Check out our New Publishers' Select for Free Articles

Archives of Environmental Contamination and Toxicology (v.46, #1)

Development of a Fragment Constant Method for Estimating the Mixture Toxicity by Z. Lin; L. Wang; P. Shi; D. Zhao; K. Yin (pp. 1-7).

Based on Group Contribution Theory, a fragment constant model to estimate mixture toxicity is proposed in this paper. The toxicity (EC_50M) of 58 mixtures is determined using Photobacterium phosphoreum. Analysis of these EC_50M and the mole fraction of the individual chemical fragments (Br, Cl, NO₂, OH, NH₂) helps work out the fragment toxicity contribution (ΔT_i) to EC_50M. Thus, a linear regression equation is established between the toxicity contribution ΔT_i and the fragment constants of Hansch f_i, and this equation is so significant that it helps provide an approach for calculating EC_50M.

Effect of Adsorption Capacity of Dissolved Humic Matter on Leachability of Dioxins from Raw and Treated Fly Ashes of Municipal Solid Waste Incinerators by Y.-J. Kim; M. Osako (pp. 8-16).

The purposes of this study are to obtain information on the leachability of dioxins depending on the samples, to confirm the effect of dissolved humic matter (DHM) on the leachability of dioxins, and to evaluate the suitability of the detoxification treatments specified by the Japanese government for the reduction of leachability of dioxins. In this study, the leachability of dioxins from raw and treated fly ash was evaluated by a 24-hour batch leaching test and by an extraction test repeated three times with DHM solution, whose concentration was determined to be 700 mg-OC/L as an initial concentration based on organic carbon (OC) from adsorption tests of DHM to fly ash.The leaching concentration from fly ash samples having high DHM adsorption capacity was low regardless of pH, and that from samples having relatively low adsorption capacity and high pH was largely increased. Therefore, it is expected that the leachability of dioxins from treated fly ashes would be reduced by avoiding high pH and enhancing the DHM adsorption capacity rather than by using the detoxification method specified. We also confirmed that increase of the leachability of HOPs due to DHM is not as large as known in condition that is composed of three phases of HOPs, DHM, and solid matrix.

Biphasic Dissipation Kinetics for Dislodgeable Foliar Residues in Estimating Postapplication Occupational Exposures to Endosulfan by G. K. Whitmyre; J. H. Ross; C. Lunchick; B. Volger; S. Singer (pp. 17-23).

Agricultural workers are exposed to pesticide residues via dermal contact with foliage upon entry of treated fields. Restricted Entry Intervals (REIs) are established based on both toxicity and exposure. Key factors for estimation of potential worker exposures are dislodgeable foliar residues (DFRs) and the manner in which DFRs dissipate over time. DFR dissipation curves vary in form and shape, and are often biphasic, reflecting different rate processes, chemical-physical influences, and partitioning. Biphasic dissipation behavior for endosulfan [6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin 3-oxide] previously reported for tomatoes and peppers has been confirmed here for endosulfan on melon, grape, and peach foliage. Use of biphasic kinetics results in more robust r² values for the regression curves that describe foliar dissipation of endosulfan compared to use of simple first-order kinetics. For endosulfan, the use of biphasic kinetics to describe the overall dissipation accurately predicts daily DFR values. In contrast, first order kinetics may overestimate DFRs and, potentially, postapplication worker exposures during the critical period when entry of treated fields is most likely to occur.

Procedures for Determining the Pesticide Sensitivity of Indigenous Soil Algae: A Possible Bioindicator of Soil Contamination? by A. Bérard; F. Rimet; Y. Capowiez; C. Leboulanger (pp. 24-31).

