Forgot your password?
New user?
New Window Opens on the Secret Life of Microbes: Scientists Develop First Microbial Profiles of Ecosystems
CAS announces the release of SciFinder Scholar for Mac OS X
Press Releases
Press Releases
| Check out our New Publishers' Select for Free Articles |
Archives of Environmental Contamination and Toxicology (v.49, #3)
Humic Acid Toxicity in Biologically Treated Soil Contaminated with Polycyclic Aromatic Hydrocarbons and Pentachlorophenol by J. K. C. Nieman; R. C. Sims; D. L. Sorensen; J. E. McLean (pp. 283-289).
Contaminated soil from a land treatment unit at the Libby Groundwater Superfund Site in Libby, MT, was amended with 14C pyrene and incubated for 396 days to promote biodegradation and the formation of soil-associated bound residues. Humic and fulvic acids were extracted from the treated soil microcosms and analyzed for the presence of pyrene residues. Biologic activity promoted 14C association with the fulvic acid fraction, but humic acid–associated 14C did not increase with biologic activity. The Aboatox flash toxicity assay was used to assess the toxicity of humic and fulvic acid fractions. The fulvic acid gave no toxic response, but the humic acid showed significant toxicity. The observed toxicity was likely associated with pentachlorophenol, a known contaminant of the soil that was removed by solvent extraction of the humic acid and that correlated well with toxicity reduction.
Trends in the Levels of Metals in Soils and Vegetation Samples Collected Near a Hazardous Waste Incinerator by M. Nadal; A. Bocio; M. Schuhmacher; J. L. Domingo (pp. 290-298).
In 1998 and 2001, the levels of a number of elements (As, Be, Cd, Cr, Hg, Mn, Ni, Pb, Sn, Tl, and V) were determined in 40 soil and 40 herbage samples collected near a new hazardous waste incinerator (HWI) (Constantí, Catalonia, Spain). In 2003, soil and herbage samples were again collected at the same sampling points in which samples had been taken in the previous surveys. During the period 1998–2003, As, Be, Cr, Ni, and V levels showed significant increases in soils. In contrast, the levels of Cd, Hg, and Sn significantly decreased. With respect to herbage, while Cr, Mn, and V concentrations significantly increased, those of As levels diminished. On the other hand, human health risks derived from metal ingestion and inhalation of soils were also assessed. In relation to noncarcinogenic risks, all elements presented a value inside the safe interval. In turn, Cd and Cr were also in the safe interval of carcinogenic risks, whereas in contrast As levels clearly exceeded the regulatory limits concerning carcinogenic risks. According to the results of the previous (2001) and current (2003) surveys, the fluctuations in the metal concentrations suggest that the influence of the HWI is minimal in relation to other metal pollution sources in the area.
Effect of Cadmium(II), Chromium(VI), and Arsenic(V) on Long-Term Viability- and Growth-Inhibition Assays Using Vibrio fischeri Marine Bacteria by E Fulladosa; J. C. Murat; I. Villaescusa (pp. 299-306).
As a complement to previous results obtained using the standard Microtox acute-toxicity test, which is based on measuring the rapid decrease of bioluminescence (5 to 30 minutes of exposure) in Vibrio fischeri bacteria in the presence of toxicants, the long-term effects of Cd(II), Cr(VI), and As(V) were studied on growth rate and viability assays of the same bacteria adapted to longer-lasting cultures, i.e., 48 or 72 hours instead of 5 or 30 minutes. Effects on viability or growth, as studied by establishing dose- and time-response curves, confirmed that these poisonous chemicals were not particularly toxic to these bacteria. Nevertheless, in the case of Cr(VI), the viability-inhibition assay appeared to be more sensitive than the Microtox acute-toxicity test. Interestingly, it was possible to observe a clear hormesis phenomenon, especially for Cd(II), under the conditions of both viability- and growth-inhibition assays.
Microcosm Evaluation of the Fate, Toxicity, and Risk to Aquatic Macrophytes from Perfluorooctanoic Acid (PFOA) by Mark L. Hanson; Jeff Small; Paul K. Sibley; Tim M. Boudreau; Richard A. Brain; Scott A. Mabury; Keith R. Solomon (pp. 307-316).
