Table 7:
Model estimates for multivariable regression analysis of smoking status, water district, bottled water use, age, sex and race/ethnicity as predictors of select serum PFAS1 (N=213).
| Variable | PFHxS | Total PFOS | Total PFOA2 | PFNA | PFHpS3 | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| Coefficient (95% CI) | p-value | Coefficient (95% CI) | p-value | Coefficient (95% CI) | p-value | Coefficient (95% CI) | p-value | Coefficient (95% CI) | p-value | |
| Smoking status4 | 32.3 (0.20, 75.1) | 0.05 | 20.9 (−2.5, 50.7) | 0.08 | 16.2 (−6.8, 43.3) | 0.18 | −4.2 (−20.5, 15.0) | 0.65 | 11.6 (−10.4, 37.7) | 0.34 |
| Home water district5 | ||||||||||
| Security | 116.0 (55.3, 200.0) | < 0.001 | 43.3 (11.6, 85.9) | 0.006 | 35.0 (4.3, 73.3) | 0.02 | 1.0 (−18.9, 25.9) | 0.92 | 66.5 (28.4, 116.0) | <0.001 |
| Widefield | 37.7 (−3.9, 97.4) | 0.08 | 41.9 (6.6, 87.8) | 0.02 | 19.7 (−9.4, 58.4) | 0.21 | 7.3 (−15.6, 36.3) | 0.58 | 25.9 (−5.2, 66.5) | 0.11 |
| Bottled water use (as of date questionnaire was administered)6 | ||||||||||
| Half tap/half bottled | −30.2 (−52.8, 3.2) | 0.07 | −3.9 (−29.5, 31.0) | 0.80 | −27.4 (−46.2, −1.7) | 0.04 | 8.5 (−16.5, 40.5) | 0.53 | −19.7 (−51.1, 9.2) | 0.16 |
| Mostly/only bottled | −37.5 (−52.8, −16.5) | 0.001 | −18.1 (−34.3, 2.8) | 0.09 | −24.4 (−39.3, −6.0) | 0.01 | −11.3 (−26.7, 6.9) | 0.20 | −18.1 (−34.3, 2.9) | 0.09 |
| Age | 2.3 (1.4, 3.4) | < 0.001 | 2.4 (1.7, 3.1) | < 0.001 | 1.6 (0.90, 2.3) | < 0.001 | 1.1 (0.50, 1.7) | 0.001 | 2.9 (2.2, 3.8) | < 0.001 |
| Sex7 | 0.30 (−22.9, 31.0) | 0.98 | 39.1 (12.7, 71.6) | 0.002 | 1.2 (−17.3, 24.6) | 0.91 | 3.5 (−13.1, 23.4) | 0.70 | 35.0 (9.9, 66.5) | 0.005 |
| Race/Ethnicity8 | ||||||||||
| NH-Nonwhite | −18.1 (−45.1, 20.9) | 0.32 | 0.20 (−26.7, 36.3) | 0.99 | −30.9 (−48.8, −5.9) | 0.02 | 12.7 (−13.1, 46.2) | 0.37 | −9.5 (−33.6, 23.4) | 0.53 |
| Hispanic | −28.1 (−51.8, 8.0) | 0.11 | −17.3 (−40.0, −11.3) | 0.23 | −13.9 (−36.9, 18.5) | 0.35 | 7.0 (−18.1, 40.5) | 0.62 | −24.4 (−45.7, 3.9) | 0.08 |
| R2 (adj.) | 0.25 | 0.27 | 0.17 | 0.04 | 0.17 | |||||
Abbreviations: PFAS, poly- and perfluoroalkyl substance; N, number of observations; CI, confidence interval; PFHxS, perfluorohexane sulfonate; Total PFOS, sum of linear perfluorooctane sulfonate and sum of perfluoromethylheptane sulfonate isomers; PFOA, Sum of linear and branched perfluorooctanoate; PFNA, perfluorononanoate; PFHpS, perfluoroheptane sulfonate; NH, Non-Hispanic; R2 (adj.), adjusted coefficient of determination;
PFAS were natural log-transformed for the analysis, however, results presented above have been back transformed and represent the percent change.
There were no branched perfluorooctanoates (PFOA) detected in any samples, therefore the “Total PFOA” value is equal to the concentration of linear PFOA.
Computed using Tobit regression to account for ~18% left-censored data.
Reference group for smoking status is never smoker.
Reference group for water district is Fountain.
Reference group for bottled water consumption is mostly/only tap water.
Reference group for sex is female.
Reference group for race/ethnicity is non-Hispanic white.