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Archives of Environmental Contamination and Toxicology (v.50, #4)

Composition, Distribution, and Characterization of Suspected Endocrine-Disrupting Pesticides in Beijing GuanTing Reservoir (GTR) by Nandong Xue; Xiaobai Xu (pp. 463-473).

GuanTing Reservoir (GTR) is one of two main water resources for the agriculture, industry, and living uses of Beijing (China). As a result of extensive pollution over the last few decades (particularly the 1980s), the reservoir has not supplied potable water to Beijing city since 1997. Composition, distribution, and characterization of 31 suspected endocrine-disrupting pesticides in surface water, pore water, and surface sediments from the reservoir are reported in this study. An analytical procedure based on solid-phase extraction (SPE) technology and capillary gas chromatography with electron-capture detection has been developed for the simultaneous determination of the 31 suspected endocrine-disrupting pesticides including the compounds hexachlorocyclohexane, cyclodiene, diphenyl aliphatic, chlordane, and other selected pesticides (hexachlorobenzene, heptachlor, endrin aldehyde, hepachlor epoxide, dicofol, acetochlor, alachlor, metolachlor, chlorpyriphos, nitrofen, trifluralin, cypermethrin, fenvalerate, and deltamethrin). The result shows that the pesticide pollution is moderate in GTR and its tributaries, although pesticide residue values in a few sites are quite high when considering their endocrine-disrupting effects and chronic health effects. Among the analyzed pesticides, p,p′-DDE, o,p′-DDT, β-HCH, endosulfan sulfate, and aldrin were the most abundant pesticides in water while o,p′-DOT, δ-HCH, β-HCH, p,p′-DDE, p,p′-DDT, and endosulfan sulfate were the most abundant in sediment. The variation in concentration of pesticides among sites can be expected to be caused by several factors such as contaminants in the rivers and drainage of contaminated water from the surrounding agricultural fields. To reduce exposure to these endocrine-disrupting compounds, the abundant current use of pesticides in the area should be minimized. Regular monitoring is needed to manage the environmental hazards due to these pesticides.

Contamination by Persistent Organic Pollutants in Dumping Sites of Asian Developing Countries: Implication of Emerging Pollution Sources by N. H. Minh; T. B. Minh; N. Kajiwara; T. Kunisue; A. Subramanian; H. Iwata; T. S. Tana; R. Baburajendran; S. Karuppiah; P. H. Viet; B. C. Tuyen; S. Tanabe (pp. 474-481).

In Asian developing countries, large amounts of municipal wastes are dumped daily in open dumping sites without proper management. This practice may cause several adverse environmental consequences and increased health risk to local communities. To elucidate contamination by persistent organic pollutants (POPs)—including dichloro-diphenyl-trichloroethane and its metabolites (DDTs), hexachlorocyclohexanes (HCHs), chlordanes, hexachlorobenzene (HCB), and polychlorinated biphenyls (PCBs)—in such dumping sites, soil samples were collected from open dumping sites and respective control sites in Cambodia, India, and Vietnam from 1999 through 2001. Our results demonstrated that DDTs, PCBs, and HCHs were dominant contaminants in the dumping sites. However, the contamination pattern was not consistent, showing higher HCHs in India than in Cambodia and Vietnam. Interestingly, in all of the countries, extremely higher levels of POPs were observed in the dumping sites compared with those in the respective control sites, suggesting significant amplification of POP contamination in the dumping sites of Asian developing countries. Mean concentrations of DDTs and PCBs were 350 and 140 ng/g dry weight, respectively, in the dumping sites of Cambodia and 26 and 210 ng/g, respectively, in India. These residue levels were hundreds to thousands times higher than those in general soils, implying possible risk to human health of the local communities, especially to the rag pickers, including children who work in these sites to collect recyclable materials. Composition of DDT compounds suggested their recent use in populated areas, which in turn might have caused increased levels of DDTs in the open dumping sites. In addition, composition of HCH isomers revealed their different use pattern in different countries.

Lipid Peroxidation in Cadmium-Treated Phaseolus coccineus Plants by E. Skórzyńska-Polit; Z. Krupa (pp. 482-487).

