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Archives of Environmental Contamination and Toxicology (v.46, #4)
Formation of Polychlorinated Naphthalenes, Dibenzo-p-Dioxins, Dibenzofurans, Biphenyls, and Organochlorine Pesticides in Thermal Processes and Their Occurrence in Ambient Air by Takumi Takasuga; Tsuyoshi Inoue; Etsumasa Ohi; Kurunthachalam Senthil Kumar (pp. 419-431).
Mono- through octachlorinated naphthalenes (PCNs) were measured in start-up, steady operation, and shutdown of machinery operation flue gas and fly ash generated during different stages of MSWI and other incineration thermal processes. Besides, electroprecipitator fly ash (EP-ash) was dechlorinated using the Hagenmeier process and analyzed for congener profiles. In addition to PCNs, polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), and major organochlorine pesticides were determined in ambient air samples from three different sites of western Japan in the summer and winter of 1992. The PCNs from flue gas contained 15,000, 4300, and 13,000 ng/m3 during start-up, steady operation, and shutdown conditions, respectively. Whereas fly ash contained 470, 370, and 1400 ng/g PCNs under start-up, steady operation, and shutdown condition, respectively. The dechlorination process reduced PCN concentrations considerably. Concentrations of PCNs and PCDD/PCDFs in air samples collected in winter were slightly higher than in summer. PCBs, organochlorine pesticides such as chlordanes, DDTs, and HCHs were higher in summer air samples. WHO toxic equivalency (WHO-TEQ) concentrations in air samples were 0.3–0.9 pg/m3 for PCDD/DFs and 0.029–0.31 pg/m3 for dioxin-like PCBs.
Residues of Hexachlorocyclohexane Isomers and Their Distribution Characteristics in Soils in the Tianjin Area, China by Z. M. Gong; F. L. Xu; R. Dawson; J. Cao; W. X. Liu; B. G. Li; W. R. Shen; W. J. Zhang; B. P. Qin; R. Sun; S. Tao (pp. 432-437).
Hexachlorocyclohexane (HCH) has a history of use in China. This paper presents the results of an investigation of HCH residue isomers and their distribution characteristics in soils near Tianjin, China. One hundred eighty-eight soil samples were collected from the Tianjin area. Four HCH isomers—α-HCH, β-HCH, γ-HCH, and δ-HCH—were detected using gas chromatography for all samples. Concentrations of the ΣHCH ranged from 1.3 to 1095 ng g−1, among which β-HCH accounted for 52.5%. In addition, residues of HCH within Tianjin’s urban areas were found to be higher. No significant differences were found between the residues of HCH in soils from waste irrigation areas and those in other areas. Total organic carbon content was determined to impact the residue levels of HCH in soils, while pH value and clay content were not related to concentrations of HCH. In general, all HCH isomers in soil samples had abnormally high residue levels, possibly the result of continuous use of HCH in this area.
Low-Level Atrazine Exposure Decreases Cell Proliferation in Human Fibroblasts by Michelle K. Manske; Lisa A. Beltz; Kavita R. Dhanwada (pp. 438-444).
There is continuing concern that release of certain chemicals into the environment leads to human exposure to toxins, particularly through contaminated ground and surface waters. The triazine herbicide atrazine (2-chloro-4-ethylamine-6-isopropylamino-S-triazine) is routinely found as a contaminant in many surface and groundwaters. Little is known of the long-term effects of atrazine exposure on human cells. The objective of this research was to examine whether low-level exposure of atrazine to normal human fibroblast cells in culture had measurable deleterious effects. We show that low-level, short-term exposure of atrazine to normal fibroblasts results in decreased cell proliferation. In two separate assays to measure cell proliferation, either a 1.5-fold decrease in the cell number occurred (saturation density analysis) or a 2-fold decrease in cell proliferation was found (MTT analysis). Experiments to measure apoptosis in cells exposed to low levels of atrazine did not show DNA fragmentation or increased caspase activity. Thus, this analysis shows that short-term exposure to environmentally relevant, low levels of atrazine can be assessed by a decrease in cellular proliferation of normal human cells.
