COPD
prevalence, morbidity, and mortality vary across countries
and across different groups within countries. COPD is the
result of cumulative exposures over decades. Often, the
prevalence of COPD is directly related to the prevalence
of tobacco smoking, although in many countries, outdoor,
occupational and indoor air pollution – the latter resulting
from the burning of wood and other biomass fuels – are
major COPD risk factors