Lipid peroxidation was examined in Phaseolus coccineus plants treated with 25 μM Cadmium (Cd) for 12 days at two different growth stages of the primary leaves. In the leaves of Cd-treated young plants, the content of free fatty acids was higher only after 8 days of plant exposure to the metal, lipoxygenase activity at pH 7.0 was enhanced after 6 and 8 days of Cd action, but at pH 8.0 it was higher than control, especially after 8 days. Non-enzymatic lipid peroxidation was higher after 6 days of young plant exposure to the metal, but after 8 days it slightly decreased. Glutathione-S-transferase activity decreased during 12 days of the metal action but it was always higher than in control. Anthocyanin content in these plants was also elevated in comparison with control. In Cd-treated older plants, the level of free fatty acids was always higher as compared to control. Lipoxygenase activity at pH 7.0 was lower after 4 days of plant exposure to the metal, but then it was close to control. The enzyme activity at pH 8.0 and the level of lipid peroxidation were lower during 12 days of Cd action in comparison with control. Glutathione-S-transferase activity and anthocyanin pigment content were higher in older Cd-treated plants than in control. Relationships between the pool of free fatty acids, a low level of lipid peroxidation, and glutathione-S-transferase activity in the primary leaves of Cd-treated Phaseolus coccineus plants are discussed. In these plants, lipid peroxidation is under the strict control of metabolism and the antioxidative system works efficiently.

Phenolic Acids as Bioindicators of Fly Ash Deposit Revegetation by L. Djurdjević; M. Mitrović; P. Pavlović; G. Gajić; O. Kostić (pp. 488-495).

The floristic composition, the abundance, and the cover of pioneer plant species of spontaneously formed plant communities and the content of total phenolics and phenolic acids, as humus constituents, of an ash deposit after 7 years of recultivation were studied. The restoration of both the soil and the vegetation on the ash deposits of the “Nikola Tesla-A” thermoelectric power plant in Obrenovac (Serbia) is an extremely slow process. Unfavorable physical and chemical characteristics, the toxicity of fly ash, and extreme microclimatic conditions prevented the development of compact plant cover. The abundance and cover of plants increased from the central part of the deposit towards its edges (ranging from 1–80%). Festuca rubra L., Crepis setosa Hall., Erigeron canadensis L., Cirsium arvense (L.) Scop., Calamagrostis epigeios (L.) Roth., and Tamarix gallica L. were the most abundant species, thus giving the highest cover. Humus generated during the decomposition process of plant remains represents a completely new product absent in the ash as the starting material. The amount of total phenolics and phenolic acids (38.07–185.16 μg/g of total phenolics and 4.12–27.28 μg/g of phenolic acids) in fly ash increased from the center of the deposit towards its edges in correlation with the increase in plant abundance and cover. Ash samples contained high amounts of ferulic, vanillic, and p-coumaric acid, while the content of both p-hydroxybenzoic and syringic acid was relatively low. The presence of phenolic acids indicates the ongoing process of humus formation in the ash, in which the most abundant pioneer plants of spontaneously formed plant communities play the main role. Phenolic compounds can serve as reliable bioindicators in an assessment of the success of the recultivation process of thermoelectric power plants’ ash deposits.

Evaluation of Aquatic Toxicities of Chromium and Chromium-Containing Effluents in Reference to Chromium Electroplating Industries by A. Baral; R. Engelken; W. Stephens; J. Farris; R. Hannigan (pp. 496-502).

This study evaluated aquatic toxicities of chromium and chromium-containing laboratory samples representative of effluents from chromium electroplating industries, and compared the aquatic environmental risks of hexavalent and trivalent chromium electroplating operations. Trivalent chromium electroplating has emerged as an acceptable alternative to hazardous hexavalent chromium electroplating. This process substitution has reduced the human health impact in the workplace and minimized the production of hazardous sludge regulated under the Resource Conservation and Recovery Act (RCRA). The thrust behind this research was to investigate whether trivalent chromium electroplating operations have lower adverse impacts on standardized toxicity test organisms. Ceriodaphnia dubia and Pimephales promelas were used to investigate toxicities of trivalent chromium (Cr (III)), hexavalent chromium (Cr (VI)), and industrial effluents. In agreement with previous studies, Cr (III) was found to be less toxic than Cr (VI). Despite having several organic and inorganic constituents in the effluents obtained from trivalent chromium plating baths, they exhibited less adverse effects to C. dubia than effluents obtained from hexavalent chromium electroplating baths. Thus, transition from hexavalent to trivalent chromium electroplating processes may be justified. However, because of the presence of organic constituents such as formate, oxalate, and triethylene glycol in effluents, trivalent chromium electroplating operations may face additional regulatory requirements for removal of total organic carbon.

