Table 6

Paired, longitudinal comparisons for firefighters who started as hazmat support members and later became technicians by 1998: year 1 v year 3 (paired samples t tests)

Variable	Year 1 (1996–7)	Year 3 (1998)	p Value
Liver function tests:
Alkaline phosphatase (U/l)		70 (17)	74 (20)	0.093
Alkaline phosphatase (U/l)		n=12	n=12
Aspartate aminotransferase (U/l)		23 (5)	22 (7)	0.535
Aspartate aminotransferase (U/l)		n=12	n=12
Alanine aminotransferase (U/l)		23 (9)	24 (16)	0.695
Alanine aminotransferase (U/l)		n=12	n=12
Renal function tests:
Blood urea nitrogen (mmol/l)^8-150		6.4 (1.8)	5.7 (1.1)	0.065
Blood urea nitrogen (mmol/l)^8-150		n=12	n=12
Creatinine (μmol/l)^8-151		106 (18)	97 (8.8)	0.007
Creatinine (μmol/l)^8-151		n=12	n=12
Haematological tests:
White blood cells (×10⁹/l)		6.8 (1.7)	6.3 (1.3)	0.458
White blood cells (×10⁹/l)		n=12	n=12
Packed cell volume (fraction)		0.44 (0.03)	0.44 (0.03)	0.428
Packed cell volume (fraction)		n=12	n=12
Platelet count (×10⁹/l)		252 (47)	227 (53)	0.003
Platelet count (×10⁹/l)		n=11	n=11

↵8-150 mg/dl=2.81 (mmol/l).
↵8-151 mg/dl=μmol/(88 l).