High levels of pollution ups risk of having heart attack
A study has found that high levels of pollution could increase the risk of having a heart attack for up to six hours after exposure, though no increased risk after the time frame was seen.
Given the transient nature of the increased risk, they speculate that the heart attack would have happened anyway and was merely brought forward by a few hours.
This is known as a short-term displacement or `harvesting` effect of pollution.
Krishnan Bhaskaran, an epidemiologist from the London School of Hygiene and Tropical Medicine, and colleagues reviewed 79,288 heart attack cases from 2003 to 2006 and exposure, by the hour, to pollution levels.