Physiological and Reproductive Effects of Beta Adrenergic Receptor Antagonists in Daphnia magna by Edward M. Dzialowski; Philip K. Turner; Bryan W. Brooks (pp. 503-510).

Although pharmaceuticals are increasingly found in surface waters, environmental levels of many of these compounds are not acutely toxic to model test organisms. Prior to conducting appropriate ecological risk assessments of pharmaceuticals, the mode of action-based biomarkers needs to be developed for non-target species. To evaluate toxicity of the β-adrenergic blockers propranolol and metoprolol on non-target biota, we assessed standard ecotoxicological endpoints after 9 days of subchronic exposure in a transgenerational study with Daphnia magna. On day 9 of exposure, the lowest observed effects concentration (LOEC) for growth were 0.44 mg L⁻¹ for propranolol and 12 mg L⁻¹ for metoprolol. Total fecundity LOECs for the 9-day exposure were 0.11 mg L⁻¹ and 6 mg L⁻¹ for propranolol and metoprolol, respectively. In addition to typical ecotoxicological endpoints, we evaluated the utility of employing the physiological biomarkers of heart rate and metabolic rate following subchronic and acute exposures to propranolol and metoprolol. Propranolol and metoprolol LOECs for heart rate were 0.055 mg L⁻¹ and 3.1 mg L⁻¹, significantly lower than the LOECs for growth and reproduction. At these concentrations, heart rate was significantly lower than the control values for both compounds. Daphnia magna endpoint sensitivity to chronic propranolol and metoprolol exposure was mortality < growth < fecundity < heart rate. Second generation D. magna were less sensitive to both compounds. Responses of the physiological biomarkers heart rate and metabolic activity suggest that propranolol and metoprolol exerts sublethal toxicity to D. magna at lower concentrations than observed in the classical endpoints.

Selenium and Other Trace Elements in Aquatic Insects in Coal Mine–Affected Streams in the Rocky Mountains of Alberta, Canada by Mark Wayland; Robert Crosley (pp. 511-522).

We determined levels of Se, As, Cd, Pb, and Zn in aquatic insects at coal mine–impacted and reference sites in streams in the Rocky Mountain foothills of west central Alberta from 2001–2003. Selenium levels were greater at coal mine–impacted sites than at reference sites in caddisflies but not in mayflies or stoneflies. Arsenic levels were greater at coal mine–impacted sites than at reference sites in caddisflies and stoneflies but not in mayflies. Zn levels were higher at coal mine–impacted sites than at reference sites in all three groups of insects. At coal mine–impacted sites, Se levels in mayflies and caddisflies were greater than those in stoneflies while at reference sites mayflies contained greater concentrations of Se than either caddisflies or stoneflies. Arsenic levels in mayflies were greater than those in caddisflies at reference and coal mine–impacted sites and were greater than those in stoneflies at reference sites. At both types of sites Cd differed amongst insect taxa in the order of mayflies > caddisflies > stoneflies. The same was true of Zn at coal mine–affected sites. At reference sites, stoneflies had greater concentrations of Zn than both mayflies and caddisflies. At both types of sites, Pb levels were greater in mayflies and caddisflies than they were in stoneflies. Of the five trace elements considered in this study, only Se was sufficiently elevated in aquatic invertebrates to be of potential concern for consumers such as fish and aquatic birds. Such was the case at both coal mine–impacted and reference sites.

Individual and Joint Actions of Selenate and Methylmercury on the Development and Survival of Insect Detritivore Megaselia scalaris (Diptera: Phoridae) by P. D. Jensen; L. R. Johnson; J. T. Trumble (pp. 523-530).

