title: Respiratory symptoms and lung function in relation to wood dust and monoterpene exposure in the wood pellet industry.
abstract: BACKGROUND
  Wood pellets are used as a source of renewable energy for heating purposes. Common exposures are wood dust and monoterpenes, which are known to be hazardous for the airways. The purpose of this study was to study the effect of occupational exposure on respiratory health in wood pellet workers.
  
  
  METHODS
  Thirty-nine men working with wood pellet production at six plants were investigated with a questionnaire, medical examination, allergy screening, spirometry, and nasal peak expiratory flow (nasal PEF). Exposure to wood dust and monoterpenes was measured.
  
  
  RESULTS
  The wood pellet workers reported a higher frequency of nasal symptoms, dry cough, and asthma medication compared to controls from the general population. There were no differences in nasal PEF between work and leisure time. A lower lung function than expected (vital capacity [VC], 95%; forced vital capacity in 1 second [FEV1], 96% of predicted) was noted, but no changes were noted during shifts. There was no correlation between lung function and years working in pellet production. Personal measurements of wood dust at work showed high concentrations (0.16-19 mg/m3), and exposure peaks when performing certain work tasks. Levels of monoterpenes were low (0.64-28 mg/m3). There was no association between exposure and acute lung function effects.
  
  
  CONCLUSIONS
  In this study of wood pellet workers, high levels of wood dust were observed, and that may have influenced the airways negatively as the study group reported upper airway symptoms and dry cough more frequently than expected. The wood pellet workers had both a lower VC and FEV1than expected. No cross-shift changes were found.
authors.affiliation: a Department of Occupational and Environmental Medicine, Faculty of Medicine and Health Örebro University , Örebro , Sweden.
authors.forename: Håkan
authors.initials: H
authors.lastname: Löfstedt
authors.affiliation: a Department of Occupational and Environmental Medicine, Faculty of Medicine and Health Örebro University , Örebro , Sweden.
authors.forename: Katja
authors.initials: K
authors.lastname: Hagström
authors.affiliation: a Department of Occupational and Environmental Medicine, Faculty of Medicine and Health Örebro University , Örebro , Sweden.
authors.forename: Ing-Liss
authors.initials: IL
authors.lastname: Bryngelsson
authors.affiliation: b Division of Ear, Nose and Throat Diseases, Department of Clinical Science , Intervention and Technology, Karolinska Institutet , Stockholm , Sweden.
authors.forename: Mats
authors.initials: M
authors.lastname: Holmström
authors.affiliation: c Department of Medical Sciences, Occupational and Environmental Medicine , Uppsala University , Uppsala , Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Rask-Andersen
mesh_terms: D000328:Adult; D001249:Asthma / Q000628:therapy; D003371:Cough; D004391:Dust; D005541:Forced Expiratory Volume; D006304:Health Status; D006801:Humans; D006967:Hypersensitivity; D007221:Industry; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D039821:Monoterpenes / Q000009:adverse effects*; D016273:Occupational Exposure / Q000009:adverse effects*; D012119:Respiration; D012129:Respiratory Function Tests; D013147:Spirometry; D011795:Surveys and Questionnaires; D013548:Sweden; D013997:Time Factors; D014797:Vital Capacity; D014934:Wood; D055815:Young Adult
chemical_list: D004391:Dust; D039821:Monoterpenes
keywords: Asthma; lung function; occupational exposure; respiratory symptoms; rhinitis; wood dust