Dispersal of Aspergillus fumigatus from Sewage Sludge Compost Piles Subjected to Mechanical Agitation in Open Air

Aerosolization of the thermophilous fungal opportunist Aspergillus fumigatus from mechanically agitated compost piles was examined at a pilot-scale sewage sludge composting facility and two other selected test sites. Aerosols of A. fumigatus downwind from stationary compost piles were insignificant in comparison with those downwind from agitated piles. These aerosols were generated by a front-end loader moving and dropping compost. Aerial concentrations of the fungus at distances downwind from the point of emission were used to determine an emission rate for A. fumigatus associated with the moving operations. The maximum emission rate, 4.6 × 10⁶A. fumigatus particles per s, was used to calculate predicted concentrations in an unobstructed plume with restrictive, neutral, and dispersive atmospheric mixing conditions up to 1 km downwind from the emission source.     

Habitat aridity and urine concentrating ability of nearctic, insectivorous bats

Urine concentrating ability of nearctic, insectivorous bats determined from renal anatomy was significantly correlated to total annual precipitation and potential evapotranspiration to precipitation ratio of the habitat where the animal was collected. Habitat aridity measured by water input accounted for as much variation in urine concentrating ability as habitat aridity measured by both water and energy input. Habitat aridity, regardless of how it was measured, explained only 25% of the among-species variation in urine concentrating ability. Factors other than habitat aridity significantly affect the urine concentrating ability of insectivorous bats.