Check out our New Publishers' Select for Free Articles

Archives of Environmental Contamination and Toxicology (v.54, #2)

Occurrence and Ordination of Dichlorodiphenyltrichloroethane and Hexachlorocyclohexane in Agricultural Soils from Guangzhou, China by Fan Gao; Jianye Jia; Xinming Wang (pp. 155-166).

On a global scale tropical regions in developing countries are thought to be significant source areas of organochlorine pesticides (OCPs), owing to a long history of widespread use and only a recent production ban or restriction on the application of these pesticides. In the present study, 32 soil samples were collected in 2004 from agriculture lands around the urban area of Guangzhou, in southern China, and analyzed for residues of OCPs including p,p’-DDT, p,p’-DDE, p,p’-DDD, and α-, β-, γ-, and δ-HCH. The dry weight concentrations of ΣHCH (ΣHCH = α-HCH + β-HCH + γ-HCH + δ-HCH) ranged from 0.2 to 103.9 ng/g, with a median of 4.4 ng/g. Residues of ΣDDT (ΣDDT = p,p’-DDT + p,p’-DDE + p,p’-DDD) ranged from 7.6 to 662.9 ng/g, with a median of 67.3 ng/g. The predominance of β-HCH among HCHs in most soil samples suggested that they were from historical contamination rather than recent input. The mean HCH α/γ-ratio of 2.72 was lower than that of technical HCHs, possibly due to more loss of α-HCH via evaporation from soil with time, conversion of γ-HCH to α-HCH or recent application of lindane in the region. The mean ratio of (DDE + DDD)/ΣDDT was 0.54, indicating that quite a portion of DDT in soils was degraded since its official ban in 1983. Higher DDT concentrations with lower (DDE + DDD)/ΣDDT ratios at a few sites suggested possible local DDT sources via the application of Dicofol. A positive but weak correlation (r = 0.449, p < 0.01) between DDT residues and TOC contents implied that soil organic matter might enhance adsorption of DDT in soils in the tropical regions. Hierarchical cluster analysis and principal component analysis were also performed to study the distribution and compositional patterns of OCPs as well as their sources and environemtal fates within the study area.

Keywords: Organochlorine pesticides; Hexachlorocyclohexane (HCH); Dichlorodiphenyltrichloroethane (DDT); Ordination; Agricultural soils; China

Characterization of Nitrous Oxide Emission from a Rice-Duck Farming System in South China by Jia-En Zhang; Ying Ouyang; Zhao-Xiang Huang (pp. 167-172).

Agricultural activities are important contributors to the emissions of greenhouse gases. This study ascertained the dynamic emission of nitrous oxide (N₂O) from a paddy field under a rice-duck farming system in South China. Two different cultivation and fertilizer treatments, namely, organic fertilizer + ducks (OF+D) and chemical fertilizer + ducks (CF+D) treatments, were employed in this study. Experimental data showed that diurnal variations of N₂O emission were highly correlated with the activities of ducklings. The rates of N₂O emission were normally increased in the early morning and late afternoon due to the frequent movement of ducklings at these time periods. Our study further revealed that the rates of N₂O emission from the paddy field varied with the types of fertilizers used as well as with the stages of the rice growth. In general, the rates of N₂O emission were higher for the CF+D treatment than for the OF+D treatment, whereas more N₂O was emitted from the paddy field at the tillering stage than at the heading stage. The global warming potential with the use of the organic fertilizer was about 22% lower than with the use of the chemical fertilizer.

Keywords: Fertilizer types; N₂O emission; Rice-duck farming; Paddy field

Cadmium Toxicity and Bioaccumulation in Freshwater Biofilms by Soizic Morin; Thi Thuy Duong; Olivier Herlory; Agnès Feurtet-Mazel; Michel Coste (pp. 173-186).

A microcosm study was undertaken to examine the effects of dissolved cadmium at various concentrations (0, 10, and 100 μg · L⁻¹) on biofilm accumulation and diatom assemblages. A natural biofilm sampled from the Riou-Mort River (Southwest France) was inoculated into three experimental systems, where biofilm settled on glass slides. Samples collected after 1, 2, 4, and 6 weeks of colonization were analyzed for metal accumulation (total metal content and intracellular metal content in the biofilm), biomass (as measured through dry weight and ash-free dry matter), and quantitative as well as qualitative analysis of diatom assemblages. There was a positive correlation between cadmium accumulation and dissolved cadmium concentrations and duration of exposure: a linear relationship was found between concentration factors (CFs) of growing biofilms and time (CFs/day = 0.25 and 0.38 under contaminations of 10 and 100 μgCd · L⁻¹, respectively). Biofilm settlement, more than photosynthetic activity, was affected by high cadmium concentrations: we observed for all stages of settlement a drastic and significant (p < 0.05) reduction in biofilm biomass and in diatom densities in the highest cadmium contamination, compared to control and low cadmium concentration units.