Despite the important roles played by insects in most ecosystems, surprisingly little is known about how anthropogenic pollutants or their mixtures interact to affect insect populations. The independent and joint actions of selenate and methylmercury on a ubiquitous insect detritivore, Megaselia scalaris (Loew), were determined in this study. Ovipositing females did not distinguish between untreated food sources and those contaminated with toxic concentrations of selenate, methylmercury, or both chemicals in combination. Even at the highest concentrations of pollutants, no negative effects were observed for the egg stage. However, larval survival was significantly decreased and development significantly prolonged by selenate and methylmercury individually at low or intermediate ecologically relevant treatment levels. Potentiation was strongly evident because mixtures containing concentrations as little as only 1% of the respective individual median lethal tolerances (LC₅₀s) caused significantly more mortality and delayed larval development than would be expected from the responses selenate and methylmercury elicit individually. However, survival and pupal development was not affected at any rate tested. Female fecundity was significantly decreased by methylmercury but not by selenate or mixture treatments. The relative toxicity to M. scalaris of each of the individual and joint treatments was selenate (LC₅₀ = 260 μg/g) < methylmercury (LC₅₀ = 22 μg/g) < the mixture at approximately 5% of the LC₅₀ concentration of each of the components (12 μg/g selenate plus 1.0 μg/g methylmercury). The increased mortality and delayed larval development within sites contaminated by selenate, methylmercury, or combination of the two have substantial implications for the ecology, population dynamics, and sustainability of M. scalaris populations. If these results can be extrapolated to other arthropod detritivores, ecosystem food-web function may be substantially affected.

Physiological Responses of Hybrid Striped Bass to Aqueous Copperin Freshwater and Saltwater by G. K. Bielmyer; J Tomasso; S J Klaine (pp. 531-538).

Copper (Cu) is an abundant trace metal, and although essential at low levels, it is also potentially toxic to aquatic organisms. Mechanisms of toxicity and consequences of exposure vary depending on ionoregulatory status (acclimated to freshwater or salt water). The goal of this research was to examine the responses of hybrid striped bass (Morone chrysops × Morone saxatilis) exposed to Cu in freshwater and 15 g/L salt water. In freshwater, a general dose- and time-dependent pattern of increasing Cu accumulation in gill tissue was evident in fish exposed to aqueous Cu (220 and 447 mg/L) for up to 96 hours. The 96-hour acute median lethal concentration for freshwater-acclimated hybrid striped bass exposed to Cu was 94 mg/L (confidence interval = 62 to 144 mg/L). Plasma osmolality and Na⁺ concentrations decreased in Cu-exposed fish. Freshwater-acclimated hybrid striped bass exposed to aqueous Cu (60 mg/L) for 3 weeks decreased in mass and accumulated Cu in gill, intestine, and liver. In salt water, no mortality occurred, and there were no statistical differences in growth, tissue Cu, or plasma ion concentrations in hybrid striped bass exposed to Cu compared with control fish. Freshwater-acclimated hybrid striped bass were very sensitive to Cu exposure and exhibited responses typical of commonly tested teleost fishes; however, the same sensitivity was not observed in salt water–acclimated fish.

Mercury in Fish Scales as an Assessment Method for Predicting Muscle Tissue Mercury Concentrations in Largemouth Bass by J. L. Lake; S. A. Ryba; J. R. Serbst; A. D. Libby (pp. 539-544).

The relationship between total mercury (Hg) concentration in fish scales and in tissues of largemouth bass (Micropterus salmoides) from 20 freshwater sites was developed and evaluated to determine whether scale analysis would allow a nonlethal and convenient method for predicting Hg concentrations in tissues. The relationship between total Hg concentration in untreated scale samples and muscle tissue is highly variable. Several different scale treatments were tried in an effort to increase the coefficient of determination and thereby enhance the effectiveness of this predictive technique. Washing scales with acetone, deionized (DI) water, detergent solution, and soap were used in conjunction with ultrasonication. The use of a mild soap solution with heating and ultrasonication increased the r² the most (from 0.69 [untreated scales] to 0.89). However, despite treatment, wide predictions of tissue Hg concentration remained. These results suggest that application of this technique as an independent method for issuance of fish advisories is inappropriate. Nevertheless, our results showed that scale analysis has potential for assessing general trends in concentration relative to a tissue criterion and for assessing Hg contamination in fish tissue as a first-level screen.

Heavy Metal Profile in Five Fish Species Included in Human Diet, Domiciled in the End Flow of River Neretva (Croatia) by E. Has-Schön; I. Bogut; I. Strelec (pp. 545-551).