Perfluorooctanoic acid (PFOA) is an anthropogenic contaminant detected in various environmental and biological matrices. This compound is a fluorinated surfactant, belonging to a class of molecules known for persistence and their global distribution, but for which little ecotoxicological data are currently available, especially under field conditions. The environmental fate and toxicity of PFOA to the aquatic macrophytes Myriophyllum sibiricum and M. spicatum were investigated using 12,000 L outdoor microcosms. Replicate microcosms (n = 3) were treated with 0.3, 1, 30, and 100 mg/L PFOA as the sodium salt, plus controls, and assessed at regular intervals over 35 days. PFOA showed no significant dissipation from the water column, except at the greatest concentration, where partitioning from the water column into other compartments is suspected. The two species of Myriophyllum were similar in their sensitivity to PFOA under these simulated field conditions. Toxicity after 14 to 35 days of exposure in the evaluated endpoints for M. spicatum was ≥5.7 mg/L PFOA for EC10s and ≥31.8 mg/L PFOA for EC50s and in M. sibiricum was ≥8.4 mg/L PFOA for EC10s and ≥35.8 mg/L PFOA for EC50s. The no observed effects concentrations (NOECs) for Myriophyllum spp. were consistently ≥23.9 mg/L PFOA. A risk assessment for these plant species estimated a negligible probability of toxicity being observed from PFOA exposure at current environmental concentrations.
Differences in Concentration of Heavy Metals Between Native and Transplanted Plagiothecium denticulatum: A Case Study of Soils Contaminated by Oil Well Exudates in South East Poland by A. Samecka-Cymerman; K. Kolon; A. J. Kempers (pp. 317-321).
For a period of 60 days, the terrestrial moss Plagiothecium denticulatum was transplanted from a clean control site to a soil contaminated with crude oil exudates (Krosno, South East Poland). Native P. denticulatum growing on this contaminated soil was collected during the same period. Concentrations of the metals Al, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, V, and Zn as well as the macroelements N, P, K, Ca, Mg, and S were determined in P. denticulatum and in soils from the contaminated and control sites. Contaminated soil was the main contributor of Ba, Co, Cr, Cu, Fe, Mn, Ni, Pb, V, and Zn to native and transplanted P. denticulatum. Other sources of contamination apart from the soil existed for Cd and Cu. Transplanted P. denticulatum accumulated significantly more Al, Cr, Cu, Ni, Pb, and Zn, and native P. denticulatum accumulated significantly more N, P, K, and Ca. Higher levels of N, P, K, and Ca in native P. denticulatum indicates a possible mechanism to prevent the loss of these elements as observed in the transplanted P. denticulatum.
Effects of Water Chemistry on the Bioavailability of Metals in Sediment toHyalella azteca: Implications for Sediment Quality Guidelines by M. Nowierski; D. G. Dixon; U. Borgmann (pp. 322-332).
Risk assessments of metals in sediments are often based on sediment-quality guidelines (SQGs) and do not take into account the chemistry of the overlying water. To determine the effects of water chemistry on the toxicity of metals in sediments, both water and sediment were collected from five metal-contaminated lakes with widely differing water chemistry near Canadian smelters. Metal bioaccumulation by Hyalella azteca was measured in laboratory exposures with each sediment and with overlying water from several different sources. The effect of water chemistry on Ni bioaccumulation from sediment was minimal. However, the effect was substantial for Cd because the effect of water chemistry on sediment-water partitioning was opposite to, and augmented, the effect of water chemistry on the Hyalella/water accumulation ratio. The effect of overlying water must be considered when conducting risk assessments for some metals in sediment (e.g., Cd). Examples are provided of equations that can be used to adjust cause-and-effect–based SQGs for water chemistry (e.g., using calcium concentrations or pH).
Comparative and Mixture Sediment Toxicity of Trinitrotoluene and Its Major Transformation Products to a Freshwater Midge by Guilherme R. Lotufo; J. Daniel Farrar (pp. 333-342).
