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Archives of Environmental Contamination and Toxicology (v.44, #2)

Direct and Indirect Exogenous Contamination by Pesticides of Rice-Farming Soils in a Mediterranean Wetland by M. Gamón; E. Sáez; J. Gil; R. Boluda (pp. 0141-0151).

It is known that the sources of soil contamination can be endogenous or exogenous and that exogenous contamination may be direct or indirect. In this work, an environmental pesticide fate study was conducted in soil profiles collected from 23 rice field sites in an important Mediterranean wetland (Albufera Natural Park, Valencia, Spain) from April 1996 to November 1997. Temporal and spatial distribution of 44 pesticide residues in an alluvial Mediterranean soil (gleyic-calcaric Fluvisol, Fluvaquent) were monitored. During this period, the levels of pesticide residues in different soil horizons (Ap1 0–12 cm, Ap2 12–30 cm, ApCg 30–50 cm, C1gr 50–76 cm, and C2r 76–100 cm) were investigated. In addition, information was collected on agricultural pesticide application practices and soil characteristics. Distribution throughout the soil profile showed that pesticide concentrations were always higher in the topsoil (Ap1 horizon), in the autumn season, and in the border with citrus-vegetable orchard soils (calcaric Fluvisol, Xerofluvent). Chlorpyrifos (organophosphorus), endosulfan (organochlorine), and pyridaphenthion (organophosphorus) insecticides were, respectively, the most detected of all the pesticides investigated. These results were associated with processes, such as nonleaching, transport by movement into surface waters, retention, volatilization, and chemical and biological degradation in the topsoil, as well as with direct and indirect exogenous contamination sources.

Statistical Implications of Pyrene and Phenanthrene Sorptive Phenomena: Effects of Sorbent and Solute Properties by S. Hwang; T. J. Cutright (pp. 0152-0159).

A 3 × 2 factorial experiment in a generalized randomly complete block was conducted to assess the effects of soil type, soil preparation, and solute concentration on the sorptive behavior of pyrene (PYR) and phenanthrene (PHE). Three bulk soils were treated to remove the soil organic matter (SOM) or clay fractions, then spiked with an initial PYR/PHE concentration of either 3 or 15 mg/L. On average, 98.3% PYR and 91.3% PHE were sorbed to the bulk soils in 24 h, with 4.96 mg PYR kg⁻¹ soil and 22.48 mg PHE kg⁻¹ soil desorbed after three successive 24-h desorption steps. Both clay minerals and SOM greatly contributed to the sorptive behavior. For example, an average 95.1% and 96.1% of the initial PYR sorbed to the clay-removed and SOM-removed subsoils, respectively. Conversely, 16.5 mg/kg and 12.9 mg/kg of the sorbed PYR was desorbed from the clay-removed and SOM-removed subsoils, respectively.

Distribution of Heavy Metals in the Street Dusts and Soils of an Industrial City in Northern Spain by A. Ordóñez; J. Loredo; E. De Miguel; S. Charlesworth (pp. 0160-0170).

This study characterizes the elemental composition of street dust and soils in Avilés (N. Spain), a medium-size city of approximately eighty thousand inhabitants, where industrial activities and traffic strongly affect heavy metal distribution. A total of 112 samples of street dust were collected within a 7-km² area, encompassing residential and industrial sites (ferrous and non-ferrous plants). Elevated geometric mean concentrations of zinc (4,892 μg · g⁻¹), cadmium (22.3 μg · g⁻¹), and mercury (2.56 μg · g⁻¹) in street dust were found in samples located near industrial areas. Two types of anthropic influence were distinguishable: the first and most important one is that related to metallurgical activity and transportation of raw materials for local industries. Secondly, exhaust emissions from traffic are an important source of lead concentration in areas with high vehicular density (geometric mean: 514 μg · g⁻¹). The zinc content in the dust samples decreased with the distance from a zinc smelter located in the northern part of the city. The same trend was found for other elements in association with zinc in the raw materials used by the smelter, such as cadmium and mercury. A simultaneous research campaign of urban soils, that involved the collection of 40 samples from a 10-km² area, revealed geometric mean concentrations of 376 μg · g⁻¹ Zn, 2.16 μg · g⁻¹ Cd, 0.57 μg · g⁻¹ Hg, and 149 μg · g⁻¹ Pb, and distribution patterns almost identical to those found for street dust.

