Highlight
- Use of ventilation hoods during cooking reduced 24-hour personal PM2.5 exposure by 29.6% in rural villages relying on wood fuel.
- Significant improvements were observed in cardiometabolic indicators, including reduced diastolic blood pressure and hemoglobin A1c levels, and improved heart rate variability.
- Pulmonary function, measured by forced expiratory volume in one second/forced vital capacity ratio, improved by 8% post-intervention.
- The study represents the first rigorous trial evidence from a real-world community setting demonstrating the health benefits of ventilation hood use during cooking.
Study Background and Disease Burden
Household air pollution (HAP) from solid fuel use, such as wood and coal, remains a major public health threat worldwide, particularly in economically underdeveloped rural areas. Exposure to fine particulate matter (PM2.5) generated by indoor combustion has been linked to increased risks of cardiovascular disease, pulmonary dysfunction, diabetes, and other chronic health conditions. Despite widespread recognition of these risks, effective intervention strategies that are feasible and scalable in low-resource community settings are scarce. Ventilation hoods represent a practical technological solution aimed at removing cooking fumes and pollutant particles from indoor air, yet trial-level evidence quantifying their effect on PM2.5 exposure and associated health outcomes is limited, especially in real-world conditions where wood remains the dominant cooking fuel.
Study Design
This community-based cluster-randomized controlled intervention study was conducted in five economically underdeveloped villages in southwest China. Over an 8-month period, 175 participants were enrolled, comprising 115 in the intervention group where ventilation hoods were installed during cooking, and 60 in control clusters without any intervention. Personal 24-hour PM2.5 exposure was measured using portable monitors before and after the intervention. Additionally, a range of cardiometabolic and pulmonary health indicators were assessed, including heart rate variability (HRV), blood pressure, hemoglobin A1c (HbA1c), insulin sensitivity, and lung function as measured by forced expiratory volume in one second (FEV1) to forced vital capacity (FVC) ratio. The study population largely relied on wood as cooking fuel, replicating real-world exposure settings where household pollution is persistent.
Key Findings
The intervention group demonstrated a statistically significant 29.6% reduction in 24-hour average PM2.5 levels after the introduction of ventilation hoods (95% confidence interval [CI]: -57.8%, -1.4%). The control group showed no comparable alteration in exposure levels.
Cardiometabolic benefits were notable: the low frequency/high frequency (LF/HF) ratio of HRV improved by 47.0% (95% CI: 2.4%, 91.5%), indicating a shift toward balanced autonomic heart regulation. Diastolic blood pressure decreased by 3.9% (95% CI: -7.5%, -0.3%), and glycemic control improved as reflected by a 4.1% reduction in HbA1c (95% CI: -6.8%, -1.3%). Furthermore, per-protocol analyses indicated additional enhancement in insulin sensitivity, suggesting metabolic benefits beyond glycemic control alone.
Pulmonary health showed marked improvement with an 8.0% increase in the FEV1/FVC ratio (95% CI: 0.7%, 15.2%), underscoring better airway function and potential reduction in obstructive pulmonary conditions.
Safety and adherence in the intervention group were satisfactory, supporting feasibility in community settings. No significant adverse events related to the use of ventilation hoods were reported.
Expert Commentary
This pioneering cluster-randomized controlled study conclusively demonstrates that installing ventilation hoods during cooking in households using solid fuels effectively reduces harmful PM2.5 exposure and translates into tangible cardiometabolic and pulmonary health improvements. The physiological mechanisms likely involve less inhalation of particulate matter that induces systemic inflammation, oxidative stress, and autonomic dysfunction, contributing to cardiovascular and metabolic dysregulation.
While the results are compelling, several considerations merit attention. The study was limited to a specific rural region in southwest China; thus, generalizability to other populations with differing cultural cooking practices, ventilation structures, and fuel types requires further validation. Furthermore, longer follow-up would help clarify if observed improvements persist and reduce clinical events.
Nonetheless, the trial addresses a major gap by providing high-quality evidence supporting a readily implementable environmental intervention. These findings align with global health priorities to reduce household air pollution and its outsized burden on cardiovascular and respiratory morbidity.
Conclusion
The use of ventilation hoods during cooking is an effective and practical intervention to significantly reduce household PM2.5 exposure, yielding broad cardiometabolic and pulmonary health benefits in underdeveloped rural settings. This intervention could serve as a scalable strategy to mitigate exposure risks associated with solid fuel use worldwide. Future research should focus on implementation science to optimize adoption, long-term health outcome studies, and cost-effectiveness analyses to support policy development and resource allocation.
References
Yang Y, Yu K, Li W, Xu X, Jia C, Yan Q, Li X, Cai H, Hu D, Gao H, Mu X, Lin Y, Niu R, Cheng M, Wang X, Wang B, Ma J, Xu Y, Wang C, Li Q, Wu T, Chen W, Qiu G. Using ventilation hood during cooking reduced household air pollution exposure and brought cardiometabolic and pulmonary health benefits: A community-based, cluster-randomized controlled intervention study. J Hazard Mater. 2025 Sep 5;495:138932. doi: 10.1016/j.jhazmat.2025.138932. Epub 2025 Jun 13. PMID: 40554334.
