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Archives of Environmental Contamination and Toxicology (v.57, #4)

Levels of Perfluorinated Chemicals in Municipal Drinking Water from Catalonia, Spain: Public Health Implications by Ingrid Ericson; José L. Domingo; Martí Nadal; Esther Bigas; Xavier Llebaria; Bert van Bavel; Gunilla Lindström (pp. 631-638).

In this study, the concentrations of 13 perfluorinated compounds (PFCs) (PFBuS, PFHxS, PFOS, THPFOS, PFHxA, PFHpA, PFOA, PFNA, PFDA, PFUnDA, PFDoDA, PFTDA, and PFOSA) were analyzed in municipal drinking water samples collected at 40 different locations from 5 different zones of Catalonia, Spain. Detection limits ranged between 0.02 (PFHxS) and 0.85 ng/L (PFOA). The most frequent compounds were PFOS and PFHxS, which were detected in 35 and 31 samples, with maximum concentrations of 58.1 and 5.30 ng/L, respectively. PFBuS, PFHxA, and PFOA were also frequently detected (29, 27, and 26 samples, respectively), with maximum levels of 69.4, 8.55, and 57.4 ng/L. In contrast, PFDoDA and PFTDA could not be detected in any sample. The most contaminated water samples were found in the Barcelona Province, whereas none of the analyzed PFCs could be detected in two samples (Banyoles and Lleida), and only one PFC could be detected in four of the samples. Assuming a human water consumption of 2 L/day, the maximum daily intake of PFOS and PFOA from municipal drinking water would be, for a subject of 70 kg of body weight, 1.7 and 1.6 ng/kg/day. This is clearly lower than the respective Tolerable Daily Intake set by the European Food Safety Authority. In all samples, PFOS and PFOA also showed lower levels than the short-term provisional health advisory limit for drinking water (200 ng PFOS/L and 400 ng PFOA/L) set by the US Environmental Protection Agency. Although PFOS and PFOA concentrations found in drinking water in Catalonia are not expected to pose human health risks, safety limits for exposure to the remaining PFCs are clearly necessary, as health-based drinking water concentration protective for lifetime exposure is set to 40 ng/L for PFOA.

Dioxin-Like and Endocrine Disruptive Activity of Traffic-Contaminated Soil Samples by T. Šídlová; J. Novák; J. Janošek; P. Anděl; J. P. Giesy; K. Hilscherová (pp. 639-650).

Pollution of surface soils by traffic, especially along major highways, can be a significant issue. Numerous studies have demonstrated traffic to be an important source of particulate matter and gas-phase organic air pollutants that produce many types of deleterious effects. This article brings original information about the presence of contaminants with specific mechanisms of action in traffic-influenced soils as determined by bioanalytical approaches and instrumental analyses. The initial phase of the study aimed to compare contamination of soils near highways with those from reference localities, whereas the second phase of the study investigated the influence of traffic pollution in soils at various distances from highways. For the reference areas, forest soils contained greater concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQs; 483 to 2094 pg/g) than did arable soils (96 to 478 pg/g), which represent the relevant reference for the studied soils along highways. The total concentration of TCDD-EQs determined in the in vitro transactivation assay ranged from 225 to 27,700 pg/g in traffic-affected soils. The greatest concentration of TCDD-EQs among the studied sites was observed in soils collected near highway D1, which is the primary thoroughfare in the Czech Republic. The concentrations of TCDD-EQs in roadside soils were the greatest and decreased with increased distance from highways, and this spatial distribution corresponded with the levels of polycyclic aromatic hydrocarbons (PAHs). Soils collected 100 m away from highways in most cases contained concentrations of TCDD-EQs similar to background values. Most TCDD-EQ presence was caused by nonpersistent compounds in soils, with a significant contribution from PAHs as well as other unknown nonpersistent chemicals. Extracts from most soils collected near highways exhibited antiestrogenic and in some cases antiandrogenic activities; for several sites the activity was also detected in soils farther from highways. The presence of TCDD-EQs and antihormonal activity in highway-affected soils points to traffic as a source of polluting compounds having specific effects.

Chlorinated Polycyclic Aromatic Hydrocarbons in Sediments from Industrial Areas in Japan and the United States by Yuichi Horii; Takeshi Ohura; Nobuyoshi Yamashita; Kurunthachalam Kannan (pp. 651-660).