Assessment of Organochlorine Pesticide Residues in West African City Farms: Banjul and Dakar Case Study by P. Manirakiza; O. Akinbamijo; A. Covaci; R. Pitonzo; P. Schepens (pp. 0171-0179).

Validated analytical procedures for the determination of 21 organochlorine pesticides have been applied to 74 water samples, 76 soil samples, and 160 vegetable samples from nine Sene-Gambian farms. Mean pesticide residue levels found were compared to the results of other studies. The main contaminants were DDTs in water (231.9 ng/L), in soil (71.4 ng/g), and in vegetables (5.03 ng/g). The distribution of pesticide residues in water and neighboring soils and the soil–plant transfer of these pesticides is briefly discussed. Different bioconcentration factors for sum HCHs, sum DDTs, and sum endosulfans obtained in this study allow us to confirm the complex processes already reported in the literature concerning the uptake and translocation of chemicals from soil to plant.

The Concentrations and Bioconcentration Factors of Copper and Zinc in Edible Mushrooms by J. Alonso; M. A. García; M. Pérez-López; M. J. Melgar (pp. 0180-0188).

Copper and zinc contents have been determined in up to 28 species of edible mushrooms from different sites in the province of Lugo (NW Spain). Two hundred thirty-eight collected samples were analyzed by an anodic stripping voltammetric technique using a drop mercury as the working electrode. The results showed that the element concentrations were species-dependent, and the highest metal levels corresponded to the following species: Calvatia utriformis (235.5 mg Cu/kg), Macrolepiota procera (217.8 mg Cu/kg), and Agaricus macrosporus (217.7 mg Cu/kg) and Calvatia utriformis (265.8 mg Zn/kg), Lactarius delicious (231.0 mg Zn/kg), and Agaricus macrosporus (221.3 mg Zn/kg) for Cu and Zn, respectively. All mushroom species bioaccumulated copper and zinc. Nevertheless, some individual samples of the species, such as Hydnum repandum, Cantharellus cibarius, and Coprinus comatus, were bioexclusors (BCF < 1). The hymenophore in mushrooms showed higher mean metal levels than the rest of the fruit bodies, with statistically significant differences. The copper and zinc concentrations were compared to literature data and levels set by legislation. It can be concluded that the consumption of these mushrooms cannot be considered a toxicological risk, and they provide an important nutritional requirement to the diet.

Impacts of Cd and Zn on the Development of Periphytic Diatom Communities in Artificial Streams Located Along a River Pollution Gradient by C. Gold; A. Feurtet-Mazel; M. Coste; A. Boudou (pp. 0189-0197).

Many field and experimental studies have been conducted to reveal modifications of periphytic diatom communities under metal pollution, but most of the approaches presented drawbacks: variability of environmental factors for field studies and lack of representativity for experimental ones. An original approach that allows growth of periphytic communities under conditions more controlled than in the field and more realistic than experimental investigations was developed to try conclusions being drawn on the real impact of metallic pollution. Artificial streams were placed on the river bank at three sites along the pollution gradient (Cd/Zn) of the River Lot (SW France): reference (upstream pollution discharge), slightly polluted (around 1.5 μg Cd · L⁻¹ and 50 μg Zn · L⁻¹), and polluted (around 6 μg Cd · L⁻¹ and 400 μg Zn · L⁻¹) sites. Structural characteristics of diatom communities growing in these artificial streams, on glass substrates, and under homogenized current velocity and water depth were compared after four durations (1, 2, 3, and 4 weeks) to study effects of metal on first steps of community development. Marked perturbations of diatom community development were observed overall in the polluted site: after 1 week, early biofilms differed already by taxonomic composition; after 4 weeks, cell density was significantly lower than in the reference site and taxonomic composition was very different. These results, generated by a methodology intermediate between field and experimental approaches, compare well with literature findings based on more traditional approaches, strongly attesting that metallic pollution affects diatom community architecture and induce rising of abnormal cells.

