Assessment of Outdoor Radiation Exposure Levels and Human Health Risk in a Major Scrap Metal Market in Abuja

Abstract

Background: Scrap metal can contain sources of radiation with the associated environmental and health risks. Radioactive substances can become associated with scrap metal in various ways and if not discovered they can be incorporated into steel and non-ferrous metals through the melting process. This can cause health hazards to workers and to the public as well as environmental concerns Objectives: this study aimed at assessing the outdoor radiation exposure levels and human health risk in a major scrap metal market in Abuja, FCT. Method: An in-situ measurement approach was adopted using a factory calibrated Radiagem-2000 Universal Survey Meter and a handheld Global Positioning System (Garmin GPS 76S) equipment. The monitor was suspended in air at one meter above the ground level. Readings were obtained between the hours of 1200 and 1600 hours since the exposure rate meter has a maximum response to environmental radiation within these hours. Results: The results showed that the average values for the outdoor exposure dose rate for the three location ranges from 0.173±0.042 μSv/h to 0.177±0.046 μSv/h with a mean of 0.176±0.045 μSv/h. These values, though, slightly higher than the standard background radiation of 0.133 μSv/h,are below the ICRP maximum permissible limit of 0.57 μSv/h. The results also show that the AEDE values are lower than the ICRP recommended limits of 1.0 mSv/y for the public and 20 mSv/y for occupationally exposed workers. The ELCR ranges from 0.5926 x 10-3 to 0.6049 x 10-3 with a mean of 0.6008 x 10-3 which is 2.1 times higher than the world’s average. The dosage to organs received shows that the testes have the highest dose while the liver has the lowest dose. The result of the dose to the organs showed that all the values are below the international tolerable limits. Conclusion: Generally, The radiological assessment shows that the study area does not constitute any immediate radiological health effect on the workers and the general public due to radiation exposure rate.