Obstructive Lung Disease Linked to Occupational Exposures in Malawian Tobacco Farmers

ABSTRACT

Nicotine and pesticide exposure in agricultural settings have been linked to the development of chronic respiratory disease in workers. However, this has not been extensively studied in Africa. The aim of this study was therefore to determine the prevalence of obstructive lung disease and its relationship to concurrent nicotine and pesticide exposure among small-scale tobacco farmers in Malawi. For this purpose, sociodemographic characteristics, occupational and environmental exposures were evaluated in relation to work-related respiratory symptoms and lung function impairment. A cross-sectional study was conducted enrolling 279 workers in flue-cured tobacco farms in Zomba, Malawi. The study instruments used for assessing the health outcomes were a standardised European Community Respiratory Health Survey II (ECRHS) questionnaire and Spirometry testing. The questionnaires were aimed at collecting relevant data on sociodemographic factors and self-reported respiratory health outcomes. Data were also collected on potential pesticide and nicotine exposures. Spirometry was done to evaluate objective respiratory impairment in accordance with American Thoracic Society guidelines. The mean age of participants was 38 years with 68% being male. The prevalence of work-related ocular nasal symptoms, chronic bronchitis, and work-related chest symptoms was 20%, 17%, and 29%, respectively. Airflow limitation (FEV1/FVC <70%) was found in 8% of workers. Self-reported exposure to pesticides varied from 72%- to 83%, whilst the prevalence of recent green tobacco sickness was 26%. Tasks linked to nicotine exposure, such as sowing (OR: 2.5; CI 1.1–5.7) and harvesting (OR: 2.6; CI 1.4–5.1), were significantly associated with work-related chest symptoms. Pesticide application (OR:1.96; CI 1.0–3.7) was associated with an increased risk of work-related oculonasal symptoms. Duration of pesticide exposure was also associated with obstructive impairment FEV1/FVC<LLN (OR: 5.11; CI 1.6–16.7) and FEV1/FVC <70% (OR: 4.68; CI 1.2–18.0). This study demonstrated that tobacco farmers in Malawi had a high prevalence of respiratory symptoms and airflow limitation due to obstructive lung disease. This could be attributed to nicotine or pesticide exposure in small-scale tobacco farming. The implementation of occupational health and safety measures to mitigate these exposures may play an important role in modifying the risk of obstructive lung disease in this population.

KEYWORDS:

• Obstructive lung disease
• tobacco farming
• pesticides
• nicotine

Acknowledgments

This paper reflects the views of the authors alone. However, we would like to thank the following people and organizations for information, advice and support: The Tobacco Commission of Malawi; the owners and staff of the farms where we conducted the study for allowing the use of their workplaces; the dedicated team of data collectors, and all staff of COM-Johns Hopkins Project for their administrative support.

Disclosure statement

The authors declare that there are no relevant financial or non-financial competing interests to report.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/1059924X.2023.2215256.

Additional information

Funding

This work was supported by the Fogarty grant through JHU-Malawi research training grant for HIV and Non-communicable disease (NCDs) which funded the whole project D43TW009609.