The easiest way to avoid exposure to outdoor tobacco smoke air pollution is to be located a reasonable distance away from active smokers. For a single smoker, this distance is approximately 2 meters (6 feet) or more. However if one is directly downwind from a smoker for a significant time period, the distance will likely have to be greater to avoid exposure. We detected air pollution as far away as 9 to 12 feet from a single smoker. In addition, if there are multiple smokers, the distance will have to be increased; for example, if there are two or three active smokers present, moving to 6 or more meters (about 20 ft) away from the group may be necessary.