Table 1. Atmospheric metrology of the daily fluorene exposure.

Variable	Freely- moving rats	Restrained controls	1.5 ppb	150 ppb
Fluorene (ppb)
day 1	n.d.	n.d.	1.43±0.06	157.2±2.5 **
day 4	n.d.	n.d.	1.42±0.03	144.3±2.0 **
day 7	n.d.	n.d.	1.30±0.09	146.1±2.2
day 10	n.d.	n.d.	1.63±0.08	152.4±2.3
day 14	n.d.	n.d.	1.54±0.06	151.7±2.4
Temperature (°C)
day 1	22.7±0.2	22.2±0.2	21.9±0.1	22.2±0.2
day 4	22.7±0.2	22.1±0.2	21.9±0.3	22.2±0.3
day 7	22.7±0.2	22.1±0.2	21.9±0.3	22.2±0.3
day 10	22.7±0.2	22.2±0.2	21.9±0.2	21.8±0.1
day 14	22.9±0.2	22.3±0.1	22.0±0.1	22.2±0.2
Humidity (%)
day 1	56.9±1.7	54.4±2.6	58.4±2.5	57.9±2.4
day 4	56.8±1.6	55.5±3.0	56.0±3.1	58.8±1.5
day 7	55.5±0.3	53.4±1.6	49.0±1.8	55.6±2.1
day 10	58.3±3.2	55.0±3.3	50.7±3.3	58.1±5.2
day 14	55.8±0.4	57.6±4.2	59.0±3.1	59.3±4.3

Only the results of 5 days of exposure chosen during all the period of 14 days are presented. The results are expressed as mean±S.E.M. calculated from the values obtained through the 6 hour-period of exposure and were compared to a test value of 22°C for temperature, 55% for humidity, and 1.50 or 150 ppm of fluorene by means of a one-sample t test. ** p<0.01, statistical significant difference from the appropriate test value.