Chlorinated polycyclic aromatic hydrocarbons (ClPAHs) are widespread environmental pollutants in the urban environment. Nevertheless, there is little information available regarding the occurrence and profiles of ClPAHs in environmental matrices. In this study, residual concentrations and profiles of 20 individual ClPAHs and 16 US EPA-priority PAHs were determined using high- resolution gas chromatography–high-resolution mass spectrometry in sediments from water bodies near industrialized areas: Tokyo Bay, Japan; the Saginaw River watershed, Michigan, USA; a former chlor-alkali plant, Georgia, USA; and the New Bedford Harbor Superfund site, Massachusetts, USA. A sediment core from Tokyo Bay showed temporal patterns in the distribution of ClPAHs from the 1950s through 2004. The fluxes of ClPAHs and 16 priority PAHs in Tokyo Bay sediment core were 0.029–0.57 ng/cm²/year and 85-609 ng/cm²/year, respectively; fluxes were lowest in the 1950s and highest in 1989–1990. In the United States, a high mean concentration of ClPAHs was found in sediment collected near a former chlor-alkali plant [8820 pg/g dry weight (dry wt)], and lower mean concentrations were found for New Bedford Harbor (1880 pg/g dry wt) and the Saginaw River watershed (1140 pg/g dry wt). Among individual ClPAHs, 6-ClBaP and 1-ClPyr were the dominant compounds in sediments; this pattern is similar to the pattern reported in the literature for waste incineration and ambient urban air samples. Significant correlation between ΣClPAH concentrations and Σparent-PAH concentrations in Tokyo Bay sediment implies that the sources and distribution of ClPAHs are directly related to those of parent PAHs. We also analyzed ClPAHs and parent PAHs in blue mussels from New Bedford Harbor. The mean concentration of ClPAHs in mussels from New Bedford Harbor was 21 ng/g lipid weight, a concentration three orders of magnitude lower than the mean concentration of parent PAHs. Low-molecular-weight ClPAHs predominated in mussel tissues. Toxic equivalents (TEQs) of ClPAHs analyzed in sediment ranged between 1.1 fg TEQ/g dry wt (Tokyo Bay) and 2.4 fg TEQ/g dry wt (Saginaw River watershed). The dioxinlike toxicity contributed by ClPAHs in sediment from contaminated areas was five orders of magnitude lower than that previously reported for dioxins.

Occurrence of Antifouling Biocides and Fluorinated Alkyl Compounds in Sediment Core from Deep Sea: Suruga Bay, Tosa Bay, and Nankai Tough, Japan by Hiroya Harino; Nozomu Iwasaki; Takaomi Arai; Madoka Ohji; Nobuyuki Miyazaki (pp. 661-669).

Contamination profiles of antifouling biocides were investigated in a deep-sea environment in Suruga Bay Japan. Significant differences in the tributyltin (TBT) and triphenyltin (TPT) concentrations in subsurface sediment between 850 and 800 m of water depth were not observed (p < 0.05). Organotin (OT) concentrations in sediment core of 0–30.5 cm from a water depth of 800 m were investigated. The butyltins (BTs) and phenyltins (PTs) concentrations were constant between 0 and 15 cm, and, subsequently, the concentration of these compounds increased. The peaks of the BTs and PTs concentrations were observed between 18 and 19 cm. The concentrations of Irgarol 1051 decreased until a core depth of 9 cm, and, the values then became near the detection limit under the 10 cm of core depth. Perfluorooctane sulfonate (PFOS) and perfluorooctanic acid (PFOA) were detected in the sediment core (0–30.5 cm) of Suruga Bay. The concentration of PFOS was high in the 0–5-cm core depth and then decreased. The concentrations of PFOA, however, were at the values near the detection limit throughout the sediment core. The BTs and PTs concentrations in surface sediment from Tosa Bay decreased with water depth. Although Irgarol 1051 was the only alternative compound detected, the value was near the detection limit. PFOS and PFOA were detected in sediment core from Tosa Bay. The concentrations of PFOS became low as the water depth became deeper. TBT, TPT, Sea Nine 211, Diuron and Irgarol 1051 were detected in sediment core (core depth: 10 cm) from the Nankai trough (water depth: 4010 m).

Polycyclic Aromatic Hydrocarbons and Polychlorinated Biphenyls in Topsoils of Harbin, China by Wan-Li Ma; Yi-Fan Li; De-Zhi Sun; Hong Qi (pp. 670-678).

