RT Journal Article SR Electronic T1 O46-4 Development of a quantitative job exposure matrix for endotoxin exposure in agriculture JF Occupational and Environmental Medicine JO Occup Environ Med FD BMJ Publishing Group Ltd SP A88 OP A88 DO 10.1136/oemed-2016-103951.235 VO 73 IS Suppl 1 A1 Ioannis Basinas A1 Inge M Wouters A1 Torben Sigsgaard A1 Dick Heederik A1 Suzanne Spaan A1 Lidwien AM Smit A1 Jakob H Bønløkke A1 Wijnand Eduard A1 Katja Radon A1 Anne Straumfors A1 Øyvind Omland A1 Caroline Duchaine A1 Dennis Nowak A1 Vivi Schlünssen A1 Hans Kromhout YR 2016 UL http://oem.bmj.com/content/73/Suppl_1/A88.1.abstract AB Objective To develop a quantitative job exposure matrix (JEM) for the assessment of endotoxin exposure among farmers and other agricultural industry workers. Methods An exposure database containing 3,384 personal endotoxin measurements from Western European and Canadian workers employed in animal and crop production and related-industries with endotoxin exposure between 1992 and 2008 was established. Data were log-transformed and modelled with linear mixed effect models where job-titles, company (within job-titles) and worker (within company) identities were treated as random effects. Fixed effects were year and season of measurement, sampling duration and an exposure prior (none, low, high) for every job code (ISCO-68) from an existing JEM for general population studies. Results The model results suggested overall levels of endotoxin exposure to decline annually by almost 2%. Season was a strong determinant of endotoxin exposure with measured concentrations being higher during the winter (β = 0.64; p < .0001) compared to the summer. Effects of sampling duration on the exposure were rather small. Predicted exposure levels were highest among wheat, vegetable, crop and poultry farmers and lowest among nursery garden workers, gardeners and horticulture farmers. Derived exposure estimates showed good agreement with endotoxin levels reported in the literature and not included in the database. Perspectives The model predictions will be used to develop a quantitative JEM with a time axis for endotoxin exposure to be used in epidemiological studies among farmers and agricultural industry workers.