Assessment of Effective Irradiance from UV Radiation in Some Welding Workshops within Ogbomoso, Nigeria

Background: Arc welding process emits different types of radiations such as ultraviolet, visible light and infrared radiation. It has been discovered that ultraviolet radiation (UVR) cause acute eye injuries such as photokeratitis with accompanying symptoms such as ocular pain, tearing, and a sensation of sand in the eye. This research aimed to assess impact of ultraviolet radiation on ocular tissues due to varied welding activities. Methods: The irradiance from the UVR emitted from imported welding machine (MMA-250), and a locally constructed welding machine were measured using ultraviolet radiometer calibrated at 365 nm. Measurements were taken at 25 - 350 cm during continuous welding to maintain consistent estimated effective irradiance. Results: The irradiances at 25 cm for locally constructed welding machine were in the range of 3.00 - 5.69 mW/cm2, and has a corresponding time limit of 0.53 - 1.0 s while irradiance at 25 cm for imported welding machine varied between 1.32 - 2.06 mW/cm2 and has a corresponding time limit of 1.5 - 2.3 s. At 50 and 100 cm, the irradiance for both locally constructed and imported welding machine are 1.23- 1.87 mW/cm and 0.58 - 1.16 mW/cm2 respectively. The irradiances at 25 - 100 cm for both welding machines were above the permissible exposure limits recommended by the American Conference of Governmental Industrial Hygienists (1.0 mW/cm2 for 16 s). The ANOVA test (p = 0.658) carried out on the effective irradiances from local and imported machines revealed that there is no significant difference between them. Conclusion: The welding activities using locally and imported welding machines may pose radiological damage to the eyes of welders and cause severe damage to the tissue of the eyes. Hence, welders should be encouraged to comply with the safety guidelines of welding activities. Key words: Ultraviolet Radiation (UVR), welding workshop, welders, irradiance.