Levels of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in 17 topsoil samples collected in and around the city of Harbin, an industrial center in Northeast China for decades, are presented. Total concentrations (ng/g dry weight [dw]) ranged from 17 to 3,260 (mean: 508) for PAHs and 0.30 to 6.17 (mean: 1.63) for PCBs. As expected, large differences of the concentration levels of PAHs and PCBs in topsoil were found among the samples from urban, suburban, and background/rural sites. Total PCB and PAH concentrations were higher in industrialized areas than those at the other sites, with a ratio of up to one order of magnitude, possibly indicating the urban source of these chemicals. The PAH profiles were similar among samples, with high percentages of high molecular weight (HMW) PAHs and domination of four-ring PAHs. Compositions of PCB homologues showed that tri-CBs and tetra-CBs were abundant in all soil samples. There was also a higher abundance of low molecular weight (LMW) PCBs and lower abundance of HMW PCBs at background sites than other areas, indicating the urban fractionation phenomenon. Pyrogenic origins were the dominant PAH sources in surface soil at most urban sites, whereas petrogenic origins were the major PAH sources in surface soil at all the rural and background sites. The TEQ concentrations (pg/g dw) of all four dioxin-like PCBs (CBs 77, 81, 105, and 118) were 0.009 for humans and mammals, 0.005 for fish, and 1.42 for birds. Strong correlations were found between PAH and PCB concentrations and soil organic matter and, also, between PAH and PCB concentrations.

Acetate Enhances the Specific Consumption Rate of Toluene Under Denitrifying Conditions by Sergio Martínez-Hernández; Eugenia J. Olguín; Jorge Gómez; Flor de María Cuervo-López (pp. 679-687).

Toluene is usually present in the environment as a contaminant along with other carbon sources which may influence its removal. In this work we studied the effect of a readily consumable carbon source such as acetate on toluene mineralization under denitrifying conditions. Continuous and batch cultures with stabilized denitrifying sludge were carried out. An upflow anaerobic sludge blanket reactor (UASB) was fed with several ratios of acetate-C/toluene-C loading rates (mg C/L-day: 100/0, 75/25, 50/50, and 0/100). Batch assays with different acetate-C/toluene-C ratios (10/70, 30/50, 50/30, and 65/20 mg C/L) were also done. As the acetate loading rate decreased in the culture, the carbon and nitrate consumption efficiency decreased by 40% and 34%, respectively. HCO₃ ⁻ and N₂ yields also decreased by 43%. Analysis of the denitrifying community using the denaturing gradient gel electrophoresis technique indicated that there was no clear relationship between its population profile and the metabolic pattern. In batch assays, when the acetate concentration was higher than that of toluene (65 mg acetate-C/L vs 20 mg toluene-C/L), the specific consumption rate of toluene (q_T) was two times higher than in assays with 20 mg toluene-C/L as the sole electron source (0.006 mg C/mg volatile suspended solids-day). It is proposed that acetate can act by enhancing the growth of microbial populations and as a biochemical enhancer. The results show that acetate addition can be useful to improve the consumption rate of toluene in contaminated water.

Removal and Accumulation of Cadmium and Lead by Typha latifolia Exposed to Single and Mixed Metal Solutions by Angel Josabad Alonso-Castro; Candy Carranza-Álvarez; Ma Catalina Alfaro-De la Torre; Leonardo Chávez-Guerrero; Ramón Fernando García-De la Cruz (pp. 688-696).

We investigated the effect of Cd and Pb on the growth of the aquatic macrophyte Typha latifolia; the removal from the solution and the accumulation of these elements by the plant were also studied. Thus, small plants of T. latifolia, collected from a noncontaminated site, were exposed for 10 days to Cd and Pb, in a single solution or in mixture solutions, at two concentrations of the metals (5 and 7.5 mg/L). Our results showed that T. latifolia removed effectively Cd and Pb from solutions and was able to accumulate these metals in the roots and, to a lesser extent, in the leaves. Our findings suggested a synergistic effect of Cd and Pb with respect to the toxicity to T. latifolia. Additionally, Cd diminished the Pb absorption by T. latifolia. Our results confirmed, using scanning electron microscopy, the internalization of Cd and Pb in T. latifolia.

Effects of an Oil Spill on the Regrowth of Emergent Vegetation in a Northern Alberta Lake by Barbara G. Wernick; Adrian M. H. deBruyn; Luanne Patterson; Peter M. Chapman (pp. 697-706).

