Geoscience Reference
In-Depth Information
of the urban population, the conditions of their homes, and interior pollution that
measurements used to record surrounding pollution do not take into consideration.
- It is extremely difficult to carry out research on an air sample and to model
levels of exposure to pollution. Research in this field combines both fluidity and
environmental dynamics. There can be a big difference between the actual
population living in a region and the proportion of this population that has been
exposed to certain pollutants. This can be explained by commuting and population
travel from home to the office. The actual amount of pollution that a population is
exposed to may vary substantially and this can be explained by the amount of time
the people spend in the area, and by the location or other characteristics associated
with the buildings in which they find themselves when they are in the area. The
conditions of a building, as well as the pollution that exists inside the building, can
strongly influence the amount of pollution that people are exposed to. Studies into
the summer heat wave that occurred in Paris in 2003 have shown how the conditions
of the buildings in the city influenced the death rate of those who died due to the
heat wave [INV 04]. These studies highlighted the social and vertical stratification
that existed in 19
th
century cities in France, and which could only be recognized by
3D (3D) GIS.
- The use of maps or GIS makes it possible to compare pollution levels with
normal air samples and, as a result, it becomes possible to partly identify a potential
health risk, which is only valid for the surrounding air.
- Epidemiological studies carried out to study the health risks associated with
exposure to pollution use values that are measured by the AASQA, meaning that
there is no need for concern about the actual amounts of pollution that are inhaled
by the inhabitants of a city. It is safe to assume that the health risk associated with
air pollution is low; however, large study samples are required in order to produce
reliable results. Measurements recorded in the surrounding air are not enough on
their own to define a health risk. These measurements only give an approximate
indication of the exact amount of exposure that an individual or group of individuals
has had to atmospheric pollution.
For any type of disease to develop, the pollutants must penetrate an organism.
The effects of pollution become much worse as the actual dosage
15
of pollution that
a person has been exposed to increases. Exposure to pollution corresponds to the
exact dosage of pollution that a person has been subjected to and can be measured
according to the following three factors:
- the concentration of pollutants present in the atmosphere: car drivers, cyclists,
traffic users, and children (who find themselves in a location that is close to car
exhaust pipes) are exposed to a higher dosage of pollution. In certain streets that are
protected from the wind, pollution levels may be higher;
- the length of time a person is exposed to pollution: city dwellers normally
spend more than 80% of their time in buildings or in transport. However, it is the
people who work outside who are exposed the most to pollution;
15 Quantity of a pollutant inhaled by a person.
