Age group ≤15 (in years)
In this group none of the recruited subjects had exposure of active smoking. After analyzing data we found subjects who were living in joint families [OR = 1.6; 95%CI = 1.0–2.5; P = 0.035], subjects who were in touch with motor vehicle air pollution and industrial smoke [(OR = 2.7; 95%CI = 1.4–5.3; P = 0.003); (OR = 2.9; 95%CI = 1.3–6.9; P = 0.013), respectively], and subjects who had exposure to ETS [OR = 6.6; 95%CI = 4.1–10.7; P < 0.001], had more chances to develop risk for disease asthma.