Keywords: Cadmium toxicity; Bioaccumulation; Biofilms; Diatom densities

Variable Growth Responses of Water Thyme (Hydrilla verticillata) to Whole-Cell Extracts of Cylindrospermopsis raciborskii by S. H. W. Kinnear; L. D. Fabbro; L. J. Duivenvoorden (pp. 187-194).

Static-renewal ecotoxicity trials monitored growth of Hydrilla verticillata in conjunction with exposure to Cylindrospermopsis raciborskii whole-cell extracts containing the cyanotoxin cylindrospermopsin (CYN). Maximum exposure concentrations were 400 μg L⁻¹ CYN over 14 days. The responses of Hydrilla to the treatments were variable according to the toxin concentrations and lengths of exposure. Plant deaths, chlorosis, and necrosis were not recorded from treated plants. However, Hydrilla experienced significant growth stimulation and redistribution of plant resources in conjunction with exposure to the whole-cell extracts. Root production was particularly impacted. The results of this study imply that root production could aid in reducing C. raciborskii cell concentrations and CYN toxicity. Results of chlorophyll analyses differed, indicating that CYN in whole-cell extracts might exert complex effects on photosynthesis. This is the first study to describe the responses of an aquatic macrophyte following exposure to C. raciborskii whole-cell extracts containing the cyanotoxin cylindrospermopsin.

Keywords: Cylindrospermopsis raciborskii ; Cyanobacteria; Cyanoprokaryotes; Cylindrospermopsin; Hydrilla verticillata macrophyte

Effects of Atrazine and Metolachlor on the Survivorship and Infectivity of Echinostoma trivolvis Trematode Cercariae by Jennifer L. Griggs; Lisa K. Belden (pp. 195-202).

Parasites play important roles in ecosystems and can be impacted by chemical inputs. In a series of experiments, we examined the impact of two common herbicides, metolachlor and atrazine, on a host–parasite system consisting of the trematode, Echinostoma trivolvis and its two intermediate hosts, the snail Planorbella trivolvis and larval Rana spp. tadpoles. Metolachlor and atrazine are two widely used agricultural herbicides that inhibit the growth of pre-emergent vegetation. Residues of these pesticides are commonly found in water bodies near agricultural areas. In our first experiment in the laboratory, we examined changes in survivorship when free-living trematode cercariae were exposed to a low concentration (10 ppb: 15 ppb) and high concentration (85 ppb: 100 ppb) mixture of metolachlor and atrazine, respectively. These exposure levels were chosen to represent the higher end of levels that have been documented in aquatic systems. There was a significant decline in cercarial survivorship in the high concentration treatment at 14 hours. In our second experiment, we exposed the parasites, the second intermediate host tadpoles, or both the parasites and the tadpoles, to the pesticide mixtures for a maximum of 10 hours prior to infection and examined subsequent tadpole infection levels. The atrazine and metolachlor mixtures had no significant effects on parasite load, although newly shed cercariae were more likely than 10-hour-old cercariae to infect tadpoles. In our final experiment, we utilized outdoor mesocosms to expose parasites, infected snail hosts, and Rana sylvatica tadpoles to the pesticide mixtures for two weeks and examined differences in tadpole parasite loads. The pesticides had no significant effect on tadpole parasite loads in the mesocosms. Overall, our findings suggest that atrazine and metolachlor mixtures at the doses we examined do not significantly alter the short-term dynamics of Echinostoma trivolvis infection in aquatic systems.

Individual and Mixture Effects of Selected Pharmaceuticals and Personal Care Products on the Marine Phytoplankton Species Dunaliella tertiolecta by Marie E. DeLorenzo; Jessica Fleming (pp. 203-210).

Pharmaceuticals and personal care products (PPCPs) entering the environment may have detrimental effects on aquatic organisms. Simvastatin, clofibric acid, diclofenac, carbamazepine, fluoxetine, and triclosan represent some of the most commonly used and/or detected PPCPs in aquatic environments. This study analyzed the individual and mixture toxicity of these six PPCPs to the marine phytoplankton species Dunaliella tertiolecta using a standard 96-hour static algal bioassay protocol. All PPCPs tested had a significant effect on D. tertiolecta population cell density. However, of the six PPCPs tested, only triclosan yielded toxicity at typical environmental concentrations. The 96-hour EC₅₀ values for triclosan, fluoxetine, simvastatin, diclofenac, and clofibric acid were 3.55 μg/L, 169.81 μg/L, 22,800 μg/L, 185,690 μg/L, and 224,180 μg/L, respectively. An EC₅₀ value could not be determined for carbamazepine; however, the highest concentration tested (80,000 μg/L) reduced cell density by 42%. Both mixtures tested—simvastatin–clofibric acid and fluoxetine–triclosan—demonstrated additive toxicity. The presence of PPCP mixtures may decrease the toxicity threshold for phytoplankton populations. Detrimental effects on phytoplankton populations could ultimately impact nutrient cycling and food availability to higher trophic levels. The results of this study are a first step toward identifying the risk of PPCPs to estuarine organisms and may benefit environmental resource managers.

