Respirable dust concentrations in equine stables. Part 1: validation of equipment and effect of various management systems.

Traditional methods of measuring airborne dust concentrations (ADC) in animal housing have included the collection of dust onto pre-weighed filters permitting the calculation of mean, not maximum, ADC. However real-time continuous particle monitors are advantageous in identifying short duration elevations in ADC which may be detrimental to equine respiratory health in the face of a relatively low mean ADC. These monitors have not previously been used to measure ADC in equine stables. Comparisons of a filter-based sampler and a real-time continuous particle monitor revealed no significant difference (P=0.079) and good agreement (>or=95% of the points fell within two standard deviations of the mean of the differences and the mean of the differences approximated zero) between the devices, with respect to mean respirable dust concentration (RDC) measurements. Investigations of the influence of various equine management systems on RDC revealed that both mean and maximum breathing zone RDC were significantly reduced (P<0.05) in equine stables by changing the environment from hay feed and straw bedding, to haylage feed and wood shavings bedding (reduction in mean - 0.0867mg/m(3) to 0.0260mg/m(3); reduction in maximum - 4.0758mg/m(3) to 0.2182mg/m(3), respectively).