Phytotoxicity of 2,4,6-Trinitrotoluene (TNT) and Octahydro-1,3,5,7-Tetranitro-1,3,5,7-Tetrazocine (HMX) in Spiked Artificial and Natural Forest Soils by P. Y. Robidoux; G. Bardai; L. Paquet; G. Ampleman; S. Thiboutot; J. Hawari; G. I. Sunahara (pp. 0198-0209).

Toxicity of 2,4,6-trinitrotoluene (TNT) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) using two terrestrial plant species, lettuce (Lactuca sativa) and barley (Hordeum vugare), was assessed in artificial soil (silica) and forest soil. Lettuce emergence was significantly decreased after 5 days of exposure to TNT nominal spiked concentrations ≥ 1,040 mg/kg dry soil in silica. Barley emergence was significantly reduced after 14 days of exposure at initial (t = 0) TNT concentrations ≥ 55.9 ± 4.5 mg/kg dry soil in silica and at ≥ 291.9 ± 42.8 mg/kg dry forest soil. Biomasses of shoot and roots of barley seeds were significantly reduced after 14 days of exposure at TNT initial exposure concentrations ≥ 55.9 ± 4.5 (LOEC) mg/kg dry soil in silica. Results were similar with the forest soil (LOEC = 91.4 ± 7.9 mg TNT/kg dry soil) using the root growth parameter, but the shoot biomass was reduced only at concentrations ≥ 291.9 ± 42.8 mg TNT/kg dry soil. Plants were not affected by an HMX exposure up to 3,320 ± 1,019 mg/kg dry soil using silica or 1,866 ± 438 mg/kg dry soil using a forest soil. During the 14-day experiments, TNT was partially transformed in the spiked soil samples, as indicated by the presence of its amino metabolites (2-ADNT and 4-ADNT). Higher quantities of metabolites were detected in forest soils having higher initial TNT concentrations (≤ 1,849.4 ± 228.2 mg/kg) compared to silica (≤ 239.3 ± 88.0 mg TNT/kg). After 14 days, TNT concentrations in spiked silica and forest soil were reduced up to 80.5% at 55.9 ± 4.5 mg/kg initial concentration and 94.4% at 91.4 ± 7.9 mg/kg initial concentration, respectively. Data indicate that TNT is the probable phytotoxicant because it decreased plant emergence and growth in the presence and absence of the ADNT metabolites.

The Combined Effects of Hardness, pH, and Dissolved Organic Carbon on the Chronic Toxicity of Zn to D. magna: Development of a Surface Response Model by D. G. Heijerick; C. R. Janssen; W. M. De Coen (pp. 0210-0217).

The effect of changes in pH, hardness, and dissolved organic carbon (DOC) and the possible interactions among these parameters on the chronic toxicity of zinc to D. magna were investigated. Based on a Central Composite Design, models were developed that can explain the observed variation in EC₁₀ and EC₅₀ as a function of these toxicity modifying factors. All three parameters significantly altered the observed effect concentrations based on net reproductive rate. The largest differences in 21-day EC₁₀s and EC₅₀s caused by these factors were 10.1 and 4.9, respectively. An increase in pH and/or DOC decreased zinc toxicity. The significant interaction between pH and DOC on observed chronic Zn toxicity is in accordance with earlier reported increased sorption efficiency of Zn to humic substances at higher pH levels. Lowest Zn toxicity was observed in tests performed with moderately hard test media (between 200 and 300 mg/L as CaCO₃). Lower or higher hardness of the test medium resulted in lower effect concentrations. Based on physico-chemical characteristics of the test media, developed models can be used to explain the variation between reported NOECs for Zn and may improve current environmental risk assessment procedures of metals.

