. 2020 Feb 18;128(2):027007. doi: 10.1289/EHP5337

Table 3.

Multivariable linear regression models for the association between potential predictors and serum concentrations of PFOA, PFOS, and PFHxS in the entire study population ( $n = 18,122$ subjects with complete records for all variables).

Predictor	$n$ (%)	% difference (95% CI)
Predictor	$n$ (%)	PFOA	PFOS	PFHxS
Gender
Female	8,892 (49.1)	Referent	Referent	Referent
Male	9,230 (50.9)	66 (61; 71)	42 (39; 45)	93 (88; 98)
Explained variance (%)		11.52	9.94	18.17
Age (y)
14–19	4,478 (24.7)	Referent	Referent	Referent
20–24	3,194 (17.6)	$- 9$ ( $- 15$ ; $- 4$ )	$- 1$ ( $- 4$ ; 3)	$- 1$ ( $- 6$ ; 4)
25–29	3,044 (16.8)	$- 12$ ( $- 18$ ; $- 5$ )	2 ( $- 2$ ; 7)	10 (3; 16)
30–34	3,304 (18.2)	$- 18$ ( $- 24$ ; $- 11$ )	8 (3; 14)	14 (6; 21)
35–39	4,102 (22.6)	$- 5$ ( $- 12$ ; 3)	20 (14; 26)	30 (21; 39)
Explained variance (%)		2.96	0.13	0.74
Country of birth
Italian, HDC	16,696 (92.1)	Referent	Referent	Referent
HMPC	1,426 (7.9)	$- 10$ ( $- 15$ ; $- 5$ )	—	—
Explained variance (%)		1.25	—	—
Educational level
Primary/Middle school	5,853 (32.3)	Referent	Referent	Referent
High school	9,012 (49.7)	$- 4$ ( $- 7$ ; 0)	1 ( $- 2$ ; 3)	$- 3$ ( $- 7$ ; 0)
University	3,257 (18.0)	2 ( $- 3$ ; 8)	6 (3; 9)	0 ( $- 4$ ; 4)
Explained variance (%)		0.33	0.33	0.26
Occupational sector
No farmer	17,903 (98.8)	Referent	Referent	Referent
Farmer	219 (1.2)	—	8 (0; 16)	—
Explained variance (%)		—	0.02	—
Predominant residential area
Red Area A	7,020 (38.7)	38 (27; 50)	5 (0; 10)	42 (33; 51)
Red Area B	11,102 (61.3)	Referent	Referent	Referent
Explained variance (%)		0.20	0.01	0.30
Current municipality of residency (Red Area A or B)
Terrazzo (B)	288 (1.6)	Referent	Referent	Referent
Albaredo D’Adige (B)	767 (4.2)	160 (131; 194)	14 (6; 23)	126 (104; 150)
Arcole (B)	899 (5.0)	189 (156; 226)	25 (16; 34)	135 (113; 159)
Bevilacqua (B)	216 (1.2)	342 (278; 416)	41 (28; 55)	268 (224; 319)
Bonavigo (B)	279 (1.5)	170 (133; 213)	16 (6; 27)	137 (110; 168)
Boschi Sant’Anna (B)	206 (1.1)	202 (158; 254)	22 (11; 35)	155 (124; 191)
Legnago (B)	2,945 (16.3)	87 (68; 109)	7 (0; 14)	59 (45; 74)
Minerbe (B)	628 (3.5)	325 (276; 381)	32 (23; 43)	241 (208; 278)
Veronella (B)	778 (4.3)	340 (289; 397)	35 (25; 46)	248 (215; 285)
Alonte (A)	346 (1.9)	236 (186; 296)	38 (25; 52)	168 (134; 207)
Asigliano Veneto (A)	161 (0.9)	275 (210; 353)	34 (19; 50)	198 (155; 249)