Soil algae are present in all kinds of soils, both arable and virgin, in large amounts and in great diversity. These photosynthetic microorganisms, which are concentrated in the top few centimeters of the soil profile, are organized in a community structure that varies depending on soil type, farming method and pesticide application. We first tested several extraction and conservation methods for soil algae, and a ¹⁴C incorporation procedure to evaluate the photosynthetic activity of these micro-organisms. In a second study, we assessed the sensitivity to atrazine of soil microalgae from two corn fields managed by different agricultural practices (conventional vs. organic). Changes in indigenous diatom communities were monitored, together with photosynthetic tests performed on the whole algal community. Comparison of the data for the treated field with those for the reference, untreated organic cornfield showed that previous atrazine application in the conventional cornfield had changed the species composition of the soil diatom communities. Short-term ecotoxicological tests, using photosynthetic activity as endpoint, also showed that the communities that had developed under pesticide stress were more tolerant to further atrazine application than the control communities. The stress caused by major environmental disturbances, such as ground dressing, was not sufficient to mask the difference between the two crops, suggesting that telluric microalgae could be used as indicators of xenobiotic contamination in soils. These initial findings about using soil microalgal communities as bioindicators are promising. In addition, their photosynthetic activity, which reflects their sensitivity to xenobiotic compounds, seems to be a relevant bioindicator of soil contamination.

Comparison of the Toxicity Using Body Residues of DDE and Select PCB Congeners to the Midge, Chironomus riparius, in Partial-Life Cycle Tests by H. Hwang; S. W. Fisher; K. Kim; P. F. Landrum (pp. 32-42).

Due to the long time course required to achieve steady state with highly lipophilic contaminants such as PCBs (polychlorinated biphenyls), data derived from short-term toxicity tests may lead to an erroneous interpretation of hazard. In addition, PCBs bioaccumulated over time can cause sublethal impairments in organisms at concentrations much lower than required for mortality. Here, the body residues of 1,1-dichloro-2,2-bis-p-chlorophenyl ethane (DDE) and select PCB congeners associated with a spectrum of chronic effects in the midge, Chironomus riparius, were evaluated. The route of exposure was ingestion of the PCB-contaminated alga, Chlorella vulgarus, and trout chow loaded with the selected test compound. Two separate exposures of midges were performed. In the first experiment, midges were exposed from the second instar to the pupal stage. In the second exposure, midges were exposed from the second instar to the adult stage. A variety of sublethal endpoints was monitored, including developmental time within a stadium, body weight, and fecundity for the female adult. The dose was assessed as the whole body residue concentration of the contaminant. Overall, the midge concentration increased with increasing exposure concentration in algae and trout chow. Body weight at the end of each stadium was the assessment parameter that was least significantly affected among the test endpoints monitored. In contrast, a significant increase in development time was the endpoint that was most frequently observed in response to contaminant exposure. Reduction in fecundity was found only for DDE-exposed midges. These data, in which chronic endpoints are related to body residues, suggest that body residues will be useful in defining sublethal hazards of DDE and some PCB congeners.

Genetic Determination of Tolerance to Lethal and Sublethal Copper Concentrations in Field Populations of Daphnia longispina by I. Lopes; D. J. Baird; R. Ribeiro (pp. 43-51).

In order to study the effects of environmental pollution on the genetic diversity of natural populations, two field populations of the cladoceran Daphnia longispina were sampled: one in a reference site (uncontaminated) and the other in a site historically stressed with acid mine drainage (AMD). Five hypotheses were formulated: (1) the stressed population presents a higher tolerance to lethal levels of copper than the reference population, (2) differences in tolerance to lethal levels, observed between the two populations, are due to the loss of sensitive lineages, (3) differences in tolerance to lethal levels of copper between the two populations are due to the appearance of new genotypes, (4) the acquisition of tolerance to lethal levels of copper involved changes in life-history patterns and fitness costs under optimal conditions, and (5) historical contamination by AMD resulted in tolerance differences to sublethal levels between populations, within categories similarly tolerant to lethality, specifically, lineages with similar tolerance to lethal levels from both populations show differences in tolerance to sublethal levels, the stressed population being more tolerant to sublethal levels of contamination than the reference population. Over 125 acclimated cloned lineages, from each population, were exposed to different copper concentrations for 24 hours. At the end of each assay, mortality and feeding inhibition were monitored. Life-cycle traits under optimal conditions were also monitored (time to first brood, number of neonates per brood, inter-brood time, body length, and ingested algae). At lethal levels of copper, significant differences were found in the frequency of sensitive lineages between the two populations. The stressed population did not include the most sensitive lineages, though the most tolerant ones were also present in the reference population. Thus, the hypothesis of presence of new genotypes in the stressed population resulting in an overall increase tolerance of the population at lethal levels was rejected. Changes in life-history patterns were detected, though they were not fully consistent with predictions of life-history theory. Furthermore, these changes in life-history patterns did not involve fitness costs. The fifth hypothesis was rejected since, at sublethal levels of copper, no significant differences were found between the feeding inhibitions of similarly lethal tolerant lineages of the two populations, with only one exception. Therefore, the present study further confirmed the genetic erosion hypothesis and gave further support to the incorporation of genetic diversity measurements into risk assessments.