A Comparison of the Metal Content of Some Benthic Species from Coastal Waters of the Florida Panhandle Using High-Resolution Inductively Coupled Plasma Mass Spectrometry (ICP-MS) Analysis by R. B. Philp; F. Y. Leung; C. Bradley (pp. 0218-0223).

Benthic marine invertebrates, sediment, and water from several locations along the Florida panhandle coast from St. Joseph Bay in the west to the mouth of the Wakulla River in the east, including from several river estuaries, were analyzed by double focusing ICP-MS (Finnigan MAT ELEMENT) for Cd, Hg, Pb, Cu, Zn, and As. All were detected in all samples. Sponges generally contained higher levels of Cd than other species. Microciona prolifera sponges from St. Joseph Bay had higher As levels (8.1–13.6 μg/g dry weight) than sponges collected from Dickerson Bay or Appalachee Bay (2.20–9.7) and higher Cd levels (0.43–0.73) than that of a single Microciona specimen collected from Dickerson Bay (0.29). Water content of As was about 20–30× higher in St. Joseph Bay than in any other location, and sediment levels of Cd were about 9× higher. Cu and Zn were higher in organic sediment from St. Joseph Bay than they were in other areas. The Pb content of several sponge species and two of tunicates was considerably higher than in other species. The uptake of most metals in this study (except As) appeared to be affected by the metal, genus, species, and location as much as by levels in either water or sediment. In general, sponges and tunicates seemed to accumulate higher levels than most other species, possibly a function of high filtration rates. The ICP-MS method is useful for environmental studies, but the instrument requires considerable maintenance.

PCB and PCDD/F Totals, TEQs, and Congener Patterns in Korean Coastal Marine Environments, 1987, 1988, 1990, and 1996–1999 by J. R. Oh; M. G. Ikonomou; M. P. Fernandez; S.-H. Hong (pp. 0224-0236).

Various mussel and oyster samples and select top sediment samples were taken over 27 industrial and pristine coastal sites form South Korea's west, south, and east coasts. Site-specific total PCB, PCDD/F, and organochlorine TEQ levels in biota were 1–306 ng/g ww, 3–9,400 pg/g ww, and 0.3–200 pg/g ww, respectively. Temporal trends showed a general decrease in total TEQ with an increase in TEQ contribution by PCDD/Fs at most locations over the past decade. Linear regression was used to establish a relationship between each contaminant total and the respective TEQ contribution. Principal component analysis was used to model the congener-specific PCB and PCDD/F data, and two three-component models were developed that describe the congener-specific patterns based on the variance between samples over the entire data set. Unique PCDD/F patterns were identified and discussed with respect to outliers identified in the previously established TEQ regressions and a distinct PCDD/F pattern was found that related to a single industrial source (i.e., steel mill). PCB patterns were explored in relation to those of common commercial mixtures of PCBs (i.e., Aroclors) and patterns were discussed with respect to TEQ. It was found that sites with relatively high PCB-TEQs showed an Aroclor 1254–like contamination.

Bioconcentration and Toxicity of Dodecylbenzene Sulfonate (C₁₂LAS) to Aquatic Organisms Exposed in Experimental Streams by D. J. Versteeg; J. M. Rawlings (pp. 0237-0246).