Concentration of three heavy metals (mercury (Hg), lead, (Pb), and cadmium, (Cd)) and one metalloid (arsenic [As]), were determined by atomic absorption spectrophotometry in five tissues (muscles, liver, kidneys, gills, and gonads) of five fish species (carp—Cyprinus carpio, tench—Tinca tinca, sval—Leuciscus svallizi, gray mullet—Mugil cephalus, and eel—Anguilla anguilla) taken out from the end fIow (last 20 km) of the river Neretva, south Croatia, in the wider region of town Metković, during the summer of the year 2003. Only Cd concentration in all fish types was higher than the maximal allowed concentration (MAC) in Croatia, but its concentration in muscles reaches this value only in four samples. However, in carp, tench, and mullet, Cd concentrations higher than MAC in some other countries were found. Hg concentration is much lower than MAC in the most countries. Pb is found in higher quantities only in carp, some values reaching MAC in Germany, and many values being higher than MAC in Denmark (with exception of gonads). As concentrations are much lower than MAC in all countries, but it seems that mullet tends to accumulate this metalloid, especially in the muscles. Therefore, in several samples, muscle As concentration in mullet reached half of the MAC value in the most countries. Of the analyzed fish types, eel, containing the smallest quantities of heavy metals, is recommended for human diet, while carp, consumed most frequently by local inhabitants and numerous tourists, shares with mullet the last place on the recommendation list. Also, it is suggested that meals prepared with analyzed fish sorts should not contain some inner organs (kidneys and liver), as well as gills (alternatively, the whole head). Our final conclusion is that fish types eating predominantly meat contain less heavy metal in their tissues, and therefore are more suitable for human diet.

Alteration of Steroid Hormone Balance in Juvenile Turbot (Psetta maxima) Exposed to Nonylphenol, Bisphenol A, Tetrabromodiphenyl Ether 47, Diallylphthalate, Oil, and Oil Spiked with Alkylphenols by Pierre Labadie; Hélène Budzinski (pp. 552-561).

In recent years, concern has been raised about the ability of some classes of environmental contaminants to disrupt the endocrine system of both humans and wildlife. In this study, juvenile turbots (Psetta maxima) were exposed under laboratory conditions to selected waterborne contaminants: oil, oil spiked with alkylphenols, bisphenol A, diallylphthalate, tetrabrominated diphenyl ether 47, and p-nonylphenol as a positive control for “estrogenic-type” effects. This work focused on sex steroids, because these hormones play a key role in the reproduction process. Analytical procedures, involving the off-line coupling of solid phase extraction and gas chromatography/mass spectrometry, were developed for the determination of 12 endogenous sex steroids levels in fish plasma, bile, and gonads. Because of the sexual immaturity of the fish used in this study, however, only six steroids could be detected in juvenile turbots. Bisphenol A and p-nonylphenol exhibited the highest potency towards steroids dynamics, lowering the ratio of androgens to estrogens in all three studied matrices. However, these two chemicals had different modes of action, because p-nonylphenol induced a decrease of androstenedione and 11-ketotestosterone levels, whereas bisphenol A exposure led to an elevation of estrone level. Overall, these two chemicals seemingly disrupted the activity of some steroidogenesis enzymes, leading to serious hormonal imbalance in juvenile turbot.

Anal Fin Morphology and Gonadal Histopathology in Mosquitofish (Gambusia holbrooki) Exposed to Treated Municipal Sewage Effluent by F. D. L. Leusch; H. F. Chapman; G. W. Kay; S. R. Gooneratne; L. A. Tremblay (pp. 562-574).

Feral mosquitofish living in undiluted treated municipal sewage in Queensland, Australia, were examined for morphologic abnormalities indicative of reproductive dysfunction. Male and female mosquitofish were captured at two sites receiving undiluted treated sewage and compared with those captured at a reference site. Several morphologic end points were examined, including length of the fourth and sixth anal fin rays and gonadal histology. Both male and female mosquitofish at one site exhibited minor elongation of the fourth anal fin ray consistent with exposure to androgenic stimulation, although the spatial extent of the effect was limited and not significant at other sites further downstream. No incidences of intersex were found. These findings suggest that the level of treatment of domestic sewage at the two sewage treatment plants assessed is adequate to prevent reproductive abnormalities in exposed mosquitofish populations.

The Potential for Chromium to Affect the Fertilization Process of Chinook Salmon (Oncorhynchus tshawytscha) in the Hanford Reach of the Columbia River, Washington, USA by A. M. Farag; D. D. Harper; L. Cleveland; W. G. Brumbaugh; E. E. Little (pp. 575-579).

