Table 2.
Urinary and serum biomarker concentrations by administered oral doses of diethyl phthalate, methyl paraben, and triclosan.
| Biomarker | Experiment 1 | Experiment 2 | ||||||
|---|---|---|---|---|---|---|---|---|
| Oral dose NOAEL/X | Oral dose (mg/kg/day) | Urine concentration (ng/mL), pooled samplea | Oral dose NOAEL/X | Oral dose (mg/kg/day) | Urine concentration (ng/mL) Mean ± SDb | Serum n > LOD/ total samples | Serum concentration (ng/mL) Mean ± SD | |
| Monoethyl phthalate (MEP)c | ||||||||
| 10 | 173.5 | 2.02 × 106 | 200 | 8.68 | 1.64 × 105 ± 6.97 × 104 | 5/5 | 19.12 ± 7.56 | |
| 100 | 17.35 | 2.43 × 105 | 10,000 | 0.174 | 5.53 × 103 ± 2.87 × 103 | 5/5 | 21.66 ± 9.21 | |
| 200 | 8.68 | 2.28 × 105 | 100,000 | 0.0174 | 2.87 × 102 ± 5.31 × 101 | 5/5 | 15.76 ± 8.89 | |
| 0d | 3.22 × 103 | 0e | 1.28 × 102 ± 8.24 × 101 | 10/10f | 12.26 ± 2.37 | |||
| Methyl paraben (MPB) | ||||||||
| 10 | 105 | 5.00 × 105 | 200 | 5.25 | 4.32 × 104 ± 1.74 × 104 | 5/5 | 1.64 ± 0.48 | |
| 100 | 10.5 | 9.02 × 104 | 10,000 | 0.105 | 1.39 × 103 ± 7.09 × 102 | 1/5 | 0.4g | |
| 200 | 5.25 | 7.70 × 104 | 100,000 | 0.0105 | 1.44 × 102 ± 9.72 × 101 | 1/5 | 0.4g | |
| 0d | 3.85 × 100 | 0e | 5.46 × 100 ± 2.27 × 100 | 5/5 | 0.96 ± 0.44 | |||
| Triclosan (TCS) | ||||||||
| 10 | 5 | 7.91 × 103 | 200 | 0.25 | 1.70 × 103 ± 5.19 × 102 | 5/5 | 186 ± 40.69 | |
| 100 | 0.5 | 1.28 × 103 | 1,000 | 0.05 | 2.88 × 102 ± 9.02 × 101 | 5/5 | 46.88 ± 20.76 | |
| 200 | 0.25 | 5.94 × 102 | 10,000 | 0.005 | 5.22 × 101 ± 1.86 × 101 | 5/5 | 4.72 ± 2.20 | |
| 0d | 5.4 × 100 | 0e | 1.81 × 101 ± 1.27 × 101 | 0/5 | — | |||
| Abbreviations: LOD, Limit of detection; NOAEL, no observed adverse effect level. aBiomarker concentration measured in a single sample from a urine pool from five individual rats for each dose group. bMean of biomarker concentrations measured in five individual urine samples for each dose group. All biomarkers measured in urine samples were detectable (> LOD); LOD (ng/mL) in urine for MEP, MPB, and TCS were 0.6, 1.0, and 2.3, respectively. For comparison, the 2009–2010 National Health and Nutrition Examination Survey urine concentration median and 95th percentile (ng/mL) for females were 59.6 and 988, respectively, for MEP; 106 and 1,230, respectively, for MPB; and 10.5 and 488, respectively, for triclosan (CDC 2014). cMonoethyl phthalate was used as the biomarker of exposure to diethyl phthalate. dOne control group of 5 rats was used for experiment 1; the pooled urine sample was analyzed for all three biomarkers (MEP, MPB, and triclosan). eOne control group of 5 rats was used for experiment 2; the 5 individual urine samples were analyzed for all three biomarkers (MEP, MPB, and triclosan). fMEP serum controls: MEP concentrations measured in serum from 5 MPB and 5 TCS animals treated with the lowest oral dose (MPB: NOAEL/100,000; TCS: NOAEL/10,000); see “Methods” for details. gConcentration measured in the single serum sample among dose group with measurement > LOD; LOD (ng/mL) in serum for MEP, MPB, and triclosan were 0.6, 0.1, and 1.1, respectively. | ||||||||