Keywords: Phytoplankton; Pharmaceuticals; Mixtures; Aquatic toxicity; Estuarine

Analysis of Organochlorine Pesticides in Coral (Porites evermanni) Samples Using Accelerated Solvent Extraction and Gas Chromatography/Ion Trap Mass Spectrometry by Dongli Wang; Xiusheng Miao; Qing X. Li (pp. 211-218).

A gas chromatography/ion trap mass spectrometry method was developed for analysis of organochlorine pesticides (OCPs) in coral samples, which were extracted with accelerated solvent extraction (ASE) and cleaned up on a sulfuric acid-modified silica gel column. The optimal ASE conditions were found to be 100°C and 2000 psi, with a mixture of acetone and methylene chloride (1:1, v/v). The target analytes include hexachlorocyclohexanes (HCHs, specifically, α-, β-, γ-, and δ-HCH isomers), heptachlor, and hexachlorobenzene (HCB), o,p′-, p,p′-dichlorodiphenyltrichloroethane (o,p′-, p,p′-DDT), o,p′-, p,p′-dichlorodiphenyl-dichloroethylene (o,p′-, p,p′-DDE), and o,p′-, p,p′-dichlorodiphenyldichloroethane (o,p′-, p,p′-DDD). Standard sand samples were used as an alternative matrix spiked with OCP standards to determine the method precision and accuracy. Average recoveries of OCPs ranged from 82% to 102%, with relative standard deviations (RSDs) of 3%–6%, at a level of 10 ng/g and from 50% to 68%, with RSDs of 13%–19% at a level of 2 ng/g. The developed method was applied for analysis of OCPs in coral samples collected from Tern Island and Bikini Atoll in the Pacific Ocean. The concentrations of HCB were 7–26 pg/g dry weight in the samples from Bikini Atoll and 3–45 pg/g in those from Tern Island, and heptachlor concentrations were 208–2200 and 44–104 pg/g in the coral samples from Bikini Atoll and Tern Island, respectively. ∑HCH (sum of α-, β-, γ-, and δ-HCH) were 8–82 pg/g in Bikini Atoll coral and 86–629 pg/g in Tern island coral, and ∑DDT (sum of o,p′-, p,p′-DDD, o,p′-, p,p′-DDE, and o,p′- p,p′-DDT) were 80–212 pg/g in Bikini Atoll coral and 593–3165 pg/g in Tern Island coral. The results suggest that coral is a viable indicator species for pollution monitoring, which pollutants and their concentrations may be related to dated carbonate layers.

Keywords: Organochlorine pesticides; Coral; Marine pollution; Environmental monitoring

The Influence of Biomass on the Toxicity of Hydrophobic Organic Contaminants by A. D. Evans; M. Nipper (pp. 219-225).

Hydrophobic organic contaminants (HOCs) enter the marine environment through several means, including industrial, urban, and agricultural runoff, and accumulate in sediments. Methods for measurement of sediment toxicity include porewater tests using sea urchin (Arbacia punctulata) fertilization and embryological development assessments. Previous studies investigating sediments from Boston Harbor determined that significant binding of contaminants to organic matter led to insufficient evidence of the bioavailability of HOCs in porewater toxicity tests. It was hypothesized that excessive biomass in testing systems prevents a critical body residue of HOCs from forming, thus curbing toxic effects. In this study, the effect of biomass on the toxicity of phenanthrene (a polycyclic aromatic hydrocarbon) and lindane (an organochlorine pesticide) were assessed individually and combined in a mixture. The fertilization toxicity test for phenanthrene and mixture solutions containing both compounds revealed less biomass in the test vial caused higher toxicity levels, the fact of which was enhanced with increased hydrophobicity. The 50% inhibition concentration (IC₅₀) of phenanthrene to sea urchin fertilization success in test vials with 50 eggs/mL (lowest biomass concentration tested) was 3.72 μmol/L, but in vials with 100 to 400 eggs/mL, the IC₅₀ was >4.12 μmol/L. Toxicity of several concentrations of the phenanthrene and lindane mixture to sea urchin fertilization success and embryological development was significantly higher at lower biomasses (50 and 100 eggs or embryos/mL) than with biomasses ≥200 eggs or embryos/mL. The results suggest that when testing environmental samples that may contain HOCs, lowering the biomass can help better estimate sediment toxicity using porewater tests.

Effect of Sewage Discharge in Spisula subtruncata (da Costa 1778) Populations by J. A. de la Ossa Carretero; Y. del Pilar Ruso; F. Giménez Casalduero; J. L. Sánchez Lizaso (pp. 226-235).

