Quality of indoor

Airborne material affecting the quality of indoor air may be classified as gases or particulate matter. Gases which may be potential problems are radon, CO, NOj, and hydrocarbons. Particulate matter may come from tobacco smoke, mold spores, animal dander, plant spores, and others as shown in Table 23-1. Other factors interact to influence our perception of indoor air quality, including humidity, temperature, lighting, and sound level. 

Indoor air (lOA) classification Categories defined by CEN 156 to classify the quality of indoor air. 

ENPs are emerging class of airborne nanoparticles having a main impact on the air quality of indoor environments these are unintentionally released into the ambient environment during the manufacture (commercial or research), handling, use or disposal of nanomaterials integrated products. Their physical and chemical characteristics differ from other nanoparticles produced through traffic [4], The health consequences of their inhalation are not yet well known. A number of studies have reported their number concentrations and size distributions in workplaces but their concentrations in ambient urban environments are largely unknown and warrant further research. Adequate methods have yet to be developed to quantify them in the presence of nanoparticles from other sources. 

Guerin, M.R. Formation and general characteristics of environmental tobacco smoke Air Pollution Control Assoc. Specialty Conf. on Combustion Process and the Quality of Indoor Environments, Niagara Falls, NY (1988). 

Indoor and Built Environment The Journal of the International Society of the Built Environment (1420-326X) (1423-0070). This journal publishes reports on any topic pertaining to the quality of indoor or built environment, and how this may affect the health, performance, efficiency, and comfort of persons in these environments. 

Societies concern with air quality has evolved from medieval times, when breathing smelting fumes was a major hazard, to where we are today (see Chapter 1). In modem society, a parallel effort has been under way to improve air quality in the outside or ambient air, which is the focus of this book, and in the industrial occupational setting in manufacturing and other traditional jobs. A combination of events is moving many countries to consider the quality of air in other locations where we live parts of our lives. Attention is now being refocused on "indoor" air quality. 

In developing countries, priorities have often been different. Industrialization, water and food supply and sanitation, infrastructure improvements, and basic health care are often the focus of the leaders of a country. In some areas, the availability of a job is much more problematic than some consideration about the quality of the air in the workplace or the home. Many dwellings in developing countries do not have closable windows and doors, so the outdoor and indoor air quality issues are different. In some houses where cooking is done by firewood or charcoal, the air quality outdoors may be considerably better than that inside the smoky residence. 

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. 

The control and regulation of indoor air quality are influenced by individual property rights and a complicated mosaic of federal, state, and local government jurisdiction with conflicts, overlaps, and gaps in addressing these issues. Table 23-3 shows a large number of agencies and departments involved in indoor air quality control efforts at the federal level. 

Effort to increase knowledge of indoor air quality problems and controls... 

In industrial premises the target levels of indoor air quality, as well as other targets (e.g. emissions), shall be specified zone by zone. 

Outdoor inhalation exposure is mainly due to traffic, energy production, heating, and natural factors such as pollen and mineral dusts. These outdoor sources of pollution also affect indoor air quality. The indoor concentration is typically 20-70% of the corresponding outdoor concentration. Occasionally the indoor concentrations of an external pollutant (especially radon) may even exceed the concentrations outdoors. ... 

The setting of indoor air quality targets is much more complicated and individualized, T his is due to the fact that the chemical process in paper making differs from paper type to paper type. Also, the amount of particles is highly dependent on the speed of the machine, the percentage of recycled mass, and the percentage of stone in the paper. 

K. Niemela, A. Tossavainen, V. Riihimaki, P. Kalliokoski, and T. Mannelin, Target levels of indoor air quality in industrial buildings. In Proceedings of the 4th International Symposium on Ventilation for Contaminant Control, vol. 18, pp. 71-76, 1994. 

Several major studies of indoor-air quality problems have shown that filters would have been able to prevent blocked ducts, fans, and heat exchangers. Other major lAQ problems such as impurities from outside and microorganisms in the system need not arise given the correct choice of filter. 

Demand-controlled ventilation (DCV) is one approach to reduce energy consumption due to ventilation, that is gaining popularity in both industrial and nonindustrial applications. It is used in cases where ventilation requirements vary with time, regularly or irregularly. The control is based on a specified level of indoor air quality by means of continuous measurement of the parameters, that are expected to primarily determine the lAQ, such as the concentration of the main contaminant liberated from the production process. The principle is thus similar to the one in some better-known nonindustrial applications, e.g., CO2 levels in rooms with dense human occupancy (theaters, classrooms, etc.) or nicotine concentration in smoking rooms. See also Section 9.6. 

Indoor air quality The actual quality of air within a space compared with a given sample or standard, related to temperature, moisture, biological content, and contaminant levels. 

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. 

As the science of indoor air quality has matured, indoor air professionals have realized that many indoor air contaminants and the associated health effects are linked to specific types of buildings and their characteristics. For example, radon is primarily an indoor air concern in homes because of the ease with which it can be transported inside residential construction from the soil beneath. On the other hand. Sick Building Syndrome (SBS) primarily afflicts office building occupants who experience acute health and comfort effects that appear to be linked to time spent in a specific building. 

Research done by experts in the field as well as in laboratories has helped them understand the relationship between lAQ, ventilation, and energy. More research is needed to link specific health symptoms with exposure to specific or a group of pollutants. The policy challenge will be to raise awareness of indoor air quality so that healthy, comfortable environments can be provided by energy efficient technology. 

Liddaineiit, M. W. (1999). A review of Ventilation and the Quality of Ventilation Air. In Proceedings of the 8th International Conference on Indoor Air Quality and Climate. Edinburgh, Scotland. 

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