Toxic chemicals indoors

In nonindustrial settings, MCS substances are the cause of indoor air pollution and are the contaminants in air and water. Many of the chemicals which trigger MCS symptoms are known to be irritants or toxic to the nervous system. As an example, volatile organic compounds readily evaporate into the air at room temperature. Permitted airborne levels of such contaminants can still make ordinary people sick. When the human body is assaulted with levels of toxic chemicals that it cannot safely process, it is likely that at some point an individual will become ill. For some, the outcome could be cancer or reproductive damage. Others may become hypersensitive to these chemicals or develop other chronic disorders, while some people may not experience any noticeable health effects. Even where high levels of exposure occur, generally only a small percentage of people become chemically sensitive. 

Some particles and fibers may be generated by indoor equipment (e.g. copy machines and printers). Mechanical abrasion and air motion may cause particle release from indoor materials. Particles are also produced by people, e.g., skin flakes are shed and droplet nuclei are generated from sneezing and coughing. Some particles may contain toxic chemicals. 

The risk to children arising from the indoor use of pesticides has also been studied. A study by Gurunathan and colleagues in the January Environmental Health Perspectives indicated that the indoor use of pesticides can unintentionally expose small children to significant amounts of toxic chemicals, as vapors can contaminate toys and household objects that children later handle or place in their mouths (Brody, 1998). 

Public concern for the hazards of particle suspensions in the indoor and outdoor environment has produced regulations limiting particle concentrations and exposure levels. In the workplace, dust hazards are constrained by total mass concentration as well as concentration of specific toxic chemicals. In the ambient air, protection is stipulated in terms of total mass concentration of suspended particles andcertain chemical species, namely, lead and sulfate. Recently, measures of exposure have begun to distinguish between fine particles less than 2.5 fxm and coarse particles between 2.5 and 10 fxm. This separation relates to the ability of particles to penetrate the human respiratory system, and to different sources of fine and coarse particles. 

Wallace, L.A. (1991). Comparison of risks from outdoor and indoor exposure to toxic chemicals. Environ. Health Perspect., 95, 7-13. 

There are numerous other sources of toxic chemicals released to the indoor environment that can account for or contribute to SBS. A few of these are as follows. 

During the past 15 years formaldehyde exposures and emission limits have been significantly lowered. Occuptional threshold limits are now 1.0 ppm or lower in most countries, and actual industrial exposures are almost always half of this value or less. Indoor air standards of 0.1 ppm are now contemplated in several nations, following established procedures for correlating occupational levels of toxic chemicals with ambient air levels. Furthermore, emission standards for UF-bonded wood products have been developed that allow the prediction of formaldehyde levels under various product use conditions before formaldehyde emitting products are installed. 

Wallace LA. 1991. Comparison of risks from outdoor and indoor exposure to toxic chemicals. 

Our environment contains various toxic chemicals. Beginning indoors, where we live and spend most of our time, and in the materials we use and come into contact with, there are a number of chemicals, any of which can affect human health in different ways and to different extents. 

Some of these plastics and rubbery materials can cause some health hazards to humans, mostly due to the additives that they contain. These hazards are in addition to other possible sources of toxins indoors. In fact, the environment of modern society, both indoors and outdoors, can (unfortunately) full of a number of toxic chemicals. And specifically in the case of indoors, the concentration of toxics can be even higher and more critical than their counterparts in the outdoors, because there is a closed environment involved with the inside. According to a study by US Federal Environmental Protection Agency (EPA), indoor air is often a greater source of exposure to hazardous chemicals than is outdoor exposure . 

Cavity insulation applications, where a solid foam is produced in situ inside the cavity walls, without dismantling the walls are done hy direct injection of the liquid mixture of components and catalyst together into the cavity. This method is simple enough to carryout, but has the risks of carrying toxic chemicals and remnants of monomer with the foam structure, that can later migrate slowly indoors. 

Some Toxic Chemicals that Can be Found Indoors... 

Table 12.1 is a general list of some toxic compounds that are commonly found indoors, due to construction materials [19]. One should consider the fact that each indoor space is unique and a specific indoor space may have different toxic chemicals compared to another space. 

Toxic chemicals emitted from indoor sources are particularly dangerous to young children who spend much of their time inside their homes. The sources of toxic chemicals in sick buildings include ... 

To date (beginning of 2011) there are no national indoor air standards for toxic chemicals in North America, Europe, or Asia. 

Exothermic chemical reactions Endothermic processes pressure Material handling and transfer Enclosed or indoor process units Access relief pressure Drainage and spill control Toxic materials Sub-atmospheric Operation in or near flammable range Dust explosion... 

Lewis, R.G. (1989) Advanced methodologies for sampling and analysis of toxic organic chemicals in ambient, outdoor, indoor, and personal respiratory air. Journal of the Chinise Chemical Society, 36, 261-77. 

A great deal of chemical transformation takes place before consumers receive their furniture, flooring, and other indoor building materials. Polymerization of glues, coatings and plashes, or heat processing of manufactured wood products, generates volatile by-products that can continue to be emitted from the material after it has been installed. Once installed, further transformations increase the load of odorous or toxic gas-phase species (Uhde and Salthammer, 2007). Reactions discussed here include oxidation and hydrolysis. 

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