A Comparison of Total, Respirable, and Real-Time Airborne Particulate Sampling in Horse Barns

Abstract

Measurements of total, respirable, and real-time airborne particulate were obtained in 12 horse barns in summer and winter. Respirable and total particulate concentrations were measured gravimetrically; real-time particulate was measured with an aerosol photometer. Total particulate (TP) ranged from nondetectable (ND) to 2.1 mg/m³ and from ND to 1.2 mg/m³ for winter and summer sampling, respectively. Respirable particulate (RP) ranged from ND to 0.2 mg/m³ and from ND to 0.7 mg/m³ for winter and summer measurements, respectively. The mean respirable fraction of particulate for summer and winter measurements was 0.63 and 0.34, respectively Real-time particulate (RTP) concentration was significantly correlated with TP for winter measurements and for pooled data but was not significantly correlated with RP for winter, summer, or pooled measurements. Peak, 10-sec average levels of RTP were estimated to range up to 22 mg/m³ in the samples collected. The data suggest that (a) airborne particulate concentrations and particle size distributions vary considerably among horse barns, and (b) real-time sampling, with an aerosol photometer, may be a more reliable measure of airborne TP than airborne RP in these environments.

Keywords:

• aerosols
• agriculture
• dust
• direct-reading instruments
• horse
• particulate

ACKNOWLEDGMENT

This work was supported by the state of Indiana and the Purdue University School of Veterinary Medicine Research account, funded by the total wager tax.

Notes

* indicates outdoor measurement.

^A Respirable particulate.

^B Total particulate.

^C Meanreal-time particulate reading.

^D Peak (10-saverage) real-time particulate reading.

^E Sample weight difference below detection limit.

^F Post weight less than preweight.

^G Indoor samples only. In calculating the mean (for samples with filter weight difference below the detection limit) the filter weight difference was set to the detection limit /√2.

^A Respirable particulate.

^B Total particulate.

^C Meanreal-time particulate reading.

^D Peak (10-secaverage) real-time particulate reading.

^E Sample weight difference below detection limit.

^F Post weight less than preweight.

^G For samples with filter weight difference below detection limit, the filter weight difference was set to the to detection limit/√2.

*p < 0.05,

**p < 0.005,

***p < 0.0005.