Table 1. Description of the study population, by quartiles (Q1 to Q4) of estimated average time-weighted H2S exposure concentration over the last 30 years for study participants who performed pre-bronchodilator spirometry to a satisfactory standard, Rotorua, New Zealand, 2008–2010.
| N | Q1 | Q2 | Q3 | Q4 | |
|---|---|---|---|---|---|
| H 2 S concentration range | (0–6 ppb) | (7–11 ppb) | (12–18 ppb) | (19–58 ppb) | |
| N | 1,204 | 304 | 313 | 293 | 294 |
| Sex: | |||||
| Female | 790 (65.6%) | 66.8% | 67.4% | 62.8% | 65.3% |
| Male | 414 (34.4%) | 33.2% | 32.6% | 37.2% | 34.7% |
| Age Group (years): | |||||
| 18–29 | 105 (8.7%) | 10.2% | 11.8% | 5.1% | 7.5% |
| 30–39 | 236 (19.6%) | 27.3% | 22.0% | 17.1% | 11.6% |
| 40–49 | 331 (27.5%) | 31.3% | 26.2% | 31.7% | 20.8% |
| 50–59 | 354 (29.4%) | 21.4% | 25.9% | 32.4% | 38.4% |
| 60+ | 178 (14.8%) | 9.9% | 14.1% | 13.7% | 21.8% |
| Ethnic Group: | |||||
| European | 960 (79.7%) | 79.3% | 76.0% | 84.0% | 79.9% |
| Maori | 203 (16.9%) | 16.1% | 19.2% | 14.0% | 18.0% |
| Other | 41 (3.4%) | 4.6% | 4.8% | 2.1% | 2.0% |
| Education: | |||||
| No qualification earned | 143 (11.9%) | 14.8% | 12.1% | 9.2% | 11.2% |
| Secondary school qualification | 28 (22.3%) | 19.4% | 19.8% | 23.9% | 26.2% |
| Non-degree or trade qualification | 460 (38.2%) | 39.5% | 36.7% | 38.6% | 38.1% |
| Bachelor’s degree | 218 (18.1%) | 17.8% | 19.8% | 18.4% | 16.3% |
| Graduate degree | 115 (9.6%) | 8.6% | 11.5% | 9.9% | 8.2% |
| Income (NZ$): | |||||
| $0-$20K | 261 (21.7%) | 33.8% | 21.4% | 16.3% | 15.3% |
| >$20K-$40K | 359 (29.8%) | 28.1% | 29.6% | 31.6% | 29.9% |
| >$40K-$60K | 416 (34.6%) | 25.8% | 38.2% | 35.8% | 38.5% |
| >$60K-$80K | 62 (5.2%) | 5.7% | 5.3% | 4.2% | 5.6% |
| >$80K | 74 (6.2%) | 4.4% | 4.0% | 9.3% | 6.9% |
| Don't Know/Refused | 32 (2.7%) | 2.3% | 1.6% | 2.9% | 3.8% |
| Tobacco Smoking Status: | |||||
| Never | 614 (51.0%) | 52.6% | 53.0% | 51.9% | 46.3% |
| Ex | 359 (29.8%) | 26.6% | 24.0% | 33.5% | 35.7% |
| Current | 231 (19.2%) | 20.7% | 23.0% | 14.7% | 18.0% |
| Asthma ever: | |||||
| No | 851 (70.7%) | 65.8% | 70.9% | 72.0% | 74.2% |
| Yes | 353 (29.3%) | 34.2% | 29.1% | 28.0% | 25.9% |
| COPD (spirometric evidence) | |||||
| No | 1,093 (90.8%) | 90.8% | 89.8% | 93.9% | 88.8% |
| Yes | 111 (9.2%) | 9.2% | 10.2% | 6.1% | 11.2% |
Abbreviations:N, number of participants; NZ$, New Zealand dollars; ppb, parts per billion, Q, quartile.