Chloroform
Volatile Organic Compounds (VOCs)
Solvent usage in motor vehicle manufacturing and
Formed
utilities, as well as other combustion sources.  Wastewa-
ter treatment and other waste disposal operations
VOCs refers to a varied group of  chemicals that are
contribute to these emissions.
easily vaporized at room temperature.  They are called
organic because their molecular structures are based on
carbon atoms frequently linked to one another in chains.
VOCs can react with other air pollutants to generate
Chromium compounds
ozone, and also react with ozone to form other toxic air
pollutants.  The contribution of  individual VOCs to
Emissions are produced by fuel combustion, steel/metal
such reactions is dependant on the VOCs’ photochemi-
manufacturing and processing, motor vehicle and
cal reactivity (Ref. 27).  Included in the group of  VOCs
refractory manufacturing.  Dry cement manufacturing
is a variety of  hydrocarbons such as alkanes, alkenes,
also contributes to chromium compound emissions.
alkynes, aromatics (such as benzene and toluene, alde-
hydes, ketones, esters and some chlorinated compounds)
(Ref. 28).  VOCs can also react to form particulate
Formaldehyde
matter.
Motor vehicles, formaldehyde production, petroleum
Sources
refining, oil and gas combustion and building materials.
Fireplaces and solvents also contribute to emission
Sources of  VOCs are diverse, including: fossil fuel
levels.
vaporation and combustion, solvent use, and industrial
processes.  Gasoline handling and fuel transfer and
distribution operations are among the  significant
Nickel compounds
contributors of  these emissions.
Various smelting manufacturing processes
Effects
The chemicals grouped as VOCs are very diverse, and,
Perchloroethylene (tetrachloroethylene)
as a result, their effects are also wide ranging.  Several of
them are HAPs and include some of  the individual
The dry cleaning industry, textile processing and metal
pollutants discussed above.  Health effects may include
degreasing
eye, nose, and throat irritation, headaches, loss of
coordination, and nausea.  More toxic VOCs may cause
damage to liver, kidney, and central nervous system.
Trichloroethylene
Some VOCs have been shown to cause cancer in
animals and some are suspected or known to cause
Emissions attributed to metal degreasing and motor
cancer in humans.  For example, long-term exposure to
manufacturing
benzene may increase susceptibility to leukemia in
humans.
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