The explosive trinitrotoluene (TNT) is a prevalent contaminant in many military installations worldwide. Limited knowledge of the comparative toxicity of sediment-associated TNT and related compounds contributes to uncertainty when assessing ecological risks in contaminated sites. Trinitrotoluene undergoes transformation when associated with soils and sediments and typically occurs as a mixture dominated by its reduction products. The objective of this study was to comparatively evaluate the single-compound toxicity of TNT and its major transformation products to the freshwater midge Chironomus tentans in 10-day exposures to sediment spiked with TNT, 2-aminodinitrotoluene (2-ADNT), 2,4-diaminonitrotoluene (2,4-DANT), or trinitrobenzene (TNB). In addition, the nature of the toxicological interactions of the latter compounds in a mixture was evaluated. Upon spiking to sediment, TNT and TNB rapidly degraded to reduced products, and disappearance of extractable compounds suggested irreversible binding to sediment particles. The high degree of transformation and reactivity occurring during 10 days at spiking concentrations as high as 4000 μmol/kg dry weight suggests that TNT and related compounds are unlikely to be encountered in fine-grained sediments at contaminated sites. Similar to previous investigations, the high reactivity of the spiked compound hampered determination of accurate toxic concentrations of TNT and related compounds, and of the nature of toxicological interaction of compounds in a mixture in this study. Sediment concentrations associated with decreased survival were similar for all four compounds, with the 10-d median lethal concentrations (LC50s) determined using initial concentrations ranging from 175 (2-ADNT) to 605 (2,4-DANT) μmol/kg dry weight. Sublethal decrease in growth was not observed for any compound. Results from the mixture experiment suggest additive interaction among TNT and related compounds in sediment exposures.
Toxicity of the Crude Oil Water-Soluble Fraction and Kaolin-Adsorbed Crude Oil on Daphnia magna (Crustacea: Anomopoda) by F. Martínez-Jerónimo; R. Villaseñor; G. Ríos; F. Espinosa-Chavez (pp. 343-352).
Crude oil is a complex mixture of hydrocarbons entering aquatic environments from accidental or normal marine and transportation activities. Toxicologic crude oil analysis is usually performed on the basis of the water-soluble fraction. However, this yields only a partial estimate of the damage caused by these contaminants because a substantial hydrophobic amount can be adsorbed onto suspended solids (biotic and abiotic), which directly affects filter-feeding species and permits bioaccumulation through trophic relationships. This study determined the acute toxic damage sustained after 48 hours caused by seven types of crude oil from Tabasco, Mexico on the cladoceran Daphnia magna. Comparisons were documented based on the responses of D. magna from application of the water-soluble fraction and exposure to entire crude oil samples adsorbed on kaolin clay. Oil-sorbed kaolin was more toxic than the water-soluble fraction in acute exposure. This confirms that tests of the water-soluble fraction tend to underestimate the toxic damage that can be produced in natural environments. Furthermore, chronic toxicity (21 days) was evaluated for crude oil samples adsorbed on kaolin at sublethal concentrations as established from Application Factors (AF) criteria. Results showed that in most cases, it is impossible to predict safe concentrations on the basis of LC50 values because samples with lower acute toxicity exercised a greater influence on D. magna reproduction and survival when subjected to chronic exposure.
Effects of Pharmaceuticals on Aquatic Invertebrates. Part I. The Antiepileptic Drug Carbamazepine by M Oetken; G Nentwig; D Löffler; T Ternes; J Oehlmann (pp. 353-361).
The effects of the antiepileptic drug carbamazepine (CBZ) were studied in three freshwater invertebrate species representing different taxonomic groups, life histories, and habitats in aquatic ecosystems. The oligochaete Lumbriculus variegatus was exposed by way of CBZ-spiked sediments at nominal concentrations between 0.625 and 10 mg/kg dry weight (dw) for 28 days. At the end of the test, reproduction and biomass were monitored as end points. The nonbiting midge Chironomus riparius was exposed to CBZ in a series of tests at nominal CBZ concentrations in sediment ranging from 0.16 to 100 mg/kg dw at 20°C and 23°C. Emergence and gender ratio were monitored at the end of the test. The freshwater snail Potamopyrgus antipodarum as the third test species was used in a chronic reproduction test for 28 days at aqueous CBZ concentrations from 0.4 to 250 mg/L. Whereas for the oligochaete and the snail no effects were observed, C. riparius exhibited a significant and concentration-dependent decrease of emergence in all test series. No observed effect concentrations and 10% effect concentrations were in the range of 33 to 140 and 70 to 210 μg/kg dw, respectively, based on measured CBZ concentrations in sediments. These low values indicate that CBZ may pose a potential threat for the survival of C. riparius and probably also for other aquatic insect populations in the field.
An Evaluation of Polycyclic Aromatic Hydrocarbon (PAH) Runoff from Highways Into Estuarine Wetlands of South Carolina by R. F. Van Dolah; G. H. M. Riekerk; M. V. Levisen; G. I. Scott; M. H. Fulton; D. Bearden; S. Sivertsen; K. W. Chung; D. M. Sanger (pp. 362-370).