A Comparison of In Situ and Laboratory Toxicity Tests with the Estuarine Amphipod Eohaustorius estuarius by B. S. Anderson; J. W. Hunt; B. M. Phillips; P. A. Nicely; R. S. Tjeerdema; M. Martin (pp. 52-60).

Amphipod survival in laboratory and in situ exposures was assessed using the eastern Pacific Haustoriid species Eohaustorius estuarius. Toxicity test results were compared using intact (unhomogenized) and homogenized sediment samples in both field and laboratory exposures. Experiments were conducted in Moss Landing Harbor, California, an impaired waterbody under 303 (d) of the US Clean Water Act. Synoptic laboratory and in situ sediment toxicity tests were conducted at two stations: Sandholdt Bridge (SB), the most contaminated station in the harbor, and at the South Jetty (SJ), a more marine station near the mouth of the harbor. We found that Eohaustorius is amenable to in situ testing. Despite highly variable field salinity regimes (6–32 PSU at SB and 21–34 PSU at SJ), in situ control survival was 87% and 84% at SB and SJ, respectively. Amphipod survival was lower in the in situ exposures relative to the laboratory exposures at both sites. Survival at SB was 30% and 76% in the homogenized in situ and laboratory samples, respectively, and 40% and 64% in the intact (unhomogenized) in situ and laboratory samples, respectively. Neither the homogenized or intact samples from the SJ station were toxic in laboratory experiments, but amphipod survival was only 40% in the intact in situ exposure at this station, possibly due to predation. These experiments suggest that the interaction of contaminants and variable physical parameters such as salinity and temperature may have resulted in lower survival in the in situ exposures. Sediment homogenization prior to in situ deployment may have reduced effects of predators in some samples.

Sublethal Effects of Trace Metals (Cd, Cr, Cu, Hg) on Embryogenesis and Larval Settlement of the Ascidian Ciona intestinalis by J. Bellas; R. Beiras; E. Vázquez (pp. 61-66).

Toxicity of Cadmium (Cd), Chromium (Cr), Copper (Cu), and Mercury (Hg) on the early developmental stages of Ciona intestinalis was investigated. Developmental defects of larvae after exposure of gametes throughout their development to the larval stage were assessed. Gamete exposure to increasing metal concentrations resulted in a significant decrease of the percentage of normally hatched larvae, showing median effective concentrations (EC₅₀) of 721 μg/L (6.42 μM) for Cd, 12772 μg/L (226 μM) for Cr, 36.6 μg/L (0.576 μM) for Cu, and 44.7 μg/L (0.223 μM) for Hg. Larval attachment was significantly affected when gametes were exposed to the metals throughout development. The EC₅₀ reducing larval attachment by 50% were 752 μg/L (6.7 μM) for Cd, 15026 μg/L (289 μM) for Cr, 67.8 μg/L (1.607 μM) for Cu, and 78.1 μg/L (0.389 μM) for Hg. Therefore, on a molar basis Hg is three times more toxic than Cu, 20–30 times more than Cd, and 700–1000 times more toxic than Cr, for both responses.

Trace Metals in the Brown Mussel Perna perna from the Coastal Waters Off Yemen (Gulf of Aden): How Concentrations Are Affected by Weight, Sex, and Seasonal Cycle by A. Sokolowski; A. S. Bawazir; M. Wolowicz (pp. 67-80).

