Sascha Usenko

Occurrence of pharmaceuticals and personal care products in fish: Results of a national pilot study in the united states

Pharmaceuticals and personal care products are being increasingly reported in a variety of biological matrices, including fish tissue; however, screening studies have presently not encompassed broad geographical areas. A national pilot study was initiated in the United States to assess the accumulation of pharmaceuticals and personal care products in fish sampled from five effluent-dominated rivers that receive direct discharge from wastewater treatment facilities in Chicago, Illinois; Dallas, Texas; Orlando, Florida; Phoenix, Arizona; and West Chester, Pennsylvania, USA. Fish were also collected from the Gila River, New Mexico, USA, as a reference condition expected to be minimally impacted by anthropogenic influence. High performance liquid chromatography-tandem mass spectrometry analysis of pharmaceuticals revealed the presence of norfluoxetine, sertraline, diphenhydramine, diltiazem, and carbamazepine at nanogram-per-gram concentrations in fillet composites from effluent-dominated sampling locations; the additional presence of fluoxetine and gemfibrozil was confirmed in liver tissue. Sertraline was detected at concentrations as high as 19 and 545 ng/g in fillet and liver tissue, respectively. Gas chromatography-tandem mass spectrometry analysis of personal care products in fillet composites revealed the presence of galaxolide and tonalide at maximum concentrations of 2,100 and 290 ng/g, respectively, and trace levels of triclosan. In general, more pharmaceuticals were detected at higher concentrations and with greater frequency in liver than in fillet tissues. Higher lipid content in liver tissue could not account for this discrepancy as no significant positive correlations were found between accumulated pharmaceutical concentrations and lipid content for either tissue type from any sampling site. In contrast, accumulation of the personal care products galaxolide and tonalide was significantly related to lipid content. Results suggest that the detection of pharmaceuticals and personal care products was dependent on the degree of wastewater treatment employed.

Gas chromatography-mass spectrometry screening methods for select UV filters, synthetic musks, alkylphenols, an antimicrobial agent, and an insect repellent in fish.

Two screening methods have been developed for simultaneous determination of ten extensively used personal care products (PCPs) and two alkylphenol surfactants in fish. The methods consisted of extraction, clean-up, derivatization and analysis by gas chromatography-mass spectrometry with selected ion monitoring (GC-SIM-MS) or gas chromatography-tandem mass spectrometry (GC-MS/MS) techniques. Among solvents tested to assess recovery of target compounds from 1-g tissue homogenates, acetone was selected as optimal for extracting compounds with dissimilar physicochemical properties from fish tissue. Initial experiments confirmed that GC-SIM-MS could be applied for analysis of lean fillet tissue (<1% lipid) without gel-permeation chromatography (GPC), and this approach was applied to assess the presence of target analytes in fish fillets collected from a regional effluent-dominated stream in Texas, USA. Benzophenone, galaxolide, tonalide, and triclosan were detected in 11 of 11 environmental samples at concentrations ranging from; 37 to 90, 234 to 970, 26 to 97, and 17 to 31 ng/g, respectively. However, performance of this analytical approach declined appreciably with increasing lipid content of analyzed tissues. Successful analysis of samples with increased lipid content was enabled by adding GPC to the sample preparation protocol and monitoring analytes with tandem mass spectrometry. Both analytical approaches were validated using fortified fillet tissue collected from locations expected to be minimally impacted by anthropogenic influences. Average analyte recoveries ranged from 87% to 114% with RSDs <11% and from 54% to 107% with RSDs <20% for fish tissue containing <1% and 4.9% lipid, respectively. Statistically derived method detection limits (MDLs) for GC-SIM-MS and GC-MS/MS methodologies ranged from 2.4 to 16 ng/g, and 5.1 to 397 ng/g, respectively.

