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PERFLUORINATED COMPOUNDS (PFCs) IN SERUM OF CATS – LINKAGE TO INDOOR EXPOSURES.
Citation:
Dye, J., P. Bost, P. Secoura, J. Reiner, J. Zweigenbaum, A. Lindstrom, AND M. Strynar. PERFLUORINATED COMPOUNDS (PFCs) IN SERUM OF CATS – LINKAGE TO INDOOR EXPOSURES. Presented at American College of Veterinary Internal Medicine Forum (ACVIM), June 12 - 15, 2013.
Impact/Purpose:
The purpose of this study was to determine if PFC serum levels in domestic cats tended to increase in proportion to time spent indoors and whether analyte patterns reflected that of food sources or with house dust as principal sources for exposure. Results indicate that house dust is a major exposure route for PFCs for indoor cats. Because, cats not unlike children, spend disporportionate time on the floor and similarly ingest dust (cats via grooming, children via hand-mouth transfer), cats may be useful sentinels to better assess PFC exposure risk in children.
Description:
The PFCs have been used in a wide range of consumer, including residential, products (e.g., stain-resistant coatings for carpets and upholstery). Carbon-fluoride bonds are highly stable, mak-ing PFCs extremely resistant to biodegradation. Thus, PFCs have become globally distributed and are ubiquitously present in serum of wildlife and people. Despite this, comparatively little is known as to how people are primarily exposed, and what (if any) health risk is associated with chronic, low-level exposure. It is hypothesized that house dust may represent a significant exposure route because PFCs can slough or volatilize from products used indoors, subsequently adsorbing to and accumulating within house dust. The purpose of this study was to determine if PFC serum levels in domestic cats tended to increase in proportion to time spent indoors and whether analyte patterns reflected that of food sources [e.g., fish products with high perfluoro-octane sulfonate (PFOS) but low perfluorohexanesulfonate (PFHxS)] or with house dust (PFOS + PFHxS + perfluorooctanoate (PFOA) ─ with high PFHxS levels in the most contaminated dust). In 2008, serum was obtained from feral and pet cats presenting to shelters and clinics in the Raleigh, NC area, including the NCSU VTH. PFC serum levels were measured using high-resolution time-of-flight mass spectroscopy. Data on housing status was available for 50 cats. From least to greatest indoor residential exposure, cats were grouped as follows: (a) feral cats (n=5), (b) pet cats living outdoors 40-75% of the time (n=8), (c) a resident shelter cat (n=1), (d) pet cats living indoors ≥ 90% of time (n=4), and (e) pet cats living exclusively indoors (n=32). Total PFC (ng/mL) serum (mean; min. & max.) concentrations were: (a) 12.9 (2.9, 24.2), (b) 17.8 (4.4, 33.1), (c) 31.7, (d) 37.0 (4.6, 63.9), and (e) 51.1 (0.5-376). In feral cats, PFC levels and analyte patterns were not unlike that reported for wild felidae, with PFOS predominating. On the other hand, for cats living largely (90-100%) indoors, PFOS+PFOA+PFHxS was typically detected, with PFHxS the predominate analyte in cats with the highest total PFC concentrations. Results indicate that house dust is a major exposure route for PFCs in indoor cats likely due to prolonged contact with carpeting and upholstery and to dust ingestion via grooming. Dust may also be an important exposure source for humans, especially children, who likewise spend time playing on floors and engage in hand-mouth transfer of dust. Hence, cats may be ideal sentinels to better assess PFC exposure risk in children. Studies are in progress to assess whether the differences in PFC serum levels or patterns in these cats may have been associated with specific clinical abnormalities or disease syndromes. (This abstract do not reflect US EPA policy).