PARAMETER NON-OILWORKERS (N=20) Mean ± SD   OIL WORKERS (N=273) Mean ± SD P-Value (2-tailed) Normal range & Unit of parameter
AGE 49.75 ± 5.15 43.63 ± 6.98 0.000  
SERVICE PERIOD 23.20 ± 7.81 16.32 ± 6.47       0.000 Up to 35Yrs
ESR 5.45 ± 7.57 9.26 ± 8.97 0.065 0-7mm/hr (M), 0-10mm/hr (F)
Hb 13.72 ± 0.93 13.38 ± 1.16 0.202 13-18g/dl (M), 12-15g/dl (F)
PCV 45.05 ± 3.05 43.94 ± 3.54 0.172 40-50%(M), 36-47%(F)
PLATELETS ×109 243.35 ± 57.94 232.45 ± 64.32 0.462 150-400 ×109 /L
TOTAL WBC × 109 7.38 ± 1.67 7.18 ± 6.94 0.898 4.0-11.0 ×109 /L
LYMPHOCYTE 44.45 ± 8.46 52.30 ± 9.33 0.000  
GRANULOCYTE 55.55 ± 8.46 47.69 ± 9.31 0.000  
T-test was the statistical tool applied. *Indicates statistically significant difference
Table 2: Haematological parameters studied in male oil workers and male non-oil workers.