Air Pollution and Global Change 173
the respiratory system. The presence of particulates, which offer surfaces
that facilitate chemical reactions, accelerates the oxidation of SO 2 to SO 3 ,
which is more toxic. Suspended particulate matter causes health damage in
any case, depending on the toxicity of the substances it contains, e.g. lead,
mercury, cadmium (Chapter 7), asbestos (Section 6.7) etc.
Research on the effects of air pollution on human health does not easily
reach specific conclusions. Conducting realistic experiments on humans is
difficult, and inference through observations (e.g. epidemiological studies)
is hindered due to the different exposure and sensitivity of different persons
and the amount of time needed for the manifestation of illness (e.g. cancer).
spheric pollutants and the synergy of their action, have not yet allowed satisfactory knowledge about the relationship between air pollution and human
health. Nevertheless, in pollution-burdened cities and industrial areas, air
pollution causes—although in a non-dramatic way—a systematic morbidity
and mortality increase.
9.2 acid rain
A serious environmental problem, directly connected with air pollution and
manifested in a local or regional level, is acid rain. This phenomenon was
first reported in industrial areas of Britain in the middle of the 19th century .
It has been observed and studied in the past decades mainly in Central and
Western Europe as well as in Eastern and Northern America. The great
concern that it caused contributed to the establishment of significant measures for the decrease of air pollution (Chapter 10, Section 10.2), resulting
in a net amelioration of the situation. However, energy production in many
developing industrial countries is based on fossil fuels and especially on
coal, which creates preconditions for the emergence of related pollution
phenomena in new areas of the planet.
A more correct term for acid rain is acid deposition, because acidity can
be deposited not only by rain or precipitation but also by gases or dust. The
phenomenon is due mainly to anthropogenic emissions of SO 2 and NO x
in the atmosphere that have as a consequence the presence of sulphuric
and nitric acid in the raindrops. The pollutants come from industrial areas,
urban agglomerations and highways, and they are oxidized in the atmosphere and react with vapours forming sulphuric and nitric acid respectively:
SO O H O H SO
2
4
2
2
2
+
+
→
NO O H O HNO
x
3
+
+
→
2
2
the respiratory system. The presence of particulates, which offer surfaces
that facilitate chemical reactions, accelerates the oxidation of SO 2 to SO 3 ,
which is more toxic. Suspended particulate matter causes health damage in
any case, depending on the toxicity of the substances it contains, e.g. lead,
mercury, cadmium (Chapter 7), asbestos (Section 6.7) etc.
Research on the effects of air pollution on human health does not easily
reach specific conclusions. Conducting realistic experiments on humans is
difficult, and inference through observations (e.g. epidemiological studies)
is hindered due to the different exposure and sensitivity of different persons
and the amount of time needed for the manifestation of illness (e.g. cancer).
spheric pollutants and the synergy of their action, have not yet allowed satisfactory knowledge about the relationship between air pollution and human
health. Nevertheless, in pollution-burdened cities and industrial areas, air
pollution causes—although in a non-dramatic way—a systematic morbidity
and mortality increase.
9.2 acid rain
A serious environmental problem, directly connected with air pollution and
manifested in a local or regional level, is acid rain. This phenomenon was
first reported in industrial areas of Britain in the middle of the 19th century .
It has been observed and studied in the past decades mainly in Central and
Western Europe as well as in Eastern and Northern America. The great
concern that it caused contributed to the establishment of significant measures for the decrease of air pollution (Chapter 10, Section 10.2), resulting
in a net amelioration of the situation. However, energy production in many
developing industrial countries is based on fossil fuels and especially on
coal, which creates preconditions for the emergence of related pollution
phenomena in new areas of the planet.
A more correct term for acid rain is acid deposition, because acidity can
be deposited not only by rain or precipitation but also by gases or dust. The
phenomenon is due mainly to anthropogenic emissions of SO 2 and NO x
in the atmosphere that have as a consequence the presence of sulphuric
and nitric acid in the raindrops. The pollutants come from industrial areas,
urban agglomerations and highways, and they are oxidized in the atmosphere and react with vapours forming sulphuric and nitric acid respectively:
SO O H O H SO
2
4
2
2
2
+
+
→
NO O H O HNO
x
3
+
+
→
2
2