Table 8

Summary of personal exposure concentrations measured in April 2000 using cyclone samplers (μg/m³)

	Respirable dust*		Cristobalite
Description	Mean	Range	Mean	Range	Number of samples
Most measurements of cristobalite were below the limit of detection.
Background	32	22–46	<4	<6	4
Gardener	134	7–444	<14	<9–23	6
Hotel housekeeper	41	31–52	<14	<15	3
Housekeeper	50	12–105	<20	<25	9
Housewife	12		<20		1
Scientist	46	16–75	<11	<13	2
Maintenance	11	6–81	<19	<20	2
Office	39		<19		1
Police	16	4–34	<10	<12	10
Public works	54	33–85	<11	<11	7
Shopworker	105	83–126	<11	<11	2