Brendola (A)	1,007 (5.6)	125 (95; 160)	21 (11; 32)	31 (16; 47)
Cologna Veneta (A)	1,208 (6.7)	243 (199; 294)	35 (24; 47)	183 (153; 217)
Lonigo (A)	2,569 (14.2)	252 (206; 303)	42 (31; 55)	173 (144; 206)
Montagnana (A)	1,146 (6.3)	264 (216; 318)	40 (29; 53)	184 (153; 219)
Noventa Vicentina (A)	1,410 (7.8)	166 (132; 206)	22 (12; 33)	101 (79; 126)
Pojana Maggiore (A)	767 (4.2)	263 (214; 320)	33 (22; 46)	180 (148; 216)
Pressana (A)	365 (2.0)	272 (218; 336)	29 (17; 42)	192 (156; 232)
Roveredo Di Gua’ (A)	263 (1.4)	243 (190; 306)	25 (13; 39)	178 (142; 219)
Sarego (A)	1,124 (6.2)	197 (157; 242)	46 (34; 59)	118 (94; 146)
Zimella (A)	750 (4.1)	236 (192; 288)	40 (28; 52)	170 (140; 204)
Explained variance (%)		12.57	6.70	14.84
Duration of residency in the Red Area (y)
$< 5$	1,082 (6.0)	Referent	Referent	Referent
5–9	1,375 (7.6)	45 (35; 56)	8 (3; 13)	27 (20; 35)
10–14	3,962 (21.9)	97 (83; 111)	17 (12; 22)	68 (59; 79)
15–19	3,380 (18.6)	120 (104; 137)	21 (16; 27)	98 (86; 111)
20–24	2,887 (15.9)	120 (104; 137)	26 (20; 31)	111 (98; 124)
25–29	2,663 (14.7)	131 (115; 148)	24 (19; 29)	125 (113; 138)
more than 30 years	2,773 (15.3)	117 (102; 132)	17 (12; 22)	117 (105; 130)
Explained variance (%)		3.40	0.91	5.34
Time-lag between the beginning of the study and blood sampling (months)
Less than 6 months	2,221 (12.3)	Referent	Referent	Referent
6–10	5,152 (28.4)	6 (0; 12)	$- 4$ ( $- 7$ ; $- 1$ )	13 (8; 18)
11–15	5,283 (29.2)	0 ( $- 7$ ; 7)	$- 8$ ( $- 12$ ; $- 4$ )	5 ( $- 1$ ; 11)
16–20	4,156 (22.9)	$- 13$ ( $- 21$ ; $- 5$ )	$- 21$ ( $- 25$ ; $- 17$ )	$- 4$ ( $- 11$ ; 3)
$\geq 21$	1,310 (7.2)	$- 23$ ( $- 31$ ; $- 15$ )	$- 26$ ( $- 30$ ; $- 21$ )	$- 12$ ( $- 19$ ; $- 4$ )
Explained variance (%)		0.43	0.62	0.42
BMI (kg/m²)
Underweight	1,437 (7.9)	—	0 ( $- 3$ ; 3)	$- 4$ ( $- 8$ ; 0)
Normal weight	11,388 (62.9)	Referent	Referent	Referent
Pre-obesity	3,895 (21.5)	—	$- 3$ ( $- 5$ ; $- 1$ )	3 (0; 6)
Obesity	1,402 (7.7)	—	$- 12$ ( $- 14$ ; $- 9$ )	5 (1; 9)
Explained variance (%)		—	0.53	0.06
eGFR (mL/min/1.73 m²)
$\geq 90$	15,691 (86.6)	Referent	Referent	Referent
$< 90$	2,431 (13.4)	5 (1; 10)	6 (3; 8)	5 (1; 8)
Explained variance (%)		0.09	0.13	0.09
Number of deliveries
0	15,490 (85.5)	Referent	Referent	Referent
1	1,100 (6.1)	$- 40$ ( $- 43$ ; $- 36$ )	$- 17$ ( $- 20$ ; $- 13$ )	$- 30$ ( $- 34$ ; $- 27$ )
2	1,213 (6.7)	$- 57$ ( $- 59$ ; $- 54$ )	$- 25$ ( $- 28$ ; $- 22$ )	$- 45$ ( $- 48$ ; $- 42$ )
