Type	Field	Possible Measures
Economic Costs	Structures and infrastructure	Loss of useful life (amortization)
		Replacement and restoration costs
	Labor productivity	Men-hours-wage losses
	Agricultural productivity	Output/surface decrease
		Biomass (e.g. timber) restoration time losses
Social Costs	Public health	Medical services costs
		Loss of life expectancy
Environmental Costs	Damage to ecosystems	Biological diversity and sustainability

Externalities of Air Pollution

• Economic Costs. They include a wide range of externalities like damage to property, structures 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 and must be replaced. 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 in their structures by oxidation. Historical structures (churches, monuments, etc.), which have the tendency 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 the productivity of the labor force in terms of total man-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 quantities produced per unit of surface.
• 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 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. Loss of life expectancy could also be a general measure, if it is possible to weight the contribution of transportation.
• Environmental Costs. They include general damage done to the ecosystem 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.