Welding fumes: a new group 1 carcinogen.
Zeidler-Erdely PC; Erdely A; Meighan T; Battelli LA; Salmen R; McKinney W; Stone S; Cumpston A; Cumpston J; Andrews RN; Kashon M; Antonini JM; Falcone LM
Toxicologist 2018 Mar; 162(1):251-252
Welding fumes were recently classified as carcinogenic to humans (Group 1) by the International Agency for Research on Cancer (IARC) based on strong epidemiological evidence and limited evidence in animals. It is estimated that 11 million workers worldwide weld full-time, and an additional 110 million have had some type of welding-related exposure. Welding exposures are complex because of the diversity of welding modalities used in the workplace; these modalities include exposures to non-carcinogenic and/or carcinogenic metal containing fumes. The objective of this study was to determine which welding fumes and their component metals are the most toxic and have the greatest tumorigenic potential. Male A/J mice received intraperitoneal injections of corn oil or the initiator 3-methylcholanthrene (MCA;10 microg/g) and one week later were exposed by whole body inhalation to air or gas metal arc-stainless steel (GMA-SS) or GMA-mild steel (MS) welding aerosols for 4 h/d x 4 d/w x 8-9 w at a target concentration of 40 mg/m3. Lung nodules were enumerated at 30 weeks post-initiation. GMA-SS and GMA-MS fumes significantly promoted lung tumor multiplicity in A/J mice initiated with MCA (16.11 +/- 1.18; 21.86 +/- 1.50, respectively) compared to MCA/air-exposed mice (7.93 +/- 0.82; 8.34 +/- 0.59, respectively). Oropharyngeal aspiration of GMA-SS and its component metals showed that GMA-SS fume was more pneumotoxic than the individual components. Component Fe2O3 was the most toxic and also the only metal to promote lung tumors in A/J mice. In conclusion, this study demonstrates that inhalation of GMA-SS and GMA-MS welding fume as well as Fe2O3 promote lung tumor formation in vivo and provides support for the epidemiology that shows welders, using mild and/or stainless steel, are at an increased risk for lung cancer.
Toxicology; Welders; Welding fumes; Fumes; Toxic fumes; Inhalation; Carcinogens; Cancer; Occupational exposure; Epidemiology; Metals; Tumorigenesis; Laboratory animals; Laboratory testing; Exposure assessment; Exposure levels; Methyl compounds; Anthracenes; Arc welding; Stainless steel; Gas welders; Lung; Lung cells; Lung tissue; Iron oxide dust and fume; Iron oxides; Tumors; Hazard communication; Hazard identification; Hazardous materials; Lung cancer; Risk factors; In vivo study
56-49-5; 12597-68-1; 1309-37-1
HELD; OD; DART
The Toxicologist. Society of Toxicology 57th Annual Meeting and ToxExpo, March 11-15, 2018, San Antonio, Texas