Exposure to waste water | ||
No (n = 446) | Yes (n = 332) | |
Age (years) | 42 (16–68) | 46 (17–66) |
Male gender | 417 (94) | 331 (100) |
Educational level | ||
Low | 104 (24) | 39 (12) |
Middle | 323 (73) | 290 (87) |
High | 15 (3) | 3 (1) |
Nationality | ||
Swiss | 342 (77) | 302 (91) |
Other countries | 104 (23) | 30 (9) |
Country of childhood | ||
Switzerland | 332 (74) | 299 (90) |
Other countries | 114 (26) | 33 (10) |
Smoking | ||
Never | 178 (40) | 99 (30) |
Former | 104 (23) | 101 (30) |
Current | 162 (37) | 132 (40) |
Pack-years* | 17.0 (0.1–129) | 20.0 (0.25–84.0) |
Alcohol | ||
No/only socially | 296 (67) | 219 (66) |
Daily | 148 (33) | 112 (34) |
GGT activity (%)† | 24.4 (8.1–167.4) | 29.1 (7.0–800) |
Duration of follow-up (years) | 3.7 (0.2–5.1) | 3.9 (0.2–5.2) |
Job change during follow-up because of any health problem | 33 (8) | 23 (7) |
Lifelong exposure to sewage at baseline (years)‡ | 0.0 (0.0–31.0) | 11.0 (0.5–39.0) |
Use of suitable gloves§ | NA | 218 (66) |
Use of an adequate mask§ | NA | 88 (27) |
Shift work | ||
Without night shift | 2 (–) | 5 (2) |
With night shift | 8 (2) | 10 (3) |
Values are as ascertained at baseline with the exception of the duration of follow-up and any job change because of health problems which relate to the entire follow-up period. Figures are median (range) or number (percentage). NA, not applicable.
*Pack-years: median and percentiles calculated in the subgroup of ex- and current cigarette smokers only; †γ-glutamyltransferase (GGT) activity expressed in per cent of the upper limit of the reference range according to sex (male: 86 U/l, female: 47 U/l); ‡lifelong exposure to sewage: 17 workers had only a former exposure. Median time elapsed since last exposure was 10 (0.5–31) years; §see Methods section for definitions of suitable gloves and adequate masks.