Environ. Sci. Technol. 2008, 42, 5879–5884
Tissue Distribution of Perfluorinated Surfactants in Common Guillemot (Uria aalge) from the Baltic Sea ¨ M AND KATRIN E. HOLMSTRO URS BERGER* Department of Applied Environmental Science (ITM), Stockholm University, SE-106 91 Stockholm, Sweden
Received February 21, 2008. Revised manuscript received May 8, 2008. Accepted May 27, 2008.
Perfluorinated alkyl surfactants (PFAS) were investigated in tissues and organs of the common guillemot (Uria aalge) from the Baltic Sea. Concentrations of 11 perfluorinated carboxylates, four perfluorinated sulfonates, and perfluorooctane sulfonamide were determined in egg, liver, kidney, and muscle of adult guillemot, as well as in liver from chicks, all sampled in 1989. Additionally, whole herring homogenates from 2005 were analyzed, herring comprising a large part of guillemot’s diet. Quantifiable concentrations of PFAS were found in all samples. Perfluorooctanesulfonate(PFOS)waspredominant,followedbyperfluorotridecanoate (PFTriDA) and perfluoroundecanoate (PFUnDA). The median concentration of PFOS was highest in eggs (325 ng/g wet weight (w wt)) followed by chick liver (309 ng/g w wt), kidney (127 ng/g w wt), adult liver (121 ng/g w wt), and muscle (14 ng/g w wt). Comparatively low levels of PFOS were found in herring, leaving a blurred picture of uptake routes. PFAS concentrations in livers of male and female guillemots did not differ significantly. Some PFAS showed higher concentrations in eggs than in female livers. The ratio of levels in egg/ female liver, indicating mother-to-egg transfer capacity, increased with increasing PFAS chain length. PFOS showed a higher tendency for transfer than carboxylates of carbon chain lengths C9-C13.
Introduction Perfluorinated alkyl surfactants (PFAS) are a group of extremely persistent compounds used in a wide variety of industrial and consumer product applications (1). After having been manufactured for several decades, they have reached ubiquitous global distribution in biota including Arctic species. In particular, piscivorous top predators such as polar bears, seals, otters, and sea birds are prone to accumulate high concentrations of perfluorinated compounds (2). Perfluorooctane sulfonate (PFOS) is the predominant PFAS in the biotic environment, but a range of other PFAS are also present, with carbon chain lengths up to C15 (3). A previous study has shown that guillemots in the Baltic Sea have been exposed to increasing levels of PFOS since the late 1960s (4), and in guillemot eggs from recent years, high concentrations of up to 1.3 µg/g wet weight (w wt) were found. A risk assessment study for PFOS in top avian predators (5) estimated a predicted no effect concentration (PNEC) of * Corresponding author phone: (+46) 8 674 7099; fax (+46) 8 674 7637; e-mail:
[email protected]. 10.1021/es800529h CCC: $40.75
Published on Web 07/11/2008
2008 American Chemical Society
1 µg/mL egg (note that 1 mL egg corresponds to approximately 1 g). According to this assessment, guillemot chicks in the Baltic Sea have no margin of safety with respect to toxic effects induced by PFOS. It is not yet known if, or how the high levels of PFOS affect the population of guillemots in the Baltic Sea. As guillemots are slow to reach maturity, long-lived, and produce only a few offspring every year, the population is particularly vulnerable to factors that affect adult survival (6). Verreault and co-workers determined PFAS in eggs and tissues of glaucous gulls (7). However, the relative levels of PFAS in eggs to the internal organs/tissues in guillemot are presently unknown. Further, our knowledge on transfer rates from mother to egg of hydrophobic persistent organic pollutants may not be applicable to PFAS because of their different and extraordinary physical-chemical properties. In this study, PFAS concentrations in both eggs and tissues of adult guillemots were therefore determined to elucidate the body burden and distribution in adult birds. So far, only PFOS and perfluorooctanoate (PFOA) have been determined in guillemot eggs (4). However, the presence of PFOS is often indicative of the presence of other PFAS in organisms. In this paper, the concentrations and patterns of perfluorinated carboxylates (PFCAs, carbon chain lengths C6-C16), perfluorinated sulfonates (C4, C6, C8, and C10), and perfluorooctane sulfonamide (PFOSA) are described in egg, liver, kidney, and muscle of adult guillemots, in liver from chicks, as well as in herring, which represents a large part of the guillemot’s diet.
Experimental Section Sample Collection and Processing. Guillemot eggs are sampled yearly from a large bird colony at the island of Stora Karlso¨ in the Baltic Sea (Figure S1 in the Supporting Information (SI)), as part of the Swedish environmental monitoring program. Adult guillemots are not part of the program, but birds found drowned in fishing nets are collected when possible. The guillemots and eggs analyzed in this study were all collected in 1989. This was the year for which most specimens and organs were available, assuring the best possible comparability and statistical power. Drowned adult guillemots were collected during winter 1989, whereas guillemot eggs were collected in mid-May. In June, guillemot chicks jump from the cliffs to leave for the sea. Not all chicks survive and the samples for this study were from nonsurvivors in 1989. Birds and eggs were transported to the Swedish environmental specimen bank, located at the Museum of Natural History in Stockholm. Birds were dissected, and tissues and eggs were stored at -85 °C until 2003 and at -20 °C thereafter, until analysis in 2007. The investigated tissues comprised adult liver (n ) 8 male and 5 female), kidney (n ) 10 male), and muscle (n ) 8 male), chick liver (n ) 10, unknown gender), and egg (n ) 8). Herring (n ) 10) of the size typically eaten by guillemots were sampled at Landsort (approximately 150 km from Stora Karlso¨) in 2005 and stored at -20 °C. In 2007 they were analyzed as whole fish homogenates. Chemicals. The target analytes (C6-C16 PFCAs, C4, C6, C8, C10 perfluorosulfonates and PFOSA) and their acronyms are given in Table 1. The origin of the analytical standard compounds including the mass-labeled internal standards is given in Table S1 in the SI. All solvents and reagents were of highest commercial purity and employed as received. Water obtained from a Milli-Q water purification unit (Millipore AB, Solna, Sweden) was used. VOL. 42, NO. 16, 2008 / ENVIRONMENTAL SCIENCE & TECHNOLOGY
9
5879
TABLE 1. Target Analytes and their Acronyms as well as Median Concentrations [ng/g w wt]a and Ranges (in Parentheses) in Samples of Common Guillemot (Sampled 1989) and Whole Herring (Sampled 2005) from the Baltic Sea compound
acronym muscle (n ) 8)
perfluorocarboxylates perfluorohexanoate PFHxA perfluoroheptanoate PFHpA perfluorooctanoate PFOA perfluorononanoate PFNA perfluorodecanoate PFDA perfluoroundecanoate perfluorododecanoate perfluorotridecanoate perfluorotetradecanoate perfluoropentadecanoate perfluorohexadecanoate perfluorosulfonates perfluorobutane sulfonate perfluorohexane sulfonate perfluorooctane sulfonate perfluorodecane sulfonate
