Carboxyhemoglobin Levels in New York City Runners

In brief: Carboxyhemoglobin (COHb) blood levels were measured in 16 New York City runners before and after one-half hour of exercise. Subjects exercised along a highway and in a park under similar weather conditions during rush-hour traffic. These COHb levels were compared to those of ten healthy, nonsmoking volunteers who stood quietly for the same time period at one of the exercise locations. The runners' COHb rose during exercise at both locations from 1.7% to 5.1% and from 1.3% to 4.2% (p <.001). COHb levels also increased in the nonrunners but to a lesser extent (from 0.83% to 2.44%, p <.05). The data indicate that running or standing near traffic in an urban area raises COHb to the levels found in chronic cigarette smokers. These findings quantify potentially harmful exposure to carbon monoxide fumes in an urban environment.