title: Feedback on Measured Dust Concentrations Reduces Exposure Levels Among Farmers.
abstract: BACKGROUND
  The high burden of exposure to organic dust among livestock farmers warrants the establishment of effective preventive and exposure control strategies for these workers. The number of intervention studies exploring the effectiveness of exposure reduction strategies through the use of objective measurements has been limited.
  
  
  OBJECTIVE
  To examine whether dust exposure can be reduced by providing feedback to the farmers concerning measurements of the exposure to dust in their farm.
  
  
  METHODS
  The personal dust levels of farmers in 54 pig and 26 dairy cattle farms were evaluated in two measurement series performed approximately 6 months apart. Detailed information on work tasks and farm characteristics during the measurements were registered. Participating farms were randomized a priori to a control (n = 40) and an intervention group (n = 40). Shortly after the first visit, owners of intervention farms only received a letter with information on the measured dust concentrations in the farm together with some general advises on exposure reduction strategies (e.g. use of respirators during certain tasks). Relationships between measured dust concentrations and intervention status were quantified by means of linear mixed effect analysis with farm and worker id as random effects. Season, type of farming, and work tasks were treated as fixed effects. Changes in exposure over time were explored primarily at a farm level in models combined, as well as separate for pig and cattle farmers.
  
  
  RESULTS
  After adjustment for fixed effects, an overall reduction of 23% in personal dust exposures was estimated as a result of the intervention (P = 0.02). Exposure reductions attributable to the intervention were similar across pig and cattle farmers, but statistically significant only for pig farmers. Intervention effects among pig farmers did not depend on the individuals' information status; but among cattle farmers a significant 48% reduction in exposure was found only among individuals that reported to have been informed. No systematic differences in changes over time considering the use of respiratory protection between the intervention and control groups were observed.
  
  
  CONCLUSIONS
  The results of the present study suggest reductions between 20 and 30% in personal exposure to inhalable dust to be feasible through simple information provided to the farm owners regarding actual levels of exposure together with instructions on basic measures of prevention. The exact reasons for these effects are unclear, but likely they involve changes in behavior and working practices among intervention farmers.
authors.affiliation: 1.Department of Public Health, Section for Environment, Occupation and Health, Danish Ramazzini Center, Aarhus University, Bartholins Allé 2, bg 1260, 8000 Aarhus C, Denmark; ibas@ph.au.dk.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Basinas
authors.affiliation: 1.Department of Public Health, Section for Environment, Occupation and Health, Danish Ramazzini Center, Aarhus University, Bartholins Allé 2, bg 1260, 8000 Aarhus C, Denmark;
authors.forename: Torben
authors.initials: T
authors.lastname: Sigsgaard
authors.affiliation: 1.Department of Public Health, Section for Environment, Occupation and Health, Danish Ramazzini Center, Aarhus University, Bartholins Allé 2, bg 1260, 8000 Aarhus C, Denmark;
authors.forename: Jakob Hjort
authors.initials: JH
authors.lastname: Bønløkke
authors.affiliation: 1.Department of Public Health, Section for Environment, Occupation and Health, Danish Ramazzini Center, Aarhus University, Bartholins Allé 2, bg 1260, 8000 Aarhus C, Denmark;
authors.forename: Nils Testrup
authors.initials: NT
authors.lastname: Andersen
authors.affiliation: 2.Department of Occupational Medicine, Danish Ramazzini Center, Aalborg University Hospital, Havrevangen 1, 9000 Aalborg, Denmark; 3.Department of Health Science and Technology, Aalborg University, Fredrik Bajers Vej 7 D2, DK-9220 Aalborg, Denmark;
authors.forename: Øyvind
authors.initials: Ø
authors.lastname: Omland
authors.affiliation: 4.Division of Environmental Epidemiology, Institute for Risk Assessment Sciences (IRAS), Utrecht University, Yalelaan 2, 3584 CM Utrecht, the Netherlands;
authors.forename: Hans
authors.initials: H
authors.lastname: Kromhout
authors.affiliation: 1.Department of Public Health, Section for Environment, Occupation and Health, Danish Ramazzini Center, Aarhus University, Bartholins Allé 2, bg 1260, 8000 Aarhus C, Denmark; 5.National Research Center for the Working Environment, Lersø Parkallé 105, 2100 Copenhagen Ø, Denmark.
authors.forename: Vivi
authors.initials: V
authors.lastname: Schlünssen
mesh_terms: D000395:Air Pollutants, Occupational / Q000032:analysis; D000818:Animals; D002417:Cattle; D004391:Dust / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods; D000067565:Farmers / Q000193:education*; D005246:Feedback; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis; D016273:Occupational Exposure / Q000032:analysis*; D011897:Random Allocation; D011795:Surveys and Questionnaires; D013552:Swine
chemical_list: D000395:Air Pollutants, Occupational; D004391:Dust
keywords: farmers; inhalable dust; intervention; livestock; organic dust; prevention