$\geq 3$	319 (1.7)	$- 63$ ( $- 67$ ; $- 59$ )	$- 22$ ( $- 27$ ; $- 17$ )	$- 48$ ( $- 52$ ; $- 43$ )
Explained variance (%)		3.42	1.15	2.19
Smoking habit
Never	11,364 (62.7)	Referent	Referent	Referent
Current	4,775 (26.4)	1 ( $- 2$ ; 5)	$- 6$ ( $- 8$ ; $- 4$ )	2 ( $- 1$ ; 4)
Former	1,983 (10.9)	$- 5$ ( $- 9$ ; $- 1$ )	$- 5$ ( $- 7$ ; $- 2$ )	$- 2$ ( $- 6$ ; 1)
Explained variance (%)		0.09	0.11	0.06
Alcohol intake (AU per week)
Never	5,525 (30.5)	Referent	Referent	Referent
$< 3$	7,438 (41.1)	2 ( $- 2$ ; 5)	5 (3; 7)	$- 1$ ( $- 4$ ; 2)
3–6	3,232 (17.8)	8 (3; 13)	7 (4; 9)	3 ( $- 1$ ; 7)
$\geq 7$	1,927 (10.6)	13 (7; 19)	11 (7; 14)	8 (3; 12)
Explained variance (%)		0.47	0.44	0.29
Water intake (L/d)
Less than 1	1,739 (9.6)	Referent	Referent	Referent
1–1.5	5,037 (27.8)	—	$- 3$ ( $- 6$ ; 0)	—
1.5–2	9,463 (52.2)	—	$- 9$ ( $- 11$ ; $- 6$ )	—
$\geq 2$	1,883 (10.4)	—	$- 14$ ( $- 18$ ; $- 11$ )	—
Explained variance (%)		—	0.41	—
Milk/Yogurt intake
I quartile	5,292 (29.2)	Referent	Referent	Referent
II quartile	3,985 (22.0)	$- 2$ ( $- 6$ ; 2)	0 ( $- 2$ ; 3)	$- 3$ ( $- 5$ ; 0)
III quartile	7,176 (39.6)	$- 3$ ( $- 6$ ; 0)	$- 1$ ( $- 3$ ; 1)	$- 1$ ( $- 4$ ; 1)
IV quartile	1,669 (9.2)	$- 8$ ( $- 12$ ; $- 3$ )	$- 7$ ( $- 10$ ; $- 4$ )	$- 5$ ( $- 9$ ; $- 1$ )
Explained variance (%)		0.14	0.19	0.09
Cheese intake
I quartile	5,433 (30.0)	Referent	Referent	Referent
II quartile	4,574 (25.2)	—	0 ( $- 2$ ; 2)	—
III quartile	4,610 (25.4)	—	0 ( $- 2$ ; 2)	—
IV quartile	3,505 (19.4)	—	$- 3$ ( $- 5$ ; $- 1$ )	—
Explained variance (%)		—	0.05	—
Meat intake
I quartile	6,867 (37.9)	Referent	Referent	Referent
II quartile	3,051 (16.8)	$- 6$ ( $- 9$ ; $- 2$ )	2 ( $- 1$ ; 4)	$- 4$ ( $- 7$ ; $- 1$ )
III quartile	6,813 (37.6)	$- 5$ ( $- 8$ ; $- 2$ )	2 (0; 4)	$- 2$ ( $- 5$ ; 0)
IV quartile	1,391 (7.7)	$- 12$ ( $- 17$ ; $- 7$ )	$- 3$ ( $- 6$ ; 0)	$- 10$ ( $- 14$ ; $- 5$ )
Explained variance (%)		0.12	0.06	0.09
Fish intake
I tertile	10,998 (60.7)	Referent	Referent	Referent
II tertile	4,725 (26.1)	$- 4$ ( $- 7$ ; $- 1$ )	4 (3; 6)	—
III tertile	2,399 (13.2)	$- 2$ ( $- 6$ ; 2)	9 (6; 11)	—
Explained variance (%)		0.02	0.22	—
Eggs intake
I quartile	5,211 (28.8)	Referent	Referent	Referent
II quartile	7,701 (42.5)	—	9 (7; 11)	—
III quartile	3,545 (19.5)	—	9 (6; 12)	—
IV quartile	1,665 (9.2)	—	13 (10; 17)	—
Explained variance (%)		—	0.35	—
Sweets/snacks/sweet beverages intake
I quartile	6,340 (35.0)	Referent	Referent	Referent