Sewage discharge is a common source of pollution in coastal marine waters. Several municipal treatment plants dump treated water in medium to fine sand Spisula subtruncata communities. This bivalve is generally considered a major food source for demersal fishes, and it is important as a dominant species in structuring the macrobenthic community during the spring and summer months. We sampled within five locations affected by sewage discharge along the Castellon coast (northwest Mediterranean Sea) where S. subtruncata (da Costa 1778) is a common bivalve. Van Veen grab samples were obtained for the study of the bivalve population and to characterize the sediment. The sewage discharges studied affect Spisula populations. In the stations near the outfalls, the abundance and the average size of S. subtruncata decreased. However, this effect did not correlate with sediment characteristics, such as granulometry or pH.

Bioaccumulation and Depuration Pattern of Copper in Different Tissues of Mystus vittatus, Related to Various Size Groups by Sriramulu Subathra; Ramasamy Karuppasamy (pp. 236-244).

The bioaccumulation pattern of copper (Cu) in gill, liver, kidney, and muscle of different sizes (fingerlings and adult age) of healthy Mystus vittatus when exposed to their respective sublethal concentrations of Cu-water, containing one-third 96-hr LC₅₀ level (6.20 and 15.95 mg L⁻¹) for short-term (120 hr) and one-eighth 96-hr LC₅₀ level (2.33 and 5.98 mg L⁻¹) for long-term experimentation, respectively, has been analyzed. The Cu shows a maximum deposition (p < 0.01) in the liver (82.12 and 70.65 μg/g) followed by gill (74.35 and 63.69 μg/g) and kidney (61.52 and 54.09 μg/g) both in fingerlings and adult fish, respectively, during 28 days of exposure. The lowest deposition of Cu is found to be 0.83 and 0.93 μg/g in fingerlings and 0.79 and 0.86 μg/g in adult muscle tissue during short-term (120 hr) and long-term (28 days) exposure periods, respectively. Comparing the accumulation of Cu on the two size groups at both exposure levels, it is obvious that the fingerlings showed higher Cu concentration in all tissues than those of adult fish. Another equally important finding is that the depuration of Cu by maintaining the bioaccumulated fish (long-term exposed group) of both size groups in quality dechlorinated ground water reveals that there is a significant (p < 0.05) reduction in Cu concentration in different tissues as the day passes. A comparison of the performance of the two size groups in respect of depuration clearly indicates that the fingerlings have taken 24–43 days (gill-kidney), whereas in mature fish it is 21–39 days (gill-kidney) to reach the level of control fish. Among the various tissues in both size groups, gill took the minimum number of days for complete recovery, whereas the muscle tissue did not significantly eliminate Cu even after 30 days of depuration. These data constitute a reference for future studies on the evolution of Cu accumulation and elimination tendency in relation to different size groups of fish in the ecotoxicological testing scheme for hazard assessment.

Keywords: Copper; Bioaccumulation; Depuration; Mystus vittatus ; Size group

Elemental Status in Sediment and American Oyster Collected from Savannah Marsh/Estuarine Ecosystem: A Preliminary Assessment by Kenneth S. Sajwan; Kurunthachalam Senthil Kumar; Sivapatham Paramasivam; Sanya S. Compton; Joseph P. Richardson (pp. 245-258).

Sediment and American oyster (Crassostrea virginica) collected from nine selected marsh/estuarine ecosystems in Savannah, Georgia were analyzed for elements such as Al, As, B, Cd, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Si, and Zn. Sediments were extracted by ammonium acetate (NH₄OAc), Mehlich-3 (M-3), and water procedures, whereas an acid digestion procedure was adopted for oyster tissue. Concentrations of elements were higher in M-3 extractions followed by NH₄OAc and water extraction procedures. Calcium and Mg was greater in sediments by any of the extractions, whereas other elements differed depending upon the extraction procedures. There were no significant spatial variations (p < 0.05) of any of elements analyzed except Mn, in NH₄OAc/water extraction procedure and Fe and Al by water extraction procedure. Contamination of Al, B, Cd, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Si, and Zn in oyster tissue ranged from 399 to 1460, 231 to 254, <1.5 to 2.9, <1.5 to 8.0, 67 to 121, 232 to 1357, 17 to 54, <0.5 to 0.64, <1.5 to 2.5, <1.5 to 4.0, 241 to 381, and 978 to 2428 μg/g dry weight (dw), respectively. Greatly elevated concentrations of elements such as P, Ca, Mg, K, and S were noticed in oyster tissue. The concentration range of Hg and As in sediment was 1.2–1.9 and 11–55 μg/g dw, respectively. The concentration range of Hg and As in oyster tissue was 130–908 and 200–912 ng/g dw, respectively. With the exception of As and Hg, other elements are several orders of magnitude greater in oyster tissue. There is no significant (p < 0.05) contamination variation in target analyses between the nine selected sites. Concentrations of heavy metals in sediment and oyster were either comparable or lower than those of other countries. Greater biota-sediment accumulation factor was noticed for P and Zn. Concentrations of Hg and P in oyster tissue were higher than the threshold limit for human consumption. Overall, the baseline data can be used for regular ecological monitoring, considering the domestic and industrial growth around this important marsh/estuarine ecosystem.

