Statistical Analysis of Occupational Hazard Exposure Among Factory Workers in Onitsha Industrial Zone, Anambra State

Industrial workers in the Onitsha Industrial Zone of Anambra State, South East Nigeria, face diverse occupational hazard exposures including chemical, physical, ergonomic, and biological hazards whose statistical characterisation is essential for occupational health policy. This study statistically analyses occupational hazard exposure among factory workers in the Onitsha Industrial Zone. A stratified random sample of 240 workers across manufacturing, food processing, and chemical production factories participated in structured interviews using the Nigerian Institute of Occupational Safety and Health hazard exposure checklist. Prevalence of exposure to each hazard category, frequency of protective equipment use, and self-reported work-related illness episodes were computed. Chi-square tests examined associations between hazard exposure and illness episodes. Noise exposure was the most prevalent hazard (81 percent), followed by chemical exposure (64 percent) and heat stress (72 percent). Personal protective equipment use was consistently practised in only 28 percent of workers despite availability in 69 percent of factories. Work-related illness was reported by 44 percent of respondents. Chi-square analysis confirmed significant associations between chemical exposure and respiratory symptoms (chi-square = 18.3, p < 0.001) and between noise exposure and self-reported hearing difficulties (chi-square = 12.7, p = 0.002). The study recommends mandatory occupational health surveillance, PPE enforcement monitoring, and worker safety training programmes in the Onitsha Industrial Zone coordinated by the Anambra State Ministry of Labour and Employment. Keywords: occupational hazard, factory workers, Onitsha, chi-square analysis, occupational health