Estimation of Estrogenic and Antiestrogenic Activities of Selected Pesticides by MCF-7 Cell Proliferation Assay by T. Okubo; Y. Yokoyama; K. Kano; Y. Soya; I. Kano (pp. 445-453).
Estrogenic activities of 20 selected pesticides—which are used for agricultural production as insecticides, fungicides and herbicides—were examined by estrogen receptor (ER)-dependent MCF-7 cell proliferation assay. Among them, chlordecone, dicofol, methoxychlor, γ-HCH, fenarimol, EPN, triadimefon, and triadimenol had estrogenic activities, all of which were suppressed by the addition of pure antiestrogen ICI 182,780. The first 5 compounds exhibited binding capacities to ERα. The antiestrogenic activity of a compound was examined by estimating its suppressive effect on cell proliferation induced by 30 pM 17β-estradiol. Strongly suspected antiestrogens were captan and myclobutanil, both of which were found to have the capacity to bind to ERα and which might exert their activities by competing at the level of ERα. Antiestrogenic activities of nitrofen, fenitrothion, fenarimol and triadimefon were also suggested. Affinities of the compounds for ERα and/or androgen receptor (AR) were lower than those of synthetic estrogen (diethylstilbestrol) and testosterone (mibolerone), respectively. Fenitrothion had the highest affinity to AR. Chlordecone, dicofol, methoxychlor, nitrofen, fenarimol, myclobutanil and pyridate had capacities to bind both ERα and AR. Chlordecone and pyridate were much more effective as competitors of estrogen binding to ERα than androgen binding to AR and, conversely, nitrofen was a more effective competitor of androgen binding to AR.
Antiestrogenic Effects of Motorcycle Exhaust Particulate in MCF-7 Human Breast Cancer Cells and Immature Female Rats by Tzuu-Huei Ueng; Hui-Wu Wang; Yu-Ping Huang; Chia-Chi Hung (pp. 454-462).
The emissions from 2- and 4-stroke motorcycles pollute the air of urban areas where motorcycle is a popular means of transportation. This study aimed to determine the endocrine-disrupting activity of motorcycle exhaust particulate (MEP) using MCF-7 human breast cancer cells and immature female Wistar rats treated with organic extracts of MEP. Treatments with 1, 10, and 50 μg/ml MEP extract for 2 and 4 days produced dose-dependent inhibition of thymidine incorporation and cell growth, respectively, in untreated and 1 nM 17β-estradiol (E2)-treated cells. Treatments of MCF-7 cells with MEP extract replaced [3H]E2 from the estrogen receptor in a time- and concentration-dependent manner. These antiestrogenic and receptor binding properties of MEP extract were blocked by cotreatment of the cells with 2 μM α-naphthoflavone, a cytochrome P450 inhibitor and aryl hydrocarbon receptor antagonist. E2 metabolism and HPLC analysis showed that treatment of MCF-7 cells with 50 μg/ml MEP extract for 24 h increased E2 2- and 4-hydroxylation in microsomes. The MEP-mediated increase in E2 2-hydroxylation was inhibited by the addition of 1 μM α-naphthoflavone to MCF-7 microsomes. Cotreatment of immature female rats with 10 μg/kg E2 and 10 mg/kg MEP extract intraperitoneally for 3 days decreased the E2-induced uterine weights. MEP extract alone showed no effect on rat uterine weight. The endocrine-disrupting activity of MEP extract was further confirmed in parallel experiments using MCF-7 cells and immature female rats treated with benzo(a)pyrene, an MEP constituent compound. The present findings demonstrate that MEP extract is antiestrogenic in vitro and in vivo and cytochrome P450 induction is an underlying mechanism.
Acute Effects of Microcystis aeruginosa from the Patos Lagoon Estuary, Southern Brazil, on the Microcrustacean Kalliapseudes schubartii (Crustacea: Tanaidacea) by W. Montagnolli; A. Zamboni; R. Luvizotto-Santos; J. S. Yunes (pp. 463-469).
