Hazardous Wastes in the Atmosphere

Primary air pollutants such as these are almost always of concern to people only adjacent to the site or to workers involved in site remediation. One such substance that has been responsible for fatal poisonings at hazardous waste sites, usually tanks that are undergoing cleanup or donolition, is the highly toxic hydrogen sulfide gas, H2S. 

An important characteristic of a hazardous waste material that enters the atmosphere is its pollution potential. This refers to the degree of environmental threat posed by the substance acting as a primary pollutant or to its potential to cause harm from secondary pollutants. 

Another characteristic of a hazardous waste material that determines its threat to the atmosphere is its residence time, which can be expressed by an estimated atmospheric half-life, Among the factors that go into estimating atmospheric half-lives are water solubilities, rainfall levels, and atmospheric mixing rates. 

Hazardous waste compounds in the atmosphere that have significant water solubilities are commonly removed from the atmosphere by dissolution in water. The water may be in the form of very small cloud or fog particles or it may be present as rain droplets. 

Some hazardous waste species in the atmosphere are removed by adsorption onto aerosol particles. Typically, the adsorption process is rapid so that the lifetime of the species is that of the aerosol particles (typically a few days). Adsorption onto solid particles is the most common removal mechanism for highly nonvolatile constituents such as benzo(a)pyrene. 

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