Indoor atmospheres

Indoor air is relatively benign, provided that the temperature is relatively constant (no marked, rapid cool-down) and particularly if the air is dehumidified. Metallographers frequently store polished metallographic mounts of aluminum specimens in sealed desiccators for weeks without any 

Another critical indoor atmosphere corrosion occurrence is that normal humidity, in the typical 40-55% relative humidity human comfort zone, can be a sufficient electrolyte to cause SCC in highly susceptible low-copper 

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Air conditioning is the treatment of air to control simultaneously its temperature, humidity, cleanliness, and distribution to meet the requirements of a conditioned space. Common use of the term air conditioning applies it to the cooling of air however, true air conditioning treats all aspects of indoor atmospheric comfort. 

See also Acid Ram Air Quality, Indoor Atmosphere Automobile Performance Climatic Effects Emission Control, Vehicle Emission Control, Power Plant Environmental Economics Environmental Problems and Energy Use Gasoline and Additives Transportation, Evolution of Energy Use and Turbines, Gas. 

The first three authors were concerned with the rusting of motorcar bodies. They found that the rusts formed on steel under sheltered and exposed conditions, respectively, differed markedly in chemical composition, structure and protective properties. The second paper gives the results of exposure tests in many different indoor atmospheres, from which the following representative rates of rusting over one year are taken. 

As a further example of the ineffectiveness of low-alloy additions in slowing down rusting under sheltered conditions, tests by BISRA in indoor atmospheres failed to reveal any substantial difference in the rusting of a chromium-copper steel and of an ordinary mild steel in most of them . The test sites covered a wide range of domestic and industrial conditions, from bathrooms to locomotive sheds. 

Fig. 12.14 Spread of silver sulphide from discontinuities in gold electrodeposits on silver substrates. The gold was deliberately scratched and the specimen exposed for 24 h to an atmosphere containing 10< o SO2. Immediately after this the sulphide stain extended 0-2 mm. Five years later, the stain extends to about 13 mm, after storage in a normal indoors atmosphere...

There are a series of papers that focus on the behavior of the radon decay products and their interactions with the indoor atmosphere. Previous studies (Goldstein and Hopke, 1983) have elucidated the mechanisms of neutralization of the Po-218 ionic species in air. Wilkening (1987) reviews the physics of small ions in the air. It now appears that the initially formed polonium ion is rapidly neutralized, but can become associated with other ions present. Reports by Jonassen (1984) and Jonassen and McLaughlin (1985) suggest that only 5 to 10% of the decay products are associated with highly mobile ions and that much of the activity is on large particles that have a bipolar charge distribution. 

Radon daughter ions and the ionization caused by the decay chains of radon and thoron in indoor air play important roles both from the contribution made by the daughter product positive ions to internal dose and from the effects of ion-pair production on the indoor atmospheric electrical parameters. 

It is difficult to use the model as a predictive model, since this would imply the knowledge of the chemical composition of the indoor atmosphere, as well as the formation rates of some relevant condensable products, which is hard to achieve. Linking... 

From the above it can be concluded that the risk for lung cancer induction from chronic indoor exposure to Rn-d is unlikely to be higher than 1.10 4/mSv. in order to understand the magnitude of this risk it has to be emphasized that man can be exposed to a multitude of different hazardous materials in the indoor atmosphere besides Rn-d, such as formaldehyde, nitrogen dioxide, carbon monoxide, nitrosamines, polyaromatic hydrocarbons, volatile organic compounds, asbestos and pesticides (Gammage and Kaye, 1985). 

ASTM. 1991. Standard practice for sampling and analysis of pesticides and polychlorinated biphenyis in indoor atmospheres. American Society for Testing and Materials. ASTM designation D4861-91. p366-379. 

Recent reports about the microdroplets formation in the starting periods of atmospheric corrosion [15-18] show that the idea of a thin uniform water layers is not completely in accordance with the reality. It has been observed that when a water drop is on the metallic surface, formed in the place where a salt deposit existed before, microdroplets are formed around this central drop. The cathodic process takes place in these surrounding microdroplets, meanwhile the anodic process takes place in the central drop. This idea is not consistent with the proposal of an uniform water layer on the surface and it is very probable that this situation could be obtained under indoor conditions. It has been determined that microdrops (about 1 micron diameter) clusters are formed around a central drop. An important influence of air relative humidity is reported on microdrops formation. There is a critical value of relative humidity for the formation of microdroplets. Under this value no microdroplets are formed. This value could be considered as the critical relative humidity. This situation is very similar to the process of indoor atmospheric corrosion presence of humid air, deposition of hygroscopic contaminants in the surface, formation of microdrops. Water is necessary for corrosion reaction to occur, but the reaction rate depends on the deposition rate and nature of contaminants. 

Leygraf. Indoor atmospheric corrosion. Proceedings 15th International Corrosion Congreso, Granada, Spain, September 22-27, 2002. 

ISO 11844-3.-Corrosion of metals and alloys. Classification of corrosivity of indoor atmospheres. Measurement of environmental parameters affecting indoor corrosivity. 

A major reason for understanding the chemistry of the atmosphere is the impact that changes can have on human health and well-being. With respect to effects due to direct inhalation of gases and particles, exposure occurs not only outdoors but also indoors as well. Indeed, the vast majority of time for most people is spent indoors. As a result, understanding the nature of the indoor atmosphere and human impacts on it is important as well. 

