Fluoride Action Network

CDC: Fourth National Report on Human Exposure to Environmental Chemicals

Source: Centers for Disease Control and Prevention, Department of Health and Human Services | December 10th, 2009
Industry type: Perfluorinated chemicals

Excerpts (Pages 247-257):

General Information
The perfluorochemicals (PFCs) are molecules in which all bonds of the alkyl chain are carbon-fluorine bonds except for the terminal functional group. Discussed here are perfluoroalkyl acids, amides, and alcohols which are by-products, end products, or processing aids used in the synthesis of fluoropolymers. Fluoropolymers have applications in waterproofing and protective coatings of clothes, furniture, and other products; and also as constituents of floor polish, adhesives, fire retardant foam, and insulation of electrical wire. A major application of one important fluoropolymer, polytetrafluoroethylene, has been the heat-resistant non-stick coatings used on cooking ware and other protected surfaces. Because of their properties, fluoropolymer products are used in a wide range of industries including aerospace, automotive, building/construction, chemical processing, electrical and electronics, semiconductor, and textiles. There are many other fluorocarbon type chemicals which are not addressed here, such as perfluorochemical telomers, finalized perfluorochemical polymer products, chlorofluorocarbons and investigational blood substitutes.

Human health effects from PFCs at low environmental doses or at biomonitored levels from low environmental exposures are unknown. The ammonium salt of PFOA has been tested at high doses in mammalian animal studies and produced (Seacat et al., 2002; Lau et al., 2004) and may be attributable to the ability of PFCs to affect altered weights of the liver, kidney, thymus and spleen; hepatotoxicity; endocrine and immune effects; and in offspring, growth retardation and delayed sexual maturation (Kennedy et al., 2004; Lau et al., 2004; U.S. EPA, 2003). Both PFOA and perfluorodecanoic acid have been shown to reduce androgen levels in laboratory animal studies (Biegel et al., 1995; Bookstaff et al., 1990). PFOA preparations used in many studies may also contain a small percentage of other chain length perfluoroalkyl acids (i.e., C5, C6, C7). The liver toxicity of several PFCs is evident by vacuolization and lipid accumulation in both rodent and monkey livers intracellular lipid binding proteins, peroxisomal proliferation, and ?-oxidation of lipids (Kudo et al., 2000, 2003; Vanden Heuvel et al., 1993). Some of the effects in animals may be mediated through peroxisomal proliferation, including immunologic effects and tumor induction, but the relevance of peroxisomal pathways in humans is unclear (Kennedy et al., 2004). PFOA has been reported to cause liver, pancreas, and testicular tumors in high dose animal testing (Biegel et al., 2001; Cook et al., 1992; Kennedy et al., 2004). Effects on serum liver enzymes in limited observational studies of human occupational exposures are unclear. Two recent cross-sectional human studies observed a negative correlation of birth weight with serum levels of PFOA (Apelberg et al., 2007; Fei et al., 2007).

… Serum PFOS levels associated with toxicity in test animals were 310-1550 fold higher than 95 percent of the levels found in a study of adults (Olsen et al., 2003a, 2005). Animal studies of PFOS have demonstrated weight loss, hepatotoxicity, and changes in thyroid hormone concentrations (Grasty et al., 2003; Thibodeaux et al., 2003; Lau et al., 2004). At doses causing maternal toxicity, developmental and teratogenic effects were demonstrated in offspring. At high but non-toxic maternal doses of PFOS, development in offspring was stunted and hypothyroxinemia was observed. Late gestational exposure to PFOS in animal studies has also demonstrated early neonatal lethality, possibly related to lung immaturity (Lau et al., 2003). PFOA, PFOS, and other PFCs have not been classified as to human carcinogenicity by IARC or NTP…

Serum levels of PFCs, particularly PFOS, appear to be higher in the U.S. than in some other countries: about two to threefold higher than in Columbia, Brazil, Poland, Belgium, Malaysia, Korea and Japan; and about eight to sixteenfold higher than in Italy and India (Kannan et al., 2004); and more than thirtyfold higher than in Peru (Calafat et al., 2006b). Notably, the sample sizes were small in these studies. In Japan, PFOS levels tended to vary within regions of the country ranging from U.S. median levels to about fivefold lower levels (Harada et al., 2004). PFC levels for the U.S. population, representing environmental exposures, are much lower than those reported for occupational exposure. In monitored workers employed at a POSF production facility with no biochemical or clinically observable effects, median levels of PFOS and PFOA were over 40 to 300-fold higher, respectively (Olsen et al., 2003b)…

Biomonitoring Information
Serum levels of PFCs (particularly PFOA and PFOS) tend to reflect cumulative exposure over several years. Twelve different PFCs were measured in the sera of NHANES 2003-2004 participants. Roughly similar levels of PFCs in serum have also been measured previously in other samples of the U.S. population. In such studies, PFOS, PFOA, perfluorohexanesulfonate (PFHxS), and perfluorononanoic acid (PFNA) are detectable in a high percentage of the participants and PFOS levels are generally 3-10 times higher than PFOA levels (Calafat et al., 2007a, 2007b; Olsen et al., 2003a, 2005). Analysis of the NHANES 2003-2004 subsample demonstrated higher levels of PFOA and PFOS in males and a slight increase in levels of PFOS with age (Calafat et al., 2007b). Slightly higher levels of PFOS and PFOA in males than females have been noted in several other studies (Calafat et al., 2007a; Harada et al., 2004; Olsen et al., 2003a). In comparing three separate reports on adults, elderly and children, the median PFCs values tend to be roughly similar in these age categories (Olsen et al., 2003a, 2004a, 2004b), and no substantial age trends were seen within adults ages 20-69 (Olsen et al., 2003a)…

See also CDC’s Media Advisory on release of report on December 10, 2009

Perfluorinated Chemicals in this Report

Perfluorinated Compounds CAS number Abbreviation
Serum Perfluorobutane Sulfonic Acid na PFBuS
Serum Perfluorodecanoic Acid 335-76-2 PFDeA
Serum Perfluorododecanoic Acid 307-55-1 PFDoA
Serum Perfluoroheptanoic Acid 375-85-9 PFHpA
Serum Perfluorohexane Sulfonic Acid 355-46-4 PFHxS
Serum Perfluorononanoic Acid 375-95-1 PFNA
Serum Perfluorooctanoic Acid 335-67-1 PFOA
Serum Perfluorooctane Sulfonic Acid 1763-23-1 PFOS
Serum Perfluorooctane Sulfonamide 754-91-6 PFOSA
Serum 2-(N-Ethyl-Perfluorooctane sulfonamido) Acetic Acid na Et-PFOSA-AcOH
Serum 2-(N-Methyl-perfluorooctane sulfonamido) Acetic Acid na Me-PFOSA-AcOH
Serum Perfluoroundecanoic Acid 2058-94-8 PFUA