Relative Importance of the Humic and Fulvic Fractions of Natural Organic Matter in the Aggregation and Deposition of Silver Nanoparticles

As engineered nanoparticles (NPs) are increasingly used, their entry into the environment has become an important topic for water sustainability. Recent investigations point to the critical role of natural organic matter (NOM) in altering the persistence of NPs by complexing with their surfaces. The NP-NOM complex, in turn, is the new entity that may potentially influence subsequent fate of NPs. To understand the relative impact of humic (HA) and fulvic fraction of NOM on the stability and mobility of silver nanoparticles (AgNPs), a combination of dynamic light scattering and quartz crystal microgravimetry with dissipation monitoring was used. In the absence of unbound NOM, (1) surface modification on either AgNP or silica substrate by different NOM fractions could lead to substantial changes in the extent and kinetics of AgNP aggregation and deposition, and (2) HA has a greater capability to enhance the transport of AgNPs by reducing their aggregation and deposition. With unbound NOM, HA seems to compete more successfully for binding sites on the substrate under electrostatically favorable conditions and formed a steric layer to prevent subsequent deposition of AgNPs. These findings highlighted the importance of NOM fraction in the overall environmental partitioning of AgNPs.

PBDE developmental effects on embryonic zebrafish.

Polybrominated diphenyl ethers (PBDEs) have become ubiquitous environmental contaminants with potential for bioaccumulation and maternal-fetal transfer that has led to regulatory bans and/or phasing out of several technical mixtures of PBDEs. In the present study, six PBDE congeners (BDE 28, BDE 47, BDE 99, BDE 100, BDE 153, BDE 183) were evaluated for developmental effects on embryonic zebrafish. These congeners were chosen because they are environmentally relevant and cover a wide range of physical-chemical properties. Alterations in behavior, physical malformations, and mortality were scored daily until 168 h postfertilization (hpf). A concentration-dependent increase in spontaneous movement indicated an early onset of behavioral responses to PBDE exposures. Spontaneous movement was affected the most by BDE 47 and BDE 28, whereas BDE 183 did not alter behavior at any concentration tested. Swimming rates were significantly increased by BDE 28 at 96 and 120 hpf, but decreased swimming activity at 168 hpf. Additionally, BDE 47 significantly decreased the swimming rate at 168 hpf. Other endpoints included malformations and mortality. Congeners with fewer bromines (BDE 28, 47, 99, and 100) also induced a curved body axis starting around 120 hpf, which was followed by mortality. BDEs 153 and 183, however, did not elicit these adverse effects. A relationship was found between log K(OW) and median lethal concentration (LC50) and median effective concentration (EC50). Structure-activity relationships in this study suggest that PBDE acute toxicity results from a receptor-mediated effect and further studies are necessary to determine these pathways.

Probabilistic ecological hazard assessment of parabens using Daphnia magna and Pimephales promelas

Parabens are common antimicrobial agents found in thousands of pharmaceuticals and personal care products. Parabens are introduced into aquatic ecosystems from wastewater treatment plant effluents and have been detected in surface waters in the low microgram per liter range. Although these compounds display low toxicity in mammals, paraben toxicity to aquatic organisms has not been investigated. Standardized acute and subchronic endpoints in larval fish (Pimephales promelas) and cladoceran (Daphnia magna) models were examined for seven different parabens (methyl-, ethyl-, isopropyl-, propyl-, isobutyl-, butyl-, benzylparaben), which encompassed a range of log P values. Paraben 48 h median lethal concentration values (LC50) ranged from 4.0 to 24.6 mg/L in D. magna and 3.3 to >160.0 mg/L in fathead minnow. Growth and reproduction in D. magna had lowest-observed-effect concentrations (LOECs) ranging from 0.12 to 9.0 mg/L and 1.5 to 6.0 mg/L, respectively. Fathead minnow growth was adversely affected at levels ranging from 1.0 to 25.0 mg/L. Aquatic toxicity of the parabens was inversely related to lipophilicity, suggesting that responses using standardized endpoints resulted from narcosis. Utilizing toxicity benchmark concentrations (e.g., LC50s, LOECs) for each compound, chemical toxicity distributions, a probabilistic hazard assessment technique, were developed to assess the probabilities of detecting parabens that elicit a response at or below a given concentration. For the responses assessed in the present study, the 5th centile values (the concentration at which 5% of parabens elicit a response) ranged from 15 microg/L to 2.43 mg/L, with D. magna growth eliciting the lowest 5th centile value and acute D. magna mortality eliciting the highest. The distributions demonstrated that at environmentally relevant concentrations in developed countries there is limited acute or subchronic aquatic hazard of parabens to the organisms and responses examined.

