Health impact assessment of solid waste disposal workers in Port Harocurt, Nigeria

The various health risks associated with solid waste disposal workers in Port Harcourt, Rivers State of Nigeria, were investigated. The aim is to assess the extent of exposure in terms of inhalation of toxic substances and its inherent adverse health effects on them since the workers are not adequately protected while doing their jobs. About 10 mL of venous blood was collected from each of the 35 solid waste disposal workers aged 21-50 years and from each of the 15 control subjects of the same age bracket who are not exposed. A well structured questionnaire was also given to all the solid waste disposal workers to assess their health profile. Haematological parameters, liver function test (LFT) and toxic substance (Pb, Cu, Zn) concentration in the blood were carried out. There were slight decrease in the haematological parameters and liver function test (LFT) results, as compared with the control subjects. The values obtained are: Hb 13.43±1.14 g dL-1, HCT 37.13±3.22%, WBC 6.35±1.86×109 L-1, platelet 236.15±104.33×109 L-1, neutrophil 42.60±11.11% and monocyte 3.05±2.41% for solid waste workers. While the values for control subjects are: Hb 14.69±0.4 g dL-1, HCT 41.77±2.74%, WBC 7.23±1.21×109 L-1, platelets 282.40±33.76×109 L-1, neutrophil 58.65±5.87% and monocyte 5.77±2.03%. The lymphocyte counts for waste disposal workers was significantly higher (50.42±11.30%) and (32.83±5.32%) for the control subjects. The AST values increased significantly for solid waste workers with a mean AST concentration of (11.19±2.36 μ L-1) and 8.97±4.07 μL-1 for the control subjects. And mean total bilirubin increased progressively as the number of years of exposure increased (19.00 μmol L-1). The peak value was for workers exposed for about 7 year. The result also showed that mean lead, copper and Zinc concentrations were high for the solid waste workers (Ph = 0.07±0.05 mg L-1, Cu =0.22±0.08 mg L-1 and Zn = 0.56±0.48 mg L-1) while that of control subjects were Ph = 0.02±0.01 mg L-1, Cu =0.11±0.04 mg L-1 and Zn = 0.30±0.04 mg L-1. Malaria parasitaemia was high amongst the solid waste disposal workers. Adequate Personal Protective Equipment (PPE) should be provided to avoid epidemic among the workers. It can be inferred that the lymphocytosis observed in this category of workers may indicate the presence of bacterial and protozoal infections, while a mild eosinophilia might be as a result of allergic disorders and helminthic infections. © 2007 Asian Network for Scientific Information.