University of Cagliari
Mercoledì 27 ottobre 2010, ore 9:15
Aula 3, Palazzo delle Scienze
Nell’ambito del programma Socrates-Erasmus, il prof. Sylvain Billet dell’Université du Littoral-Côte d’Opale (France) terrà una conferenza su "Health Effects of Air Pollution"
Health Effects of Air Pollution
The concept of environment is usually used to describe a wide range of non-genetic factors such as diet, lifestyle and infectious agents. Human activities are strongly implied in environment alterations, with marked effects since the industrial revolution of the XIXth century. These modifications of the environment are called pollutions. Among them, atmospheric ones are known to cause severe health effects. Emission sources have to be considered when dealing with air pollution, and may include natural processes such as wildfires, volcano eruption and dust storms, as well as anthropogenic activities. The atmosphere represents a huge, complex and stratified system constituted by several distinct layers, each of them exhibiting specific characteristics such as temperature or composition. Even in the lowest layer, where human beings live, the atmosphere composition is heterogeneous, reflecting both local sources and long-range transport of pollutants, but also depends on meteorological variables like wind and rain. Man-made pollutions encompass combustion processes used for heating, power production, industry, and motor vehicles. Regardless the magnitude of air pollution exposure, it is common practice to categorize its constituents as gases or particles. The latter belongs to the class of poorly soluble particles that include carbon black, coal mine dust, and titanium dioxide too. The class is rapidly expanding with engineered nanoparticles. For example, urban air is known to contain a complex mixture of oxidizing gases and particles of different sizes and composition. This geographical heterogeneity of the atmosphere causes a diversity of the adverse effects on human health that can be related to air pollution exposure. However, an increasing number of publications show that exposure to pollutants such as airborne particulate matter and ozone has been associated with increases in mortality and hospital admissions due to some respiratory and cardiovascular diseases. These effects have been found in short-term studies, which relate day-to-day variations in air pollution and health, and long-term studies, which follow cohorts of exposed individuals over time. Effects have been seen at very low levels of exposure, and it is still unclear whether a threshold concentration exists for particulate matter and ozone below which no effects on health are likely to happen. Among the high number of studies, two US cohort surveys suggested that exposure to fine particulate matter in the air was associated with life shortening. Exposure to air pollutants can damage human beings and animals biomolecules, and this may cause diseases such as cancer. Exposure to whole diesel engine exhaust has been classified as probably carcinogenic to humans (group 2A) by the International Agency for Research on Cancer based on limited evidence in humans and sufficient evidence in experimental animals. More recently, epidemiological studies have shown associations between the level of fine particles in air pollution and lung cancer mortality.
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