Pipe smoking is dangerous, not less harmful that cigarettes and can cause COPD. You ask, “Is a pipe still a significant threat?” The answer is, YES. How significant a threat depends on how much smoking a person does and how deeply one inhales the smoke. Pipe smoking is a very bad idea for a person with COPD.
The following is from a reputable medical journal, The Annals of Internal Medicine.
The Association of Pipe and Cigar Use With Cotinin Levels, Lung Function, and Airflow Obstruction: A Cross-sectional Study
Rodriguez, Josanna MD; Jiang, Rui MD, DrPH; Johnson
Annals of Internal Medicine Issue: Volume 152(4), 16 February 2010, pp 201-210 Abstract
Background: Cigarette smoking is the major cause of chronic obstructive pulmonary disease, but studies on the contribution of other smoking techniques are sparse.
Objective: To determine whether pipe and cigar smoking was associated with elevated cotinine levels, decrements in lung function, and increased odds of airflow obstruction.
Participants: Men and women aged 48 to 90 years without clinical cardiovascular disease at enrollment who were part of MESA (Multi-Ethnic Study of Atherosclerosis).
Results: Self-reported current pipe and cigar smokers had elevated urine cotinine levels compared with never-smokers. (Cotinine is a biomonitoring marker for tobacco smoke. Pipe-years smoked were associated with significant reductions in lung function (COPD). Participants who smoked pipes or cigars had increased odds of airflow obstruction (COPD
Conclusion: Pipe and cigar smoking increased urine cotinine levels and was associated with decreased lung function and increased odds of COPD, even in participants who had never smoked cigarettes.