Toxic blooms of the cyanobacterium Microcystis aeruginosa, a microcystin producer, have been observed in the past two decades in the Patos Lagoon estuary (southern Brazil). This cyanobacterium reaches the estuary from northern waters and accumulates as toxic blooms in the shallow margins of the environment. Microcystins are phosphatase (PP1 and PP2A) inhibitors and cause animal death via alteration of the liver cell cytoskeletons and intrahepatic hemorrhage. The massive accumulation of toxic material affects the survival of several benthonic estuarine local organisms. The tanaidacea Kalliapseudes schubartii is a benthonic estuarine species which occurs at high densities throughout the year in mixohaline areas of the Patos Lagoon. This microcrustacean is of high ecological relevance and plays an important role in the estuarine food web, as it is consumed on a large scale by estuarine fish. This work verifies the acute toxicity of aqueous extracts of M. aeruginosa RST9501 and of sediments spiked with lyophilized material of the same strain on K. schubartii; it also evaluates the sublethal effects on tanaidacean oxygen consumption rates and glycogen levels under acute exposure to M. aeruginosa aqueous extracts. The strain M. aeruginosa RST9501 was cultured in BGN/2 medium. The aqueous extracts were prepared using the lyophilized material from the strain cultures. Acute tests were performed over 96 h at a salinity of 15, at six toxic concentrations, and resulted in an average 96-h LC50 of 1.44 mg ml−1. The spiked sediment tests were performed with a 10-day duration, using the lyophilized material in three proportions of powder/sediment and showed an average LC50 of 1.79 mg ml−1. Oxygen consumption was determined after 24 and 48 h of incubation in adult organisms exposed to sublethal aqueous extract concentrations and showed a significant increase at the highest concentrations. This suggests alterations in the organism’s metabolism by exposure to the cyanobacterium extract. The glycogen levels were determined with a commercial kit (Glicox 500; DOLES Ltd.); after 24 and 48 h the dosages were administered in the same organisms utilized in the oxygen consumption test and did not demonstrate significant differences. The results demonstrate the possible risks of intoxication to which the natural populations of K. schubartii were exposed in the environment and emphasize the importance of studies involving sublethal concentrations of M. aeruginosa to other organisms of the trophic web in this aquatic system.
Effect of Herbal Molluscicides and Their Combinations on the Reproduction of the Snail Lymnaea acuminata by Amrita Singh; D. K. Singh (pp. 470-477).
Effects of sublethal treatment (20 and 60% of LC50/24 h) of the plant-derived molluscicides Annona squamosa Linn. and Lawsonia inermis Linn. and their combinations with other herbal molluscicides, such as Cedrus deodara Roxb, Azadirachta indica A. Juss, bulb powder of Allium sativum Linn. and Polianthes tuberosa Linn., and oleoresin of Zingiber officinale Rosc., and acetogenins extracted from the seeds of A. squamosa Linn., on the reproduction of the snail Lymnaea acuminata have been studied. It was observed that the plant-derived molluscicides singly and in binary combinations with other herbal molluscicides and the extracted acetogenins caused a significant reduction in the fecundity, hatchability, and survival of young snails. Withdrawal of the snails to fresh water after the above treatment caused a significant recovery in the fecundity of the snail Lymnaea acuminata. Twenty-four-hour sublethal treatment with the acetogenins caused a maximum reduction in the protein, amino acid, DNA, and RNA in the ovotestis of treated Lymnaea acuminata.
Aquatic Snails from Mining Sites Have Evolved to Detect and Avoid Heavy Metals by H. Lefcort; D. P. Abbott; D. A. Cleary; E. Howell; N. C. Keller; M. M. Smith (pp. 478-484).
