Effect of welding fume on heart rate variability among workers with respirators in a shipyard

Bor-Cheng Han; I-Jung Liu; Hsiao-Chi Chuang; Chih-Hong Pan; Kai-Jen Chuang

doi:10.1038/srep34158

Effect of welding fume on heart rate variability among workers with respirators in a shipyard

Sci Rep. 2016 Sep 28:6:34158. doi: 10.1038/srep34158.

Authors

Bor-Cheng Han¹, I-Jung Liu², Hsiao-Chi Chuang^{3

4}, Chih-Hong Pan^{5

6}, Kai-Jen Chuang^{1

7}

Affiliations

¹ School of Public Health, College of Public Health and Nutrition, Taipei Medical University, Taipei, Taiwan.
² Department of Nursing, Cardinal Tien College of Healthcare &Management, New Taipei City, Taiwan.
³ School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei, Taiwan.
⁴ Division of Pulmonary Medicine, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan.
⁵ Institute of Labor, Occupational Safety and Health, Ministry of Labor, Taipei, Taiwan.
⁶ School of Public Health, National Defense Medical Center, Taipei, Taiwan.
⁷ Department of Public Health, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.

Abstract

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 μm in diameter (PM_2.5) was measured by a dust monitor. The association between 5-minute mean PM_2.5 and log₁₀-transformed HRV indices was analyzed by mixed-effects models. We found 5-minute mean PM_2.5 was associated with 8.9% and 10.3% decreases in SDNN and r-MSSD. Effect of PM_2.5 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 PM_2.5 exposure on HRV among workers performing welding in a shipyard.