Calibration of the Welding Advanced REACH Tool (weldART)

Aduldatch Sailabaht; Fan Wang; John W Cherrie

doi:10.1016/j.ijheh.2020.113519

Calibration of the Welding Advanced REACH Tool (weldART)

Int J Hyg Environ Health. 2020 Jun:227:113519. doi: 10.1016/j.ijheh.2020.113519. Epub 2020 Apr 6.

Authors

Aduldatch Sailabaht¹, Fan Wang², John W Cherrie³

Affiliations

¹ Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Riccarton, Edinburgh, EH14 4AS, UK; Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190, Thailand. Electronic address: aduldatch.s@ubu.ac.th.
² Centre of Excellence in Sustainable Building Design, Heriot-Watt University, Riccarton, Edinburgh, EH14 4AS, UK. Electronic address: fan.wang@hw.ac.uk.
³ Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Riccarton, Edinburgh, EH14 4AS, UK; Institute of Occupational Medicine, Research Avenue North, Edinburgh, EH14 4AP, UK. Electronic address: j.cherrie@hw.ac.uk.

PMID: 32272436
DOI: 10.1016/j.ijheh.2020.113519

Abstract

Objectives: This paper reports a study to develop and calibrate a deterministic model of welding fume exposure based on a four-compartment mass-balance model - The Welding Advanced REACH Tool (weldART). To achieve this aim, measurements of welding fume exposure were collected along with data on exposure determinants needed in the modelling.

Methods: The welding fume exposure data was obtained from workers in a structural steel fabrication plant. Welders were engaged in three processes: flux-cored arc welding (FCAW), shielded metal arc welding (SMAW) and gas tungsten arc welding (GTAW). Aerosol concentration was measured using 13 mm diameter Swinnex sampling heads and MicroPEM direct-reading aerosol monitors. The model was initially developed with three spatial compartments (near-field (NF), far-field (FF), and welding plume (WP)). However, in the welding scenario investigated the FF had a very large volume and it was necessary to subdivide the room volume into an intermediate zone representing the FF along with the remaining room zone (RM). We fitted linear equations forced through the origin to the gravimetric concentrations measured inside the welders' visor and the weldART model estimates. The flowrates between the model compartments were adjusted by trial and error to obtain proportionate concentrations in each compartment.

Results: The FCAW process generated higher welding fume particulate concentrations than SMAW and GTAW. The MicroPEM monitors considerably underestimated and were poorly correlated with the corresponding data from the Swinnex samplers. It was concluded that the MicroPEM data were unreliable. The model calibration showed a strong association between the personal exposure measurement and the weldART model values (R² = 0.94), with the average estimated value 1.3 times the measurements. The NF and the FF model estimates were poorly correlated with the corresponding compartment measurements (R² = 0.37 and 0.35, respectively), although on average the model estimates were close to the measurement data (ratio of modelled to measured 0.9, and 1.0, respectively).

Conclusions: The calibration shows that the weldART model is able to predict the exposure of welding fume particulate.

Keywords: Advanced REACH tool; Calibration; Exposure modelling; Fume; Welding; weldART.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Air Pollutants, Occupational / analysis*
Calibration
Environmental Monitoring
Humans
Inhalation Exposure / analysis*
Models, Theoretical*
Occupational Exposure / analysis*
Particulate Matter / analysis*
Steel
Welding*

Substances

Air Pollutants, Occupational
Particulate Matter
Steel