Occurrence of Pharmaceuticals and Personal Care Products in German Fish Tissue: A National Study

German Environment Specimen Bank (GESB) fish tissue samples, collected from 14 different GESB locations, were analyzed for 15 pharmaceuticals, 2 pharmaceutical metabolites, and 12 personal care products. Only 2 pharmaceuticals, diphenhydramine and desmethylsertraline, were measured above MDL. Diphenhydramine (0.04-0.07 ng g(-1) ww) and desmethylsertraline (1.65-3.28 ng g(-1) ww) were measured at 4 and 2 locations, respectively. The maximum concentrations of galaxolide (HHCB) (447 ng g(-1) ww) and tonalide (AHTN) (15 ng g(-1) ww) were measured at the Rehlingen sampling site in the Saar River. A significant decrease in HHCB and AHTN fish tissue concentrations was observed from 1995 to 2008 at select GESB sampling sites (r(2) = 0.69-0.89 for galaxolide and 0.89-0.97 for tonalide with p < 0.003). Galaxolide and tonalide fish tissue concentrations in Germany were ∼19× and ∼28× lower, respectively, as compared to fish tissue concentrations measured in a United States nationwide PPCP study conducted in 2006. Proximity of the sampling locations to the upstream wastewater treatment plant discharging point and mean annual flow at the sampling location were found to significantly predict galaxolide and tonalide fish tissue concentrations (HHCB: r(2) = 0.79, p = 0.021 and AHTN: r(2) = 0.81, p = 0.037) in Germany.

Simultaneous analysis of select pharmaceuticals and personal care products in fish tissue using pressurized liquid extraction combined with silica gel cleanup

Analytical improvements were developed and validated for measuring select personal care products (PCPs) and two pharmaceuticals in fish tissue. The method was validated using fortified fillet tissue for twelve PCPs including fragrance materials, alkylphenols, photo initiators, and triclosan as well as two pharmaceuticals including carbamazepine (anti-seizure) and diazepam (anti-convulsant). The analytical method utilized pressurized liquid extraction (PLE) combined with silica gel cleanup, gel permeation chromatography, and gas chromatography ion-trap tandem mass spectrometry. Silica gel cleanup was combined with the PLE to produce one automated extraction/cleanup technique. This analytical improvement served to reduce the incurred cost, time, and loss of potential target analytes associated with independent cleanup steps. The combined extraction/cleanup technique resulted in an average increase of 10% in analyte recoveries. Average triplicate recoveries and relative standard deviations for the entire method, using 2.5 g of fish fillet tissue, were 92 ± 9% (recoveries ranged from 64 to 131%). The sensitivity of the analytical methods was improved by optimizing the resonant collision induced dissociation energy to the hundredths place (0.01 V). Improvements in ion production range from 24 to 122% for six of the 12 PCPs. Statistically derived method detection limits (MDLs) were also lowered on average by a factor of 8 and ranged from 1.2 to 38 ng/g wet weight. MDLs for carbamazepine and diazepam were 18 and 3.7 ng/g wet weight, respectively. Galaxolide and tonalide were measured in an environmental sample at concentrations of 81 and 5.5 ng/g wet weight, respectively.

Sources and Deposition of Polycyclic Aromatic Hydrocarbons to Western U.S. National Parks

