Cardiorespiratory response to exercise of nonsmokers occupationally exposed to second hand smoke (SHS)

Occupational exposure to Second Hand Smoke (SHS) continues to be an issue, even in countries with strong tobacco control legislation. The current study assessed the effect of chronic occupational exposure to SHS on cardiorespiratory exercise response among healthy adult non-smokers.

60 healthy non-smokers; 38 men, 22 women, aged 18-58 years with body mass index (BMI)<30 were separated into exposed to occupational SHS (exposed, n=30) and those non-exposed (controls, n=30) to occupational SHS in the hospitality sector. All individuals underwent baseline spirometry and ergospirometry testing. Non-smoking status was confirmed with exhaled CO, SHS exposure with urine cotinine measurement and indoor environmental pollution with PM2.5 concentration. Statistical differences among groups were determined with an independent t-test and p-value set to <0.05.

The exposed group had an average range of 6.9% to 14% lower exercise performance against their % predicted compared to controls. Significant mean differences ±standard deviation found between groups for ergospirometry were: oxygen uptake (VO₂, mL/minute) 11.8 ±3.9 (p=0.004) and 11.7 ±4.8 (p=0.019); carbon dioxide output (VCO₂) 14.0 ±3.7 (p<0.001) and 13.4 ±5.0 (p=0.009); metabolic equivalents (METS) 11.9 ±3.9 (p=0.003) and 11.7 ±4.9 (p=0.018) and for oxygen pulse (VO₂/HR) 16.6 ±7.551 (p=0.032) and 11.9 ±4.554 (p=0.011) at points of maximum oxygen uptake (VO₂max) and recovery (RC) against % predicted values, respectively.

Chronic occupational SHS exposure among non-smokers deteriorates CR exercise performance. Its impact on chronic disease development should be further explored. These results add to the evidence of the importance of enforcing clean indoor air legislations..