Evaluation of respiratory symptoms and ventilatory function amongst food vendors in Calabar, Nigeria: A cross-sectional comparative study

<b>Background</b><br /> Data from studies evaluating lung functions in individuals exposed to fumes generated during the preparation of roasted food items is lacking in the Nigerian setting. We aimed to evaluate the ventilatory functions of participants with direct exposure to smoke from roasted food and compared the findings with their counterparts (controls).<br /> <b>Methods</b><br /> We conducted a cross-sectional comparative study involving food vendors (cases) of smoked food and workers (controls) operating in the same vicinity but not directly exposed to the smoke. A spirometer was used to measure the forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and peak expiratory flow rate (PEFR). Thereafter, the percentage predicted FEV1, FVC, and FEV1/FVC indices were used to determine ventilatory impairment in both cases and controls.<br /> <b>Results </b><br /> A total of 600 participants were enrolled, of which half (50.0%) were cases while the remaining 50.0% were in the control group. Respiratory symptoms such as coughing and wheezing, and the duration of presentation were higher in cases compared with the controls, with a statistically significant difference; <i>p</i> = 0.003, <i>p</i> = 0.001 and <i>p</i> = 0.011, respectively. In addition, impaired ventilatory functions were significantly higher in the cases compared with the controls (<i>p</i> <0.001). Similarly, a significant proportion of the food vendors with ≥ 5 years of exposure had obstructive and mixed patterns of lung defects and a lesser proportion with normal lung functions compared with those with < 5 years of exposure (<i>p</i> = 0.009). Likewise, the mean FEV1 (<i>p</i> <0.001), FVC (<i>p</i> <0.001), and PEFR (<i>p</i> = 0.005) were significantly higher in controls compared with cases.<br /> <b>Conclusion</b><br /> The direct exposure of food vendors to smoke may impair lung function. Driving awareness of this occupational hazard is very crucial as it is a common source of livelihood in the Nigerian setting.