Search

The aim of the project was to investigate whether there were diminished health effects in swine farm workers during summer compared with winter, as seasonal differences in concentrations of bioaerosols have been reported. Twenty-four workers were visited once during each season. Before and after a work shift, they underwent lung function testing and blood sampling. During work, they wore personal air sampling equipment. The mean endotoxin exposure of the workers was highest during winter (25,690 vs. 6,553 EU/m(3); p = 0.004). Although exposures to endotoxin and CO(2) varied between the seasons, no differences in lung function were found between them. White blood cell concentration increased over the work shift from 5.74-6.82 in winter (p < 0.0001) and from 5.80-6.38 in summer (p = 0.014). These increases differed between the two seasons (p = 0.032). Plasma tumour necrosis factor concentrations fell over the work shift only during winter (1.34-1.24 pg/ml (p = 0.03) (p = 0.014 for the difference between seasons). Plasma interleukin-6 increased over the work shift independently of season (p = 0.0006). The study supported our hypothesis of adverse effects on lung function and immune system, but less so during summer than during winter among Quebec swine farm workers.

Le monde agricole québécois a actuellement la volonté de mettre en place une filière biomasse pour la production de chaleur à la ferme. Toutefois, la législation sur la qualité de l’air du Québec ne permet pas de valoriser aisément des cultures énergétiques à cette fin. Dans la littérature, le manque de facteurs d’émission en lien avec la combustion de biomasses lignocellulosiques limite l’actualisation du règlement, plutôt contraignant dans le moment, pour répondre aux besoins du milieu. Par ailleurs, la variabilité des propriétés physico-chimiques des plantes agricoles rend le dossier encore plus complexe. Le présent projet visait donc à quantifier l’influence des caractéristiques (espèce, composition chimique, date de récolte, forme, etc.) des cultures dédiées ayant le meilleur potentiel de développement au Québec sur les émissions atmosphériques (particules et gaz) lors de la combustion à la ferme. Une revue critique de la littérature a d’abord ciblé, en plus du bois (référence), quatre biomasses agricoles d’intérêt : le saule à croissance rapide, le panic érigé, le miscanthus et l’alpiste roseau. Ces cultures pérennes ont ensuite été acquises de divers producteurs selon la forme du produit (copeaux, granules ou vrac) et sa date de récolte (automne ou printemps). Au total, 12 différentes biomasses ont été brûlées dans une chaudière multi-combustible de 29 kW au Laboratoire sur les énergies en agriculture durable (LEAD) de l’Institut de recherche et de développement en agroenvironnement (IRDA). Au cours de 36 essais expérimentaux (3 répétitions), les paramètres d’opération (masse du combustible, températures de la chambre, de l’effluent gazeux et de l’eau de l’échangeur de chaleur, débits des gaz et du fluide caloporteur, etc.) et les concentrations de 11 gaz (CO, CO[indice inférieur 2], CH[indice inférieur 4], N[indice inférieur 2]O, NO, NO[indice inférieur 2], NH[indice inférieur 3], SO[indice inférieur 2], HCl, H[indice inférieur 2]O et O[indice inférieur 2])

The aim of the project was to investigate whether there were diminished health effects in swine farm workers during summer compared with winter, as seasonal differences in concentrations of bioaerosols have been reported. Twenty-four workers were visited once during each season. Before and after a work shift, they underwent lung function testing and blood sampling. During work, they wore personal air sampling equipment. The mean endotoxin exposure of the workers was highest during winter (25,690 vs. 6,553 EU/m3; p = 0.004). Although exposures to endotoxin and CO2 varied between the seasons, no differences in lung function were found between them. White blood cell concentration increased over the work shift from 5.74–6.82 in winter (p < 0.0001) and from 5.80–6.38 in summer (p = 0.014). These increases differed between the two seasons (p = 0.032). Plasma tumour necrosis factor concentrations fell over the work shift only during winter (1.34–1.24 pg/ml (p = 0.03) (p = 0.014 for the difference between seasons). Plasma interleukin-6 increased over the work shift independently of season (p = 0.0006). The study supported our hypothesis of adverse effects on lung function and immune system, but less so during summer than during winter among Québec swine farm workers.