Following a train derailment in August 2005, Wabamun Lake (Alberta, Canada) was exposed to ~149,500 L of bunker “C” oil, much of which became entrained in the abundant Schoenoplectus tabernaemontani (= Scirpus validus) beds in the eastern basin of the lake. We assessed the regrowth of emergent macrophytes during the subsequent two growing seasons. Postspill measures of productivity, including transect length, total cover, and biomass were within the variability of prespill data collected in 2001, with the exception of a few specific areas in which biomass appeared to be affected. We conclude that exposure to oil during the late growing season in August 2005 and through the winter senescent period and regrowth in the summers of 2006 and 2007 did not cause large-scale changes to S. tabernaemontani communities. Physical factors such as cleanup activities and vegetation management appeared to be responsible for the reduced regrowth observed at some locations. Few previous studies have been published on the effects of oil spilled into freshwater on macrophyte communities; thus, the results of this study are expected to provide useful information for the assessment of future freshwater oil spills.

Biochemical Response of the Copepod Tigriopus japonicus Mori Experimentally Exposed to Cadmium by Ming-Hua Wang; Gui-Zhong Wang (pp. 707-717).

The response of the copepod (Tigriopus japonicus Mori) to cadmium (Cd) additions was investigated under laboratory-controlled conditions in a 12-day exposure. Superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione-S-transferase (GST), acetylcholinesterase (AchE), reduced glutathione (GSH), the ratio of reduced to oxidized glutathione (GSH/GSSG), and metallothionein (MT) were analyzed for Cd treatments (0, 10, 20, 40, and 100 μg/L) after exposure for 1, 4, 7, and 12 days. Additionally, thiobarbituric reactive species assay was used to evaluate lipid peroxidation (LPO) of the copepod after the 12-day exposure. The results indicated that Cd treatments significantly influenced the biochemical indexes (SOD, GPx, GST, AchE, GSH, and GSH/GSSG) after certain exposure times. Exposure to Cd induced LPO in the treated copepods, hinting that the copepods had suffered from oxidative damage. During exposure, the Cd initiated an induced MT synthesis in the copepods by day 7, which peaked at day 12 and which was probably responsible for Cd detoxification. Thus, Cd exposure significantly affected the detoxification process and antioxidant system of this copepod, and T. japonicus could be used as a suitable bioindicator of exposure to Cd using SOD, GPx, GST, LPO, and GSH/GSSG as biomarkers.

Biochemical Response of the Copepod Tigriopus japonicus Mori Experimentally Exposed to Cadmium by Ming-Hua Wang; Gui-Zhong Wang (pp. 707-717).

Kinetics of Cadmium Uptake and Subcellular Partitioning in the Earthworm Eisenia fetida Exposed to Cadmium-Contaminated Soil by Lianzhen Li; Dongmei Zhou; Peng Wang; Willie J. G. M. Peijnenburg (pp. 718-724).

To understand the bioaccumulation kinetics of cadmium (Cd) at the subcellular level, toxicokinetics and subcellular fractionation of Cd were determined for the terrestrial earthworm Eisenia fetida exposed to Cd-contaminated red soil. The bioaccumulation factor was 1.74 after exposure to soil containing 1 mg Cd/kg dry weight for 21 days. Four distinct compartments with different Cd-binding affinities were obtained by sequential centrifugations, including the cytosolic fraction (G), the organelles fraction (F), the granular fraction (D), and the tissue, cell membrane, and intact cell fraction (E). Most of the accumulated Cd in the organisms existed as fraction G. Cd bound to the tissue and cell membrane fraction (E) was <8% of total Cd. Only approximately 3% of Cd existed in fraction F, and <1% was found in fraction D. Accumulation and elimination kinetics of Cd in different fractions were accurately described by one-compartment models, and kinetic parameters (uptake rate constant k 1 and elimination rate constant k 2) were derived. Fractions G and F were responsible for the linear accumulation pattern during 3 weeks of exposure, whereas fractions D and E showed a nonlinear uptake curve, and steady state was achieved after 7 and 14 days of exposure, respectively.

An Ecological Risk Assessment of the Acute and Chronic Effects of the Herbicide Clopyralid to Rainbow Trout (Oncorhynchus mykiss) by J. F. Fairchild; A. L. Allert; K. P. Feltz; K. J. Nelson; J. A. Valle (pp. 725-731).