This study investigated the concentrations and potential toxicity of polycyclic aromatic hydrocarbons (PAHs) associated with highway runoff into adjacent estuarine wetlands from road segments representing three levels of average daily traffic (ADT): low (<5,000 ADT), moderate (10,000–15,000 ADT), and high use (>25,000 ADT) based on SC Department of Transportation data. Sediments from three estuarine wetland habitats (tidal creeks, Spartina marsh, and mud flats) adjacent to these road segments were sampled to represent nine highway use class/habitat type combinations. Surficial sediments were collected at 3, 25, and 50 meters from the upland/wetland interface along transects established perpendicular to the road at each site, with additional samples taken from the road berm. Average PAH concentrations, representing 25 compounds, ranged from 3.9 to 11,000 ng/g dry weight. Berm samples had significantly greater total PAH concentrations than samples taken in any of the wetland habitats. Average total PAH concentrations decreased with increasing distance from the road berm within the wetland habitats sampled, but the differences were not statistically significant. Average total PAH concentrations also were not significantly different among the wetland habitats compared. Analysis of PAH profiles indicated that the PAH source was dominated by pyrogenic combustion products rather than from petrogenic sources. This, combined with the presence of dibenzothio-phene, which is a tire oxidation product, indicated that the primary source of PAHs was related to vehicles. Two sites with total PAH concentrations exceeding published bioeffects levels were resampled for bioassay tests using the amphipod Ampelisca verrilli, the polychaete Streblospio benedicti, and the clam, Mercenaria mercenaria, with the first two assays conducted under UV lighting since previous studies had demonstrated enhanced UV toxicity of PAHs for these species. No toxicity was observed in the amphipod or polychaete assays. Toxicity was observed in the juvenile clam assay at one site, possibly due to the combined effects of PAHs and other contaminants present.
Modulatory Effect of Cadmium Exposure on Deltamethrin-Induced Oxidative Stress in Channa punctata Bloch by F Atif; S Parvez; S Pandey; M Ali; M Kaur; H Rehman; H A Khan; S Raisuddin (pp. 371-377).
The modulatory effect of cadmium pretreatment (0.2 mg/kg b.w. i.p.) on deltamethrin-induced oxidative stress and alterations of antioxidants was studied in freshwater fish Channa punctata Bloch. Lipid peroxidation (LPO) was measured as one of the indicators of oxidative stress. Activities of glutathione peroxidase, glutathione reductase, and glutathione-S-transferase were also studied in liver, kidney, and gills. Levels of reduced glutathione (GSH) were measured in various tissues. Fish pretreated with cadmium and subsequently exposed to deltamethrin showed significantly reduced LPO values when compared with deltamethrin-exposed fish. Conversely, in the kidney, a potentiation response was observed. Deltamethrin exposure in fish resulted in significant alteration in activities of glutathione-dependent antioxidant enzymes. In the cadmium preexposed fish, which were subsequently exposed to deltamethrin, antioxidant enzymes showed a tendency toward normalization over deltamethrin-only exposed fish in liver and gills. GSH also showed a similar pattern in liver and gills but in kidney it remained elevated. Cadmium alone had no significant effect on various parameters at the concentration used in this study. When metallothionein (MT) induction was studied, only liver showed an MT-like protein band in sodium dodecylsulfate–polyacrylamide gel electrophoresis analysis. These results demonstrate a modulatory role of cadmium on the oxidative stress and other related parameters in liver and gills. These findings are important in the context of exposure to a mixture of pollutants in aquatic environment.
Chronic Toxicity of Un-ionized Ammonia to Early Life-Stages of Endangered Colorado Pikeminnow (Ptychocheilus lucius) and Razorback Sucker (Xyrauchen texanus) Compared to the Surrogate Fathead Minnow (Pimephales promelas) by J. F. Fairchild; A. L. Allert; L. C. Sappington; B. Waddell (pp. 378-384).