Ameliorating Effect of Chloride on Nitrite Toxicity to Freshwater Invertebrates with Different Physiology: a Comparative Study Between Amphipods and Planarians by A. Alonso; J. A. Camargo (pp. 259-265).

High nitrite concentrations in freshwater ecosystems may cause toxicity to aquatic animals. These living organisms can take nitrite up from water through their chloride cells, subsequently suffering oxidation of their respiratory pigments (hemoglobin, hemocyanin). Because NO ₂ ⁻ and Cl⁻ ions compete for the same active transport site, elevated chloride concentrations in the aquatic environment have the potential of reducing nitrite toxicity. Although this ameliorating effect is well documented in fish, it has been largely ignored in wild freshwater invertebrates. The aim of this study was to compare the ameliorating effect of chloride on nitrite toxicity to two species of freshwater invertebrates differing in physiology: Eulimnogammarus toletanus (amphipods) and Polycelis felina (planarians). The former species presents gills (with chloride cells) and respiratory pigments, whereas in the latter species these are absent. Test animals were exposed in triplicate for 168 h to a single nitrite concentration (5 ppm NO₂-N for E. toletanus and 100 ppm NO₂-N for P. felina) at four different environmental chloride concentrations (27.8, 58.3, 85.3, and 108.0 ppm Cl⁻). The number of dead animals and the number of affected individuals (i.e., number of dead plus inactive invertebrates) were monitored every day. LT₅₀ (lethal time) and ET₅₀ (effective time) were estimated for each species and each chloride concentration. LT₅₀ and ET₅₀ values increased with increases in the environmental chloride concentration, mainly in amphipods. Results clearly show that the ameliorating effect of chloride on nitrite toxicity was more significant in amphipods than in planarians, likely because of the absence of gills (with chloride cells) and respiratory pigments in P. felina. Additionally, this comparative study indicates that the ecological risk assessment of nitrite in freshwater ecosystems should take into account not only the most sensitive and key species in the communities, but also chloride levels in the aquatic environment.

In Vitro Biotransformation of Amitriptyline and Imipramine with Rat Hepatic S9 Fraction: Evaluation of the Toxicity with Spirotox and Thamnotoxkit F™ Tests by Grzegorz Nałęcz-Jawecki (pp. 266-273).

Pharmaceutical products, as well as their related metabolites, end up in the aquatic environment after use. Little is known about the effects and the hazard of exposure to drugs for aquatic organisms. This study was designed to assess the ecotoxicity of amitriptyline (AMI), imipramine (IMI), and their metabolites. The tested drugs were very toxic to the protozoan Spirostomum ambiguum and the crustacean Thamnocephalus platyurus with the LC50 values around 1 mg l⁻¹. Moreover, simple additivity occurs between the drugs and their N-desmethyl metabolites. Tested compounds were incubated with S9 rat hepatocyte fraction at 37°C for 4 hours. Unchanged drugs and metabolites were determined using high-pressure liquid chromatography–photodiode array detector. AMI and IMI were biotransformed almost completely. Three AMI and IMI metabolites were detected: desmethyl-, didesmethyl-, and N-oxide. The toxicity of the deproteinated reaction mixtures (TU) was compared to the toxicity equivalency units (TEU) calculated based on the concentrations of the drugs and their LC50 values. It has been demonstrated that the toxicity of mixture of metabolites to Spirotox and Thamnotoxkit F™ is higher than the predicted value calculated from the concentrations of the drugs and their N-desmethylated derivatives in the sample. The results indicate that the harmfulness of the drug metabolites should be taken into consideration in the ecotoxicological studies.

Keywords: Antidepressants; Pharmaceuticals; Metabolites·; Spirostomum ambiguum ; Thamnocephalus platyurus

Toxicity of Cadmium for Silver Catfish Rhamdia quelen (Heptapteridae) Embryos and Larvae at Different Alkalinities by Ana Paula S. Benaduce; Daiani Kochhann; Érico M. M. Flores; Valderi L. Dressler; Bernardo Baldisserotto (pp. 274-282).