Clopyralid (3,6-dichloro-2-pyridinecarboxylic acid) is a pyridine herbicide frequently used to control invasive, noxious weeds in the northwestern United States. Clopyralid exhibits low acute toxicity to fish, including the rainbow trout (Oncorhynchus mykiss) and the threatened bull trout (Salvelinus confluentus). However, there are no published chronic toxicity data for clopyralid and fish that can be used in ecological risk assessments. We conducted 30-day chronic toxicity studies with juvenile rainbow trout exposed to the acid form of clopyralid. The 30-day maximum acceptable toxicant concentration (MATC) for growth, calculated as the geometric mean of the no observable effect concentration (68 mg/L) and the lowest observable effect concentration (136 mg/L), was 96 mg/L. No mortality was measured at the highest chronic concentration tested (273 mg/L). The acute:chronic ratio, calculated by dividing the previously published 96-h acutely lethal concentration (96-h ALC₅₀; 700 mg/L) by the MATC was 7.3. Toxicity values were compared to a four-tiered exposure assessment profile assuming an application rate of 1.12 kg/ha. The Tier 1 exposure estimation, based on direct overspray of a 2-m deep pond, was 0.055 mg/L. The Tier 2 maximum exposure estimate, based on the Generic Exposure Estimate Concentration model (GEENEC), was 0.057 mg/L. The Tier 3 maximum exposure estimate, based on previously published results of the Groundwater Loading Effects of Agricultural Management Systems model (GLEAMS), was 0.073 mg/L. The Tier 4 exposure estimate, based on published edge-of-field monitoring data, was estimated at 0.008 mg/L. Comparison of toxicity data to estimated environmental concentrations of clopyralid indicates that the safety factor for rainbow trout exposed to clopyralid at labeled use rates exceeds 1000. Therefore, the herbicide presents little to no risk to rainbow trout or other salmonids such as the threatened bull trout.

Porphyrin Pattern and Methemoglobin Levels in Columba livia Applied to Assess Toxicological Risk by Air Pollution in Urban Areas by Matteo Sicolo; Maria Tringali; Federica Orsi; Angela Santagostino (pp. 732-740).

The study has explored two conservative biomarkers, porphyrin pattern in guano and methemoglobin levels in blood of Columba livia, in order to assay their potential use for monitoring toxic effects induced by exposure to urban air pollution. Fieldwork was conducted between October 2003 and June 2005 in the city of Milan, Italy, by sampling the pigeons in different areas almost twice a week. Six air contaminants, CO, PM10, NO₂, O₃, SO₂, and C₆H₆, plus polycyclic aromatic hydrocarbons (PAHs) in fine particles, temperature, and UV index, were considered. Protoporphyrins from pigeon excreta sampled outdoors were always higher than in indoor animals, particularly in winter. A positive correlation (p < 0.001) of protoporphyrin with PAHs was observed. In terms of the values of methemoglobinemia, animals exposed to urban air showed significant differences from season to season but only in summer and autumn did the outdoor pigeons show higher values than indoor animals. In summer, a regression model with a positive correlation between O₃ and benzene was determined (p < 0.01). The use of Columba livia as a sentinel for urban air pollution as well as for detecting complex interactions between contaminants in the urban air pollutant mixture was discussed.

Small Mammals Collected from a Site with Elevated Selenium Concentrations and Three Reference Sites by Gary M. Santolo (pp. 741-754).

Small mammals were trapped in July, August, and September 1999 at Kesterson Reservoir (Merced County, CA), a site with elevated concentrations of selenium (Se), and at three nearby reference sites. Deer mice (Peromyscus maniculatus) were the most frequently trapped species at all of the sites, and western harvest mice (Reithrodontomys megalotis) and house mice (Mus musculus) were also trapped frequently. About half the animals collected from the reference sites were in reproductive condition, compared to less than a quarter of the animals from Kesterson. A lower proportion of the deer mice trapped at Kesterson was male, compared to about half at the reference sites. Deer mice from Kesterson also tended to have a lower condition index (body weight/body length) than those from the reference sites. Mice from Kesterson had enlarged livers, based on a higher liver-to-body-weight ratio (% liver). Male mice from Kesterson tended to have a smaller anogenital distance than male mice from reference sites, suggesting some feminization of Kesterson mice. Mice from Kesterson had higher liver Se concentrations than mice from reference sites, and some mice from reference sites had surprisingly low liver Se concentrations. It is possible that the effects observed were caused by physical stressors at Kesterson such as lower water and food availability but it also suggests that long-term exposure to elevated levels of Se may be, in part, the cause of some of the differences observed in small mammals from Kesterson.

Bioavailability and Bioaccessibility of Arsenic in a Soil Amended with Drinking-Water Treatment Residuals by Rachana Nagar; Dibyendu Sarkar; Konstantinos C. Makris; Rupali Datta; Victor L. Sylvia (pp. 755-766).