The Hanford Nuclear Reservation in south central Washington was claimed by the federal government as a site for the production of plutonium. During the course of production and operation of the facilities at Hanford, radionuclides and chromium were discharged directly into the river and also contaminated the groundwater. This study was designed to assess the effects of chromium (Cr) on Chinook salmon (Oncorhynchus tshawytscha) fertilization under exposure conditions similar to those of the Hanford Reach of the Columbia River. Chinook salmon gametes were exposed to aqueous Cr concentrations ranging from 0 to 266 μg Cr l⁻¹. The current ambient water-quality criteria (AWQC) established for the protection of aquatic life (United States Environmental Protection Agency [USEPA] 1986) is 11 μg Cr l⁻¹. Cr has been measured in pore water from bottom sediments of the Columbia River at concentrations >600 μg Cr l⁻¹. Under exposure conditions designed to closely mimic events that occur in the river, the fertilization of Chinook salmon eggs was not affected by concentrations of Cr ranging from 11 to 266 μg Cr l⁻¹. Data suggest that the instantaneous nature of fertilization likely limits the potential effects of Cr on fertilization success. As a result, the current AWQC of 11 μg Cr l⁻¹ is most likely protective of Chinook salmon fertilization.

Heavy Metal Distribution in Tissues and Eggs of Chinese Alligator (Alligator sinensis) by Qianghua Xu; Shengguo Fang; Zhenwei Wang; Zhiping Wang (pp. 580-586).

Chinese alligator (Alligator sinensis) is a critically endangered species endemic to China. Concentrations of heavy metals (As, Fe, Mn, Cu, Pb, Cd, Cr, Zn, and Hg) were examined in the tissues of Chinese alligators to elucidate the background distribution of these metals in the alligator body. Generally, within the body compartments, metal concentrations were high in liver, kidney, and heart, and low in pancreas and gonad. Study of heavy metal levels in the feces and eggs of Chinese alligator suggested that Chinese alligators could reduce body burden of toxic substances by excreting them to feces and/or sequestrating them into eggs to a lesser extent. In addition, to test whether eggshell or egg membrane could be used as surrogates to measure heavy metal load in egg contents, the correlation of metal concentrations between three egg compartments was determined. Of the nine elements analyzed, concentrations of iron, copper, and zinc in the shell membrane were highly correlated with the levels in egg contents, whereas no metal was significantly correlated between eggshell and egg contents. This suggested that the shell membrane could be a useful bioindicator for Fe, Cu, and Zn contaminations in the eggs of Chinese alligator. In a comparison of metal contents in the eggs of individuals from the Anhui captive population, the wild population in Anhui Province, and those of the Changxing captive population, higher Cu, Zn, and Cd levels and a lower Pb level were found in the Changxing individuals, indicative of specific pollutants in different areas. In addition, the majority of metal elements in the muscles of Chinese alligators and American alligators are in the same ranges. As a result of the data found in the eggs of the two alligator species, the Chinese alligators may be exposed to a higher level of metal pollutants. The study provided measurement of the heavy metal distribution in the endangered Chinese alligator for the first time and could serve as the background for the monitoring of possible heavy metal contaminations in the alligator habitats.

Interactive Alterations of Arsenic and Malathion in the Disposition Kinetics of Pefloxacin by N. Suresh Babu; J. K. Malik; G. S. Rao; Manoj Aggarwal; V. Ranganathan (pp. 587-593).

Assessment of deleterious effects produced by concurrent exposure to commonly encountered chemicals is of great concern to find out toxicological consequences arising as a result of their interactions and for a more comprehensive management of chemical-induced untoward effects. The naturally occurring heavy metal arsenic is present in food and water. Malathion is one of the most widely used pesticides in agriculture and public health practices worldwide. Humans, animals, and birds are exposed to these chemicals through environmental processes. Since arsenic and malathion are shown to exert an inhibitory effect on cytochrome P450 activities, their continuous exposure may alter the disposition kinetics of drugs that are predominantly metabolized hepatically. The current study was undertaken to evaluate the impact of subchronic exposure of arsenic, malathion, and their combination on the disposition kinetics of widely used fluoroquinolone antimicrobial pefloxacin in chickens. Broiler chickens were exposed to either arsenic (50 ppm), malathion (500 ppm), or arsenic (50 ppm) plus malathion (500 ppm). Arsenic and malathion were given in drinking water and feed, respectively. Following 28 days of exposure, all birds received a single oral dose of pefloxacin (10 mg/kg) and the plasma concentrations and the disposition kinetic parameters of the drug were determined. In the birds not exposed to arsenic and/or malathion, the elimination half-life (t_1/2β), area under the plasma concentration-time curve (AUC), maximum plasma drug concentration (C_max), mean residence time (MRT), and bioavailability of pefloxacin were 8.46 ± 0.24 h, 39.06 ± 1.13 μg.h.ml^-1, 2.69 ± 0.19 μg.ml⁻¹, 12.29 ± 0.48 h, and 60.52 ± 1.74%, respectively. Exposure to arsenic was associated with a significant increase in C_max (4.28 ± 0.45 μg.ml⁻¹) and a nonsignificant increase in the values of AUC (48.96 ± 2.55 μg.h.ml^-1) and bioavailability (74.55 ± 3.8 %) of pefloxacin. The values of AUC (51.62 ± 4.76 μg.h.ml^-1), t_1/2β (12.57 ± 1.26 h), MRT (19.94 ± 1.99 h), and bioavailability (78.59 ± 7.25 %) of pefloxacin were significantly increased in malathion-exposed birds. Concomitant exposure to arsenic and malathion did not affect the disposition kinetic variables of pefloxacin. The study shows that subchronic malathion exposure significantly alters the elimination kinetics of pefloxacin. Following concurrent exposure, arsenic nullifies the malathion-induced changes in disposition kinetics of pefloxacin by possibly diminishing the cytochrome P450-catalyzed bioactivation of malathion.