Ammonia-contaminated groundwater enters the Upper Colorado River from beneath the abandoned Moab Uranium Mill Tailings Pile near Moab, Utah. This reach of the Upper Colorado River was designated as critical habitat for four endangered fish species because it is one of the few existing areas with known spawning and rearing habitats. Un-ionized ammonia (NH3) concentrations frequently exceed 1.00 mg/L in backwaters adjacent to the tailings pile, which exceeds the Utah 30-d average chronic water quality criterion for un-ionized ammonia (0.07 mg/L NH3; temperature 20°C; pH 8.2) by a factor of more than 10. However, there is little published information regarding the sensitivity of endangered fishes to ammonia. We conducted 28-d static renewal studies with post-swim-up larvae to determine the relative sensitivity of Colorado pikeminnow (Ptychocheilus lucius), razorback sucker (Xyrauchen texanus), and the standard surrogate fathead minnow (Pimephales promelas) to NH3. Chronic values (ChVs) for mortality and growth were determined as the geometric mean of the no observed effect concentration and the lowest observed effect concentration based on analysis of variance. The ChVs for growth of fathead minnow, Colorado pikeminnow, and razorback sucker were 0.43, 0.40, and 0.67 mg/L NH3, respectively. The ChVs for mortality of fathead minnow, Colorado pikeminnow, and razorback sucker were 0.43, 0.70, and 0.67 mg/L NH3, respectively. Therefore, the ChVs for mortality and growth were similar for fathead minnow and razorback sucker; however, the ChV for growth was lower than the ChV for mortality for Colorado pikeminnow. Maximum likelihood regression was used to calculate 28-d lethal concentrations (LCx) for each species. The 28-d LC50, LC20, and LC1 values for fathead minnow were 0.69, 0.42, and 0.13 mg/L NH3, respectively. The 28-d LC50, LC20, and LC1 values for Colorado pikeminnow were 0.76, 0.61, and 0.38 mg/L NH3, respectively. The 28-d LC50, LC20, and LC1 values for razorback sucker were 0.54, 0.38, and 0.25 mg/L NH3, respectively. The fathead minnow, Colorado pikeminnow, and razorback sucker are relatively similar in sensitivity and rank at the 35th, 49th, and 31st percentiles, respectively, of the theoretical chronic fish sensitivity distributions for NH3. The existing water quality criteria for NH3, if met by remediation activities at the Moab site, would be protective of these endangered fishes even if fish sensitivity is based on the conservative LC1 value.
Chemical Characterization of Polychlorinated Biphenyls, -Dibenzo-p-Dioxins, and -Dibenzofurans in Technical Kanechlor PCB Formulations in Japan by Takumi Takasuga; Kurunthachalam Senthil Kumar; Yukio Noma; Shinichi Sakai (pp. 385-395).
Technical polychlorinated biphenyl (PCB) formulations—Kanechlor KC-200, KC-300, KC-400, KC-500, KC-600 and KC-1000—produced in Japan were analyzed for the chemical characterization of PCBs, -dibenzo-p-dioxins (PCDDs), and -dibenzofurans (PCDFs) using high-resolution gas chromatography–high-resolution mass spectrometry (HRGC-HRMS) by isotope dilution technique. The homologue/congener profiles of Kanechlor formulations resembled those of Clophen, Aroclor, and Delor, respectively, from Germany, the United States, and Czechoslovakia. Twenty-seven major PCB congeners contributed 50% (in KC-200) to 69–71% (in KC-600, 1000, and 500) to total PCBs. Average total PCB concentrations were 510,000, 800,000, 830,000, 840,000, 870,000, and 880,000 μg/g in KC-1000 (51%), KC-200 (80%), KC-500 (83%), KC-400 (84%), KC-300 (87%), and KC-600 (88%), respectively. Kanechlors also contained PCDDs and PCDFs (4.3 to 0.35 μg/g) as impurities which were approximately 1/10,000 to the PCB concentrations. Congener characterization and concentrations of PCBs and PCDFs were considerably varied in between Kanechlor formulations. The potential for the emissions of PCDDs and PCDFs from Kanechlor was estimated to be 1.94 kg and 464.4 kg, respectively. The average WHO-toxic equivalent (TEQ) was 16 (KC-500) >12 (KC-400) >10 (KC-1000) >4.1 (KC-600) >3.5 (KC-300) >1.9 (KC-200) on μgTEQ/g. Non- and mono-ortho PCBs were the major contributors to the total TEQ in Kanechlor formulations, whereas the PCDD/DF contribution was <2.0%. The environmental input of TEQs from Kanechlors can be estimated to be between 112 and 941 kg.
Lead Contamination in American Woodcock (Scolopax minor) from Wisconsin by S.M. Strom; K.A. Patnode; J.A. Langenberg; B.L. Bodenstein; A.M. Scheuhammer (pp. 396-402).
