Tue, 06 April, 2021
The International Institute of Welding (IIW) has released a new statement regarding lung cancer and arc welding.
The statement has been prepared by the IIW Commission VIII, “Health, Safety and Environment,” which is chaired by TWI Technology Manager Geoff Melton. Commission VIII studies phenomena occurring during welding which potentially affect health, safety and the environment, and the development of technical guidance documents for correct management of the fabrication process in industry. Commission VIII acts as the global interdisciplinary forum for exchange of knowledge in the field, supported by the expertise of its members representing different scientific disciplines including Medicine, Chemistry, Occupation Hygiene and Welding Engineering.
The IIW is the world’s largest network and centre of reference for welding and allied joining technologies, operating a global body for the science and application of joining technologies as well as a forum for networking and knowledge exchange.
In 2018, The International Agency for Research on Cancer (IARC) published Monograph 118, in which welding fumes were evaluated and reclassified as Group 1 (carcinogenic to humans). Based on this assessment, IARC revised its evaluation from 1990, when it classified welding fumes as “possibly carcinogenic” to humans (Group 2B). This reclassification was based on epidemiological excess risk for lung cancer and the suppressive effect on the immune system caused by welding fumes.
You can see the IIW statement on lung cancer and welding in full here:
LUNG CANCER AND ARC WELDING OF STEELS
Assessment of the International Agency for Research on Cancer (IARC)
Monograph 118, 2018
In 2018, IARC published Monograph 118, in which welding fumes were evaluated, and has reclassified them as Group 1 (carcinogenic to humans). Based on this assessment, IARC revised its evaluation from 1990, when it classified welding fumes as “possibly carcinogenic” to humans (group 2B).
This assessment was based on an epidemiological excess risk for lung cancer and was supported by publications on local and systemic inflammatory processes and a suppressive effect on the immune system caused by welding fumes.
In 2003, IIW Commission VIII issued a statement on the excess risk of lung cancer in electric arc welders. In 2011, this statement was reconfirmed (Ref. Welding in the World, 55, 12-20, 2011).
IIW recommended that to eliminate the excess risk of lung cancer, welders and their managers must ensure that:
- Exposure to welding fumes is minimised, at least to national guidelines,
- There is no further exposure of welders to asbestos, and
- Welders are encouraged and assisted not to smoke tobacco.
Since 2011, more human studies have been published. On the balance of evidence, the grade of risk excess has been confirmed. This assessment has been corroborated also in a meta-analysis published subsequently after the IARC monograph 118 (Honaryar et al. 2019). Again, the excess risk has been shown irrespective of the type of steel (mild steel or stainless steel) welded.
In addition to lung cancer, IARC stated that there is also an excess risk for kidney cell cancer, as shown in several epidemiological studies. The evidence was rated “limited” due to the fact that any confounding effect of solvents could not be ruled out.
IARC also classified ultraviolet radiation from arc welding as carcinogenic (sufficient evidence, group 1), based on an excess risk of uveal melanoma of welders found in some epidemiological studies.
Therefore, based on the current state of knowledge, IIW confirms its statement from 2011 and encourages all those responsible to reduce the exposure to welding fume to a minimum.
IIW recommends that to eliminate the excess risk of lung cancer, welders and their managers must ensure that exposure to welding fume is minimized, at least to national guidelines.