According to a study more than four in 10 women with asthma are more likely to develop the chronic obstructive pulmonary disease (COPD). The researchers at American Thoracic Society examined risk factors for developing asthma and COPD overlap syndrome known as ACOS. Those who develop ACOS experience increased exacerbations and hospitalizations and have a lower quality of life compared to those who have asthma or COPD alone. The authors reported that individual risk factors played a more significant role in the development of ACOS than exposure to fine particulate matter a major air pollutant that because of its microscopic size