Toxicants in polluted environments are often patchily distributed. Hence, rather than being passive absorbers of pollution, some organisms have evolved the ability to detect and avoid toxicants. We studied the avoidance behavior of Physella columbiana, an aquatic pulmonate snail, in a pond that has been polluted with heavy metals for more than 120 years. Populations of this snail are rare at reference sites and are only robust at heavy-metal-polluted sites. We hypothesized that the snails are able to persist because they have evolved the ability to minimize their exposure to metals by actively avoiding metals in their environment. Using a Y-maze flow tank, we tested the avoidance behavior of snails to heavy-metal-polluted sediments and single-metal solutions of cadmium, zinc, or lead. We also tested the avoidance behaviors of the snails’ laboratory-reared offspring raised in nonpolluted conditions. In addition, we tested the avoidance behavior of a small population of snails from a reference pond.Although all the snails we tested were able to detect low concentrations of heavy metals, we found that snails from the polluted site were the most sensitive, that their offspring were somewhat less sensitive, and that snails from the reference site were the least sensitive. This suggests that the ability of polluted-site snails to avoid heavy metals is both genetic and environmental. The concentrations of metals avoided by the snails from the polluted site were below the levels found at hot spots within their natal pond. The snails may be able to persist at this site because they decrease their exposure by moving to less-polluted sections of the pond. One application of our findings is the use of aquatic snails and our Y-maze design as an inexpensive pollution detector. Environmental pollutants such as lead, zinc, and arsenic are a problem throughout the world. People in underdeveloped countries often lack sophisticated pollution detection devices. We have developed a behavioral assay of aquatic pollution that is easy to use, is extremely sensitive (detection below 10 ppb), and can be constructed for fewer than US $100. Pulmonate snails are widely distributed in tropical, subtropical, and temperate parts of the globe, and they are often common in polluted waters. For countries such as India and Bangladesh, which must test thousands of shallow wells for possible contamination with heavy metals, our assay would be a good initial test. Once snails detected metals, then those samples could be confirmed by spectrometers. We encourage scientists in underdeveloped nations to consider our assay as an option.
Heavy Metals in Sediments and Lobster (Panulirus gracilis) from the Discharge Area of the Submarine Sewage Outfall in Mazatlán Bay (SE Gulf of California) by F. Morales-Hernández; M. F. Soto-Jiménez; F. Páez-Osuna (pp. 485-491).
Concentrations of selected heavy metals in lobster (Panulirus gracilis) tissues and sediments (bulk and bioavailable fractions) from an area influenced by sewage discharge in Mazatlán Bay were determined. Cd, Cu, Fe, Pb, and Zn in the sediments showed enrichment factors higher than one related to the discharge and were higher than the lower values of the sediment quality guidelines proposed by NOAA and CCME. In addition to the high levels, relatively high bioavailability in the sediments was estimated for Cd, Cu, Mn, Pb, and Zn, suggesting a possible adverse effect on the associated benthic organisms. A high concentration of Cr, Fe, Mn, and Ni was found in the exoskeleton of P. gracilis. The hemolymph, hepatopancreas, gills, and gonads concentrate Cu, Cd, and Zn to levels higher than the available concentration in the sediments (BCF > 1). However, most of the metals studied in the edible muscle tissue in P. gracilis ranged within the recommended limits for human consumption, except Pb, which was found to be above the acceptable level for shellfish and represents a health risk.
Tumor Prevalence and Biomarkers of Exposure in Brown Bullhead (Ameiurus nebulosus) from Back River, Furnace Creek, and Tuckahoe River, Maryland by A. E. Pinkney; J. C. Harshbarger; E. B. May; M. J. Melancon (pp. 492-501).
