Wind gusts airborne detritus down toward Ichigaya-yanagicho, an intersection in central Tokyo infamous for having the highest density of carbon monoxide in Tokyo during the 1970s. Researchers at the time linked this poisonous gas to the area's high incidence of lung cancer, and the outcry from citizens helped stimulate stricter automobile emission standards in Japan. Today, thanks to wind, as well as the winds of change, the air seems pretty clear.