Table 1.

Eight-hour time weighted level^* of dust during longeing in indoor arena (unit: mg/m³)

The area sample and personal sample 1 were analyzed on 13 Jan 2012, and the total dust of the personal sample 2 was analyzed on 25 Jan 2006.

^*Eight-hour time-weighted levels of dust during longeing were generated with the assumption that all other exposure totaled zero, and were calculated assuming that he trained 7 horses per day, spending 25 minutes on each horse.

^†As there was no information on the respirable crystalline silica (RCS) in personal sample 2, we used the data from personal sample 1 (showing that 1.7% of total dust is RCS). This yielded an RCS concentration of 0.086 mg/m³.