Brown bullheads (Ameiurus nebulosus) were collected from 2 locations near Baltimore, Maryland, Back River and Furnace Creek, and 1 (reference) location, Tuckahoe River, to compare the prevalence of tumors (liver and skin) and visible skin lesions (fin erosion and abnormal barbels). Cytochrome P450 activity measured as ethoxyresorufin-O-deethylase, biliary PAH-like fluorescent metabolites, and fillet contaminant concentrations were determined as indicators of exposure in a randomly selected subset of the fish. There were no significant differences in liver tumor prevalence: Back River = 8% (4/50), Furnace Creek = 0% (0/50), and Tuckahoe River = 2.6% (1/39; p = 0.20, extension of Fisher’s exact test). Skin tumor prevalence was as follows: Furnace Creek = 12% (6/50), Back River = 8% (4/50), and Tuckahoe River = 0% (0/39; p = 0.063). In the Back River fish, there was a 40% (20/50) prevalence of fin erosion and a 28% (14/50) prevalence of abnormal (shortened, clubbed, or missing) barbels. Fin erosion was not observed in the other collections, and only 10% (5/50) of the Furnace Creek fish had abnormal barbels (p < 0.001 for both lesions). There were statistically significant differences in mean EROD activity, with levels in Furnace Creek and Back River fish approximately twice that found in Tuckahoe River fish. There were also significant differences in mean benzo(a)pyrene-like bile metabolite concentrations: the lowest mean was in the Tuckahoe River fish, 8 times higher in Furnace Creek fish, and 13 times higher in Back River fish. Of the 3 groups, the Back River bullheads appear to be most adversely affected by contaminant exposure because they had the highest prevalence of liver tumors, fin erosion, and abnormal barbels.
Comparison of Two Sites in Mobile Bay Using In VivoBiomarkers in Largemouth Bass, Sediment Bioassays, and Sediment Contaminant Analysis by S. Annavarapu; C. M. Foran; P. Gardinali; C. Metzger; K. L. Willett (pp. 502-510).
This research addresses whether chemical contaminants are having a biologically measurable effect on largemouth bass (Micropterus salmoides), an important fish species in the Mobile Bay National Estuary. Bass and sediment samples were collected in September 2001 from Big Bateau and D’Olive Bays; the latter has been suggested to be an environmentally impacted site. There was a significant difference in the age distribution of bass collected from the two sites. However, none of the animals showed any evidence of reproductive activity or had mature gametes. The age and gonadosomatic index were greater in animals collected from the Bateau site. Fish liver microsome ethoxyresorufin-O-deethylase (EROD) activities (elevated in the presence of CYP1A-inducing contaminants) were not significantly different between sites but were significantly higher in older bass. Plasma steroid concentrations in younger animals (less than 1 year old) tended to be higher and more variable than the concentrations found in older animals. Once the significant effects of age on plasma steroid concentrations were removed, an analysis of the residual change in steroids revealed no differences in testosterone or estradiol between animals collected at the two sites. Sediments were collected for chemical extraction and analysis in two bioassays: the H4IIE rat hepatoma EROD assay and the yeast estrogen screen (YES assay). The H4IIE bioassay indicated the presence of sediment BaP induction equivalents between 72 and 320 ng/g, whereas the YES assay indicated that potent estrogenic substances were not present in the sediment samples. The H4IIE bioassay results were higher for D’Olive samples, which was consistent with higher PAH concentrations in those sediments. Taken together the biomarkers and chemical analysis suggested generally low organic contamination at these two sites.
Reproductive Assessment of Japanese Medaka (Oryzias latipes) Following a Four-Week Fluoxetine (SSRI) Exposure by Christy M. Foran; James Weston; Marc Slattery; Bryan W. Brooks; Duane B. Huggett (pp. 511-517).
The occurrence of environmental pharmaceutical products has recently received considerable attention, but impacts on the aquatic environment are largely unknown. Fluoxetine is a widely prescribed antidepressant and acts physiologically as a selective serotonin reuptake inhibitor (SSRI). To determine its potential to disrupt teleost reproductive function, Japanese medaka (Oryzias latipes) were exposed to fluoxetine at aqueous nominal concentrations of 0, 0.1, 0.5, 1 and 5 μg/L for 4 weeks. The last 14 days of this exposure included a reproductive assessment in which no significant changes were observed in egg production, rate of fertilization and spawning, or hatching success of fertilized eggs. A low incidence (1.97–2.53%; 4.02–5.16-fold greater than controls) of developmental abnormalities was observed in offspring from all fluoxetine treatments. Adult gonadal somatic index, hepatic vitellogenin, and ex vivo gonadal steroidogenesis were also unaffected. Circulating plasma estradiol levels in females were significantly increased by 0.1 and 0.5 μg/L treatments. Our study provides novel information on fish biochemical, physiological, and reproduction responses to environmentally realistic fluoxetine concentrations.
