Effects of LPG and Ventilation Interventions on Reducing HAP and Improving Cardiopulmonary Health

Effects of Liquefied Petroleum Gas and Ventilation Interventions on Reducing Household Air Pollution From Solid Fuel Use and Improving Cardiopulmonary Health: A Multi-center, 2×2 Factorial Randomized Controlled Trial

The goal of this clinical trial is to evaluate the independent and synergistic effects of liquefied petroleum gas (LPG) substitution and improved ventilation on household air pollution (HAP) reduction and cardiopulmonary health. The main questions it aims to answer are:

1. Does LPG substitution or improved ventilation reduce HAP and improve cardiopulmonary health?
2. Would the combined intervention of LPG substitution and improved ventilation outperform single interventions?
3. What is the cost-effectiveness of such interventions, and are they sustainable?
4. Does the intervention reduce the incidence of cardiopulmonary clinical events?

Participants will be randomized in 4 groups:

A: Solid fuel + no ventilation facilities group (300 households): Continued use of solid fuels without installation of ventilation facilities and receipt of standardized health education. No LPG stoves or ventilation equipment will be provided during the intervention period. However, after the primary endpoint assessment at 12 months, all households in Group A will be provided with LPG stoves and ventilation facilities of equivalent specifications free of charge, along with health guidance. Phased cash compensation will be provided during the intervention period.

B: Liquefied petroleum gas (LPG) + no ventilation facilities group (300 households): Provided with LPG stoves and instructed to use them during cooking, with regular LPG supply throughout the intervention period. Participants will also receive standardized health education.

C: Solid fuel + ventilation facilities group (300 households): Continued use of solid fuels while being provided with ventilation facilities and instructed to use them during cooking. Electricity costs will be compensated during the intervention period. Participants will also receive standardized health education.

D: LPG + ventilation facilities group (300 households): Provided with both LPG stoves and ventilation facilities and instructed to use both during cooking. Regular LPG supply and electricity cost compensation will be provided throughout the intervention period. Participants will also receive standardized health education.

1. Inclusion Criteria Primary Participants：

   • Aged 18-75 years;
   • Local permanent residents with no plans for long-term travel or relocation within one year;
   • Kitchen suitable for installation of ventilation facilities;
   • Responsible for daily household cooking, cooking ≥5 times per week;
   • To control for community penetration of pollution, households will be preferentially recruited in naturally ventilated, open villages, avoiding valleys or basins that hinder pollutant dispersion; preference for detached houses with ≥10 m distance from neighboring kitchens and well-sealed doors and windows.

   Secondary Participants:

   • Elderly individuals aged 65-75 living with the primary participant;
   • Children aged 3-6 living in the same household.

2. Exclusion Criteria:

   • Clinical diagnosis of major chronic diseases such as severe respiratory diseases, cardiovascular diseases, malignant tumors, or end-stage renal disease;
   • Pregnant or breastfeeding women;
   • Current smokers or individuals with self-reported exposure to productive dust or other occupational hazards;
   • Individuals who are unable to fully understand the study process or clearly express their own complaints, such as those with psychiatric disorders or severe neuroses, or who cannot cooperate with the study for other reasons.