Table 5.
Adjusted proportional change in geometric mean (GM) of covariates (95% CI) and serum PFAS concentration among firefighters from Maximum Likelihood Regression (MLE) modelsa
| Variable | n | PFNA | PFOA | PFOS | PFHxS | PFDA | PFBS | PFUnDA |
|---|---|---|---|---|---|---|---|---|
| Frequency of SCBA use during salvage/overhaul | ||||||||
| Rarely/ never | 54 | reference | reference | reference | reference | reference | reference | reference |
| Sometimes | 14 | 1.90 (1.25,2.87)† | 1.19 (0.86,1.64) | 1.29 (0.88,1.89) | 0.75 (0.39,1.47) | 1.44 (1.02,2.04)† | 0.83 (0.25, 2.79) | 3.64 (1.41,9.39)† |
| Often/ always | 12 | 1.47 (0.99,2.18)* | 0.99 (0.73,1.35) | 0.88 (0.61,1.27) | 0.59 (0.31,1.12) | 1.17 (0.84,1.63) | 0.46 (0.15, 1.48) | 1.12 (0.45,2.79) |
| Used firefighting foam in the last year | ||||||||
| No | 50 | reference | reference | reference | reference | reference | reference | reference |
| Yes | 25 | 1.29 (0.94,1.79) | 1.10 (0.86,1.39) | 1.19 (0.92,1.54) | 1.26 (0.79,2.00) | 1.08 (0.82,1.41) | 1.64 (0.64, 4.18) | 1.23 (0.59,2.56) |
| Position in the fire department | ||||||||
| Driver | 21 | reference | reference | reference | reference | reference | reference | reference |
| Officer | 25 | 1.61 (1.13,2.29)† | 1.42 (1.07,1.90)† | 1.25 (0.90,1.74) | 0.98 (0.53,1.79) | 1.45 (1.05,2.00)† | 0.27 (0.09, 0.78)† | 3.18 (1.34,7.51)† |
| Firefighter | 40 | 2.12 (1.54,2.93)‡ | 1.42 (1.09,1.85)† | 1.26 (0.93,1.70) | 0.91 (0.53,1.58) | 1.47 (1.10,1.97)† | 0.54 (0.21, 1.41) | 1.99 (0.91,4.36)† |
| Frequency of hand washing during a 24hr work shift (times/shift) | ||||||||
| <=10 | 21 | reference | reference | reference | reference | reference | reference | reference |
| 11–15 | 24 | 0.92 (0.62,1.36) | 0.90 (0.66,1.22) | 0.87 (0.63,1.20) | 1.83 (1.03,3.23)† | 1.08 (0.77,1.51) | 0.81 (0.27, 2.43) | 0.50 (0.20,1.22) |
| 16–20 | 20 | 1.02 (0.68,1.53) | 0.99 (0.72,1.36) | 1.20 (0.86,1.67) | 2.90 (1.61,5.23)‡ | 0.90 (0.63,1.27) | 0.77 (0.25, 2.40) | 0.65 (0.26,1.64) |
| >20 | 21 | 0.70 (0.46,1.06)* | 0.95 (0.69,1.30) | 0.74 (0.53,1.03)* | 1.42 (0.78,2.58) | 0.76 (0.53,1.07) | 2.13 (0.68, 6.62) | 0.59 (0.23,1.50) |
| Frequency of washing and/or showering after an incident | ||||||||
| Sometimes | 11 | reference | reference | reference | reference | reference | reference | reference |
| Always | 75 | 0.79 (0.50,1.26) | 0.98 (0.69,1.40) | 0.91 (0.62,1.35) | 2.08 (1.04,4.15)† | 1.01 (0.68,1.49) | 0.52 (0.15, 1.83) | 0.89 (0.32,2.52) |
| Assigned to the Airport | ||||||||
| No | 72 | reference | reference | reference | reference | reference | reference | reference |
| Yes | 14 | 2.26 (1.61,3.19)‡ | 1.00 (0.75,1.35) | 1.03 (0.74,1.42) | 0.61 (0.34,1.08)* | 1.05 (0.75,1.45) | 1.05 (0.75, 1.45) | 2.04 (0.88,4.73) |
| Any fire in 24 hours prior to sample collection | ||||||||
| No | 71 | reference | reference | reference | reference | reference | reference | reference |
| Yes | 15 | 0.94 (0.64,1.37) | 0.95 (0.71,1.27) | 1.14 (0.83,1.56) | 1.48 (0.84,2.63) | 0.84 (0.61,1.16) | 1.68 (0.60, 4.74) | 0.94 (0.40,2.20) |
| Number of fires in the year prior to the sample collectionb | ||||||||
| <=9 | 17 | reference | reference | reference | reference | reference | reference | reference |
| 10–15 | 17 | 0.80 (0.54,1.19) | 0.84 (0.60,1.18) | 0.98 (0.66,1.44) | 0.98 (0.50,1.95) | 1.04 (0.70,1.54) | 1.04 (0.70, 1.54) | 0.50 (0.18,1.40) |
| 16–19 | 15 | 0.90 (0.60,1.36) | 1.04 (0.73,1.48) | 1.01 (0.67,1.53) | 1.32 (0.64,2.69) | 1.02 (0.68,1.54) | 1.02 (0.68, 1.54) | 0.70 (0.24,2.02) |
| >=20 | 17 | 0.64 (0.43,0.97) | 0.74 (0.52,1.05) | 0.72 (0.48,1.08) | 0.84 (0.41,1.72) | 0.78 (0.51,1.18) | 0.78 (0.51, 1.18) | 0.72 (0.25,2.09) |
a
Models adjusted for race/ethnicity, age and years of service with SFFD.
b
Data from participants who consented to grant access to their fire history from SFFD
*
pvalue≤ 0.1
†
pvalue≤ 0.05
‡
pvalue≤ 0.001