Effects of Multiple Routes of Cadmium Exposure on the Hibernation Success of the American Toad (Bufo americanus) by S. M. James; E. E. Little; R. D. Semlitsch (pp. 518-527).
The effects of multiple routes of cadmium exposure on juvenile American toads (Bufo americanus) were evaluated using environmentally relevant concentrations. During or after exposure, toads were individually hibernated for 172 days at approximately 4°C. The following experiments were conducted: (1) dermal exposure (hibernation in soil contaminated with up to 120 μg Cd/g (dry weight)); (2) injection exposure (single injection with cadmium to achieve a maximum whole-body nominal concentration of 3 μg Cd/g (wet weight) 12 days before hibernation in uncontaminated soil); and, (3) oral exposure (feeding with mealworms containing ≤16 μg Cd/g (dry weight) for 50 days before hibernation in uncontaminated soil). We hypothesized that sublethal levels of cadmium would become lethal during hibernation because of combined chemical and cold stress. No prehibernation mortality occurred in the injection and oral exposure studies. There was a significant treatment effect on whole-body cadmium concentration in toads orally or dermally exposed and on percent of cadmium retention in toads orally exposed. There was also a trend of increased time-to-burrowing and more toads partially buried with greater cadmium concentration in the dermal study, which indicated avoidance. In all 3 experiments, no significant differences were found among cadmium treatments in hibernation survival, percent of mass loss, or locomotor performance. However, toads fed mealworms averaging 4.7 μg Cd/g (dry weight) had only 56% survival compared with 100% survival for controls. Although our results suggest that environmentally relevant levels of cadmium do not pose a great risk to American toads, factors such as soil type or prey species may increase cadmium bioavailability, and other amphibian species may be more sensitive to cadmium than B. americanus.
Effects of Vinclozolin on Spermatogenesis and Reproductive Success in the Japanese Quail (Coturnix coturnix japonica) by L. Niemann; B. Selzsam; W. Haider; C. Gericke; I. Chahoud (pp. 528-533).
In a one-generation reproduction study, the major agricultural fungicide vinclozolin was administered to adult Japanese quail for a period of 6 weeks at dietary levels of 125 and 500 ppm. Fertility and reproductive performance were not affected up to the highest concentration, although the examination of additional endpoints in the drakes (spermatid count, histology of the testis) provided some evidence of an inhibition of spermatogenesis at both dietary concentrations. Likewise, there were no indications of systemic toxicity in the adult birds. Plasma hormone concentrations (estradiol, testosterone, progesterone, T3, and T4) showed a large interindividual variance but treatment-related differences between the groups could not be established. There were no clear-cut indications of antiandrogenic effects in quail, although a limited transfer of the test substance into the eggs was proven.
Phosphorus Amendment Reduces Bioavailability of Lead to Mallards Ingesting Contaminated Sediments by Gary H. Heinz; David J. Hoffman; Daniel J. Audet (pp. 534-541).
