Measurement and Prediction of Workplace Exposure to Solar Ultraviolet Radiation in Makurdi, Benue State, Nigeria

Aims: To measure and predict the workplace exposure to solar ultraviolet radiation in Makurdi, Benue State, Nigeria.

Study Design: Experimental design through area monitoring method and Newton divided interpolation difference method.

Place and Duration of Study: Makurdi Metropolis, Benue State and Department of Physics, Nasarawa State University Keffi, Nigeria, between April and June 2021.

Methodology: Digital broad band meter was used to measure UV irradiance at SRS junction (Traffic light) and Kanshio (construction site) at hourly intervals from 10:00am- 4:00pm. The exposure results were used to derive a predicting function using the Newton Divided Difference Interpolation method and were plotted into MATLAB to generate the predicted results. Also, the UV index was also calculated.

Results: The mean irradiant values were 179.100J/m2 and 173.53J/m2 with erythema effective irradiances 227.300J/m2 and 205.000J/m2 which is 1.14 and 1.03 minimum erythema doses (MED)/hr, while the predicted mean values were 179.100±0.025J/m2 and 172.800±0.004J/m2 for the traffic wardens and construction site workers respectively. The mean values were higher than the ICNIRP recommended safety limit of 30.000J/m2 for occupational exposure and MED for skin type I was exceeded by a factor of 1. The calculated UV index was 8 for construction site and 9 for traffic light wardens.

Conclusion: High level of accuracy of the prediction model implies that it can be used for prediction of SUV radiation. However, high mean irradiant values with high UV index indicates high risk of harm from unprotected sun exposure. Therefore, use of sun protective clothing is recommended and reduce time in the sun especially between 1:00pm and 2:00pm to prevent over exposure that will lead to serious harmful effects.