Two of three studies that assessed risk by duration of employment as a welder showed positive trends.3,4 These studies also showed increased ocular melanoma risk associated with eye burns-a proxy for UV exposure-and one reported a positive exposure-response association for cumulative occupational exposure to artificial UV radiation, including welding.3,4 Risks persisted after adjustment for sun exposure, sun bed use, or both.4-6 Welding fumes are produced when metals heated above their melting point vaporise and condense to fine particles (mostly <1 μm in size). In one oropharyngeal aspiration study and one inhalation study in male A/J mice, gas metal arc-stainless steel welding fumes promoted 3-methylcholanthrene-induced lung tumours.13,14 Absorption and excretion of metals (chromium, nickel, and manganese) was shown in people exposed to welding fumes, but data for particle deposition and clearance in welders were scarce. 2 International Agency for Research on Cancer, Chromium, nickel and welding, IARC Monogr Eval Carcinog Risks Hum, Vol. 49, 1990, 1-648 3 CM Vajdic, A Kricker, M Giblin, Artificial ultraviolet radiation and ocular melanoma in Australia, Int J Cancer, Vol. 112, 2004, 896-900 4 P Guenel, L Laforest, D Cyr, Occupational risk factors, ultraviolet radiation, and ocular melanoma: a case-control study in France, Cancer Causes Control, Vol. 12, 2001, 451-459 5 EA Holly, DA Aston, DK Ahn, AH Smith, Intraocular melanoma linked to occupations and chemical exposures, Epidemiology, Vol. 7, 1996, 55-61 6 JM Seddon, ES Gragoudas, RJ Glynn, KM Egan, DM Albert, PH Blitzer, Host factors, UV radiation, and risk of uveal melanoma. A case-control...