buildup in levels of oxides and inorganic sulfates
from the local steel and zinc smelters. More than
20 individuals died and 6,000 people developed
respiratory problems. The official government
report [57] on the Donora episode noted that the
health effects were likely related to a combination
of contaminants and identified sulfur dioxide as a
chief culprit. The word smoke did not appear in
the report. The attention previously focused on
smoke was now broadening to include other airborne materials and, indeed, more broadly to air
quality.
Despite early concerns about whether airborne
materials could cause disease, relatively little
research was conducted prior to World War I to
improve our knowledge of the relationship
between the air pollution and disease. The unfortunate use of poisonous gases in World War
I provided a stimulus for developing a better
understanding of how these specific agents produced disease. Unfortunately, the meager literature generated indicates that research in this area
was not substantial or very long-lasting. In retrospect, the lack of research related to airborne
toxicants is probably not surprising considering
the generally low level of biomedical research
activity in the first third of the twentieth century.
The strong preventive medicine orientation that
exists today toward diseases of both occupational
and environmental origin had not yet developed.
Between World War I and World War II, concern for airborne materials impacting on human
health centered primarily on occupational exposures. World War II brought with it renewed concern for purposeful exposures of people to toxic
gases and biological agents. In both the United
Kingdom and the United States, major research
efforts were conducted to better understand the
effects of these agents thereby providing
improved approaches to defending against their
use and effects. World War II also brought with it
major research efforts focusing on the potential
toxic effects of uranium and newly discovered
radionuclides such as plutonium and fission product related to the manufacture and use of nuclear
weapons and, later, the development of nuclear
reactors as energy sources to generate electrical
power. These activities are noteworthy since
many of the basic concepts of aerosol science
and inhalation toxicology trace their roots to
those research efforts.
The post-World War II era brought with it an
increased awareness of air pollution arising from
another source – motor vehicles. Perhaps nowhere
was this more the case than in the Los Angeles
basin with its marked increase in population,
industry, and cars. As concern increased for the
Los Angeles smog in the late 1940s and 1950s, the
name “Bay of Smokers,” which was coined in
1542 by Juan Rodrigues Cabrillo for San Pedro
Bay, took on a contemporary tone. Haagen-Smit
[25] of the California Institute of Technology
reported the scientific basis for photochemical
smog – reactions among oxides of nitrogen and
hydrocarbons from vehicle exhaust in the presence of sunlight produced ozone and other photochemical oxidants that were the key components
of Los Angeles smog. It is noteworthy that his
early research was motivated by understanding
the effects of smog on citrus fruit production.
Haagen-Smith’s findings were another key factor
in broadening the concern for air quality from
smoke to ozone and other air contaminants.
Post WWII then was a major and continuing
increase in the use of airplanes both to transport
people and goods. Indeed, transport of goods by
aircraft is a central element of the global economy
that emerged in the latter part of the twentieth
century. As with ships, aircraft as sources of air
pollution did not attract much attention in the late
twentieth century when attention began to focus
on air quality in the vicinity of major airports. In
the case of some areas, such as the Los Angeles
International Airport and a nearby harbor, concern
has developed for the contribution of multiple
sources: aircraft, cargo ships, locomotives, trucks,
and passenger cars.
So far the discussion has centered on air pollution from combustion of hydrocarbons, from
recently fixed carbon in wood and other plant
materials to the fossil fuel energy sources, coal,
oil, and natural gas, created in earlier geologic
eras. With each of these fuel sources hydrocarbons are combusted releasing thermal energy, CO,
CO 2 , H 2 O, variable amounts of Nitrogen Oxides,
and traces of other elements.
10
Air Quality Guidelines and Standards
from the local steel and zinc smelters. More than
20 individuals died and 6,000 people developed
respiratory problems. The official government
report [57] on the Donora episode noted that the
health effects were likely related to a combination
of contaminants and identified sulfur dioxide as a
chief culprit. The word smoke did not appear in
the report. The attention previously focused on
smoke was now broadening to include other airborne materials and, indeed, more broadly to air
quality.
Despite early concerns about whether airborne
materials could cause disease, relatively little
research was conducted prior to World War I to
improve our knowledge of the relationship
between the air pollution and disease. The unfortunate use of poisonous gases in World War
I provided a stimulus for developing a better
understanding of how these specific agents produced disease. Unfortunately, the meager literature generated indicates that research in this area
was not substantial or very long-lasting. In retrospect, the lack of research related to airborne
toxicants is probably not surprising considering
the generally low level of biomedical research
activity in the first third of the twentieth century.
The strong preventive medicine orientation that
exists today toward diseases of both occupational
and environmental origin had not yet developed.
Between World War I and World War II, concern for airborne materials impacting on human
health centered primarily on occupational exposures. World War II brought with it renewed concern for purposeful exposures of people to toxic
gases and biological agents. In both the United
Kingdom and the United States, major research
efforts were conducted to better understand the
effects of these agents thereby providing
improved approaches to defending against their
use and effects. World War II also brought with it
major research efforts focusing on the potential
toxic effects of uranium and newly discovered
radionuclides such as plutonium and fission product related to the manufacture and use of nuclear
weapons and, later, the development of nuclear
reactors as energy sources to generate electrical
power. These activities are noteworthy since
many of the basic concepts of aerosol science
and inhalation toxicology trace their roots to
those research efforts.
The post-World War II era brought with it an
increased awareness of air pollution arising from
another source – motor vehicles. Perhaps nowhere
was this more the case than in the Los Angeles
basin with its marked increase in population,
industry, and cars. As concern increased for the
Los Angeles smog in the late 1940s and 1950s, the
name “Bay of Smokers,” which was coined in
1542 by Juan Rodrigues Cabrillo for San Pedro
Bay, took on a contemporary tone. Haagen-Smit
[25] of the California Institute of Technology
reported the scientific basis for photochemical
smog – reactions among oxides of nitrogen and
hydrocarbons from vehicle exhaust in the presence of sunlight produced ozone and other photochemical oxidants that were the key components
of Los Angeles smog. It is noteworthy that his
early research was motivated by understanding
the effects of smog on citrus fruit production.
Haagen-Smith’s findings were another key factor
in broadening the concern for air quality from
smoke to ozone and other air contaminants.
Post WWII then was a major and continuing
increase in the use of airplanes both to transport
people and goods. Indeed, transport of goods by
aircraft is a central element of the global economy
that emerged in the latter part of the twentieth
century. As with ships, aircraft as sources of air
pollution did not attract much attention in the late
twentieth century when attention began to focus
on air quality in the vicinity of major airports. In
the case of some areas, such as the Los Angeles
International Airport and a nearby harbor, concern
has developed for the contribution of multiple
sources: aircraft, cargo ships, locomotives, trucks,
and passenger cars.
So far the discussion has centered on air pollution from combustion of hydrocarbons, from
recently fixed carbon in wood and other plant
materials to the fossil fuel energy sources, coal,
oil, and natural gas, created in earlier geologic
eras. With each of these fuel sources hydrocarbons are combusted releasing thermal energy, CO,
CO 2 , H 2 O, variable amounts of Nitrogen Oxides,
and traces of other elements.
10
Air Quality Guidelines and Standards