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ASTHMA

Figure 1

Figure 2

eases decreased during the strike and returned to prior levels when Ozone in controlled exposure studies has been shown to drop
the mill re-opened. 2 forced vital capacity (FVC) and forced expiratory volume (FEV1)
1
Diesel exhaust and diesel exhaust particles have been shown to rapidly probably due to a sensory neural reflex. Ozone also leads
have an immediate effect on lungs. Mast cells and neutrophils are to increased neutrophilic inflammation within a few hours of ex-
1
increased.1 Studies have shown an increase in inflammatory markers posure. Studies have shown that there are increased hospital ad-
3
and antioxidants like glutathione. More interestingly diesel exhaust missions 24 to 48 hours after ozone exposure. 1
has been associated with increased incidence of allergy, which is an- Keeping track of these various pollutants and deciding when they
other trigger for asthma. This association was first noted in Japan. are a significant threat to our respiratory health can be problematic
In 1951 there were 20,000 diesel cars in Japan, by 1988 there were as each one has separate values and times of exposure before they
7,600,000. Before World War II, allergy to Japanese cedar was very become significant (see NAAQS above). The EPA has conveniently
rare.4 By 1974 the overall incidence had risen to 3.8% and by 1981 developed an Air Quality Index (AQI) that integrates all the various
4
was 9.4%. The highest incidence (13.2%) occurred in schoolchild- pollutants (see Figure 1). They also explain what these values mean
ren living in areas with cedar trees and heavy traffic.4 Further studies for different populations (see Figure 2). The information can be ac-
have shown that diesel exhaust particles are associated with a switch cessed at https://www.airnow.gov/index.cfm?action=aqibasics.aqi
to a T helper cell type 2 (Th2) which is associated with increased
IgE production. 1
Ninety three percent of sulfur dioxide comes from point sources The actual values for San Antonio each day and the predicted val-
(factories) and while studies have shown it is a potent bronchocon- ues for tomorrow can be found at
strictor, its affects are often difficult to separate from particulate https://www.airnow.gov/index.cfm?action=airnow.local_city&map
2
pollution. Nitrogen dioxide is a potent bronchoconstrictor as well, center=0&cityid=240 . The EPA also publishes an extensive doc-
but it is also a precursor of ozone. 2 ument called the Menu of Control Measures which lists the things
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visit us at www.bcms.org 31