The most comprehensive and systematic review of worldwide traffic emissions makes it quite clear that, although there are "substantial gaps" in what we know about breathing traffic pollution-affected air and its effect on health, there is enough evidence to show that it does cause asthma exacerbation in children and that there is "suggestive evidence" of other health consequences. The panel, which drew its conclusions after careful review of the results of over 700 studies from around the world linking traffic and disease, found that up to 45 percent of the population in larger cities could be affected by traffic emissions. At a time when we there is so much talk about the cost of health care, we can't help but think this externality would be a great place to apply income derived from any higher gas taxes.
[Source: HEI via Green Car Congress | Image: Al Pavangkanan - C.C. License 2.0]