Table 2.
Demographics and TTHM concentrations for exposure areas.
| Area of TTHM exposure
|
|||
|---|---|---|---|
| Characteristic | Low | Medium | High |
| No. of post codes included in exposure area | 9 | 5 | 11 |
| Average maternal age range (years) | 25–29 | 30–34 | 30–34 |
| SEIFAa | |||
| Range | 945–1,026 | 1,002–1,100 | 873–1,082 |
| Average | 994.2 | 1033.6 | 982.1 |
| Median | 989.8 | 1028.0 | 997.6 |
| Average THM concentration (μg/L) | |||
| TTHM | 54.0 | 109.3 | 137.0 |
| Chloroform | 2.0 | 9.0 | 15.0 |
| Bromoform | 31.0 | 39.5 | 39.0 |
| BDCM | 5.0 | 19.5 | 29.0 |
| DBCM | 17.0 | 44.0 | 54.5 |
| Median THM concentration (μg/L) | |||
| TTHM | 51.0 | 115.0 | 140.0 |
| Chloroform | 1.0 | 8.2 | 11.0 |
| Bromoform | 29.0 | 38.0 | 40.0 |
| BDCM | 3.3 | 19.0 | 27.0 |
| DBCM | 16.0 | 44.5 | 53.0 |
| Maximum individual site THM concentration (μg/L) | |||
| TTHM | 140.0 | 160.0 | 190.0 |
| Chloroform | 5.2 | 19.0 | 52.0 |
| Bromoform | 54.0 | 66.0 | 78.0 |
| BDCM | 13.0 | 44.0 | 57.0 |
| DBCM | 28.0 | 72.0 | 81.0 |
| Minimum individual site THM concentration (μg/L) | |||
| TTHM | 36.0 | 39.0 | 61.0 |
| Chloroform | 1.0 | 1.0 | 2.8 |
| Bromoform | 20.0 | 6.3 | 9.6 |
| BDCM | 2.6 | 3.1 | 6.8 |
| DBCM | 10.0 | 12.0 | 18.0 |
| 25th percentile THM concentration (μg/L) | |||
| TTHM | 42.0 | 93.25 | 120.0 |
| Chloroform | 1.0 | 6.20 | 8.1 |
| Bromoform | 24.0 | 33.50 | 20.0 |
| BDCM | 3.2 | 14.75 | 19.0 |
| DBCM | 13.0 | 34.75 | 46.0 |
| 75th percentile THM concentration (μg/L) | |||
| TTHM | 62.0 | 130.0 | 150.0 |
| Chloroform | 3.15 | 10.25 | 16.0 |
| Bromoform | 34.0 | 47.25 | 53.0 |
| BDCM | 3.8 | 24.00 | 35.0 |
| DBCM | 18.0 | 53.25 | 62.0 |
a
Low values indicate areas of disadvantage, and high values indicate areas of advantage.