The effects of seasonal cycle, sex of individuals, and changes of soft tissues weight on accumulated trace metal concentrations (Cd, Cu, Fe, Mn, Pb, Zn) were examined in the brown mussel Perna perna collected monthly from a natural rocky habitat in the coastal waters off Yemen, the Gulf of Aden, for a period of ten months. Basic hydrological parameters were recorded simultaneously. All metals analyzed displayed seasonal fluctuations with different temporal patterns and variable amplitudes. Similar seasonal cycles were observed for Cu, Mn, and Pb with an increase in accumulated concentration during the rainy period (NE monsoon), and a decrease thereafter. The concentrations of Cu, Mn, and partially Pb appeared to be related to environmental changes, the concentration of Pb possibly also being related to changes in body weight. Accumulated concentrations of Cu and Mn thus seem to reflect actual metal bioavailability in the ecosystem quite efficiently. The tissue levels of Fe and Cd changed inversely to fluctuations in body weight with additional variation due to monsoon-related environmental changes. The behaviors of Fe and Cd are therefore driven by seasonally changing body weight with a considerable contribution of external factors including fluctuations in hydrological conditions and metal exposure. The Zn concentrations tended to increase gradually throughout most of the year regardless of its concentration in the environment. Zinc is considered to be mainly regulated by physiological mechanisms in the mussel, making its accumulated metal concentration independent to some degree of environmental levels. Significant differences in trace metal concentrations between sexes (in favour of females) might have resulted from more intense formation of reproductive tissues and metal accumulation in sexual products of females during the prespawning and spawning periods.

Differences in Prey Capture in Grass Shrimp, Palaemonetes pugio, Collected Along an Environmental Impact Gradient by M. H. Perez; W. G. Wallace (pp. 81-89).

The waterways and associated salt marshes along the western border of Staten Island, New York (Arthur Kill) have long been under environmental duress. Environmental threats include industrial and municipal discharges, oil spills, and possible leachate from landfills. These impacts are compounded due to the low flushing of this body of water. Grass shrimp, Palaemonetes pugio, inhabiting the Arthur Kill are, therefore, potentially at risk of exposure to metal and organic pollutants. Successful prey capture (of live brine shrimp, Artemia franciscana) was used to compare the relative health of shrimp collected from three sites along an environmental impact gradient. Study sites included a relatively unimpacted harbor (Great Kills Harbor, GK) and two creeks adjoining the Arthur Kill (Nassau Creek, NC, and Richmond Creek, RC). Shrimp originating from GK exhibited a rate of prey capture (6.3 prey h⁻¹) that was about two times greater (p < 0.05) than that of shrimp originating from a creek behind a series of landfills (RC, 3.2 prey h⁻¹). The rate of prey capture for shrimp collected from a creek impacted by historic smelting activities (NC) was intermediate (5.4 prey h⁻¹). Laboratory studies with shrimp from a pristine site (Tuckerton, NJ) exposed to RC conditions (i.e., sediment and water) for eight weeks indicate that reduced prey capture can be induced in healthy shrimp. Finally, video analysis suggests that reduced prey capture in RC shrimp may not be the result of less effort, but rather the combination of (1) 80% fewer (p < 0.05) prey being captured with a lunge type of attack and (2) a greater reliance (p < 0.05) on a less efficient grab type of foraging behavior (64% success rate for RC versus 87% success rate for GK; p = 0.058). These results indicate that sublethal toxicity in environmentally impacted populations can occur and that prey capture may be used to assay the relative health of field specimens. Additionally, impaired prey capture may have important implications for the energy flow within impacted environments.

Monitoring Dibutyltin and Triphenyltin in Fresh Waters and Fish in the United States Using Micro-Liquid Chromatography-Electrospray/Ion Trap Mass Spectrometry by T. L. Jones-Lepp; K. E. Varner; D. Heggem (pp. 90-95).

There is a growing body of evidence that toxic organotins are making their way into terrestrial and aquatic mammals including humans. In the United States, one possible route of environmental exposure to organotins (specifically dibutyltin and triphenyltin) is via fresh surface waters and fish taken from those waters. A unique methodology was used for quantitative and speciation of the organotins. This green-chemistry method combines two extraction techniques (solid-phase extraction for waters; hexane/tropolone extraction for fish) with μ-liquid chromatography-electrospray/ion trap mass spectrometry (μ-LC-ES/ITMS) as the detection method. A small survey looking for organotins in fresh surface waters across the United States, and fish from those waters, was conducted. Various concentrations of dibutyltin and triphenyltin were detected in fresh water, ranging from nondetect to 2 ppb, and nondetect to 6 ppb, respectively. In fish dibutyltin and triphenyltin were detected from nondetect to 200 ppb, and nondetect to 400 ppb, respectively.

