Aluminum smelter-derived polycyclic aromatic hydrocarbons and flatfish health in the Kitimat marine ecosystem, British Columbia, Canada.

From 2000-2004 a monitoring study was conducted to evaluate the impacts of aluminum smelter-derived polycyclic aromatic hydrocarbons (PAHs) on the health of fish in the marine waters of Kitimat, British Columbia, Canada. These waters are part of the historical fishing grounds of the Haisla First Nation, and since the 1950s the Alcan Primary Metal Company has operated an aluminum smelter at the head of the Kitimat Arm embayment. As a result, adjacent marine and estuarine sediments have been severely contaminated with a mixture of smelter-associated PAHs in the range of 10,000-100,000 ng/g dry wt. These concentrations are above those shown to cause adverse effects in fish exposed to PAHs in urban estuaries, but it was uncertain whether comparable effects would be seen at the Kitimat site due to limited bioavailability of smelter-derived PAHs. Over the 5-year study we conducted biennial collections of adult English sole (Parophrys vetulus) and sediment samples at the corresponding capture sites. Various tissue samples (e.g. liver, kidney, gonad, stomach contents) and bile were taken from each animal to determine levels of exposure and biological effects, and compare the uptake and toxicity of smelter-derived PAHs with urban mixtures of PAHs. Results showed significant intersite differences in concentrations of PAHs. Sole collected at sites nearest the smelter showed increased PAH exposure, as well as significantly higher prevalences of PAH-associated liver disease, compared to sites within Kitimat Arm that were more distant from the smelter. However, measures of PAH exposure (e.g., bile metabolites) were surprisingly high in sole from the reference sites outside of Kitimat Arm, though sediment and dietary PAHs at these sites were low, and fish from the areas showed no biological injury. PAH uptake, exposure, and biological effects in Kitimat English sole were relatively lower when compared to English sole collected from urban sites contaminated with PAH mixtures from other sources. These findings indicate that while smelter-associated PAHs in Kitimat Arm appear to be causing some injury to marine resources, they likely have reduced bioavailability, and thus reduced biological toxicity, compared to other environmental PAH mixtures.

Endocrine disrupting chemicals in fish bile: a rapid method of analysis using English sole (Parophrys vetulus) from Puget Sound, WA, USA.

This study describes a recently developed and rapid method to measure bisphenol A (BPA), 17ß-estradiol (E2) and 17α-ethynylestradiol (EE2) in bile of fish using enzymatic hydrolysis of samples followed by solid-phase extraction and ultra-performance liquid chromatography with tandem mass spectrometry. The limits of quantitation (LOQ) for BPA, EE2 and E2 were 6.3ngmL(-1), 12.5ngmL(-1) and 6.3ngmL(-1), respectively. These compounds were analyzed in bile of male English sole (Parophrys vetulus) collected from urban and non-urban sites in Puget Sound, WA, USA. The BPA and E2 concentrations (and occurrence) ranged from

Reduced cytochrome P4501A activity and recovery from oxidative stress during subchronic benzo[a]pyrene and benzo[e]pyrene treatment of rainbow trout.

This study assessed the role of aryl hydrocarbon receptor (AHR) affinity, and cytochrome P4501A (CYP1A) protein and activity in polyaromatic hydrocarbon (PAH)-induced oxidative stress. In the 1-100nM concentration range benzo[a]pyrene (BaP) but not benzo[e]pyrene (BeP) competitively displaced 2nM [(3)H]2, 3, 7, 8-tetrachloro-dibenzo-p-dioxin from rainbow trout AHR2α. Based on appearance of fluorescent aromatic compounds in bile over 3, 7, 14, 28 or 50days of feeding 3µg of BaP or BeP/g fish/day, rainbow trout liver readily excreted these polyaromatic hydrocarbons (PAHs) and their metabolites at near steady state rates. CYP1A proteins catalyzed more than 98% of ethoxyresorufin-O-deethylase (EROD) activity in rainbow trout hepatic microsomes. EROD activity of hepatic microsomes initially increased and then decreased to control activities after 50days of feeding both PAHs. Immunohistochemistry of liver confirmed CYP1A protein increased in fish fed both PAHs after 3days and remained elevated for up to 28days. Neither BaP nor BeP increased hepatic DNA adduct concentrations at any time up to 50days of feeding these PAHs. Comet assays of blood cells demonstrated marked DNA damage after 14days of feeding both PAHs that was not significant after 50days. There was a strong positive correlation between hepatic EROD activity and DNA damage in blood cells over time for both PAHs. Neither CYP1A protein nor 3-nitrotyrosine (a biomarker for oxidative stress) immunostaining in trunk kidney were significantly altered by BaP or BeP after 3, 7, 14, or 28days. There was no clear association between AHR2α affinity and BaP and BeP-induced oxidative stress.