The present study evaluated the effect of waterborne Cd in eggs and larvae of silver catfish, Rhamdia quelen, at two alkalinity levels (63 and 92 mg · L⁻¹ CaCO₃): 0.5 (control), 4.5, 8, and 18 μg · L⁻¹ Cd. The fertilization rate was similar in all treatments, but the number of eggs with irregular surface was significantly higher in those exposed to 18 μg · L⁻¹ Cd and 63 mg · L⁻¹ CaCO₃. Three days after hatching survival of larvae exposed to 4.5 and 8 μg · L⁻¹ Cd and 63 mg · L⁻¹ CaCO₃ was significantly lower than that of control larvae, and 21 days after hatching survival decreased with the increase in waterborne Cd levels and total cadmium accumulation in the larvae. These significant differences and relationships were not observed in larvae maintained at 92 mg · L⁻¹ CaCO₃. Furthermore, in the lower alkalinity, a higher incidence of barbels and spinal column deformities was observed in the highest waterborne Cd concentration. At the end of the experimental period, 21 days after hatching, larval survival rate, length, weight, head height, membranous layer thickness, and biomass decreased with the increase in waterborne Cd levels in the lower alkalinity. However, these relationships were not observed in larvae maintained at 92 mg · L⁻¹ CaCO₃. The percentage specific growth rate was lower in larvae exposed to the highest waterborne Cd concentration at 63 mg · L⁻¹ CaCO₃. These results suggest that alkalinity of 92 mg · L⁻¹ CaCO₃ reduces waterborne Cd toxicity in silver catfish larvae.

Keywords: Fish; Eggs; Sodium bicarbonate; Metal

Effects of Diazinon on Mummichog (Fundulus heteroclitus) Larvae Produced from Eggs Differentially Treated with PCB126 by C. M. Couillard; M. Lebeuf; B. Légaré; S. Trottier (pp. 283-291).

During their formation, fish eggs receive a load of contaminants including polychlorinated biphenyls (PCBs) from their mother and then, after spawning, are exposed to pesticides present in water. This is the first study investigating the interaction between PCBs and organophosphorous pesticides in fish. The effect of diazinon was evaluated in mummichog (Fundulus heteroclitus) larvae produced from eggs differentially treated with 3,3′,4,4′,5 pentachlorobiphenyl (PCB126). A few hours after fertilization, eggs were treated topically with a solution of PCB126 (100 pg/μl) in dimethyl sulfoxide (DMSO) (Group P), DMSO (Group D), or not treated (Group N). Newly hatched larvae from Groups P and D were exposed to diazinon (125–12,900 ng/L) in saltwater and Group N larvae to saltwater alone. Diazinon caused a dose-responsive inhibition of cholinesterase (ChE) activity at environmentally realistic concentrations (≥361 ng/L), with up to 85% inhibition at 12,900 ng/L. Body length was also inversely related to diazinon at concentrations ≥361 ng/L and was significantly reduced (by 4%) at 12,900 ng/L compared to controls. Mummichog larvae were highly sensitive to PCB126 with an eightfold induction of the activity of ethoxyresorufin-O-deethylase at a dose of 710 pg PCB126 or 3.6 pg TCDD-TEQ/g wet weight. Treatment with PCB126 also caused a slight reduction in body length but no effect on ChE activity. This study indicates that the effects of PCB126 and diazinon on body length are cumulative because no significant synergistic or antagonistic interactions were observed. Longer term studies with several doses of PCB126 are needed to fully assess the overall impact of joint exposure to diazinon and PCB126 on growth and survival of fish larvae.

Assessment of Metals in Fish from Lake Macquarie, New South Wales, Australia by A. C. Roach; W. Maher; F. Krikowa (pp. 292-308).

The concentrations of the metals cadmium, copper, mercury, lead, silver, selenium and zinc were measured in the muscle and gonad tissues of five species of fish, yellowfin bream (Acanthopagrus australis), silverbiddy (Gerres subfasciatus) and trumpeter whiting (Sillago maculata), southern log finned goby (Favonigobious lateralis), and the halfbridled goby (Arenigobius frenatus) from the contaminated Lake Macquarie NSW and three relatively uncontaminated reference estuaries, Wallis Lake, Port Stephens, and St. Georges Basin NSW. Fish from Lake Macquarie were found to have elevated concentrations of selenium, lead, cadmium, and zinc in one or both of these tissues in these species. Increased concentrations relative to background concentrations were most often observed at Cockle Bay, the site with the highest concentrations of these metals in sediments. The degree to which fish accumulated metals appeared to be related to life history characteristics of the species, with sediment-dwelling fish showing the greatest propensity to accumulate metals.

Keywords: Lake Macquarie; Metals; Fish; Bioaccumulation; Estuaries; Sediments; Cadmium; Lead; Selenium; Zinc; Australia

Effects of Biological and Technical Factors on Brain and Muscle Cholinesterases in Nile Tilapia, Oreochromis niloticus: Implications for Biomonitoring Neurotoxic Contaminations by A. Pathiratne; L. W. H. U. Chandrasekera; P. K. C. De Seram (pp. 309-317).

