Measurement of Background Radiation Levels in Onitsha Market, Anambra State

Background radiation is a naturally occurring phenomenon resulting from cosmic rays, terrestrial radioactive materials, and anthropogenic sources. In densely populated commercial environments such as the Onitsha Main Market in Anambra State, South East Nigeria, human exposure to background radiation can be elevated by the presence of building materials, imported goods, and electronic waste. This study measures background radiation levels across 15 designated points within the Onitsha Main Market using a calibrated Geiger-Muller counter. Measurements are taken during peak trading hours and in the early morning to determine temporal variation. Results are compared against the International Commission on Radiological Protection recommended dose limit of 1 millisievert per year for the general public. Preliminary findings indicate that dose rates in areas with concentrated electronic goods range from 0.12 to 0.29 microsieverts per hour, which remain within permissible limits but warrant periodic monitoring. The study maps spatial variation across market sections and identifies zones of relatively elevated reading associated with ceramic tile and granite display areas. The findings underscore the need for routine radiological surveillance in high-traffic commercial areas in South East Nigeria and contribute baseline data for future comparative studies. Recommendations are directed at the Anambra State Ministry of Environment and Mineral Resources for integration into market safety guidelines. Keywords: background radiation, Geiger-Muller counter, Onitsha market, dose rate, radiological safety