Improved flatfish health following remediation of a PAH-contaminated site in Eagle Harbor, Washington.

Eagle Harbor in Puget Sound, WA became a Superfund site in 1987 due to polycyclic aromatic hydrocarbons (PAHs) released chronically from a nearby creosoting facility. Early studies here (1983-1986) demonstrated up to an approximately 80% prevalence of toxicopathic liver lesions, including neoplasms, in resident English sole (Parophrys vetulus). These lesions in English sole are consistently associated with PAH exposure in multiple field studies, and one laboratory study. Later studies (1986-1988) incorporated biomarkers of PAH exposure and effect, including hepatic CYP1A expression and xenobiotic-DNA adducts, and biliary fluorescent aromatic compounds (FACs). Before site remediation, lesion prevalences and other biomarker values in this species from Eagle Harbor were among the highest compared to other sites in Puget Sound and the US Pacific Coast. To sequester PAH-contaminated sediments, in 1993-1994, a primary cap of clean sediment was placed over the most-contaminated 54acres, with a 15-acre secondary cap added from 2000-2002. Lesion prevalences and biomarker values before primary capping were reduced compared to 1983-1986, consistent with facility closure in 1988 and shore-based source controls begun in 1990. Liver lesion risk, hepatic CYP1A activities, and levels of biliary FACs from fish collected immediately after and at regular intervals up to 2 years after primary capping were variable relative to pre-capping. Over the entire monitoring period since primary capping (128 months), but particularly after 3 years, there was a significantly decreasing trend in biliary FACs, hepatic DNA adducts and lesion risk in English sole. In particular, lesion risk has been consistently low (<0.20) compared to primary cap initiation (set at 1.0), from approximately 4 years after primary capping through April 2004. These results show that the sediment capping process has been effective in reducing PAH exposure and associated deleterious biological effects in a resident flatfish, and that longer term monitoring of pollutant responses in biological resources, such as resident fish, is needed in order to demonstrate the efficacy of this type of remediation.

Using fluorescent aromatic compounds in bile from juvenile salmonids to predict exposure to polycyclic aromatic hydrocarbons.

We provide data from four different studies in which fish were fed polycyclic aromatic hydrocarbons (PAHs) that were used to develop a predictive relationship between dose (mug/g fish/d) and metabolites of PAHs in bile. Juvenile salmonids were fed various doses of total PAH that were applied as a mixture to fish pellets. The number of PAHs in each mixture ranged from 10 to 21 different low- and high-molecular-weight compounds, and their relative proportions and abundance were based on stomach concentrations observed for field-collected fish. Although we examined both the phenanthrene (PHN) and benzo[a]pyrene signals for the fluorescent aromatic compounds (FACs) in bile, the PHN signal exhibited the highest correlation and was considered to be the better choice for predicting exposure. A large database of PHN FAC values for field-collected fish was examined and used to predict dose by the method of inverse prediction. The goal of the present study was to develop a predictive relationship that would allow estimation of an exposure dose for an observed value of PHN FACs from juvenile salmonids sampled in the field. This dose would then be used to estimate adverse effects based on toxicity results from laboratory studies. Additional analyses were performed to determine ventilation doses from water concentrations of total PAH and then relate those to PHN FAC values.

Contaminant exposure in outmigrant juvenile salmon from Pacific Northwest estuaries of the United States.