Earlier incubation and greenhouse studies in our laboratory confirmed the effectiveness of drinking-water treatment residual (WTR) in decreasing soil arsenic (As) bioaccessibility as determined with in vitro tests, which led us to hypothesize a similar outcome if animal studies were to be conducted. Our objective was to evaluate the potential of WTR in lowering soil As bioavailability by conducting in vivo experiments and compare the in vitro to the in vivo As data. This study was performed using 6-week-old male BALB/c mice that were fed with an As-contaminated soil slurry using the gavage method. Blood and stomach contents were collected at 1 and 24 h after feeding. Urine and excreta were collected at time 0 (before feeding) and 24 h after feeding. Relative As bioavailability (RBA) values calculated from the blood samples of mice fed with WTR and WTR-amended soil samples ranged from 13% to 24% and from 25% to 29%, respectively; both were significantly (p < 0.001) lower than that of the unamended (no-WTR) soil (~100% RBA). Absolute As bioavailability (ABA) in the gastric phase was significantly (p < 0.001) lowered, to 7–16%, in the WTR-amended soil compared with that of the unamended control (26%). A significant (p < 0.001) linear correlation (r = 0.94) was observed between the in vitro (stomach-phase) and the in vivo RBA data. Percentage recovery of As obtained from four mice tissue compartments (i.e., blood, stomach, urine, and fecal matter) after oral and intramuscular administrations was 63–80%. Results illustrate the effectiveness of in situ WTR amendment in decreasing in vivo soil As bioavailability, thereby lowering the potential cancer risk via an oral ingestion pathway.

Combined Effects of Repeated Administration of 2,3,7,8-Tetrachlorodibenzo-p-dioxin and Polychlorinated Biphenyls on Kidneys of Male Rats by Chun-Feng Lu; Yi-Mei Wang; Shuang-Qing Peng; Li-Bo Zou; De-Hong Tan; Gang Liu; Ze Fu; Qiao-Xu Wang; Jing Zhao (pp. 767-776).

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and polychlorinated biphenyls (PCBs) are persistent environmental contaminants that exist as complex mixtures in the environment, but the possible interactions of TCDD and PCBs have not been systematically investigated. The main objective of this study was to investigate the combined nephrotoxic effects of TCDD and PCBs on rats and to reveal the potential interactions between TCDD and PCBs. Male Sprague–Dawley rats were intragastrically administered TCDD (10 μg/kg), PCBs (Aroclor 1254, 10 mg/kg), or the combination (10 μg/kg TCDD + 10 mg/kg Aroclor 1254). After 12 consecutive days of exposure, all treatments induced nephrotoxicity, as evidenced by significant increases in the levels of serum creatinine and blood urea nitrogen, changes of kidney histopathology, and significant renal oxidative stress. Most of these effects were more remarkable in the combined-exposure group. Furthermore, all treatments induced renal cytochrome P450 1A1 (CYP1A1) protein expression, and the induction was more conspicuous in the combined-exposure group. These findings suggested that the nephrotoxicity induced by TCDD and PCBs in the present study might be attributable to the high expression of CYP1A1. In addition, the result of the two-way analysis of variance revealed that the combined effects of TCDD and PCBs were complicated, being additive, synergistic, or antagonistic depending on the selection of toxicity end points under the present experimental condition. This study demonstrates that combined exposure to TCDD and PCBs induced significant nephrotoxicity in rats, and there were complicated interactions between the two pollutants on the nephrotoxicity.

Reproductive Effects of Di(2-ethylhexyl)phthalate in Immature Male Rats and Its Relation to Cholesterol, Testosterone, and Thyroxin Levels by Giuliana G. K. Botelho; Munisa Golin; Aedra C. Bufalo; Rosana N. Morais; Paulo R. Dalsenter; Anderson J. Martino-Andrade (pp. 777-784).