Seasonal snowpack, lichens, and lake sediment cores were collected from fourteen lake catchments in eight western U.S. National Parks and analyzed for sixteen polycyclic aromatic hydrocarbons (PAHs) to determine their current and historical deposition, as well as to identify their potential sources. Seasonal snowpack was measured to determine the current wintertime atmospheric PAH deposition; lichens were measured to determine the long-term, year around deposition; and the temporal PAH deposition trends were reconstructed using lake sediment cores dated using (210)Pb and (137)Cs. The fourteen remote lake catchments ranged from low-latitude catchments (36.6 degrees N) at high elevation (2900 masl) in Sequoia National Park, CA to high-latitude catchments (68.4 degrees N) at low elevation (427 masl) in the Alaskan Arctic. Over 75% of the catchments demonstrated statistically significant temporal trends in SigmaPAH sediment flux, depending on catchment proximity to source regions and topographic barriers. The SigmaPAH concentrations and fluxes in seasonal snowpack, lichens, and surficial sediment were 3.6 to 60,000 times greater in the Snyder Lake catchment of Glacier National Park than the other 13 lake catchments. The PAH ratios measured in snow, lichen, and sediment were used to identify a local aluminum smelter as a major source of PAHs to the Snyder Lake catchment. These results suggest that topographic barriers influence the atmospheric transport and deposition of PAHs in high-elevation ecosystems and that PAH sources to these national park ecosystems range from local point sources to diffuse regional and global sources.

The Western Airborne Contaminant Assessment Project (WACAP): An Interdisciplinary Evaluation of the Impacts of Airborne Contaminants in Western U.S. National Parks

The National Park Service Organic Act of 1916 (1) required protection of the national parks for perpetuity by tasking the National Park Service (NPS) to maintain these lands “...unimpaired for the enjoyment of future generations.” Near the close of the last century, the NPS became aware of a new body of research describing a potential ecosystem threat that could not be ignored. Toxic airborne contaminants were increasingly being found in the world’s most pristine alpine and polar ecosystems, far from where such chemicals were produced or used, and the risks to the national parks of the western U.S. were unknown. Airborne contaminants present a broad range of potential risks to these ecosystems, largely due to bioaccumulation and or biomagnification of toxicants in biota, particularly vertebrates, that can result in loss of fecundity, unfit offspring, maladaptive behavior, and even death. As an outgrowth of these concerns, the Western Airborne Contaminants Assessment Project (WACAP) was initiated in 2002 to determine the risk from airborne contaminants to ecosystems and food webs in national parks of the U.S. The specific objectives that guided design and implementation of WACAP were the following: 1. Determine if contaminants were present in western national parks. 2. If contaminants were present, determine in what way and where they were accumulating (geographically and by elevation). EP A Environ. Sci. Technol. 2010, 44, 855–859

Evolved resistance to PCB- and PAH-induced cardiac teratogenesis, and reduced CYP1A activity in Gulf killifish (Fundulus grandis) populations from the Houston Ship Channel, Texas.

The Houston Ship Channel (HSC), connecting Houston, Texas to Galveston Bay and ultimately the Gulf of Mexico, is heavily industrialized and includes several areas that have historically been identified as containing significant levels of mercury, dioxins, furans, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). Gulf killifish, Fundulus grandis, inhabit this entire estuarine system, including the most contaminated areas. F. grandis is the sister species of the well-established estuarine model organism Fundulus heteroclitus, for which heritable resistance to both PCB and PAH toxicity has been documented in several populations. F. grandis collected from two Superfund sites on the HSC and from a reference population were used to establish breeding colonies. F1 embryos from HSC populations were approximately 1000-fold more resistant to PCB126- and 2-5-fold more resistant to coal tar-induced cardiovascular teratogenesis, relative to embryos from the reference population. Reciprocal crosses between reference and contaminated populations exhibit an intermediate level of resistance, confirming that observed protection is genetic and biparentally inherited. Ethoxyresorufin-O-deethylase (EROD) data confirm a reduction in basal and induced cytochrome P4501A (CYP1A) activity in resistant populations of F. grandis. This result is consistent with responses previously described for resistant populations of F. heteroclitus, specifically a recalcitrant aryl hydrocarbon receptor (AHR) pathway. The decreased levels of cardiovascular teratogenesis, and decrease in CYP1A inducibility in response to PCB126 and a PAH mixture, suggest that HSC F. grandis populations have adapted to chronic contaminants exposures via a mechanism similar to that previously described for F. heteroclitus. To the best of our knowledge, this is the first documentation of evolved pollution resistance in F. grandis. Additionally, the mechanistic similarities between the population adaptation observed in this study and previous work in F. heteroclitus suggest that genetic variation predating the evolutionary divergence of these two species may best explain the apparent rapid parallel evolution of pollution resistance in genetically and geographically distinct species and populations.