To better understand the dynamics of contaminant uptake in outmigrant juvenile salmon in the Pacific Northwest, concentrations of polychlorinated biphenyls (PCBs), DDTs, polycylic aromatic hydrocarbons (PAHs) and organochlorine pesticides were measured in tissues and prey of juvenile chinook and coho salmon from several estuaries and hatcheries in the US Pacific Northwest. PCBs, DDTs, and PAHs were found in tissues (whole bodies or bile) and stomach contents of chinook and coho salmon sampled from all estuaries, as well as in chinook salmon from hatcheries. Organochlorine pesticides were detected less frequently. Of the two species sampled, chinook salmon had the highest whole body contaminant concentrations, typically 2--5 times higher than coho salmon from the same sites. In comparison to estuarine chinook salmon, body burdens of PCBs and DDTs in hatchery chinook were relatively high, in part because of the high lipid content of the hatchery fish. Concentrations of PCBs were highest in chinook salmon from the Duwamish Estuary, the Columbia River and Yaquina Bay, exceeding the NOAA Fisheries' estimated threshold for adverse health effects of 2400 ng/g lipid. Concentrations of DDTs were especially high in juvenile chinook salmon from the Columbia River and Nisqually Estuary; concentrations of PAH metabolites in bile were highest in chinook salmon from the Duwamish Estuary and Grays Harbor. Juvenile chinook salmon are likely absorbing some contaminants during estuarine residence through their prey, as PCBs, PAHs, and DDTs were consistently present in stomach contents, at concentrations significantly correlated with contaminant body burdens in fish from the same sites.

Metabolites in bile of fish from São Sebastião Channel, São Paulo, Brazil as biomarkers of exposure to petrogenic polycyclic aromatic compounds.

This study reports the analysis of polycyclic aromatic compound (PAC) metabolites, as biomarkers of exposure to PACs in marine environment. PAC metabolites were measured in bile samples from 14 species of demersal fish caught in the São Sebastião Channel (SSC), SE Brazilian coastline. Naphthalene (NPH) equivalents, phenanthrene (PHN) equivalents, and benzo[a]pyrene (BaP) equivalents were quantified using a reverse-phase high-performance liquid chromatography coupled with fluorescence detection method. For all samples, the means (+/-standard deviation, n=37) of concentrations obtained for NPH, PHN, and BaP equivalents were, respectively, 290,000+/-200,000 ng/g, 18,000+/-14,000 ng/g, and 970+/-1900 ng/g. These results indicate recent exposure of these fish to PACs in their environment. In addition, two species (Cyclichthys spinosus and Prionotus nudigula) of fish were analyzed in order to investigate local sources of PAC contamination in the SSC and the influence of the petroleum terminal in fish caught in remote areas. The results showed that these fish species potentially migrate along the channel, especially P. nudigula. Correlations among groups of PAC metabolites indicate the same petrogenic source for NPH and PHN equivalents and a combustion source (e.g., automobile, ships) for BaP equivalents. The ratio BaP/PHN equivalents (0.05+/-0.07, n=37) confirms the predominance of petrogenic PACs for contamination by these chemicals in this region.

Organochlorines in the free-ranging Hawaiian monk seal (Monachus schauinslandi) from French Frigate Shoals, North Pacific Ocean.

The Hawaiian monk seal (Monachus schauinslandi) is an endangered species found only in the Hawaiian Island chain. The largest subpopulation, at French Frigate Shoals, has been in decline since 1989. In order to assess organochlorine (OC) levels in the Hawaiian monk seals, whole blood and blubber samples were collected in 1999 from 46 free-ranging Hawaiian monk seals at French Frigate Shoals, and were analyzed for eight dioxin-like polychlorinated biphenyls (PCBs) as well as six other PCB congeners, DDT and DDT metabolites. Average levels of the total PCBs in blood samples from adult male, juvenile and reproductive female groups were 4800, 4000 and 3000 ng/g lipid wt., respectively, whereas 3200, 1300 and 1200 ng/g, respectively, in blubber from the three corresponding groups. p,p'-DDE was the only DDT detected in blubber samples, and no DDTs were detected in blood samples. Concentrations of the total PCBs in adult males were significantly higher than the levels measured in either reproductive females or juveniles. There were significant correlations between age and blubber p,p'-DDE, estimated mass and total blood PCBs or blubber p,p'-DDE, and body condition and total blood PCBs. Although it is clear that the Hawaiian monk seal has been exposed to OCs, it is unclear what biological effects, if any, these xenobiotics may have on the animals.