Urban pollution.

Air pollution represents a health risk for people living in urban environment. Urban air consists in a complex mixture of chemicals and carcinogens and its effects on health can be summarized in acute respiratory effects, neoplastic nonneoplastic (e.g. chronic bronchitis) chronic respiratory effects, and effects on other organs and systems. Air pollution may be defined according to origin of the phenomena that determine it: natural causes (natural fumes, decomposition, volcanic ash) or anthropogenic causes which are the result of human activities (industrial and civil emissions). Transport is the sector that more than others contributes to the deterioration of air quality in cities. In this context, in recent years, governments of the territory were asked to advance policies aimed at solving problems related to pollution. In consideration of the many effects on health caused by pollution it becomes necessary to know the risks from exposure to various environmental pollutants and to limit and control their effects. Many are the categories of "outdoor" workers, who daily serve the in urban environment: police, drivers, newsagents, etc.