An initial survey of lead levels in American woodcock (Scolopax minor) from Wisconsin was conducted in 1998 using wing bones from hunter-donated woodcock. The results of this initial survey indicated that young-of-year woodcock were accumulating extremely high levels of lead in their bones. Similar collections were made (using steel shot) between 1999 and 2001. The combined results of this collection indicated that 43.4% of young-of-year woodcock (range 1.5–220.0 μg/g dry wt) and 70% of woodcock chicks (range 9.6–93.0 μg/g dry wt) had bone lead levels in the elevated range (>20 μg/g dry wt). Blood samples were collected from chicks at a site considered elevated based on bone lead results (Mead Wildlife Area) and a site considered background (Navarino Wildlife Area). These samples were analyzed for lead concentration and aminolevulinic acid dehydratase activity. The mean blood lead concentrations of woodcock chicks from both sites did not reach levels that are considered elevated in waterfowl (>0.200 μg/ml). However, blood lead concentrations of chicks from the Mead Wildlife Area were significantly higher than lead levels in chicks from Navarino Wildlife Area (p = 0.002). Although the ultimate sources of lead exposure for Wisconsin woodcock currently remain unidentified, anthropogenic sources cannot be ruled out. Our results indicate that elevated lead exposure in Wisconsin woodcock is common and begins shortly after hatch.
A Risk Assessment Approach to DDE Exposure Based on the Case of the Eastern Screech-Owl (Megascops asio) in Apple Orchards of Southern Quebec,Canada by N. L. Richards; P. Mineau; D. M. Bird (pp. 403-409).
As part of a larger study assessing exposure of the Eastern screech-owl to pesticides in apple orchards from consumption of contaminated small-mammal prey, we evaluated the potential for owls in orchards of southern Quebec to be exposed to persistent contaminants with emphasis on DDE. Levels were highest in short-tailed shrews (0.94 to 26.29 μg/g wet wt). Based on a worst-case scenario, it is possible that consumption of small-mammal prey in orchards of the study area may result in exposure to DDE at a level associated with significant eggshell thinning; however, consumption of other prey, (e.g., robins) may represent a more important threat. Other organochlorines and persistent contaminants such as trace metals and PCBs, reported elsewhere, were found at negligible levels only. Based on an evaluation of the data used, we identify critical information required to enhance the proposed risk assessment.
Effects of Crude Oil and Diesel Exposures on Biochemical Activities of Polymorphonuclear Leukocytes in Cattle by A. A. Khan; C. Embury; M. M. Schuler; M. N. Hiltz; R. W. Coppock; M Dziwenka (pp. 410-414).
Cattle exposed to low doses of an Alberta crude oil, Pembina Cardium crude oil (PCCO), or a winter diesel oil no. 2 (WDO-2) were assessed for their biochemical activities in polymorphonuclear leukocyte (PMNL) cells (mainly neutrophils). The study used a randomized block design containing five treatment groups (8 animals/group). The animals were dosed per gavage with the test substance on study days 0, 14, 28, and 42. The dosages given (on per kg body weight) were: Group 1 (control), 10 mL/kg of potable water; Group 2, 5 mL/kg WDO-2; Group 3, 2.5 mL/kg PCCO; Group 4, 5 mL/kg PCCO; and Group 5, 10 mL/kg PCCO. Blood was collected at the specified intervals during the pre- and post-exposure periods, and the biochemical activities of isolated PMNL were analyzed. Cattle groups exposed to WDO-2 and PCCO showed moderate and statistically significant reductions (p < 0.01) in the activities of (1) phorbol myristate acetate (PMA) stimulated cellular respiration (respiratory burst), (2) NADPH-oxidase (PMA-stimulated production of superoxide anion), (3) myeloperoxidase, and (4) n-acetylglucosidase as compared to the control group. These biochemical parameters also showed statistically significant (p < 0.01) dose-related periodic (study day) trends. In general, these biochemical activities were decreased after each dosing; however, they subsequently recovered to near the pre-dosing levels. Such a biochemical response in PMNL provides a valuable biological tool to follow exposure effects in cattle accidentally exposed to low doses of petroleum hydrocarbons.
Organochlorine Pesticides, Polychlorinated Biphenyls, and Polybrominated Diphenyl Ethers in Irrawaddy Dolphins from India by K. Kannan; K. Ramu; N. Kajiwara; R. K. Sinha; S. Tanabe (pp. 415-420).