Phthalates are chemicals employed in several industrial products and there is a growing body of evidence demonstrating that they induce numerous adverse effects on the reproductive system. This study was carried out to assess possible alterations induced by the plasticizer di(2-ethylhexyl phthalate (DEHP) on cholesterol, testosterone, and thyroxine (total T4) levels, as well as to discuss the significance of these data in global changes observed in the reproductive tract of pubertal animals. Wistar rats aged 21 days received DEHP orally at 0, 250, 500, and 750 mg/kg/day for 30 days and were examined for different reproductive endpoints. At the end of the treatment, significant decreases in relative weight of testosterone-dependent organs, delayed preputial separation, and low serum testosterone were observed at the highest DEHP dose. The plot of the relationship between DEHP dose and serum cholesterol revealed a biphasic effect. The concentration of cholesterol in serum was significantly reduced at 250 mg/kg/day DEHP but returned to control values at 750 mg/kg/day. Cholesterol levels measured in testicular tissue increased with DEHP treatment. Serum T4 levels were not affected by DEHP at any dose, indicating the absence of a link between total thyroxin concentration and phthalate effects on cholesterol levels. Taken together these results indicate that effects observed in serum and testicular cholesterol levels may reflect distinct effects of DEHP on cholesterol synthesis and usage. These results confirm and extend previously reported findings showing that alterations in cholesterol balance may play a role in the suppression of steroidogenesis induced by DEHP in rats.

Vitamin C and Resveratrol Supplementation to Rat Dams Treated with Di(2-ethylhexyl)phthalate: Impact on Reproductive and Oxidative Stress End Points in Male Offspring by Giuliana G. K. Botelho; Aedra C. Bufalo; Ana Claudia Boareto; Juliane C. Muller; Rosana N. Morais; Anderson J. Martino-Andrade; Karen R. Lemos; Paulo R. Dalsenter (pp. 785-793).

This study was carried out to assess the influence of di(2-ethylhexyl)phthalate (DEHP) alone or associated with antioxidants on the male reproductive system in newborn rats, emphasizing the implications of oxidative stress and hormonal balance during prenatal and early postnatal periods. Wistar females were exposed by oral route to DEHP alone or associated with antioxidants from gestational day 7 to lactational day 2 according to the following treatment regimens: (C) vehicle control (canola oil + 1% Tween-80); (V) vitamin C (200 mg/kg) + canola oil; (R) resveratrol (10 mg/kg) + canola oil; (D) DEHP (500 mg/kg) + 1% Tween-80; (DV) DEHP (500 mg/kg) + vitamin C (200 mg/kg); and (DR) DEHP (500 mg/kg) + resveratrol (10 mg/kg). Two male pups per litter were randomly selected and necropsied on postnatal day 2. The brain and liver were removed and weighed and anogenital distance (AGD) was measured. Additionally, the testes were removed for assessment of intratesticular testosterone levels and histopathology; the liver was used to measure biomarkers of oxidative stress. Vitamin C and resveratrol alone did not affect the reproductive end points and did not induce oxidative stress. Exposure of dams to DEHP alone and associated with antioxidants resulted in hepatomegaly in offspring and significantly increased the incidence of multinucleated gonocytes in seminiferous cords. Testosterone and AGD presented a trend to decrease in DEHP-exposed groups. Catalase activity increased only in groups exposed to DEHP associated with antioxidants, although GST (gluthatione-S-transferase) activity decreased in all DEHP-exposed groups. The levels of hydroperoxides increased only in group exposed to DEHP associated with vitamin C. These results indicate that the association of DEHP with antioxidants was unable to ameliorate DEHP-induced reproductive changes, and the coadministration of DEHP and these antioxidants might even contribute to an overall increase in oxidative stress.

Total PCBs, Dioxin–Furan TEQs, and Total Mercury Concentrations in Mink in and out of the Rochester Embayment Area of Concern Near and Inland from the Shore of Lake Ontario by James M. Haynes; James J. Pagano; Sara T. Wellman (pp. 794-802).

In terms of reproductive and other adverse outcomes after exposure to polychlorinated biphenyls (PCBs), dioxins, and furans, the mink (Mustela vison) is one of the most sensitive mammals. Our objective was to determine if there are differences in the concentrations of total mercury (Hg), total PCBs, and dioxin–furan toxic equivalents (TEQs) between mink living in and out of the Rochester Embayment of Lake Ontario (RELO) Area of Concern (AOC) and between mink living near the shore of Lake Ontario and inland. Concentrations of total Hg in the brain, total PCBs and dioxin–furan TEQs in adipose, and total PCBs in liver were significantly higher for mink living near the shore of Lake Ontario than inland. For mink living in and out of the AOC, differences in total PCBs and dioxin–furan TEQs in adipose and the liver were substantial but not significant. Correlations among concentrations of total Hg, total PCBs, and dioxin–furan TEQs in mink were high. Our results suggest that contamination of mink living near the southern shore of Lake Ontario primarily comes from contact with the Lake Ontario food web, not from sources in the RELO AOC.

