The INTERvening for LUNG Health Trial

This research study is being done to find out whether a community health volunteer-delivered, multi-component program can improve lung health for people at risk of chronic respiratory diseases (such as asthma or COPD) in Bhaktapur, Nepal. The program focuses on reducing tobacco smoke exposure, reducing indoor and outdoor air pollution exposure, preventing respiratory infections (including vaccination and mask use during viral seasons), and encouraging safe physical activity. The "index participant" is the main enrolled participant in the household who is randomized to the intervention or control arm. The participant will be in the study for about 40 months and will have 11 research visits: one at baseline and then every 4 months through month 40. At visits, staff will do breathing tests (spirometry before and after an inhaled medicine), measure exhaled carbon monoxide, check blood pressure, measure height/weight at selected visits, and ask questions about symptoms, smoking, infections, vaccines, and quality of life. The participant will also wear an activity monitor (accelerometer) for 2 weeks at baseline and at follow-up visits. If individual is a household member (not the index participant), the participant may be asked to complete baseline and follow-up assessments every 4 months through month 40, will receive the influenza vaccine and will primarily be asked to use masks and handwashing during household respiratory illness episodes (only if the index participant is randomized to the intervention) and will not be asked to wear an activity monitor. If the participant is in the pilot phase, participation will last about 2 months. the participant will complete baseline procedures and pilot follow-up visits during those 2 months instead of the full 40-month schedule.

Inclusion Criteria * Age ≥9 years at enrollment. * Resident of the Bhaktapur district and member of a household willing to participate in study procedures. * Pre-bronchodilator FEV1/FVC at or below the 10th percentile (Z-score ≤ -1.28) based on Global Lung Function Initiative reference equations. * Presence of at least one respiratory risk factor, including: * usual cough or phlegm, wheezing in the past 12 months, self-reported prior pulmonary tuberculosis, physician-diagnosed asthma, ever smoking, or occupational exposure to dust or smoke. * Willing and able to provide written informed consent (or assent with parental/guardian permission for participants \