Mycotoxins in Poultry Feed in Kuwait by M. U. Beg; M. Al-Mutairi; K. R. Beg; H. M. Al-Mazeedi; L. N. Ali; T. Saeed (pp. 594-602).

A survey was conducted at a poultry feed production unit in Kuwait for mycotoxin contamination in the samples of yellow maize, soybean meal, wheat bran used as raw material and the poultry feed prepared for broiler starter, broiler finisher, and layer mash. Individual aflatoxins were determined by high-pressure liquid chromatography after immunoaffinity column purification. Repeated analysis revealed average aflatoxin concentration in maize at 0.27 ppb (range 0 to 1.69 ppb), soybean meal at 0.20 ppb (range 0 to 1.27 ppb), wheat bran at 0.15 ppb (range 0 to 1.07 ppb), prepared poultry feed for broiler starter at 0.48 ppb (range 0 to 3.26 ppb), broiler finisher at 0.39 ppb (range 0 to 1.05 ppb), and layer mash at 0.21 ppb (range 0 to 1.30 ppb). Other mycotoxins (ochratoxin, fumonisin, deoxynivalenol (DON), and zearalenone), were detected by quantitative enzyme-linked immunosorbent assay. The average levels of ochratoxin A ranged from 4.6 to 9.6 ppb, fumonisin from 1.4 to 3.2 ppm, DON from 0.17 to 0.29 ppm, and zearalenone from 46.4 to 67.6 ppb in various commodities and prepared feed samples. The study revealed the coexistence of determined mycotoxins, although their concentrations in general were found to be lower than the permissible levels, wherever defined, for the poultry feed.

Persistent Organochlorine Contaminants in Liver and Fat of Birds of Prey from Greece by D. G. Hela; I. K. Konstantinou; T. M. Sakellarides; D. A. Lambropoulou; T. Akriotis; T. A. Albanis (pp. 603-613).

The concentrations of persistent organic pollutants, such as DDT and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), cyclodienes (Cycls), and polychlorinated biphenyls (PCBs), were measured in livers and subcutaneous fat tissues of six Accipitridae and four Falconidae bird species from different areas in Greece. This is the first report of persistent organochlorine (OC) pollutants in birds of prey tissues presented for Greece and the Eastern Mediterranean region. Accumulation patterns of OCs found in birds suggested that the predominant contaminants were p,p′-dichlorodiphenyldichloro-1,1-ethylene (DDE) and PCBs, whereas Cycls and HCHs occurred at low concentrations only. Concentration values of p,p′-DDE ranged from nondetected to 19,518.72 ng/g wet wt in livers and from nondetected to 2679.19 ng/g wet wt in fat. Total PCB levels ranged from 1.01 to 7419.43 ng/g and from 3.25 to 490.10 ng/g wet weight for liver and fat samples, respectively. Higher-chlorinated PCBs such as 118, 138, 153, and 180 predominated in both the liver and subcutaneous fat samples, a pattern comparable to that observed in birds from other European countries. No significant differences in mean concentrations of OCs are detected between species. Hepatic concentrations were in general higher than the fat concentrations showing depleted fat stores in most birds. Concentration ranges were also found in lower or similar levels to those reported for birds in other regions. Variation of OCs levels in bird tissues could be due to different causes of death, with a subsequent effect on body lipid levels, and different feeding and migration habits. The liver PCB levels reported in this study are below the concentrations currently believed to exert mortality or ecotoxicological effects. On the contrary, in some cases p,p′-DDE concentrations were higher than the reported effect values for birds of the same families and could be associated with sublethal effects.

