Table 3. Associations between Sociodemographic Factors and Detection of PFAS in Community Water Systemsa,b.
| dependent variable |
||||||
|---|---|---|---|---|---|---|
| PFOAc | PFOAd | PFOSc | PFOSd | ≥1 PFAS (of 5 total)c,e | ≥1 PFAS (of 5 total)d,e | |
| (1) | (2) | (3) | (4) | (5) | (6) | |
| All Systems | ||||||
| % Hispanic/Latino | 6.1*** | 4.4*** | 3.8*** | 2.3** | 2.7** | 1.7* |
| (3.2, 9.0) | (2.1, 6.8) | (1.3, 6.4) | (0.3, 4.4) | (0.6, 4.8) | (−0.1, 3.5) | |
| % non-Hispanic Black | 3.9* | 1.6 | 5.8*** | 3.7** | 3.4** | 1.0 |
| (0.0, 8.0) | (−2.0, 5.2) | (2.5, 9.2) | (0.7, 6.8) | (0.5, 6.3) | (−1.7, 3.7) | |
| % under federal poverty line | –17.6*** | –13.1*** | –15.9*** | –11.5*** | –9.4*** | –5.7*** |
| (−21.8, −13.2) | (−17.4, −8.5) | (−19.7, −11.8) | (−15.9, −7.0) | (−13.2, −5.5) | (−9.8, −1.4) | |
| N | 7873 | 7873 | 7873 | 7873 | 6199 | 6199 |
| Stratification by Urban Versus Rural Status | ||||||
| Urban Systems (≥50% Residents in Urban Areas) | ||||||
| % Hispanic/Latino | 5.2*** | 3.6*** | 2.7* | 1.4 | 1.7 | 0.8 |
| (2.1, 8.3) | (1.1, 6.1) | (−0.1, 5.5) | (−0.7, 3.7) | (−0.6, 4.2) | (−1.1, 2.9) | |
| % non-Hispanic Black | 2.8 | 0.6 | 4.6** | 2.5 | 2.4 | 0.0 |
| (−1.8, 7.6) | (−3.3, 4.7) | (0.9, 8.4) | (−0.6, 5.8) | (−1.1, 6.0) | (−3.1, 3.2) | |
| % under federal poverty line | –16.8*** | –12.7*** | –14.5*** | –10.8*** | –10.6*** | –7.2*** |
| (−21.5, −12) | (−17.5, −7.7) | (−18.6, −10.2) | (−15.0, −6.3) | (−14.8, −6.2) | (−11.6, −2.5) | |
| N | 4735 | 4735 | 4735 | 4735 | 3933 | 3933 |
| Rural Systems (<50% Residents in Urban Areas) | ||||||
| % Hispanic/Latino | 2.0 | 1.1 | 5.3* | 3.9 | 0.6 | 0.3 |
| (−5.8, 10.4) | (−6.4, 9.2) | (−0.1, 10.9) | (−1.4, 9.5) | (−3.8, 5.1) | (−4.1, 4.8) | |
| % non-Hispanic Black | 4.3* | 4.9** | 2.5 | 2.3 | 2.6 | 3.1 |
| (−0.4, 9.3) | (0.5, 9.5) | (−1.8, 7.0) | (−2.0, 6.7) | (−1.6, 6.9) | (−1.0, 7.3) | |
| % under federal poverty line | 9.9** | 11.2*** | 0.0 | 4.3 | 10.3*** | 10.6*** |
| (2.2, 18.3) | (3.5, 19.4) | (−9.2, 10.1) | (−4.8, 14.2) | (4.0, 17.1) | (4.5, 17.1) | |
| N | 3138 | 3138 | 3138 | 3138 | 2266 | 2266 |
Results are from logistic regressions that are adjusted for state fixed effects and include clustered standard errors at the county level. Coefficients (with 95% confidence intervals) refer to percent changes in the odds of detecting PFAS (>5 ng/L) associated with one percentage-point higher proportions of each sociodemographic factor.
CWS are the unit of analysis. These CWS were included in statewide sampling from 18 states. *p < 0.1; **p < 0.05; and ***p < 0.01.
No additional adjustment for CWS characteristics and PFAS sources.
Includes adjustment for CWS characteristics (water source type, water system size, and a binary indicator for treatment for PFAS) and PFAS sources within the 8-digit hydrologic unit code of the CWS (airports, MFTA, major industrial facilities, WWTP total existing effluent, and landfills).
This outcome refers to detection of at least one of the five total PFAS (PFOA, PFOS, PFNA, PFHxS, and/or PFBS) over 5 ng/L. Systems that did not report measurements of all the five PFAS during their sampling periods are excluded from this model but are further analyzed in Figure S4 and Table S18.