Objective: To evaluate the prevalence of respiratory symptoms, ventilatory function disorder and immediate hypersensitivity reactions in a population exposed to flour and cereal dusts in five flour mills in Morocco.
Methods: The study of 373 exposed and 301 non-exposed subjects consisted of an analysis of working conditions and a medical survey.
Results and conclusion: The prevalence of clinical respiratory symptoms was 64.1% among exposed subjects and 41.2% among non-exposed subjects. Cough, expectoration, rhinitis, conjunctivitis, dermatitis, asthma and chronic bronchitis were more frequent among mill-workers. Spirometry was abnormal in 31.6% of those exposed: anomalies were found in both flow and volume. Among exposed subjects with a ventilatory disorder, 77.9% had only small airways syndrome or a light deficit. Smoking was the cause of excess morbidity. Skin prick tests were positive for at least one allergen in 65.4% of exposed compared to 27.2% non-exposed subjects. The prevalence of positive skin tests to occupational allergens alone was higher among those exposed (42.4%) than among the non-exposed (9.9%). The implementation of adequate medical and technical prevention may reduce this risk.