. J., and H. C. Shields, Potential Reactions among Indoor Pollutants, Atmos. Environ., 31, 3487-3495 (1997b). 

Indoor air quality has been a public health concern for several decades now. Indoor air quality is affected both by infiltration of outdoor air in buildings and indoor sources such as smoking, gas cooking, and use of consumer products [6]. Penetration of particles into indoor environments depends on particle size, air exchange rates, and other factors. Consideration of indoor sources is important because they may be associated with significant health effects, e.g., environmental tobacco smoke. Presence of indoor sources may further complicate assessment of the impact of outdoor air on indoor air. In this chapter we separately describe the impact of indoor sources and outdoor air on indoor pollution, because health effects of outdoor and indoor generated particles may differ as their composition differs [7]. 

Indoor Pollutants. In general, the term indoor air pollution refers to home and nonfactory public buildings such as office buildings and hospitals. Pollution can come from heating and cooking, pesticides, tobacco smoking, radon, gases, and microbes from people and animals. 

Sparks, L.E., Tichenor, B.A., Chang, J. and Guo, Z. (1996) Gas-phase mass transfer model for predicting volatile organic compound (VOC) emission rates from indoor pollutant sources. Indoor Air, 6, 31 40. 

Gunschera, J., Fuhrmann, F., Salthammer, T., Schulze, A. and Uhde, E. (2004) Formation and emission of chloroanisoles as indoor pollutants. Environmental Science and Pollution Research, 11/3,147-51. 

Weschler, C.J. (2004) Chemical reactions among indoor pollutants what we ve learned in the new millennium. Indoor Air, 17 (Suppl. 7), 184-94. 

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