Evaluating the semi-chronic effects of household air pollution exposure on cardiopulmonary health under two different ventilation conditions

Household air pollution (HAP), particularly from cooking-related particulate matter (PM_2.5), poses significant health risks but remains understudied compared to ambient air pollution. We evaluated the short-term cardiorespiratory effects of exposure to cooking-generated PM_2.5 and examined the efficacy of automated indoor air quality interventions. Using a crossover design, seven cohorts of two participants each were exposed to two residential conditions over four weeks in a Living Lab: the Standard Control Condition (SCC), featuring basic HVAC, and the Advanced Control Condition (ACC), which included automated range hoods, portable air cleaners and exhaust systems activated by PM_2.5 sensors. PM_2.5 concentrations were continuously monitored in the breathing zone at the room level. The physiological markers, blood pressure (BP), heart rate (HR), heart rate variability (HRV) and fractional exhaled nitric oxide (FeNO), were measured on the occupant before and after cooking events. Cooking events caused substantial short-term increases in PM_2.5 levels, median concentrations rose from < 1 µg/m³ to 263.7 µg/m³ under SCC and to 168.9 µg/m³ under ACC during HRV measurement periods, with exposure levels exceeding WHO 24-hour guidelines up to 82% of the time. Compared to SCC, the ACC significantly reduced PM_2.5 exposure (p < 0.05). Systolic blood pressure (SBP) decreased significantly post-cooking under ACC (ΔSBP = -3.1 ± 10.0 mmHg) but not in the SCC (ΔSBP = -0.9 ± 8.0 mmHg; p < 0.05). HR and HRV showed no statistically significant differences between conditions, though trends in RMSSD, SDNN and LF/HF ratio suggested improved autonomic balance under ACC. HR decreased post-cooking under ACC but increased slightly under SCC (ΔHR = -4.5 ± 6.5 bpm vs. 1.0 ± 1.1 bpm; 95% CI: (-9.8 to -1.2)). FeNO decreased significantly within both conditions pre- to post-cooking, but the difference in reduction between conditions did not reach statistical significance, despite a trend toward greater decline in the ACC. These findings suggest that semi-chronic exposure to cooking-related PM_2.5 can adversely affect cardiovascular function, particularly systolic BP and HR, and that automated indoor air quality interventions can meaningfully reduce pollutant exposure and associated physiological impacts. Our results support the implementation of HAP mitigation strategies in residential settings and highlight the need for further research among populations with existing cardiopulmonary conditions.