Atmosphere Is Filled With Toxic Chemicals Which

¶ … atmosphere is filled with toxic chemicals which technology and policy tries to deal with and eliminate in various ways. Reducibly, however, certain workers have to work with toxic chemicals. The question then becomes one of how to make this environment as healthy as possible and how to rid the environment of these elements in as rapid and complete a ways as possible so that the atmosphere remains healthy for both themselves and fellow workers.

Two types of ventilation systems have been created for diffusing toxic factors. They are called the Dilution (or general) ventilation system and the Local exhaust ventilation system. Each has its particular advantages and disadvantages as well as its particular qualities. These will be discussed in the following essay so that the reader, were he or she compelled to select one above the other, would know which to choose.

The key difference between the two systems is that whilst Dilution (or general) ventilation system 'dilutes' the contaminated air by mixing it with uncontaminated, non-polluted air, local exhaust ventilation captures the polluted air at or near the source and directs it ('exhausts' it) outside. This is the closest to the air conditioning system that we have in our private homes.

Both types of ventilation system deal with contaminated substances and diffuse its presence. Local exhaust ventilation traps contaminated air in or near the source and directs it outside in contrast to dilution ventilation that directs throughout the workspace. Local exhaust ventilation is usually used in the following cases: For air contaminants that are strongly toxic; for significant amounts of dusts or fumes; in the case of few emission sources; and when emission sources infiltrate the workers' breathing zones. In short, local exhaust ventilation is more effective for toxic chemical pollutants than dilution ventilation is.

Dilution ventilation, on the other hand, works by spreading the polluted air throughout the building, via fans in ceiling and walls, thereby mixing polluted air with unpolluted air and diminishing the toxic effect. Whilst weakening the polluted air, it also has the detrimental effect of introducing the polluted air to those who are further from the source of pollution.

Dilution ventilations have the following limitations: They cannot remove contaminants entirely; they cannot be used for strongly toxic chemicals; they are ineffective for dusts, metal fumes or large amounts of gases or vapors; they require large amounts of air to be heated or cooled; and they cannot handle surges of gases or vapors or irregular emissions. On the other hand, dilution ventilation is usually cheaper than exhaust ventilation in installation and operating costs. It is also easier in that it requires less maintenance and upkeep than exhaust ventilation.