Influence of body length, body weight, gender, sexual maturity, and tissue storage on brain and muscle cholinesterases (ChE) in Nile tilapia was evaluated considering its potential use in biomonitoring neurotoxic contaminations in tropical environments. Results show that ChE activities in both tissues decreased significantly with increased total length (4–24.5 cm) or body weight (1–186 g) of the fish and the relationships were curvilinear. Comparisons of the slopes and elevations of the regression lines of the logarithmic ChE and body size relationships of males with those of females indicated that gender had no significant effect on the body size-specific ChE activities. Response of the ChE of sexually mature males to chlorpyrifos exposure was similar to that of females. Gonadal maturity stage of this fish does not seem to influence ChE activities. Storage of tissues at –80°C for 28 days had no significant effect on ChE activities in the control fish and the fish exposed to carbofuran. However, a partial reactivation of brain ChE activities was observed in the fish exposed to carbosulfan after 28 days of storage. The results emphasize the importance of consideration of body size of the fish and storage time of the tissues in order to formulate accurate conclusions about the neurotoxic chemical exposure when ChE of the fish is used in biomonitoring programs.

Keywords: Brain; Carbosulfan; Carbofuran; Chlorpyrifos; Cholinesterase; Muscle; Tilapia

Combined Effects of Different Food Rations and Sublethal Copper Exposure on Growth and Energy Metabolism in Common Carp by Shodja Hashemi; Ronny Blust; Gudrun De Boeck (pp. 318-324).

Common carp (Cyprinus carpio) were fed two different rations, 0.5% body weight (low ration; LR) and 5% body weight (high ration; HR), throughout acclimation, sublethal (64 μg/L) Cu exposure for 28 days, and a subsequent 2-week recovery period. Growth, liver water content, and liver energy stores were assessed during this period. Growth rates were elevated in HR fish compared to LR fish, as was the hepatic lipid content. This was associated with a higher water content in the livers of LR fish. Liver glycogen levels were similar in both feeding treatments and remained relatively stable during Cu exposure. Cu exposure caused a significant reduction in growth in both HR and LR fish. Reduction in growth coincided with significant changes in liver and blood composition. Liver lipid levels dropped significantly during the first days of the exposure in both feeding treatments, and the difference between LR and HR lipid levels disappeared during Cu exposure. During the first week of Cu exposure, the difference in liver water content disappeared as well, with a significant reduction of the water levels in the LR fish. A rise of hepatic protein was observed after 2 and 4 weeks of Cu exposure in the LR carp and after 4 weeks of exposure in the HR fish. Cu exposure led to pronounced increases in plasma ammonia concentrations in HR carp. Growth and energy stores recuperated during the 2-week recovery period in both feeding treatments. The observed changes during Cu exposure are probably related to physiological disturbances like hypoxia and stress, as well as an inhibition of ammonia excretion.

Keywords: Food rations; Sublethal copper exposure; Common carp; Energy metabolism; Growth

Acute and Chronic Toxicity of Fluoxetine (Selective Serotonin Reuptake Inhibitor) in Western Mosquitofish by T. B. Henry; M. C. Black (pp. 325-330).

Fluoxetine is a biologically active pharmaceutical chemical that has been detected at parts-per-trillion levels in surface waters in North America and Europe. This has generated concern because negative effects in aquatic organisms are possible. Known as a selective serotonin reuptake inhibitor, fluoxetine (e.g., Prozac; Elli Lilly) is neurologically active and widely prescribed for clinical depression in humans. In the present investigation, acute and chronic toxicities of fluoxetine were evaluated in an environmentally relevant species, western mosquitofish Gambusia affinis. Acute toxicity (5 to 5340 ppb fluoxetine) was assessed in neonates (age 24 to 48 hours) exposed in glass aquaria for 7 days; chronic toxicity (0.05 to 5 ppb fluoxetine) was examined in fish exposed from age neonate to age 91 days; and effects of chronic exposure (100 days) on sexual maturation was investigated in mesocosm tanks (100 L) in fish exposed (7 to 71 ppb) from age 59 to 159 days. Acute toxicity of fluoxetine in neonate western mosquitofish was observed to have a 7-day median lethal concentration of 546 ppb. Chronic exposure did not affect survival, growth, or sex ratio; however, increased lethargy in fish exposed to ≥0.5 ppb fluoxetine was observed. In fish exposed from age 59 to 159 days (juvenile to adult life stages), delayed development of external adult sexual morphology was observed at 71 ppb fluoxetine, which consisted of delayed onset of the presence of the black spot in the posterior abdomen in female fish and delayed formation of the elongated anal fin (gonopodium) in male fish. The present study demonstrated that chronic exposure of western mosquitofish to fluoxetine can affect sexual development; however, it does so only at concentrations 3 to 4 orders of magnitude higher than those previously found in the environment.

Lead Pellet Ingestion and Liver-Lead Concentrations in Upland Game Birds from Southern Ontario, Canada by N. Kreager; B. C. Wainman; R. K. Jayasinghe; L. J. S. Tsuji (pp. 331-336).

