Table 5.

Association between exposure to PFAS and thyroid cancer. Abbreviations: CI: confidence interval; EDC: endocrine disrupting chemicals; HR: hazard ratio; NDI: national death index; OR: odds ratio; PFOA: perfluorooctanoic acid; RR: risk ratio; SMR: standardized mortality ratio.

Author (Year)	EDC Type	Study Design	Country	Investigated Population	Measurement of Exposure	Association with Thyroid Cancer
Barry et al. (2013) [89]	PFOA	Cohort	United States	C8 Health Project (n = 32,254)	Estimated PFOA serum levels	No lag: HR: 1.10 (95% CI 0.95–1.20) 10-year lag: HR: 1.04 (95% CI: 0.89–1.20)
Vieria et al. (2013) [90]	PFOA	Case-control	United States	Incident cancer cases among residents living near the DuPont Teflon-manufacturing plant in Parkersburg, West Virginia (n = 19,716) using cancer registry data	Estimated individual-level annual PFOA serum exposure categories	Very high: OR: 0.8 (95% CI: 0.2–3.5) High: OR: 0.7 (95% CI: 0.2–2.1) Medium: OR: 0.9 (95% CI: 0.4–2.3) Low: OR: 1.2 (95% CI: 0.8–1.7)
Olsen et al. (2004) [91]	PFOA	Case-control	United States	Fluorochemical production facility employees (n = 652 cases) and film plant employees (n = 659 controls)	Health claims data	RR (95% CI): unable to calculate
Leonard et al. (2008) [92]	PFOA	Case-control	United States	Workers at polymer manufacturing facility (n = 6027) Workers at other DuPont facilities (n = 72,882)	Causes of death (Dupont Epidemiology Registry) or (NDI Plus)	SMR: 628.6 (95% CI: 129.7; 1836.9)