GEO Brasil - UNEP

the state of the atmosphere
Box 1
the state of environment in Brazil
Studies developed in São Paulo
indicate a 30 percent increase in the
number of deaths caused by
respiratory diseases in children under
the age of five This could be related to
an increase of 75mg/m3 in the
concentration of nitrogen dioxide
(WHO, 2000)
Also in São Paulo, a study
developed by the State Secretariat of
Health in partnership with the
University of São Paulo and the
Technology and Environmental
Sanitation Company of the State of São
Paulo (CETESB), demonstrated that 10
percent of hospital stays for respiratory
diseases for children and nine percent
of deaths for the elderly are related to
the high atmospheric concentrations
of particle material (FREITAS, 2002)
The estimated number of deaths
caused by problems stemming from
atmospheric pollution in the world is
around three million This number
represents five percent of the total of
55 million deaths that occur annually
in the world (WHO, 2000)
In some populations around 30 to
40 percent of asthma cases and 20 to
30 percent of all respiratory illnesses
are related to atmospheric pollution
(WHO, 2000)
In some populations, a reduction
of 20 percent in air pollution in the air
in closed environments could reduce
the mortality rates related to severe
respiratory infections by at least four
to eight percent (WHO, 2000)
Under the denomination “particulate material” the
pollutants are joined by “total suspension particles”, “
inhalable particles ” and “smoke” They are particles of solid
or liquid material, which are suspended in the air in the
form of dust, fog, aerosol, smoke, soot etc The main sources
of these substances are thermoelectric plants, steel
industries, burnings, diesel vehicles, cement factories and
some branches of the chemical industry The resulting
effects from the increase of these pollutants concentration
include breathing problems such as asthma and bronchitis
Besides, such pollutants may cause damages to vegetation,
reduction of visibility and soil contamination (CETESB
1999)
contributed to its exhaustion The main groups of such
substances are the CFCs, the molecules at which would be
degraded by solar radiation in high atmosphere, releasing
chlorine atoms, which, would then react with the ozone,
destroying it
Other ozone destructive substances are the haloes, carbon
tetrachloride, methyl chloroform, hydrofluorocarbons
(HCFCs), hydro bromofluor carbons, brome chloromethane
and methyl bromide Such substances are widely used in
air-cooling systems, as aerosol propellants, in foam
production and use of solvents, and in equipment for fire
extinction, among other uses
2 The Ozone Layer Reduction Problem
During the 70’s and 80’s, several studies alerted for a possible
reduction of the ozone layer, and consequent increase in
the ultraviolet radiation incidence At the beginning, the
problem was diagnosed in the Southern Hemisphere,
particularly over the Antarctic, where a large rarefaction
(“hole”) in the concentration of ozone was identified
Subsequently, the same phenomenon was observed over
the Arctic 1 ; however, in smaller intensity
In Parallel, studies demonstrated that certain substances
produced by man and which contained chlorine (Cl) and
bromine (Br), when in contact with the stratospheric ozone,
In order to avoid worsening the problem, in 1977, the United
Nations Program for the Environment (UNPE) co-ordinated
a meeting of specialists from several countries In 1981,
UNPE created a work group with the main objective of
establishing bases for the organisation of a global
convention, aiming at fighting the causes of ozone layer
reduction The Vienna Convention, as it became known,
was held in 1985 and it was ratified by approximately 30
countries, which were committed to adopting appropriate
measures to protect human health, and the environment
from the negative effects of the ozone layer reduction The
adoption of a series of tools was also established, aiming at
facilitating the co-operation in research, and information
exchanges on the production and consumption of ozone
1
In these regions the cold atmosphere and the presence of polar clouds that retain a certain amount of reactive substances make the problem more serious, as
discussed in the following text These substances are particularly those that contain chlorine and bromine The destruction of the polar ozone layer is accelerated by
atmospheric circulation that transports these substances from the tropics to the poles
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