One-hundred twenty-three gizzards from upland game birds (chukar, Alectoris chukar; and common pheasant, Phasianus colchicus) harvested by hunters in southern Ontario, Canada, were examined for lead pellet ingestion by manual examination of gizzard contents and by radiography. Lead pellets were found to be ingested by chukars (6/76; 8%) and the common pheasant (16/47; 34%). Further, 13% (17/129) of the bird (wild turkey, Meleagris gallopavo; Hungarian partridge, Perdix perdix; chukar; and common pheasant) livers analyzed had elevated lead concentrations (≥6 μg/g wet weight [ww]). Liver-lead concentrations above Health Canada’s guideline for human consumption of fish protein (<0.5 μg/g ww) were found in 40% (51/129) of livers analyzed. Data indicate that the ingestion of lead pellets in upland game birds and the potential consumption of lead-contaminated meat by humans are concerns related to the continued use of lead shotshell for hunting.

Keywords: Lead pellet ingestion; Liver-lead concentrations; Upland game birds; Canada; Lead shotshell

Chronic Oral Exposure to Bunker C Fuel Oil Causes Adrenal Insufficiency in Ranch Mink (Mustela vison) by F. C. Mohr; B. Lasley; S. Bursian (pp. 337-347).

Animals living in the near-shore marine environment are predisposed to contact with chemical contaminants through land- and ocean-based activities. The release of petroleum hydrocarbons into the marine environment is a stressor to this environment and its resident wildlife. The stress response to chemical threats is dependent on an intact hypothalamic-pituitary-adrenal axis, which also may be a target to the effects of these chemicals. Ranch mink (Mustela vison) were used as surrogates for sea otters (Enhydra lutris) to examine the development of adrenal hypertrophy after chronic, oral exposure to low concentrations of bunker C fuel oil. Animals were fed three different concentrations of fuel oil (48, 520, and 908 ppm) or mineral oil (control) for 60–62 days. At the end of the exposure, blood and fecal samples were collected and organs were weighed and examined microscopically. In all fuel oil groups, exposure resulted in adrenal hypertrophy, an adaptation suggestive of adrenal activation. However, concentrations of serum and fecal glucocorticoids and serum progesterone were not elevated over control values. Hematologic parameters and serum chemistries showed no changes consistent with increased adrenal activity. In addition, adrenal glands from animals fed the higher concentrations of fuel oil contained large numbers of heavily vacuolated cells. We conclude that petroleum hydrocarbons are inducing an adrenal insufficiency that leads to the adaptive enlargement of the gland. This would increase the susceptibility of fuel oil-exposed animals to the deleterious effects of other environmental stressors.

Keywords: Adrenal insufficiency; Bunker C fuel oil; Ranch mink; Mustela vision ; Oral exposure

Blood Levels of Polycyclic Aromatic Hydrocarbons in Children of Lucknow, India by Vipul K. Singh; Devendra K. Patel; S. Ram; N. Mathur; M. K. J. Siddiqui; Jai Raj Behari (pp. 348-354).

Polycyclic aromatic hydrocarbons (PAHs) are compounds with two or more fused benzene rings produced by incomplete combustion of organic substances involved in natural and anthropogenic processes. Children are exposed to these compounds through inhalation, dietary ingestion, and, also, soil at the playground. It has been well established that PAHs have carcinogenic, mutagenic, and teratogenic effects. Considering possible health risks due to PAHs exposure among children, the present study was carried out in collaboration with the Pediatrics Department, King George’s Medical University (KGMU), Lucknow, to determine its exposure in children by estimating blood PAHs levels. Due to the variable composition of PAHs mixtures emitted from different environmental sources, any single compound or metabolite may not be representative of all exposure conditions. For these reasons, the measurement of blood PAHs levels as a possible biomarker, especially of the EPA (Environmental Protection Agency, USA) priority list, has been proposed. Acenaphthylene, anthracene, phenanthrene, fluoranthene, naphthalene, pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, and benzo(a)pyrene were determined by HPLC-FD/UV. On the basis of the individual compound, the median (50th percentile) of naphthalene (19 ppb) was highest, however, benzo(a)pyrene (4.0 ppb) level was found to be lowest among all detected PAHs. The median level of total noncarcinogenic PAHs (113.55 ppb) was higher than the total carcinogenic PAHs (32.35 ppb) in blood samples of children. A significant correlation was found between period of time spent in the surrounding breathing zone of the cooking place and total noncarcinogenic PAHs (p < 0.05), while the blood carcinogenic PAHs level in children was found to be associated with lower status of their families (p < 0.05). It is speculated that there may be chances of health hazards through exposure to PAHs, those not yet declared hazardous and present at higher concentrations in the Indian environment. Further study with a larger sample size and accompanying environmental data is desired to validate the findings of this pilot study and strengthen the database of PAHs exposure in India.

Keywords: Children; Polycyclic aromatic hydrocarbons; India

Sections

Personal tools

Archives of Environmental Contamination and Toxicology (v.54, #2)

Sections

Personal tools

Local resources

Archives of Environmental Contamination and Toxicology (v.54, #2)