Over the years, pollution has gained greater importance due to its environmental aspect in large cities, the impact on global warming, and its leading role in several of the main causes of mortality, such as cardiovascular disease and cancer 1 .Throughout the history of medicine, researchers have noted a direct relationship between air quality and health.It all began with the miasma theory 2 , which stated that diseases such as cholera, the black plague and malaria (from Italian words meaning ¨bad air), stemmed from contact with poisonous vapors known as ¨miasmä (from the Greek word for ¨contamination), a product of the putrefaction of matter.This led to the appearance of ''il dottore della peste'' in Venice in the 17th century: doctors garbed in a bird shaped mask with two lower holes full of spices, roses, herbs, and vinegar; a hat, and a robe, which helped them avoid these diseases that apparently were derived from contaminated air (fig.1).Winter of 1952 in London was an unforgettable season due to the increased local atmospheric contamination, together with a thermal inversion, which created the famous ''great smoke'' 3 : a dense air mass which prevented transit in the streets, triggered chaos in the city, and called into ques-