Fish, mollusks, and crustaceans were caged in the tail pool of streams during a C₁₂LAS (dodecyl benzene sulfonate) model ecosystem experimental program. Bioconcentration of total C₁₂LAS and individual isomers and acute and chronic toxicity were investigated during this study. Toxicity endpoints were based on water and tissue (i.e., body burden) concentrations at which adverse effects were observed. At 32 days, total C₁₂LAS bioconcentration factors (BCFs) for the fathead minnow and three invertebrate species ranged from 9 to 116. In general, bioconcentration was affected by isomer position, exposure concentration, and species. BCF values tended to decrease as isomer position moved from external (e.g., 2-phenyl) to internal (e.g., 5,6-phenyl). BCFs also decreased as exposure concentration increased. Mean acute 4-d LC₅₀ values ranged from 1.5 to >3.0 mg/L for the six species tested. Lethal body burdens associated with 50% mortality (LBB₅₀) varied from 0.21 to 0.60 mmole/kg (wet weight). During the 32-day chronic exposures, the EC₂₀ values were 0.27 (0.204–0.352), 0.95 (0.597–1.29), and approximately 1.0 mg/L for Corbicula (length), Hyalella (survival), and fathead minnow (survival), respectively. At these EC₂₀ values, C₁₂LAS body burdens were 0.035, 0.23, and 0.19 mmoles/kg wet weight in Corbicula, Hyalella, and fathead minnow, respectively. Fish exposed to wastewater treatment plant effluent had total C₁₂LAS tissue concentrations ranging from 0.0005 to 0.0039 mmoles/kg wet weight. These concentrations are approximately 45–360 times below the tissue concentration associated with subtle effects in the model ecosystem stream exposures. Total C₁₂LAS body burdens in feral and caged Corbicula exposed to WWTP effluents were approximately 0.0013 mmoles/kg; approximately 25-fold below concentrations associated with effects in stream exposures.

The Effects of Anti-Androgenic and Estrogenic Disrupting Contaminants on Breeding Gland (Nuptial Pad) Morphology, Plasma Testosterone Levels, and Plasma Vitellogenin Levels in Male Xenopus laevis (African Clawed Frog) by J. H. van Wyk; E. J. Pool; A. J. Leslie (pp. 0247-0256).

Nuptial pads are areas, digits, and forearm characterized by epidermal keratin hooks and dermal breeding glands opening on the epidermis surface in male frogs. The presence of the epidermal hooks and secretory activity of the breeding glands are androgen-dependent and considered functioning during mating. Chemical pollutants released into the aquatic environment by humans are suspected of disrupting the normal hormonal pathways and functioning. Among the best known of these endocrine-disrupting contaminants (EDCs) are compounds that mimic the steroid 17β-estradiol. However, recently specific anti-androgenic activity by certain EDCs, including DDE and several fungicides, have been shown in mammalian studies. The African clawed frog, Xenopus laevis, has been proposed as an ideal species to be used as a model system for screening of endocrine disruptors. In this study we employed a newly developed ELISA for the measurement of plasma vitellogenin (VTG), normally produced in the liver of females under the influence of estrogens but also in males when exposed to exogenous estrogens. Furthermore, we investigated the potential of breeding (nuptial) gland activity to be employed as a biomarker system for screening for anti-androgenic activity by certain EDCs. Our results indicate that the pharmaceutic anti-androgen flutamide did significantly (p < 0.05) effect the androgen-dependent breeding (nuptial) glands and plasma testosterone concentrations in male X. laevis. Our results further confirm that the dicarboximide fungicide vinclozolin mimics the anti-androgenic action of flutamide. Vinclozolin, however, did not significantly effect the plasma testosterone concentration. Results also confirm the ability of 17β-estradiol to stimulate production and release of VTG in the liver of male X. laevis, although we could not confirm the in vivo induction of VTG by estrogenic mimics octylphenol and nonylphenol. Although more dose-response research is needed, this preliminary study confirms the potential of VTG production and breeding gland activity as biomarkers to screen chemicals and environmental samples for estrogenic and anti-androgenic activity using X. laevis males.

Embryotoxic Thresholds of Mercury: Estimates from Individual Mallard Eggs by G. H. Heinz; D. J. Hoffman (pp. 0257-0264).