Assessment of Effects in Mink Caused by Consumption of Carp Collected from the Saginaw River, Michigan, USA by S. J. Bursian; K. J. Beckett; B. Yamini; P. A. Martin; K. Kannan; K. L. Shields; F. C. Mohr (pp. 614-623).

Polychlorinated hydrocarbons, including polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs), are ubiquitous environmental contaminants that bioconcentrate in the food chain. Numerous studies have demonstrated mink (Mustela vison) to be one of the most sensitive species to this group of compounds. In recent studies, a lesion characterized by osteoinvasion of epithelial cells into the mandible and maxilla of young mink fed diets containing 3,3’,4,4’,5-pentachlorobiphenyl (PCB 126) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was observed. The objective of the present study was to determine if proliferation of maxillary and mandibular squamous epithelia could be induced in ranch mink exposed to environmentally-derived polychlorinated hydrocarbons (PCBs, PCDDs, and PCDFs) in utero, during lactation, and throughout the growth period. Adult female mink were fed diets containing 0, 10, 20, or 30% carp (Cyprinus carpio) collected from the Saginaw River, Bay City, Michigan, USA, that provided 0.03, 0.83, 1.1, and 1.7 mg total PCBs (tPCBs)/kg feed and 2.5, 28, 47, and 73 ng TCDD toxic equivalents (TEQs)/kg feed, respectively, three weeks prior to breeding through weaning of the resulting offspring. Mink kits were maintained on their respective diets for up to 27 weeks of age. At 6 and 27 weeks of age, six to eight mink in each treatment group were necropsied and their jaws examined for evidence of maxillary and mandibular squamous epithelial proliferation. Results indicated that inclusion of up to 30% carp in the diet (1.7 mg tPCBs/kg feed, 73 ng TEQs/kg feed) had no effect on mink reproduction and kit survivability. However, maxillary and mandibular squamous epithelial proliferation was evident in four of the seven 27-week-old juveniles in the 20% carp group (1.1 mg tPCBs/kg feed, 47 ng TEQs/kg feed) and six of the eight juveniles in the 30% carp group (1.7 mg tPCBs/kg feed group, 73 ng TEQs/kg feed). Hepatic concentrations of tPCBs and TEQs increased in both the 6-week-old kits and the 27-week-old juveniles as the percentage of dietary carp increased. The livers of 6-week-old kits were also assessed for the presence of polybrominated diphenyl ethers, which increased as the percentage of Saginaw River carp in the diet increased.

Physiological Responses of Hybrid Striped Bass to Aqueous Copper in Freshwater and Saltwater by G. K. Bielmyer; J. Tomasso; S. J. Klaine (pp. 624-624).

Copper (Cu) is an abundant trace metal, and although essential at low levels, it is also potentially toxic to aquatic organisms. Mechanisms of toxicity and consequences of exposure vary depending on ionoregulatory status (acclimated to freshwater or salt water). The goal of this research was to examine the responses of hybrid striped bass (Morone chrysops × Morone saxatilis) exposed to Cu in freshwater and 15 g/L salt water. In freshwater, a general dose- and time-dependent pattern of increasing Cu accumulation in gill tissue was evident in fish exposed to aqueous Cu (220 and 447 μg/L) for up to 96 hours. The 96-hour acute median lethal concentration for freshwater-acclimated hybrid striped bass exposed to Cu was 94 μg/L (confidence interval = 62 to 144 μg/L). Plasma osmolality and Na⁺ concentrations decreased in Cu-exposed fish. Freshwater-acclimated hybrid striped bass exposed to aqueous Cu (60 μg/L) for 3 weeks decreased in mass and accumulated Cu in gill, intestine, and liver. In salt water, no mortality occurred, and there were no statistical differences in growth, tissue Cu, or plasma ion concentrations in hybrid striped bass exposed to Cu compared with control fish. Freshwater-acclimated hybrid striped bass were very sensitive to Cu exposure and exhibited responses typical of commonly tested teleost fishes; however, the same sensitivity was not observed in salt water–acclimated fish.

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Archives of Environmental Contamination and Toxicology (v.50, #4)