Effect of welding fume on heart rate variability among workers with respirators in a shipyard
Welding fume exposure is associated with heart rate variability (HRV) reduction. It is still unknown whether respirator can reduce effect of welding fume on HRV among welding workers in a shipyard. We recruited 68 welding workers with respirator and 52 welding workers without respirator to measure HRV indices, including standard deviation of normal to normal intervals (SDNN) and square root of the mean squared differences of successive intervals (r MSSD) by ambulatory electrocardiographic (ECG) Personal exposure to particulate matter less than or equal to 2.5 mm in diameter (PM2.5) was measured by a dust monitor. The association between 5 minute mean PM2.5 and log10 transformed HRV indices was analyzed by mixed effects models. We found 5 minute mean PM2.5 was associated with 8.9% and 10.3% decreases in SDNN and r MSSD. Effect of PM2.5 on HRV indices was greatest among workers without respirator {SDNN: 12.4% (95% confidence interval 18.8 6.9) r MSSD: 14.7% (95% confidence interval 20.8 8.6) Workers with respirator showed slight decreases in HRV indices {SDNN: 2.2% (95% confidence interval 6.3 1.9) r MSSD: 4.0% (95% confidence interval 6.4 1.6) We conclude that respirator use reduces the effect of PM2.5 exposure on HRV among workers performing welding in a shipyard.
Scientific reports