COPD, airflow limitation and chronic bronchitis in farmers: a systematic review and meta-analysis

Abstract

IntroductionThe current definition of chronic obstructive pulmonary disease (COPD) associates persistent airflow limitation and chronic respiratory symptoms. Agricultural work has been associated with an increased risk of developing COPD, but the prevalence and definition of the disease vary greatly between studies. This meta-analysis aimed to assess the association between agricultural work and COPD using the most widely used definitions of the disease.MethodsInclusion criteria were: (1) design: cross-sectional or longitudinal, (2) groups: at least one group of farmers and a control group of non-farmers, (3) outcome: prevalence or unadjusted OR of COPD, airflow limitation and/or chronic bronchitis, (4) study subjects: groups of exposed subjects comprising ≥30 individuals and with a mean age ≥40 years and (5) language: English and French language, full-length, original publications in peer-reviewed journals.ResultsIn total, 22 manuscripts were included in the meta-analysis. Eight studies assessed only the prevalence of airflow limitation, nine assessed only the prevalence of chronic bronchitis and four assessed the prevalence of both these parameters. Only one assessed the prevalence of COPD according to its current definition, and this study also provided the prevalence of airflow limitation. Ten studies showed a positive association between farming exposure and airflow limitation or chronic bronchitis, and 12 showed no association (OR (95% CI)=1.77 (1.50 to 2.08), p<0.001). Cattle, swine, poultry and crop farming were associated with either airflow limitation or chronic bronchitis.ConclusionAlthough some features of COPD are associated with some agricultural work, well-designed studies with appropriate diagnostic criteria should be conducted to draw strong conclusions about the relationship between COPD and farming.

A cohort study of banana plantation workers in the French West Indies: first mortality analysis (2000–2015)

“…Mortality from chronic lower respiratory diseases was nonsignificantly increased in men. Agricultural work has been associated with a greater risk of developing chronic obstructive pulmonary disease (Guillien et al 2019). The elevated mortality by suicide, although non-significant, is consistent with the high suicide rate in agricultural workers reported in a number of studies (Milner et al 2013, Klingelschmidt et al 2018).…”

The Exposome in Human Evolution: From Dust to Diesel

“…Those in the highest quartile of endotoxin exposure per work shift had a 10% loss in lung capacity (24.5 mL reduction; Mitchell et al 2015). Such high endotoxin levels likely exceed those of ancient savanna aerosols; however, agricultural workers frequently incur chronic bronchitis and airflow limitation (Guillien et al 2019). As noted above, dust of African origin has high levels of viable microbes (Yahya et al 2019).…”

Farming, pesticide exposure and respiratory health: a cross-sectional study in Thailand

“…First, the response rate was high compared with a range between 42% and 92% in previous similar cross-sectional studies included in recent systematic reviews. (4,5) This was achieved in part because in the study villages, the local public health volunteer system helped our research team to communicate with eligible participants before and during the fieldwork. Second, the study questionnaire focusing on farming and pesticide use considered the local context, including local crops and best-selling pesticides, so that the farming exposure data reflected local participants' exposures.…”

“…Whether farming has a role in COPD remains unclear in developing countries. (5) Thailand is one of the largest rice exporters in the world and 31% (11.6 of 37.9 million) of its working population is in the agricultural sector (6), accounting for 11% of gross domestic product. The poorer, lower 40% of the population, are more likely to work in agriculture.…”