Table 4.

Linear mixed effect model of exposure determinants for hydrogen sulphide index (IN) in sewage workers

Factor	B	SE	eB
Intercept	5.02*	1.35	151.42
Job type:
Inside big plants	−2.55	1.52	0.08
Pump stations and small plants	−1.73	1.51	0.18
Working on sewer network	0	0	1.00
Collecting sewage from cesspools	0.42	1.46	1.52
Time of the year:
Winter	0	0	1.00
Spring	−2.49*	0.88	0.08
Summer	−1.10	0.82	0.33
Autumn	−1.36*	0.65	0.26
Place:
Capital 1	−1.14	1.10	0.32
Capital 2	0.07	1.22	1.07
Capital 3	−2.80*	1.09	0.06
City 1	−2.07*	1.00	0.13
City 2	0	0	1.00
Rural 1	−1.90	1.33	0.15
Rural 2	−0.38	0.69	0.68
Rural 3	0.57	0.90	1.77
Flushing
No	−1.10*	0.47	0.33
Some	−1.16*	0.45	0.31
More than 3 timers or over 10 min	0	0	1.00
Random effects	Variance
Within worker	1.83
Between worker	< 0.000

B regression coefficient, SE Standard error, e^B Determinants for calculating GM for different operations of work

*p < 0.05