Associations between polyfluoroalkyl substance and organophosphate flame retardant exposures and telomere length in a cohort of women firefighters and office workers in San Francisco

Table 1 Descriptive statistics for model parameters by occupation

	Full cohort (N = 163)	Firefighters (N = 84)	Office Workers (N = 79)			Full cohort	Fire- fighters	Office workers
	Mean (SD) or GM (GSD)^a	Mean (SD) or GM (GSD)^a	Mean (SD) or GM (GSD)^a	p-value^b	LOD^c	DF^d(%)	DF(%)	DF(%)
Age (years)
	47.93 (8.10)	47.38 (4.58)	48.52 (10.64)	0.23	–	–	–	–
Dairy consumption (times per week)
	14.45 (8.19)	13.98 (7.30)	14.96 (9.07)	0.47	–	–	–	–
Egg consumption (times per week)
	3.71 (1.93)	3.96 (2.00)	3.46 (1.84)	0.23	–	–	–	–
Telomere Length (mean TRF in kbp^e)
	7.90 (1.12)	8.10 (1.09)	7.68 (1.13)	0.01*	–	–	–	–
PFAS (ng/mL)
PFHxS	3.68 (2.79)	4.55 (2.82)	2.94 (2.64)	0.01*	0.02	100	100	100
PFOA	1.16 (1.76)	1.13 (1.70)	1.19 (1.83)	0.44	0.02	100	100	100
PFOS	4.18 (2.08)	4.33 (1.83)	4.03 (2.35)	0.39	0.02	100	100	100
PFNA	0.69 (1.94)	0.77 (1.98)	0.61 (1.87)	0.09	0.05	100	100	100
PFDA	0.26 (2.09)	0.27 (1.77)	0.24 (2.42)	0.31	0.02	99	100	98
PFUnDA	0.18 (4.44)	0.23 (3.67)	0.14 (5.19)	0.06	0.02	80	87	73
PFBuS	0.13 (4.28)	0.13 (4.19)	0.13 (4.42)	0.85	0.02	73	74	72
OPFRs (ng/mL)
BDCPP	1.92 (5.11)	4.05 (4.59)	0.87 (3.85)	≤0.01*	0.20	95	100	90
BCEP	0.40 (6.11)	0.87 (5.72)	--^f	--^g	0.10	60	79	39
DBuP	0.20 (3.92)	0.41 (3.95)	--^f	--^g	0.10	56	82	28
TBBPA	--^f	--^f	--^f	--^g	0.20	44	46	41
DpCP	--^f	--^f	--^f	--^g	0.10	29	42	16

^a Geometric mean (GM) and geometric standard deviation (GSD) computed for egg consumption, all PFAS, and all OPFRs due to skewed distributions
^b p-values derived from Wilcoxon rank-sum tests
^c LOD = limit of detection
^d DF = detection frequency
^e kilobase pairs
^f GMs were not calculated for chemicals with detection frequencies below 50%
^g Wilcoxon rank-sum tests were not performed for chemicals with detection frequencies below 50% in any group
^h All summary statistics calculated using LOD/sqrt [2] for those chemicals with less than 100% detection frequency

ISSN: 1476-069X