Respiratory and Reproductive Characteristics of Eastern Mosquitofish (Gambusia holbrooki) Inhabiting a Coal Ash Settling Basin by B. P. Staub; W. A. Hopkins; J. Novak; J. D. Congdon (pp. 96-101).

Coal fly ash and effluent from coal ash settling basins negatively affects metabolism and reproduction in a variety of organisms, including a number of fish species. Some species, most notably the eastern mosquitofish (Gambusia holbrooki), are known to maintain viable populations in areas contaminated by coal ash. While eastern mosquitofish are present in these systems, their degree of tolerance to coal ash has not been investigated using sublethal metrics of exposure. It is possible that eastern mosquitofish persist in habitats affected by coal ash, but experience significant costs such as changes in metabolism and fecundity. Thus, we investigated the effects of coal ash on standard metabolic rate and reproduction of eastern mosquitofish inhabiting a coal-ash contaminated settling basin. Standard metabolic rates of mosquitofish from the ash contaminated site and a reference site (mean O₂ consumption = 0.286 mL/g · h ± 0.007 and 0.291 ± 0.008 mL/g · h, respectively) were not significantly different. Despite elevated contaminant concentrations in ash basin females (selenium, arsenic, copper, and cadmium) and their offspring (selenium), brood sizes and offspring viability did not differ between clutches collected from ash basin and reference site females. Our data provide further evidence of the high degree of tolerance of eastern mosquitofish to exposure to aquatic coal ash disposal generated by power plants. However, the basis for such tolerance to ash remains unclear. Further investigations are required to determine whether such tolerance is a result of species-specific characteristics or population characteristics due to local adaptation.

Synthetic Musk Toxicity to Early Life Stages of Zebrafish (Danio rerio) by G. Carlsson; L. Norrgren (pp. 102-105).

Synthetic musk substances have been found in a number of environmental samples. Some of these chemicals have been detected in concentrations above 1 μg/L in water, which raises concern about possible effects on aquatic life. The toxicity of four synthetic musks, 4-tert-butyl-2,6-dimethyl-3,5-dinitrophenylethanone (musk ketone), 1-tert-butyl-3,5-dimethyl-2,4,6-trinitrobenzene (musk xylene), 1-(5,6,7,8-tetrahydro-3,5,5,6,8,8-hexamethyl-2-naphthalenyl)ethanone (AHTN, tonalide) and 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-[g]-2-benzopyrane (HHCB, galaxolide), were studied in zebrafish by the use of two different early life-stage methods. In the first method, specific developmental characteristics during the first 48 hours were studied. In the second method, hatching and survival times were studied on eggs and larvae. The results on heart rate in the first test gave the following LOECs: musk ketone 10 μg/L, musk xylene and AHTN 33 μg/L, and HHCB showed no effect up to 1000 μg/L. In the study of survival time, LOEC for musk ketone was 100 μg/L, for musk xylene 33 μg/L, and AHTN gave no effect on survival time up to 100 μg/L. The LOECs for musk ketone, musk xylene, and AHTN in this study are in the range of what has been measured in sewage effluents and recipients, and consequently these substances may have adverse impact on wild fish.

Screening of Organochlorines in Freshwater Fish Collected from the Pearl River Delta, People’s Republic of China by H. Y. Zhou; M. H. Wong (pp. 106-113).

HCHs, DDTs, and PCBs were analyzed in fish flesh collected from fish ponds in the Pearl River Delta and compared with those from the Mai Po Marshes (a nature reserve) in Hong Kong, which was considered an unpolluted area. The concentrations for these contaminants were <0.01–7.8 ng/g lipid for HCHs, 22.3–381 ng/g lipid for DDTs, and 60–480 ng/g lipid for PCBs. Nevertheless, levels of HCHs and DDTs in fish flesh were lower than the China National Environmental Protection Agency maximum permissible limits set for foodstuffs. As for PCBs, 16% of fish collected from the Pearl River Delta exceeded the US EPA guideline concentration.

