P-200 AIrborne Exposure to Laboratory Animal Allergens: 2005-2022

Introduction The use of animals remains pivotal in many research studies. Predominantly mice are the species used, followed by rats. However, exposure to laboratory animals allergens is a well recognized cause of sensitisation with symptoms including occupational asthma (OA). Since late 2004 we have been monitoring major mouse and rat allergens, (mus m 1 and rat n 1 respectively), in air samples collected in animal facilities. Methods We have investigated the levels and changes in mus m 1 and rat n1 over the period 2005-2022. We estimated the annual incidence rate of OA based on case reports to the SWORD scheme (Manchester University), and the size of the sector from the number of personal license holders. Results 5441 mus m 1 and 2042 rat n 1 results met the criteria for inclusion. Samples were derived from 429 site visits to 89 facilities. Approximately 10% of sites undertake annual monitoring. A significant downward shift in mus m 1 personal sample results was apparent from 2014 onwards, as well as significant downward trend in its 90th percentile from 2008. We calculated the annual incidence rate of OA as declining from 0.68-1.67 per 1000 staff for 2004-2006 to 0.30-0.81 per 1000 staff in 2017-2019. ie. about a 55% decrease. Discussion and conclusion A decrease is apparent in personal exposure in the predominant species used, together with a decrease in OA. A number of activities remain a potential source of high exposure in some facilities. The data allow facilities to benchmark their own monitoring results against their peers.