Every year air pollution is responsible for the premature deaths of over 3.7 million people worldwide, particularily because of its destructive effects on the cardiovascular system, and it is hence thought to be the primary cause for heart attacks. Most populations exposed to concentrated air pollution are often associated with increased heart attacks, lung cancer, DNA mutations, and premature births and deaths. It is the smaller particles (ranging in size from 2.5 micrometers or smaller) that are the most dangerous because of their ability to easily penetrate the lungs or bloodstream and spread to other internal organs. However, a recent study has shown that taking the supplement viatmin B could help counteract the effects. According to investigations, four weeks of persistently taking vitamin-B supplements can reverse the affects that two hours of constant exposure to polluted air can have.