Long-Term Metal PM2.5 Exposures Decrease Cardiac Acceleration and Deceleration Capacities in Welders.

Abstract

The aim of the study was to clarify whether long-term metal particulates affect cardiac acceleration capacity (AC), deceleration capacity (DC), or both. We calculated chronic exposure index (CEI) for PM2.5 over the work life of 50 boilermakers and obtained their resting AC and DC. Linear regression was used to assess the associations between CEI PM2.5 exposure and each of AC and DC, controlling for age, acute effects of welding exposure, and diurnal variation. Mean (standard deviation) CEI for PM2.5 exposure was 1.6 (2.4) mg/m-work years and ranged from 0.001 to 14.6 mg/m-work years. In our fully adjusted models, a 1 mg/m-work year increase in CEI for PM2.5 was associated with a decrease of 1.03 (95% confidence interval: 0.10, 1.96) ms resting AC, and a decrease of 0.67 (95% confidence interval: -0.14, 1.49) ms resting DC. Long-term metal particulate exposures decrease cardiac accelerations and decelerations.