The main externalities of air pollution include:
- Economic Costs. They include a wide range of externalities like damage to property, superstructures and infrastructure and loss of productivity of people and crops. Acid rains (and depositions), smog and ozone pollution change the temporal scale during which investments on infrastructure can be amortized, their maintenance and replacement. For instance, buildings that are often amortized over 20-30 years may lose from one to five years of useful life (depending on the materials involved) when progressively damaged by forms of oxidation. Historical structures (churches, monuments, etc.), tend to be located in heavy traffic central areas, are damaged by oxidation / demineralization and can have expensive restoration costs. A number of European cities are facing this problem, notably in England, France and Italy. Besides health costs, air pollution directly impacts on labor productivity force in terms of total people-hours with time lost at home, health facilities or attending for the care of others. Crops and timber products are also directly affected by air pollutants, and losses may be expected in their yield.
- Social Costs. Almost all air pollutants have some physiological impacts on human beings, mostly, but not limited, to the cardiovascular and respiratory systems. Some impacts are clear and straightforward like carbon monoxide, while others are far more pernicious and indirect like lead and HC/VOCs. It would be difficult, for instance, to attribute a case of lung cancer to general air pollution or to other causes like smoking, furthermore extract the transport contribution to it. Considering that the majority of the population lives in urban areas and are thus continuously exposed to air pollution emissions, transportation accounts for a major source of social costs. Medical costs associated with air pollution thus have a fairly wide range of consequences. The burden of diseases on society, such as the loss of life expectancy can also be a general measure, if it is possible to weight the contribution of transportation.
- Environmental Costs. They include general damage done to ecosystems through the atmosphere, except for what may be considered economically useful to human activities (like crops). Environmental costs are the most difficult, if possible, to assess in a comprehensive manner. It could refer to biological diversity and sustainability, which air pollutants have a high proficiency to affect.