Pulmonary functions of wheat flour mill workers and controls in Ibadan, Nigeria.

BACKGROUND

The impact of grain dust exposure on lung functions of grain handlers in Nigeria has remained largely undocumented. Lung functions of wheat flourmill workers and control subjects were assessed, and the prevalence of lung function abnormalities was compared among the occupational groups.

METHODS

Study subjects consisted of 91 flour-millers, 30 matched internal controls from the maintenance unit of the same flourmill factory and 121 matched external controls. A cross-sectional analytical design is utilized; data were collected using structured interviews, anthropometric measurements, spirometry, and area dust sampling.

RESULTS

The flour-millers recorded significantly lower mean lung functions compared with control subjects (P < 0.05), for FEV(1) and FVC, when observed values were expressed as percentages of predicted normal values. Furthermore, 29% of flour-millers, compared with 15% of external controls and 10% of internal controls, presented with at least one abnormal test result of ventilatory function.

CONCLUSIONS

The study concluded that wheat flour-mill workers in Nigeria are at an increased risk of developing abnormalities of lung functions compared with control subjects, and the dominant pattern of respiratory disease among them is airway obstruction.