Bioaccumulation Profiles of Chemical Contaminants in Fish from the Lower Willamette River, Portland Harbor, Oregon by D. Sethajintanin; E. R. Johnson; B. R. Loper; K. A. Anderson (pp. 114-123).

Twenty-five PCBs (polychlorinated biphenyls), 15 organochlorine (OC) pesticides, and mercury were determined in fish from the Willamette River in Oregon, including a Portland Harbor superfund site. Fish were collected during the summer of 2000 along a 20-mile stretch of the lower Willamette River. Concentrations of ΣPCBs (sum of 25 individually determined PCB congeners) and ΣDDTs (sum of p,p′-DDT, p,p′-DDE, and p,p′-DDD) in fish ranged from 14 to 530 and from 18 to 510 ng/g-wet weight, respectively. ΣPCBs concentrations at all sites exceeded US EPA fish advisory’s screening values. Hexachlorobiphenyl congener 153 was the most abundant of the PCBs detected and p,p′-DDE was the most abundant OC pesticide detected. Low levels of dieldrin were detected in fish at all sites with the highest concentration at the superfund site (4.6 ng/g-wet weight), while other OC pesticides tested were near or below detection limits (≈2 ng/g). In general, organic chemical contaminant concentrations were highest in fish from the superfund site and were lower further upriver. Smallmouth bass had the highest levels of OC compounds of three fish species examined. They also had the largest site-to-site variations whereas black crappie had little variation throughout the study area. Mercury levels in fish ranged from 13 to 520 ng/g. Historical fish residue data are limited from the Portland Harbor superfund site, what data is available is over a decade old, generally consisted of only a few fish (≤3) and analyses quantified only a few PCB congeners (<3).

Contamination by Persistent Organochlorines in Cetaceans Incidentally Caught Along Brazilian Coastal Waters by N. Kajiwara; S. Matsuoka; H. Iwata; S. Tanabe; F. C. W. Rosas; G. Fillmann; J. W. Readman (pp. 124-134).

Wide ranges of organochlorine residues were determined in the blubber of franciscana (Pontoporia blainvillei), estuarine dolphin (Sotalia guianensis), Atlantic spotted dolphin (Stenella frontalis), and long-beaked common dolphin (Delphinus capensis) incidentally caught along Brazilian coastal waters. Concentrations of DDTs and PCBs were the highest, followed by CHLs, TCPMOH, dieldrin, TCPMe, heptachlor epoxide, HCB, and HCHs. Unexpectedly, significant pollution of PCBs, DDTs, TCPMe, and TCPMOH were observed in cetaceans from Brazil, implying the occurrence of local sources in the Southern Hemisphere comparable to those in the Northern Hemisphere, probably by high industrialization in Brazil. On the other hand, CHLs, HCB, HCHs, heptachlor epoxide, and dieldrin residue levels in Brazilian dolphins were much lower than those in other species from the Northern Hemisphere. Significant correlations of TCPMe and TCPMOH were found along with PCBs and DDTs, indicating the highly bioaccumulative nature of all these compounds and/or possible similar pollution sources.

Efficient In Vitro Paraquat Removal via Irreversible Immobilization into Zeolite Particles by A. Walcarius; R. Mouchotte (pp. 135-140).

A new efficient mineral adsorbent, zeolite ZSM-5, has been evaluated for its ability to durably immobilize the herbicide paraquat in conditions simulating acute poisoning by oral ingestion of this toxic compound. The sorption properties have been studied in water, normal saline solution, as well as in artificial and simulated human gastric juices. Uptake kinetics and capacities have been determined and compared to the ion exchange resin Amberlite IR-120. Significant advantages of ZSM-5 over the resin have been demonstrated, especially with respect to long-term retention capability of the toxic herbicide. This solid is a promising primary treatment of acute paraquat poisoning.

Sections

Personal tools

Archives of Environmental Contamination and Toxicology (v.46, #1)

Sections

Personal tools

Local resources

Archives of Environmental Contamination and Toxicology (v.46, #1)