A number of studies have documented that concentrations of some of the directly emitted species found in outdoor atmospheres can be quite high indoors if there are emission sources present such as combustion heaters, gas stoves, or tobacco smoke. In addition, there is evidence for chemistry analogous to that occurring outdoors taking place in indoor air environments, with modifications for different light intensities and wavelength distributions, shorter residence times, and different relative concentrations of reactants. In Chapter 15, we briefly summarize what is known about the chemical composition and chemistry of indoor atmospheres. 

At the beginning of this book, we presented some discussion of health-based air quality standards. In the final chapter, which follows this one, the scientific bases of control measures for various pollutants are discussed. In between, the complex chemistry that occurs in both polluted and remote atmospheres, and that converts the primary pollutants into a host of secondary species, has been detailed. To provide further perspective on airborne gases and particles and human exposure levels, we briefly treat indoor air pollution in this chapter. As we shall see, for many species it is simply a question of emissions leading to elevated levels indoors. However, there is some chemistry that occurs in indoor atmospheres as well, and it is of interest to compare this to that occurring outdoors. 

For excellent summaries of general exposure and health effects data for 243 substances, see the California Air Resources Board report (1997b). Each summary describes the physical properties, sources, and concentrations both outdoors and indoors, atmospheric persistence, health effects, and other risk assessment information. 

Atmospheric components get into the indoor atmosphere by one of three routes ... 

An on-line model has been developed for conservators to help them estimate indoor atmospheric concentrations of the common museum pollutants (Blades et al., 2000). This is especially useful if used in conjunction with targeted analytical campaigns to assess the atmosphere in a museum or gallery, although the interpretation of the results of such measurements is usually not straightforward (Section 12.8). 

Part of the mission of most museums and galleries will involve the display of artifacts to either the general public or specialist audiences. This in turn means that there can be a conflict between two of the major missions for the museum s existence the conservation management of the artifacts on the one hand and the demands to display those artifacts on the other. People can affect indoor atmospheres in two ways, either directly or indirectly. 

Clausen, P.A. and Wolkoff, P. (1997) Degradation products of TENAX TA formed during sampling and thermal desorption analysis indicators of reactive species indoors. Atmospheric Environment, 31, 715-25. 

With this convention, the effective dose equivalent in the average indoor atmosphere is given in terms of the PAEC by... 

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. 

Information on levels of 2-butoxyethanol in air is very limited. 2-Butoxyethanol was reported among 34 major eompounds identified in high-volume air samples at a semi-rural site in the United Kingdom however, no eoneentrations were given (Welch and Watts 1990). Analysis of data from the National Ambient Volatile Organic Compounds (VOCs) Database indicates that, for 14 samples, the daily arithmetic mean and median indoor atmospheric concentrations of 2-butoxyethanol in a non-industrial office setting were 0.214 ppb (v/v) (1.03 g/m ) and 0.075 ppb (0.36 g/m ), respectively (Shah and Heyderdahl 1988 Shah and Singh 1988). 2-Butoxyethanol was found in only 1 of 6 samples of indoor air from 14 homes in northern Italy, at a concentration of 1.7 ppb (8 g/m ) (DeBortoli et al. 1986). 

There is rather extensive information in the available literature documenting occupational exposures to 2-butoxyethanol. Extremely low exposures have been reported for non-industrial office settings. Data from the National Ambient VOCs database indicate that for 14 samples from non-industrial offices, the daily mean and median indoor atmospheric concentrations of 2-butoxyethanol were 0.214 ppb (v/v)... 

Brunnemann, K.D., J.D. Adams, D.P.S. Ho, and D. Hoffmann The influence of tobacco smoke on indoor atmospheres. II. Volatile and tobacco-specific nitrosamines in mainstream and sidestream smoke and their contribution to indoor poUntion Proc. 4th Joint Conf. on Sensing of Environmental PoUntants, New Orleans, LA, Am. Chem. Soc. (1977) 876-880. 

A method of estimating concentrations of pentachlorophenol, tetrachlorophenol and lindane in the indoor atmosphere of rooms after application of wood protection agents was given by Zimmerli and Zimmermann (1979). Filter papers were soaked with paraffin oil and exposed in the room. The amount of chemical absorbed per unit of time was proportional to the concentration in air. 

In consumer s use, applications of gas sensors related to environmental pollutant gases are carried out mainly for security and amenity. Examples of the applications are, for instance, in the protection from a incomplete burning of combustion apparatus for home use and in the ventilation or condition of indoor atmosphere. A combustion monitoring sensor using SnOj was developed by Tanaka et al.[110] of Figaro Engineering, Japan. The gas water-heater... 

D22.05 D6327-98 Standard Test Method for Determination of Radon Decay Product Concentration and Working Level in Indoor Atmospheres by Active Sampling on a Filter... 

US Department of Health and Human Services, Washington Naumova YY, Eisenreich SJ, Turpin BJ et al (2002) Polycyclic aromatic hydrocarbons in the indoor and outdoor air of three cities in the US. Environ Sci Technol 36 2552-2559 Naumova YY, Offenberg JH, Eisenreich SJ et al (2003) Gas/particle distribution of polycyclic aromatic hydrocarbons in coupled outdoor/indoor atmospheres. Atmos Environ 37 703-719 Offenberg JH, Baker JE (1999) Aerosol size distributions of polycyclic aromatic hydrocarbons in urban and over-water atmospheres. Environ Sci Technol 33 3324-3331 Ohta S, Nakao T, Nishimura H et al (2002) Contamination levels of PBDEs, TBBPA, PCDDs/ DFs, PBDDs/DFs and PXDDs/DFs in the environment of Japan. Organohalogen Compd 57 57-60... 

As pointed out in the introduction, outdoor and indoor atmospheric corrosion... 

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