Eighty pairs of mallards (Anas platyrhynchos) were fed an uncontaminated diet until each female had laid 15 eggs. After each female had laid her 15th egg, the pair was randomly assigned to a control diet or diets containing 5, 10, or 20 μg/g mercury as methylmercury until she had laid a second set of 15 eggs. There were 20 pairs in each group. After the second set of 15 eggs, the pair was returned to an uncontaminated diet, and the female was permitted to lay another 30 eggs. For those pairs fed the mercury diets, the even-numbered eggs were incubated and the odd-numbered eggs were saved for possible mercury analysis. Mercury in the even-numbered eggs was estimated as the average of what was in the neighboring odd-numbered eggs. Neurological signs of methylmercury poisoning were observed in ducklings that hatched from eggs containing as little as 2.3 μg/g estimated mercury on a wet-weight basis, and deformities were seen in embryos from eggs containing about 1 μg/g estimated mercury. Although embryo mortality was seen in eggs estimated to contain as little as 0.74 μg/g mercury, there were considerable differences in the sensitivity of mallard embryos, especially from different parents, with some embryos surviving as much as 30 or more μg/g mercury in the egg.

Mercury Occurrence in Prothonotary Warblers (Protonotaria citrea) Inhabiting a National Priorities List Site and Reference Areas in Southern Alabama by Blakely M. Adair; Kevin D. Reynolds; Scott T. McMurry; George P. Cobb (pp. 0265-0271).

Mercury occurrence in prothonotary warblers (Protonotaria citrea) was evaluated over two years in southern Alabama. Mercury was found in warbler nestlings and adults inhabiting National Priority List (NPL) sites in McIntosh, Alabama. Food items that were collected from nestlings also contained elevated mercury. When mercury concentrations in soil, food, and nestling were plotted at each nest box location, the distribution of mercury in the three matrices yielded information that direct bioaccumulation factors could not. There were site differences in mercury accumulation in nestlings inhabiting the NPL sites. Nestling mercury accumulation correlated with solid mercury concentrations near the nest box where the nestling was raised. Trophic transport of mercury was poorly defined by mercury in food; however, closer examination of prey items shows that food source influences accumulation. Mercury distributions in matrices provide useful information of uptake that can be integrated with risk assessment endpoints.

Biological Effects of Gestational and Lactational PCB Exposure in Neonatal and Juvenile C57BL/6 Mice by S. M. Arena; E. H. Greeley; R. S. Halbrook; L. G. Hansen; M. Segre (pp. 0272-0280).

The purpose of this study was to obtain a better understanding of polychlorinated biphenyl (PCB) immunotoxicity in the developing mouse. Adult female mice were dosed with three subcutaneous injections per week of 50 mg/kg Aroclor 1242 (A1242), Aroclor 1254 (A1254), or corn oil for 2 weeks and then mated with nondosed males. First-litter pups were sacrificed at 7 or 28 days of age. At both ages, the tissue concentration of PCB was significantly higher in both the A1242 and A1254 pups than in oil-treated controls. Seven-day-old pups exposed to A1242 or A1254 had significantly decreased splenic IL-2 production. Alterations in the percentages of T cell subsets compared to controls were observed in A1242-exposed pups; an increased spleen somatic index was noted only in A1254-exposed pups. Twenty-eight-day-old pups exposed to A1254 demonstrated a significant decrease in thymus somatic index, an increase in liver somatic index, a 25% decrease in total circulating T₄, and decreased B cell percentages relative to their controls. Alteration in the percentages of CD3^int T cells was observed in A1254-exposed 28-day-old pups. A significant increase in 7-ethoxyresorufin-O-deethylase (EROD) and 7-benzoxyresorufin-O-dearylase (BROD) activity was measured at both ages in A1254-exposed pups and in A1242-exposed 28-day-old pups. These data confirm that during gestation and lactation A1242 and A1254 are transferred from dams to pups and that such exposure results in immune-related effects in neonatal (7-day-old) and juvenile (28-day-old) mice. Furthermore, A1254 exposure produces more frequent and pronounced effects than exposure to A1242.

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Archives of Environmental Contamination and Toxicology (v.44, #2)