II quartile	4,936 (27.2)	$- 1$ ( $- 5$ ; 3)	$- 2$ ( $- 4$ ; 0)	$- 3$ ( $- 6$ ; 0)
III quartile	4,555 (25.2)	$- 3$ ( $- 6$ ; 1)	$- 2$ ( $- 4$ ; 1)	$- 4$ ( $- 7$ ; $- 1$ )
IV quartile	2,291 (12.6)	$- 8$ ( $- 13$ ; $- 3$ )	$- 5$ ( $- 7$ ; $- 2$ )	$- 9$ ( $- 13$ ; $- 5$ )
Explained variance (%)		0.03	0.08	0.06
Bread/pasta/cereals intake
I tertile	7,497 (41.4)	Referent	Referent	Referent
II tertile	7,880 (43.5)	2 ( $- 2$ ; 6)	—	1 ( $- 2$ ; 5)
III tertile	2,745 (15.1)	8 (3; 14)	—	7 (3; 12)
Explained variance (%)		0.02	—	0.02
Fruit/vegetables intake
I tertile	5,435 (30.0)	Referent	Referent	Referent
II tertile	5,738 (31.7)	0 ( $- 3$ ; 4)	6 (4; 9)	3 (0; 6)
III tertile	3,776 (20.8)	4 (0; 8)	7 (4; 9)	6 (3; 10)
IV tertile	3,173 (17.5)	4 (0; 9)	8 (5; 11)	7 (4; 11)
Explained variance (%)		0.02	0.23	0.08
Growing vegetables for personal consumption
No	8,891 (49,1)	Referent	Referent	Referent
Yes	9,231 (50.9)	3 (0; 6)	10 (8; 12)	3 (1; 6)
Explained variance (%)		0.33	2.52	0.73
Raising animals for personal consumption
No	14,334 (79.1)	Referent	Referent	Referent
Yes	3,788 (20.9)	$- 4$ ( $- 8$ ; $- 1$ )	24 (21; 26)	—
Explained variance (%)		0.05	1.19	—
Total variance explained (%)		37.44	22.61	43.10

Note: Red Area: the area of the Veneto Region including municipalities supplied by PFAS contaminated waterworks. Red Area A: part of Red Area whose municipalities are located on the groundwater contamination plume. Red Area B: part of Red Area whose municipalities are located outside the groundwater contamination plume. HDC were defined as not Central–Eastern Europe, North America, Oceania, Israel and Japan. HMPC were defined as Central-Eastern Europe, North Africa, sub-Saharan Africa, Asia except Israel and Japan, and Central and South America countries. Duration of residency in the Red Area was calculated as the number of years spent in the Red Area between 1980 and 2013 (when granular activated carbon filters were installed). Intake of food items was categorized based on quartiles or tertiles. Predictors shown for each PFAS were selected using a stepwise approach based on the Akaike information criterion (AIC). Values of % difference were derived from beta coefficients. —, no data. AU, alcohol units; BMI, body mass index; eGFR, estimated glomerular filtration rate; HDC, highly developed countries; HMPC, high migratory pressure countries; PFHxS, perfluorohexanesulfonic acid; PFOA, perfluorooctanoic acid; PFOS, perfluorooctanesulfonic acid.