Page 421 - Fundamentals of Air Pollution 3E

III. Conversion of Physical Data and Criteria to Standards 373

TABLE 22-5
U.S. Ambient Air Criteria for Ozone
Concentration of ozone
in air (ppm)" Human symptoms and vegetation injury threshold
10,0 Severe pulmonary edema; possible acute bronchiolitis; decreased
blood pressure; rapid weak pulse
1.0 Coughing; extreme fatigue; lack of coordination; increased airway
resistance; decreased forced expiratory volume
0.5 Chest constriction; impaired carbon monoxide diffusion capacity;
decrease in lung function without exercise
0.3 Headache; chest discomfort sufficient to prevent completion of
exercise; decrease in lung function in exercising subjects
0.25 Increase in incidence and severity of asthma attacks; moderate eye
irritation
0.15 For sensitive individuals, reduction in pulmonary lung function;
chest discomfort; irritation of the respiratory tract, coughing and
wheezing. Threshold for injury to vegetation
0. 12 United States National Primary and Secondary Ambient Air Quality
Standard, attained when the expected number of days per
calendar year with maximum hourly average concentrations
above 0.12 ppm is equal to or less than 1, as determined in a
specified manner
3
" I ppm — 1958 fj.g m~ ozone.
Sources: Air Quality Criteria for Ozone and Other Photochemical Oxidants, EPA 600/8-78-
004. U.S. Environmental Protection Agency, Research Triangle Park, NC, April 1978; Revisions
to National Ambient Air Quality Standards for Photochemical Oxidants, Fed, Reg. Part V,
Feb. 9, 1979, pp. 8202-8237.
40 CFR § 50, July 1992.

The main philosophical question that arises with respect to air quality
standards is what to consider an adverse effect or a cost associated with
air pollution. Let us examine several categories of receptors to see the
judgmental problems that arise.

III. CONVERSION OF PHYSICAL DATA AND
CRITERIA TO STANDARDS

Although air quality standards are based predominantly on biological
criteria, students should understand the physical criteria that also deserve
consideration.
Most materials will deteriorate even when exposed to an unpolluted
atmosphere. Iron will rust, metals will corrode, and wood will rot. To
prevent deterioration, protective coatings are applied. Their costs are part