Figure 1From: Sources of variation for indoor nitrogen dioxide in rural residences of Ethiopia Type of fuel and its use pattern that was observed during 24 hours of indoor NO 2 sampling, Butajira, Ethiopia, 2000-2002 (n = 16899). For each type of fuel, the number in brackets indicates the proportion of type fuel used singly and in combination with others in reference to respondent's judgment comparing with the usual days.Back to article page