An important research paper by University of Copenhagen has highlighted about the dangers of second-hand smoking, but stating that it increases the risk of chronic obstructive pulmonary disease (COPD). The disease can happen to non-smokers also, but it especially takes place among passive smokers.

Study researchers have said children and teenagers who come in contact with cigarette's smoke face the increased risk of getting diagnosed with the disease. The inhaled smoke is not at all good for their lung function.

It is very important to have normal growth in lung function. For the study, the researchers have divided the participants on the basis of lung function and the presence or absence of COPD during the participants' last study visit.

At least three cohorts were used during the study in which participants' lung was assessed on regular basis. For two cohorts, the follow-up period was of around 25 years. The researchers also said that COPD could take place in many ways and it is very important to intervene on time so the loss is not much.

Measures that can reduce the disease's risk include not smoking during teenage years; asthma treatment even in childhood and reducing one's exposure to agents that can cause the disease like passive smoking.

The study researchers have said other factors that could add to the development of the problem include genetics and environmental factors.