Table 2.
Limit of detection, percent detectable results, and geometric means for complete study sample and subgroups (μg/L).a
| Analyte and speciesb | Complete sample (n = 45) | Random sample (n = 30) | High-BPA subgroup (n = 15) | ||||||
|---|---|---|---|---|---|---|---|---|---|
| n (%) > LOD | GM all time periods | GM 17, 23, 29 weeks | n (%) > LOD | GM all time periods | GM 17, 23, 29 weeks | n (%) > LOD | GM all time periods | GM 17, 23, 29 weeks | |
| Bisphenol A (LOD = 0.4 μg/L) | |||||||||
| Total | 135 (100) | 7.7 | 8.9, 7.5, 6.7 | 90 (100) | 7.5 | 7.8, 7.4, 7.2 | 45 (100) | 8.1 | 11.6, 7.8, 5.9 |
| Free | 133 (100) | 5.4 | 7.2, 5.2, 4.3 | 89 (100) | 5.3 | 6.0, 5.6, 4.5 | 44 (100) | 5.6 | 10.5, 4.6, 3.8 |
| Conjugated | 133 (100) | 1.3 | 1.1, 1.3, 1.6 | 89 (100) | 1.2 | 1.0, 1.1, 1.4 | 44 (100) | 1.7 | 1.5, 1.8, 1.9 |
| Butyl paraben (LOD = 0.2 μg/L) | |||||||||
| Total | 135 (100) | 6.3 | 6.7, 6.1, 5.9 | 90 (100) | 6.4 | 7.6, 6.0, 5.7 | 45 (100) | 6.1 | 5.3, 6.4, 6.5 |
| Free | 133 (100) | 1.8 | 1.8, 1.8, 1.8 | 89 (100) | 1.8 | 1.8, 1.8, 1.9 | 44 (100) | 1.8 | 1.8, 1.9, 1.8 |
| Conjugated | 133 (100) | 3.1 | 3.6, 3.1, 2.8 | 89 (100) | 3.5 | 4.8, 3.8, 2.5 | 44 (100) | 2.5 | 2.0, 2.2, 3.3 |
| Methyl paraben (LOD = 1.0 μg/L) | |||||||||
| Total | 135 (100) | 1235.7 | 1,332, 1,249, 1,134 | 90 (100) | 1213.7 | 1,297, 1,256, 1,097 | 45 (100) | 1280.9 | 1,405, 1,234, 1,212 |
| Free | 133 (100) | 25.7 | 24.1, 26.4, 26.7 | 89 (100) | 25.7 | 24.7, 25.2, 27.3 | 44 (100) | 25.7 | 22.9, 28.9, 25.5 |
| Conjugated | 133 (100) | 1204.5 | 1,308, 1,212, 1,104 | 89 (100) | 1181.0 | 1,271, 1,218, 1,066 | 44 (100) | 1253.5 | 1,392, 1,202, 1,186 |
| Propyl paraben (LOD = 0.2 μg/L) | |||||||||
| Total | 135 (100) | 32.3 | 29.5, 37.8, 30.2 | 90 (100) | 36.4 | 40.1, 38.3, 31.4 | 45 (100) | 25.4 | 16.1, 36.9, 27.8 |
| Free | 133 (100) | 1.6 | 1.4, 1.7, 1.6 | 89 (100) | 1.7 | 1.6, 1.6, 1.7 | 44 (100) | 1.4 | 1.1, 1.9, 1.3 |
| Conjugated | 133 (100) | 28.9 | 25.5, 35.1, 27.3 | 89 (100) | 33.1 | 35.7, 36.2, 28.2 | 44 (100) | 22.1 | 12.3, 33.0, 25.6 |
| Benzophenone‑3 (LOD = 0.4 μg/L) | |||||||||
| Total | 128 (95) | 6.1 | 4.4, 7.0, 7.3 | 86 (96) | 6.7 | 5.3, 6.5, 8.7 | 42 (93) | 5.0 | 3.0, 7.9, 5.2 |
| Free | 13 (10) | NC | NC | 9 (10) | NC | NC | 4 (9) | NC | NC |
| Conjugated | 13 (10) | NC | NC | 9 (10) | NC | NC | 4 (9) | NC | NC |
| 2,4-DCP (LOD = 0.2 μg/L) | |||||||||
| Total | 60 (44) | NC | NC | 42 (47) | NC | NC | 18 (40) | NC | NC |
| Free | 2 (2) | NC | NC | 1 (1) | NC | NC | 1 (2) | NC | NC |
| Conjugated | 2 (2) | NC | NC | 1 (1) | NC | NC | 1 (2) | NC | NC |
| 2,5-DCP (LOD = 0.2 μg/L) | |||||||||
| Total | 19 (14) | NC | NC | 11 (12) | NC | NC | 8 (18) | NC | NC |
| Free | 0 (0) | NC | NC | 0 (0) | NC | NC | 0 (0) | NC | NC |
| Conjugated | 0 (0) | NC | NC | 0 (0) | NC | NC | 0 (0) | NC | NC |
| Abbreviations: 2,4-DCP, 2,4-dichlorophenol; 2,5-DCP, 2,5-dichlorophenol; GM, geometric mean; LOD, limit of detection; NC, not calculated due to < 50% detection. aComplete sample (n = 45 participants, 135 samples); random sample: randomly selected participants with no previously measured BPA concentrations (n = 30 participants, 90 samples); high-BPA subgroup: participants with high BPA concentrations in a previous random selection (n = 15 participants, 45 samples). bInstrumental readings used for total concentrations; values > LOD used for free concentrations. Conjugated concentrations, which are the difference between measured total and free concentrations, were calculated if both total and free were > LOD. Two specimens lacked reportable free phenol concentrations due to instrument error. | |||||||||