A young man with his back to the camera is being watched by youths sitting at two picnic tables before a backdrop of grass and trees.
A young man with his back to the camera is being watched
To reflect concerns about the inherent limitations in the number of studies supporting a causal association between long-term exposure and mortality, an Alternative benefit estimate was derived from the large number of time-series studies that have established a likely causal relationship between short-term measures of PM and daily mortality statistics.