Histological Lesions in Mink Jaws Are a Highly Sensitive Biomarker of Effect After Exposure to TCDD-Like Chemicals: Field and Literature-Based Confirmations by James M. Haynes; Sara T. Wellman; Kerrie J. Beckett; James J. Pagano; Scott D. Fitzgerald; Steven J. Bursian (pp. 803-807).

The mink (Mustela vison) is one of the most sensitive mammals to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-like chemicals. By literature review we established that a histological lesion of the jaw bone of mink, evidenced by squamous epithelial hyperplasia in the gingival tissue that forms nests or cords that infiltrate the periodontal ligament and alveolar bone causing osteolysis of the mandible and maxilla that could lead to squamous cell carcinoma, is the most sensitive known biomarker of effect following exposure of mink to TCDD-like chemicals. Lesions have been observed when total TCDD toxic equivalents (TEQ: dioxins, furans, coplanar polychlorinated biphenyls or PCBs) in liver exceed 40 ng/kg wet weight (ww) or when total PCB exceeds 1698 ng/g ww. This is the second report of histological evidence of this lesion in wild-caught mink, and it is the first report of the lesion being grossly detectable in naturally exposed mink. Some mink living near the south shore of Lake Ontario (exposed to the lake’s food web), but not inland mink (not exposed to the lake’s food web), accumulate more than 40 ng total TEQ/kg or 1698 ng total PCB/kg in liver. Because of its sensitivity, the jaw lesion biomarker is very useful for assessing the health of wildlife populations exposed to TCDD-like chemicals.

Model Estimates Bioaccumulation of Total PCBs, Dioxin–Furan TEQs, and Total Mercury in Mink Liver Based on Concentrations in Lake Ontario Water by Sara T. Wellman; James M. Haynes; James J. Pagano (pp. 808-815).

We used stable isotope analysis and a bioaccumulation model to estimate concentrations of total polychlorinated biphenyls (PCBs), dioxin–furan toxic equivalents (TEQs), and total mercury (Hg) in mink and to compare predicted ranges with their chemical concentrations in mink liver (PCB, TEQ) and brain (Hg). Actual concentrations were within predicted bounds for total PCB, dioxin–furan TEQ, and Hg except in two cases (lowest PCB and highest Hg) which were very close to predicted bounds. Based on ¹⁵N analysis, the trophic level of mink ranged from 3.4 to 3.9. Animals at the upper end of the range were exposed to Lake Ontario water and its food web, whereas those at the lower end were captured at inland locations. Because of the complexity of wetland (an important habitat for mink in this study) food webs with pelagic, littoral, and terrestrial carbon sources and overlapping ¹³C signatures, whether the origins of mink diets were aquatic or terrestrial could not be determined. We have established a nondestructive biomonitoring tool to reasonably estimate concentrations of total PCBs, TEQs and total Hg in mink tissues as concentrations of these chemicals change in their water supply.

Increases in Cytosolic Calcium Ion Levels in Human Natural Killer Cells in Response to Butyltin Exposure by Rhonda Lane; Sabah O. Ghazi; Margaret M. Whalen (pp. 816-825).

This study investigated whether exposures to butyltins (BTs), tributylin (TBT), and dibutyltin (DBT) were able to alter cytosolic calcium levels in human natural killer (NK) cells. Additionally, the effects of cytosolic calcium ion increases on the activation state of mitogen-activated protein kinases (MAPKs) in NK cells were also investigated. NK cells are an intital immune defense against the development of tumors or viral infections. TBT and DBT are widespread environmental contaminants, due to their various industrial applications. Both TBT and DBT have been shown to decrease the ability of NK cells to lyse tumor cells (lytic function). TBT has also been shown to activate MAPKs in NK cells. The results of this study indicated that TBT increased cytosolic calcium levels by as much as 100% after a 60-min exposure to 500 nM TBT, whereas DBT increased cytosolic calcium levels to a much smaller extent (and required higher concentrations). The results also indicated that increases in cytosolic calcium could activate MAPKs but only for a short period of time (5 min), whereas previous studies showed that activation of MAPKs by TBT last for at least 6 h. Thus, it appears that TBT-stimulated increases in cytosolic calcium might contribute to, but are not fully responsible for, TBT-induced activation of MAPKs.

Toxicity of Sediment Cores Collected from the Ashtabula River in Northeastern Ohio, USA, to the Amphipod Hyalella azteca by Christopher G. Ingersoll; Nile E. Kemble; James L. Kunz; William G. Brumbaugh; Donald D. MacDonald; Dawn Smorong (pp. 826-827).

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Archives of Environmental Contamination and Toxicology (v.57, #4)