Although solar radiation is the most commonly recognized source of UV radiation (UVR), occupational exposures can contribute due to the intensity and chronicity of exposure. Arc welding is a process whereby metal is fused together by heat produced from an electric arc. The electric arc that forms between the electrode and the base metal emits radiation in the full UV spectrum including UVA (400–315 nm), UVB (315–290 nm), and UVC (290–100 nm) wavelengths. Welders, therefore, have an increased risk for broad-spectrum, intense exposure to UVR, which may play a notable role in UV-related skin disease without proper protection. We report 3 welders with skin disease attributed to occupational exposure to UVR.
A 41-year-old man presented for evaluation of treatment-resistant cutaneous lupus. During the 10-year disease course, the patient was treated by both dermatologists and rheumatologists with frequent exacerbations and poor disease control. At the time of presentation, treatment with hydroxychloroquine 200 mg twice daily, azathioprine 50 mg twice daily, intramuscular methylprednisolone acetateinjectable suspension 40 mg, and prednisone 20 mg daily was failing. Physical examination revealed polycyclic erythematous plaques typical of subacute cutaneous lupus erythematosus. A skin biopsy confirmed the diagnosis. Upon further discussion of exacerbating risk factors, the patient noted UVR exposure while working as a welder. Although he had been previously told to avoid sunlight, he did not realize that this recommendation included all forms of UV light. Once this work exposure was eliminated, he was restarted on hydroxychloroquine 200 mg twice daily and topical steroids, and he responded with complete and sustained clearance of disease. When he returned to welding, utilization of sunscreen and sun-protective clothing enabled him to maintain control of his subacute cutaneous lupus erythematosus on oral hydroxychloroquine 200 mg twice daily and topical steroids.
A 55-year-old man presented with numerous actinic keratoses and persistent erythema in a well-demarcated area involving the forehead, temples, and lateral cheeks but sparing the periorbital area. The patient also experienced UVR exposure from welding (up to 4 to 5 times per week during his career spanning more than 20 years). He cited frequent burns in areas where his protective equipment did not cover his skin. He also reported that he often forgoes wearing protective equipment, even though it is available, and only uses safety goggles due to the extreme heat of the working environment as well as the awkwardness of wearing full protective gear while performing certain aspects of the job.
A 63-year-old man presented with a growth on the left side of the upper forehead. A biopsy revealed a squamous cell carcinoma, keratoacanthoma type. He worked as a welder for 40 years until retiring 1 year prior to presentation. He welded daily and always wore a tall face shield. Although the face shield covered most of his face, the scalp and some parts of the upper face were not well protected. In addition to the keratoacanthoma, which presented just outside of the area protected by the face shield, the patient had numerous actinic keratoses on the scalp.
Welding and UVR Exposure
Arc welders endure large amounts of UVR exposure, which is substantial enough to have notable health effects. The duration of exposure, electrical current used, angle of exposure, amount of ventilation, and the distance from the welding arc play a role in overall UVR exposure.1,2 Maximum permissible exposure (MPE) limits to UVR have been set by the International Commission on Non-Ionizing Radiation Protection and the National Institute for Occupational Safety and Health.3,4 The quantity of radiation produced by the arc allows for an exposure time of only a few seconds to minutes before surpassing MPE to UV light.1,5 Welders are exposed to total-body UVR doses up to 3000 times the MPE, and mean cumulative exposure calculated over an 8-hour workday can reach 9795 mJ/cm2.6
Workers in close proximity to welders also receive large UVR doses and may not be aware of its hazardous effects. Nearby nonwelders can be exposed to 13 times the MPE of UVR.6 At distances up to 10 m from the arc, the irradiance is large enough to reach MPE to UVR in less than 3 hours.1