161 VENTRICULAR ARRHYTHMIA EVENTS IN BOILERMAKER CONSTRUCTION WORKERS EXPOSED TO METAL-RICH FINE PARTICLES
Epidemiological and toxicological studies suggest a link between metal-rich fine particulate exposures and cardiovascular autonomic responses such as heart rate variability, yet the occurrence of ventricular arrhythmias has not been investigated. We sought to investigate the occurrence of ventricular arrhythmias in a cohort of boilermaker construction workers exposed to metal-rich welding fumes.
Using a panel study, we monitored 36 male boilermaker construction workers by 24 h ambulatory electrocardiogram (ECG) on both a workday during welding fume exposures and a non-workday. ECGs were analysed and the presence of an hourly ventricular arrhythmia (one or more ventricular event in a 1 h period) was reported. The hourly arrhythmia data was matched and summarised by workday and non-workday periods. The effect of previous workday exposure was investigated by stratifying the work and non-work periods. The frequency of arrhythmias between periods was compared using Fisher’s exact test.
The 36 participants were monitored over 49 non-workday and 49 workdays. The 8 h TWA mean (SD) workday PM2.5 exposure was 0.73 (0.50) mg/m3. There were 153 h with a ventricular arrhythmia over the 999 monitored non-workday person-hours and 120 over the 999 monitored workday person-hours. When the data were stratified by whether the participant worked the day prior to being monitored, on non-workdays, participants who worked the previous day had an increased frequency (20%) in hours with arrhythmias as compared to workers who were not working the previous day (14%) and this difference was statistically significant (p = 0.02). On workdays there was no statistically significant difference in hourly arrhythmias between those who worked and those who did not work the previous day. The exposure–response relationship between hourly ventricular arrhythmias and current and previous workday exposures will be presented.
Ventricular arrhythmia events may be influenced by longer term (previous day) exposures and …