Volatile Organic Compounds (VOC) 1985-2007

Volatile Organic Compounds (a.k.a. Reactive Organic Gases (ROG)) are precursors to the formation of ozone (O₃). The natural component of the ozone (O₃) background originates from three sources: stratospheric O₃ which is transported down to the troposphere, O₃ formed from the photochemically-initiated oxidation of biogenic and geogenic methane and carbon monoxide, and the photochemically-initiated oxidation of biogenic VOCs. The magnitude of this natural part cannot be precisely determined for two reasons. First, the part due to long-range transport of anthropogenic precursor emissions is not known. Second, NO_x plays an important role in the oxidation of methane, carbon monoxide and the biogenic VOCs and it is not possible to determine amount of O₃ that would have been formed just due to natural NOx emissions. However, some estimates can be made.

A wide array of health effects has been attributed to short-term (1 to 3 hrs), prolonged (6 to 8 hrs), and long-term (months to years) exposures to O₃. Those acute health effects induced by short-term exposures to O₃ concentrations as low as 0.12 ppm, generally occur while subjects are engaged in heavy (e.g., running) exercise, include: transient pulmonary function responses, transient respiratory symptoms and effects on exercise performance, increased airway responsiveness, transient pulmonary inflammation, and increased hospital admissions and emergency room visits for respiratory causes. Similar health effects have been observed following prolonged exposures to O₃, at concentrations of O₃ as low as 0.08 ppm and at lower levels of exercise than for short-term exposures. Although chronic effects such as structural damage to pulmonary tissue and impaired host defense mechanisms have been established in a substantial number of laboratory animal studies, there remains little of no evidence of association between ambient O₃ exposures and carcinogenicity and/or genotoxicity at this time O₃ and its transformation products also are a major component of pollution related acidic deposition and visibility degradation. is a criteria pollutant, and has a national ambient air quality standard (NAAQS) (exit DNR) . For more information please read the USEPA staff paper (PDF, 1554KB) on ozone.

A graph shows the number of stationary sources reporting volatile organic compound emissions from 1985-2007.

The graph above shows the reported actual amount of volatile organic compounds (VOC) emitted from stationary air pollution sources from 1985-2007 in the State of Wisconsin. A similar graph shows the actual tonnage of reported VOC from stationary sources from 1985-2007. The graph shows how the reported VOC emissions ranged from approximately 53,300 tons in 1985 to approximately 29,900 tons in 2007.

The VOC air emissions as reported from 1985-2007 were analyzed, sorted into Source Industrial Classification (SIC) code categories. SIC codes are four digit numbers assigned to each company supplying a general description of the products manufactured or sold by the company. A pie chart of the major industrial source categories showing the contribution the major source categories emitting VOC for that year can be seen by choosing any of the following years:

With the exception of Menominee County, all Wisconsin counties reported VOC emissions from 1985-2007 which are avaiable in an Excel spreadsheet (XLS, 30KB). This information was sorted in alphabetical order by county. This information does not include emissions from portable sources (i.e. rock crushers, hot mix asphalt plants.)

This information is also available by city in an Excel Spreadsheet (XLS, 142KB). This information was sorted first, alphabetically by county, and second, alphabetically by municipality in that county. This information does not include emissions from portable sources (i.e. rock crushers, hot mix asphalt plants.)

Information on each reporting company's actual 2007 volatile organic compound emissions (also known as Reactive Organic Gases or ROG) are also available in an Excel Spreadsheet (XLS, 306KB). This information was sorted according to facility identification number.

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