Lead poisoning of waterfowl has been reported for decades in the Coeur d’Alene River Basin in Idaho as a result of the ingestion of lead-contaminated sediments. We conducted a study to determine whether the addition of phosphoric acid to sediments would reduce the bioavailability of lead to mallards (Anas platyrhynchos). When sediments were amended with 1% phosphorus under laboratory conditions, and diets containing 12% amended sediment were fed to mallards, reductions in tissue lead were 43% in blood, 41% in liver, and 59% in kidney with sediment containing about 4,520 μg/g lead on a dry-weight basis and 41, 30, and 57% with sediment containing about 6,990 μg/g lead. When sediments were treated with phosphorus and left to age for about 5 months in the field, reductions in lead were 56% in blood, 54% in liver, and 66% in kidney at one site with about 5,390 μg/g lead and 64, 57, and 77% at a second site with about 6,990 μg/g lead. In the field, the inability to mix the phosphoric acid uniformly and deeply enough into the sediment may have resulted in more than 1% phosphorus being added to the sediment. Although both lab and field amendments of phosphorus substantially reduced the bioavailability of lead, lead concentrations in the tissues of mallards fed the amended sediments were still above those believed to be harmful to waterfowl. Based on earlier studies of sediment toxicity to waterfowl in the Coeur d’Alene River Basin, combined with the results of our amendment study, the addition of phosphoric acid as we used it might only significantly benefit waterfowl where sediments or soils contain less than 1,000–2,000 μg/g lead.
Avian Mortality Events in the United States Caused by Anticholinesterase Pesticides: A Retrospective Summary of National Wildlife Health Center Records from 1980 to 2000 by M. A. Fleischli; J. C. Franson; N. J. Thomas; D. L. Finley; W. Riley Jr. (pp. 542-550).
We reviewed the U.S. Geological Survey National Wildlife Health Center (NWHC) mortality database from 1980 to 2000 to identify cases of poisoning caused by organophosphorus and carbamate pesticides. From the 35,022 cases from which one or more avian carcasses were submitted to the NWHC for necropsy, we identified 335 mortality events attributed to anticholinesterase poisoning, 119 of which have been included in earlier reports. Poisoning events were classified as confirmed (n = 205) when supported by findings of ≥50% inhibition of cholinesterase (ChE) activity in brain tissue and the detection of a specific pesticide in the gastrointestinal contents of one or more carcasses. Suspected poisonings (n = 130) were defined as cases where brain ChE activity was ≥50% inhibited or a specific pesticide was identified in gastrointestinal contents. The 335 avian mortality events occurred in 42 states. Washington, Virginia, and Ohio had the highest frequency of events, with 24 (7.2%), 21 (6.3%), and 20 (6.0%) events, respectively. A total of 8877 carcasses of 103 avian species in 12 orders was recovered. Because carcass counts underestimate total mortality, this represents the minimum actual mortality. Of 24 different pesticides identified, the most frequent were famphur (n = 59; 18%), carbofuran (n = 52; 15%), diazinon (n = 40; 12%), and fenthion (n = 17; 5.1%). Falconiformes were reported killed most frequently (49% of all die-offs) but Anseriformes were found dead in the greatest numbers (64% of 8877 found dead). The majority of birds reported killed by famphur were Passeriformes and Falconiformes, with the latter found dead in 90% of famphur-related poisoning events. Carbofuran and famphur were involved in mortality of the greatest variety of species (45 and 33, respectively). Most of the mortality events caused by diazinon involved waterfowl.
Measurement of Toxaphene Congeners in Pooled Human Serum Collected in Three U.S. Cities Using High-Resolution Mass Spectrometry by John R. Barr; Adrian R. Woolfitt; Vincent L. Maggio; Donald G. Patterson Jr. (pp. 551-556).
Because human toxaphene exposure data are largely lacking, we surveyed human serum pools collected from U.S. residents to determine the feasibility of measuring toxaphene in human samples and to determine whether additional analytical requirements were needed for routine measurement of toxaphene. We report a method for quantification of toxaphene congeners in human serum using a mixed-bed gradient solid-phase extraction and analysis using gas chromatography–high-resolution mass spectrometry with electron-impact ionization. In this method, we monitored low-mass fragment ions that were common to all 22 congeners. To verify the specific congeners detected, we further analyzed the extract using negative methane chemical ionization. We used this method to measure two specific congeners, Parlar 26 and 50, at concentrations ranging from about 3 to 30 pg/ml (0.7−7 ng/g lipid) in pooled human serum collected in Atlanta, Chicago, and Cincinnati. We identified several analytical parameters that must be strengthened to routinely measure toxaphene congeners in human samples.