Outdoor air quality

For many industrialized countries, efforts to improve the outdoor air quality have been under way for the majority of this century. In many locations around the world, significant improvements have taken place. Air quality in many major cities such as London, New York, and Chicago has improved from the conditions present in the first half of the twentieth century. Mechanisms and control programs are in place in the developed countries to continue the improvement of ambient air quality. Considerable effort and energy have been expended to characterize, evaluate, and control air pollution emissions to the atmosphere. 

Deals with issues that affect the quality of our air and protection from exposure to harmful radiation. OAR de >el-ops national programs, technical policies, and regulations for controlling air pollution and radiation exposure. Areas of concern to OAR include indoor and outdoor air quality, stationaiy and mobile sources of air pollution, radon, acid rain, stratospheric ozone depletion, radiation protection, and pollution prevention. 

Extrapolating exposure estimates to all urban cities In the world would Indicate that as many as 625 million people, mostly In developing countries, are exposed to unacceptable levels of 02 pollution and about 1.25 billion people live In urban areas where SPN levels exceed acceptable guidelines. This means that less than 20 percent of city dwellers live In environments that can be considered to have acceptable outdoor air quality levels. 

Quackenboss, J. J., J. D. Spengler, M. S. Kanarek, R. Letz, and C. P. Duffy, Personal Exposure to Nitrogen Dioxide Relationship to Indoor/Outdoor Air Quality and Activity Patterns, Environ. Sci. Technol., 20, 775-783 (1986). 

The difference in infiltration between components and particle sizes documents that indoor air quality differs from outdoor air quality, even in the absence of indoor sources. This may result in measurement error in exposure estimates that exclusively focus on outdoor concentrations. Furthermore heterogeneity in the size of estimated health effects may occur in epidemiological studies using exposure estimates based upon outdoor concentrations performed in different locations that differ in factors affecting infiltration. 

Indoor air quality is influenced by outdoor air quality. Therefore, it is helpful to know the chemical gas pollutants in outdoor air for indoor air quality control. 

In many countries the building codes include certain general regulations to guarantee proper and sanitary conditions in buildings. Generally it is required that the indoor environment should not be injurious to health and that indoor air quality should be at least the same as outdoor air quality, e. g., as is stated in a German directive on non-industrial workplaces (Bundesanstalt fur Arbeitsschutz, 1988). 

A helium microwave cavity plasma or MIP serves as the heart of a unique instmment dedicated to the analysis of particles with diameters between 1 and 20 pim. The analysis of small particles is becoming increasingly important in fields as diverse as the semiconductor industry where extremely low levels of contaminants can destroy semiconductor chips, to indoor and outdoor air quality and the health impact of respirable particles. This instrument is basically an atomic emission spectrometer, but designed to count particles, calculate particle size, and determine the chemical composition of each particle analyzed, one by one. 

There is an increasingly widespread use and exposure to scented products. Fragrances are complex mixtures of primarily volatile compounds that influence both indoor and outdoor air quality. In order to detect an odour, molecules of the substance must be airborne. Once in the air, they break down, mix with other pollutants, and form other compounds that often are more irritant or allergenic than the original substance (Bridges 2002). Fragrances such as air fiesheners are used in products to scent the environment. They are added in large amounts to toiletries, cosmetics, household products, and a wide variety of other consumer products. 

Quackenboss JJ, Spengler JD, Kanarek MS, Letz R, Duffy CP (1986) Personal exposure to nitrogen dioxide relationship to indoor/outdoor air quality and activity patterns. Environ Sci Technol 20 775-783... 

A green adhesive is one that eliminates toxins to the greatest extent possible. These products, which focus as much on human health as performance, can be developed by reducing off-gassing to nearly undetectable levels in order to prevent indoor and outdoor air quality problems. Another important green... 

Todsy s existing standards and codes ensure that we have safe structures, safe transportation systems, safe drinking water, safe indoor/outdoor air quality, safe products, and reliable services. Standards also encourage uniformity in the size of parts and components that are made by various manufacturers around the world. 

You should be miliar with the role of the ] A and the standards it sets for drinking water, outdoor air quality, and indoor air quality. 

When a ventilation system removes air from a space through dilution or local exhaust, the contaminants go elsewhere with the removed air, usually outdoors. Outdoor air quality standards limit the dumping of contaminants. As a result, it is common to clean the contaminants from the exhausted air. Some contaminants collected by local exhaust systems may have economic value. There are several types of equipment for removing airborne particulates and gases or vapors from exhausted air. See Section 25-6. 

Yocum, J.E., 1982. Indoor—outdoor air quality relationships a critical review. J. Air Pollut. Control Assoc. 32, 500-520. 

Meteorologists and climatologists have introduced constraining anthropogenic sources in prognostic weather and climate models to better understand urban heat islands as well as outdoor air quality and contaminant dispersion in cities. 

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