Fig. 1From: The role of environmental exposure to non-cigarette smoke in lung diseaseReproduced with permission from the World Health Organization [8], Copyright (2016)Global use of clean fuels in 2014, by the World Health Organization. Countries with the lowest (< 5%) and the highest (> 95%) proportion of people using clean fuels as the primary domestic source of energy are shaded dark and light blue, respectively.Back to article page