To improve the database for emission inventories, PM10 emissions for the most common dairy housing situation in Switzerland were determined. Measurements were taken on six naturally ventilated dairy loose housings with cubicles, solid floors and an outdoor exercise area in two out of three seasons (summer, transitional season, winter) per farm. PM10 was collected cumulatively over 72 h using impactors at 9 to 14 measuring points in the housing area, outdoor exercise area, and in the background. Emissions were determined by a tracer ratio method with two tracer gases (SF6, SF5CF3). PM10 concentrations in the animal area were usually just above or within the range of the background concentration. The PM10 emissions varied between 0.02 and 2.1 g LU-1 d-1 across all farms. With the present amount of data, there was no recognisable relationship with the considered influencing variables. At 0.64 g cow-1 d-1 the derived PM10 emission factor is considerably lower than the emission factors used in inventories to date.
