Volatile Organic Compounds

Volatile organic compounds represent a wide range of organic chemicalsthat are emitted into the atmosphere. Combined with nitrogen dioxide, these chemicals contribute to the formation of ground-level ozone. Many types of volatile organic compounds are emitted into the atmosphere. Trees are the largest source of volatile organic compounds; motor vehicles rank second. Stationary sources (storage and transports, solvent use) release only a small portion of the total volatile organic compounds in the Southern Appalachian region. Nationally, the main source of volatile organic compounds from human activity is associated with those released from highway vehicles. Emissions of volatile organic compounds have increased nationally between 1940 and 1970 and have decreased since 1970 (see figure) (EPA 1995). Overall, future emission levels of volatile organic compounds in the Southern Appalachians are projected to increase by 2010 as vehicle miles traveled increase with an increasing population (SAMAB 1996c).