The Irrawaddy dolphin (Orcaella brevirostris) is at risk of extinction throughout its range as a result of incidental catches, habitat degradation, and pollution. Populations of Irrawaddy dolphins are constrained by the species’ narrow habitat requirement—lagoons, estuaries, rivers, and lakes—and are therefore particularly vulnerable to the effects of human activities. In this study, for the first time, concentrations of organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were determined in tissues of Irrawaddy dolphins collected from Chilika Lake, India, to understand the status of contamination. Dichlorodiphenyltrichloroethane and its metabolites (DDTs) were the predominant contaminants found in Irrawaddy dolphins; the highest concentration found was 10,000 ng/g lipid weight in blubber. Hexachlorocyclohexanes (HCHs) were the second most prevalent contaminants in dolphin tissues. Concentrations of PCBs, chlordanes, hexachlorobenzene, tris(4-chlorophenyl)methane, and tris(4-chlorophenyl)methanol were in the ranges of few ng/g to few hundreds of ng/g on a lipid-weight basis. In general, concentrations of OC pesticides and PCBs in Irrawaddy dolphins were lower than the concentrations reported for coastal and riverine dolphins collected in Asia. PBDEs were detected in the blubber of Irrawaddy dolphins at concentrations ranging from 0.98 to 18 ng/g lipid weight. BDE congener 47 accounted for 60% to 75% of the total PBDE concentrations. Although these results establish the baseline levels of persistent organic pollutants in Irrawaddy dolphins, efforts should be made to decrease the sources of contamination by DDTs and HCHs in Chilika Lake.
Cotton Liners to Mediate Glove Comfort for Greenhouse Applicators by J. Stone; C. Coffman; P. M. Imerman; K. Song; M. Shelley II (pp. 421-428).
Greenhouse applicators’ acceptance of cotton knit gloves worn as liners under nitrile chemical-resistant gloves (CRG) for pesticide application was investigated through a wear study in Iowa and New York. Comfort was assessed by questionnaires and interviews with 10 applicators. Contamination levels of four pesticides on CRG and liners at thumb, forefinger, palm, and cuff locations were determined by chemical analysis using high-performance liquid chromatography or gas chromatography. Applicators reported feeling more comfortable with cotton liners under their CRG than without and that cotton liners were easy to manage. Contamination was significantly greater on nitrile CRG than on cotton liners underneath, but a few liner specimens had measurable contamination. No significant contamination differences were found between right- and left-hand gloves. Contamination varied significantly by hand location, with cuffs least, and by pesticide, with chlorpyrifos most. These results support the Environmental Protection Agency’s recommendation that liners should be disposable, but further work on liners and their laundering feasibility seems indicated.
Persistent Organochlorine Compounds in Human Breast Milk from Mothers Living in Penang and Kedah, Malaysia by Agus Sudaryanto; Tatsuya Kunisue; Shinsuke Tanabe; Mami Niida; Hatijah Hashim (pp. 429-437).
This study determined the concentrations of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), organochlorine (OC) pesticides, and tris(4-chlorophenyl) methane (TCPMe) in human breast milk samples collected in 2003 from primipara mothers living in Penang, Malaysia. OCs were detected in all the samples analyzed with DDTs, hexachlorocyclohexane isomers (HCHs), and PCBs as the major contaminants followed by chlordane compounds (CHLs), hexachlorobenzene (HCB), and TCPMe. The residue levels of DDTs, HCHs, and CHLs were comparable to or higher than those in general populations of other countries, whereas PCBs and HCB were relatively low. In addition, dioxins and related compounds were also detected with a range of dioxin equivalent concentrations from 3.4 to 24 pg-TEQs/g lipid wt. Levels of toxic equivalents (TEQs) were slightly higher than those in other developing countries but still much lower than those of industrialized nations. One donor mother contained a high TEQs level, equal to the mean value in human breast milk from Japan, implying that some of the residents in Malaysia may be exposed to specific pollution sources of dioxins and related compounds. No association was observed between OCs concentrations and maternal characteristics, which might be related to a limited number of samples, narrow range of age of the donor mothers, and/or other external factors. The recently identified endocrine disrupter, TCPMe, was also detected in all human breast milk samples of this study. A significant positive correlation was observed between TCPMe and DDTs, suggesting that technical DDT might be a source of TCPMe in Malaysia. The present study provides a useful baseline for future studies on the accumulations of OCs in the general population of Malaysia.