Impact of farm modernity on the prevalence of chronic obstructive pulmonary disease in dairy farmers

Abstract

Dairy farming is associated with an excess of chronic obstructive pulmonary disease (COPD). The dairy industry has been changing for the past three decades with larger, more efficient farms and potentially less exposure to agents involved in COPD development. However, the impact of farm modernisation on COPD prevalence is unknown. We studied respiratory symptoms, respiratory function by spirometry and tobacco smoking in 575 male dairy farmers working either in traditional or in modern farms in the French Doubs region. COPD was defined by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criterion (forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) <0.70) and by the Quanjer reference equation (FEV1/FVC<lower limit of normal (LLN)). Modern farms were defined either as having a separation between the house and the cowshed (model 1) or as having a loose housing system for the animals (model 2). The prevalence of COPD in dairy farmers was 12.0 ± 2.7% (GOLD), and 5.6 ± 4.1% (LLN definition). By multivariate analysis using the LLN definition, tobacco smoking (OR (95% CI) 3.96 (1.53 to 10.3) and 3.42 (1.32 to 8.84) for models 1 and 2, respectively) and characteristics of traditional farms (1.97 (1.02 to 4.47) and 5.20 (1.73 to 15.64) for models 1 and 2, respectively) were associated with higher COPD prevalence. Working in a traditional farm plus current smoking had an additive effect on COPD prevalence in model 1 and a synergistic effect in model 2. These findings support a positive impact of farm modernity on COPD prevalence in dairy farmers. Occupational and smoking-related risk factors are of nearly the same magnitude.

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

“…It is noteworthy that this increased risk of COPD traits among dairy farmers may have decreased during the last few years. Our group recently investigated the impact of farm modernity on respiratory outcomes such as airflow limitation and chronic bronchitis in dairy farmers 12. This study demonstrated that working in a modern farm (with a separation between the house and the cowshed and using a loose housing system) decreased the risk of airflow limitation twofold after adjustment for age and for smoking habits 12…”

Smoking habits in French farmers: a cross-sectional study

“…The youngest farmers are also those who are likely to be exposed for decades to occupational airborne pollutants. As it is likely that the combination of tobacco smoking and occupational exposures has an additive or even synergistic effect on COPD [ 8 ], it seems important to initiate smoking prevention strategies in active farmers.…”

“…Tobacco smoking is in its own right a well-established risk factor for the development of chronic respiratory diseases, especially chronic bronchitis and COPD [ 6 , 7 ]. Notably, there is an additive or even a synergistic effect on the decline in lung function and on the development of COPD [ 8 ] between tobacco and some occupational farming exposures. It therefore seems essential not only to prevent occupational exposure in farmers, but also to fight against tobacco smoking, especially in those who are exposed to noxious occupational airborne contaminants [ 9 ].…”

Factors determining the exposure of dairy farmers to thoracic organic dust

“…Several studies have shown that dairy farmers are more likely to suffer from respiratory disorders like chronic bronchitis, non-atopic asthma and chronic obstructive pulmonary disease (COPD) than is the general population (Dalphin et al, 1998;Gainet et al, 2007;Omland et al, 2011;Reynolds et al, 2013, Guillien et al, 2016. This increased risk of pulmonary disease may result from repeatedly inhaling organic dust (Eduard et al, 2009;Thaon et al, 2011;Jouneau et al, 2012;Marescaux et al, 2016).…”