Changing DNA damage in peripheral blood mononuclear cells by Comet Assay IV parameters from never-smoking control individuals through current smokers or ex-smokers with normal lung function and patients with stabile chronic obstructive pulmonary disease (COPD) of the Global Initiative for Chronic O

*Adjusted for age, gender, body mass index, smoking history (pack-years), status of a current smoker and forced expiratory volume in one second % predicted. #Novel derived parameters.