Evaluation of Noise and Vibration Levels in a Small-Scale Block Moulding Industry in Abuja Municipal Area Council

The informal block moulding industry provides essential construction materials and employment across Nigerian urban and peri-urban areas, yet workers in these establishments face significant exposure to noise and vibration from concrete mixers, vibrating presses, and power screeds without adequate occupational health protections. This study evaluates noise and vibration exposure levels in five block moulding establishments operating in the Nyanya and Karu areas of Abuja Municipal Area Council, Federal Capital Territory. Noise levels were measured using a Class 1 sound level meter at operator workstations and site boundary points during peak production hours. Hand-arm vibration exposure was assessed using a triaxial accelerometer mounted on the handles of the vibrating machines, with daily vibration exposure values calculated following ISO 5349-1 methodology. Mean operator noise exposures ranged from 88 to 96 dBA, exceeding the 85 dBA 8-hour permissible limit at all sites. Hand-arm vibration daily exposure values exceeded the EU Directive action value of 2.5 metres per second squared at four of the five sites. A structured safety audit found that no site provided functional hearing protection or anti-vibration gloves to workers, and none had conducted formal health surveillance. The study recommends development of a mandatory occupational health standard for Nigeria's informal construction materials sector and provision of subsidised personal protective equipment. Keywords: occupational noise, hand-arm vibration, block moulding, informal industry, Abuja.