Serum cytokine levels related to exposure to volatile organic compounds and PM2.5 in dwellings and workplaces in French farmers – a mechanism to explain nonsmoking COPD

Abstract

Christelle Audi,1,* Nour Baïz,1,* Cara N Maesano,1 Ollivier Ramousse,2 Damien Reboulleau,3 Antoine Magnan,3 Denis Caillaud,4 Isabella Annesi-Maesano1 1Sorbonne Universités, UPMC Univ Paris 06, INSERM, Institut Pierre Louis d’Epidémiologie et de Santé Publique, UMRS 1136, Epidemiology of Allergic and Respiratory Diseases Department, Medical School Saint-Antoine, Paris, 2Mutualité Sociale Agricole, Clermont-Ferrand, Auvergne, 3Centre du Thorax de Nantes INSERM, UMR1087, Institut du thorax, Nantes, 4Respiratory Diseases Department, CHU Clermont-Ferrand, Clermont-Ferrand, Auvergne, France *These authors contributed equally to this work Abstract: Although French farmers smoke less on average than individuals from the general population, they suffer more from COPD. Exposure to biological and chemical air pollutants in the farm may be the cause of these higher COPD rates. This study investigates the role of biocontaminants, including the relationship of exposure to volatile organic compounds (VOCs) and fine particulate matter (of diameter of 2.5 µm [PM2.5]) objectively measured in the farm settings (dwellings and workplaces) to serum cytokines involved in COPD, in a sample of 72 farmers from 50 farms in the Auvergne region, France. Mean concentrations of VOCs were highest inside the home, while levels of PM2.5 were highest in workplaces (stables and granaries). After adjusting for confounders, high exposure to PM2.5 was significantly associated with a decreased level of serum cytokines (among others, IL13: β: –0.94, CI: –1.5 to –0.2, P-value =0.004; IL8: β: –0.82, CI: –1.4 to –0.2, P-value =0.005) and high exposure to VOCs according to a VOC global score with a decreased IL13 level (β: –0.5, CI: –0.9 to –0.1, P-value =0.01). Moreover, respiratory symptoms and diseases, including COPD, were associated with a decreased level of serum cytokines significantly in the case of IL5. An alteration of immune response balance in terms of cytokine levels in relation to indoor chemical air pollution exposure may contribute to respiratory health impairment in farmers. Keywords: indoor rural air pollution, COPD, French farmers, VOCs, PM2.5, cytokines

Keywords

• Indoor rural air pollution
• COPD
• French farmers
• VOCs
• PM2.5
• Cytokines.