Shilts, Randy, and William Greider.And the Band
Played On: Politics, People, and the AIDS Epidemic.
New York: St. Martin’s Press/Stonewall Inn Edi-
tions, 2000. Updated description of the outbreak
of the AIDS epidemics and how the lack of recog-
nition by agencies contributed to its spread. Shilts
was a newspaper reporter who later succumbed to
the illness.
Stine, Gerald.AIDS Update 2007. San Francisco:
Benjamin Cummings, 2007. Yearly update on re-
search into the AIDS virus, as well as information
about biological events that follow infection. Dis-
cussion about the progress of treatment is also in-
cluded. Preventives currently undergoing testing
such as preexposure prophylaxis are also de-
scribed.
Richard Adler
See also Cancer research; Drug use; Health care;
Homosexuality and gay rights; Johnson, Magic;
Medicine; Science and technology.
Air pollution
Definition Degradation of air quality by various
chemical and particulate agents.
Air pollution continued to be a major environmental
concern during the decade in spite of significant air-quality
improvements that had occurred and continued to occur. In
addition to the standing concerns of sulfur dioxide, nitro-
gen oxides, ozone, carbon monoxide, and particulates such
as lead in the atmosphere, the impact of greenhouse gases
in causing global warming was of concern.
The Clean Air Act of 1970 (CAA) continued to be
the major means of regulating air quality in the
1990’s. It would be amended in 1990 and 1997 to fur-
ther strengthen it and to deal with emerging prob-
lems. By the end of the 1990’s, the CAA had helped
to produce a significant improvement in air quality
in the United States. By 2000, there was a 29 percent
decrease in total pollutants in the air since 1970,
with a substantial amount of this decrease occurring
during the 1990’s. Lead in the atmosphere showed
the largest decrease, spurred on by the phaseout of
lead in gasoline. Sulfur dioxide (SO 2 ) levels im-
proved markedly. Nitrogen oxides in the atmo-
sphere continued to climb, a result of increased
automobile use. Smog—surface ozone, another
automobile-generated pollutant—also continued to
be a major problem. In spite of an improving situa-
tion, about half of the people in the United States
continued to breathe air that did not always meet
the standards of the CAA.
In addition to atmospheric pollution, indoor air
pollution was a developing concern during the
1990’s. In some cases, air pollutants are two to five
times more concentrated indoors than outside.
Modern sealed buildings often make it difficult to
bring in fresh air, and ventilating systems often circu-
late pollutants in office buildings. Various chemical
agents such as air fresheners can contribute to in-
door pollution. In addition, some types of fungi and
viruses could be found in large buildings, coming at
times from faulty cooling towers. The most danger-
ous form of indoor air pollution throughout the de-
cade came from cigarette smoke. During the 1990’s,
many local governments either regulated smoking
indoors or banned it completely in an effort to deal
with the impact of secondhand smoke.Sources of Pollution and Its Impact The usual cul-
prits noted above continued to be responsible for air
pollution during the decade. As was the case for ear-
lier decades, industrial production and automobiles
were responsible for most of the air pollution during
the 1990’s.
Sulfur dioxide continued to be the major form of
air pollution during the 1990’s, causing, among
other problems, acid deposition, which affected
water quality and killed fish as well as plants. Coal-
burning electric power plants were the major source
of SO 2 during the decade, producing between 80
and 85 percent of all SO 2. The problem of acid depo-
sition remained most acute in the eastern United
States in spite of significant cuts in emissions. The
CAA required that 445 power plants cut their sulfur
emissions by 50 percent in 1995, with another 700 re-
quired to cut emissions in 2000.
Nitrogen oxides in the atmosphere come from a
variety of sources, such as coal-fired power plants,
but approximately one-third come from motor vehi-
cle emissions. By 2000, nitrogen emissions were one-
third greater than sulfur emissions and had grown
by 4 percent from 1981 to 2000. Many nitrogen com-
pounds are part of surface-level smog and dissipate
readily, so are not a source of acid deposition. Cata-
lytic converters in U.S. automobiles provided a ma-
jor source of nitrogen emissions until the mid20 Air pollution The Nineties in America