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Archives of Environmental Contamination and Toxicology (v.33, #4)
Effects of a Lipophilic Environmental Pollutant (DDT) on the Phospholipid and Fatty Acid Contents of Bacillus stearothermophilus by M. M. Donato; A. S. Jurado; M. C. Antunes-Madeira; V. M. C. Madeira (pp. 341-349).
Cultures of Bacillus stearothermophilus grown in a complex medium containing 1 μM DDT, exhibited longer lag adapting periods, decreased specific growth rates, and lower growth yield as compared to control cultures. The membrane lipid composition from cells grown in the presence of the insecticide was significantly different from that of control cells. The effects of DDT (2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane) on growth and lipid composition of bacterial cells were also determined in cultures grown in a medium supplemented with Ca2+ (membrane stabilizer) to further clarify the influence of growth conditions on bacterial responses to the toxicant. The main membrane-lipid changes induced by DDT relate to a very significant increase (74%) of the relative concentration of a phosphoglycolipid, an increase of the phosphatidylethanolamine content, with a parallel decrease of phosphatidylglycerol and an unidentified phospholipid X0. The changes of the phospholipid acyl chains relate to an increase of straight chains and a parallel decrease of branched chains. The effects of DDT-induced lipid composition alterations on membrane physical properties were monitored by fluorescence polarization studies with bacterial polar lipid dispersions. Changes in the membrane lipids upon growing the bacteria in a DDT-containing medium promoted, as expected, more ordered membranes with a shift of the phase transition temperature to higher values. Data are interpreted in the frame of an adaptation mechanism to counteract the membrane perturbation resulting from the accumulation of the insecticide molecules in the lipid bilayer.
Comparative Fate of 1,1-Diphenylethylene (DPE), 1,1-Dichloro-2,2-bis(4-Chlorophenyl)-Ethylene (DDE), and Pentachlorophenol (PCP) Under Alternating Aerobic and Anaerobic Conditions by C. Strömpl; J. H. Thiele (pp. 350-356).
Bacterial degradation of 1,1-dichloro-2,2-bis-(4-chlorophenyl)-ethylene (DDE) and its dehalogenated derivative 1,1-diphenylethylene (DPE) has not yet been shown and may require culture adaptation and special culture conditions. We compared the degradability of DPE, DDE, and pentachlorophenol (PCP) in aerobic/anaerobic sequenced batch reactor systems. Reactors operated under aerobic/methanogenic and aerobic/denitrifying conditions were inoculated with bacterial consortia from anaerobic granular sludge, long-term PCP- and DDE-contaminated soil, and pulp and paper waste pond sediment. The culture was gradually acclimatized to low concentrations of DPE, DDE, and PCP in defined minimal growth media with benzoate, phenol, ethanol, and formate as primary carbon sources. DDE remained refractory for 105 days, whereas DPE and PCP were degraded. This suggests that DDE is extremely recalcitrant to degradation by aromatic organochlorine-degrading bacteria from long-term polluted soils and sediments. The results confirm that the chlorination of DDE is a major biodegradation barrier for adapted bacteria under aerobic and anaerobic conditions.
Concentrations of Chlorinated Organic Compounds in Biota and Bed Sediment in Streams of the San Joaquin Valley, California by L. R. Brown (pp. 357-368).
Samples of resident biota and bed sediments were collected in 1992 from 18 sites on or near the floor of the San Joaquin Valley, California, for analysis of 33 organochlorine compounds. The sites were divided into five groups on the basis of physiographic region and land use. Ten compounds were detected in tissue, and 15 compounds were detected in bed sediment. The most frequently detected compound in both media was p,p′-DDE. Concentrations of ΣDDT (sum of o,p′- and p, p′ forms of DDD, DDE, and DDT) were statistically different among groups of sites for both tissue and sediment (Kruskal-Wallis, p < 0.05). Concentrations in both media were highest in streams draining the west side of the valley. Concentrations of ΣDDT in tissue were significantly correlated with specific conductance, pH, and total alkalinity (p < 0.05), which are indicators of the proportion of irrigation return flows in stream discharge. Concentrations in sediment on a dry-weight basis were not correlated with these water-quality parameters, but total organic carbon (TOC) normalized concentrations were significantly correlated with specific conductance and pH (p < 0.05). Regressions of the concentration of ΣDDT in tissue, as a function of ΣDDT in bed sediment, were significant and explained up to 76% of the variance in the data. The concentration of ΣDDT in sediment may be related to mechanisms of soil transport to surface water with bioavailability of compounds related to the concentration of TOC in sediment. The results of this study did not indicate any clear advantage to using either bed sediment or tissues in studies of organochlorine chemicals in the environment. Some guidelines for protection of fish and wildlife were exceeded. Concentrations of organochlorine chemicals in biota, and perhaps sediment, have declined from concentrations measured in the 1970s and 1980s, but remain high compared to other regions of the United States.
Concentration and Transport of Chlordane and Nonachlor Associated with Suspended Sediment in the Mississippi River, May 1988 to June 1990 by C. E. Rostad (pp. 369-377).
Technical chlordane, a formerly widely used organochlorine pesticide, has become widespread in the environment. The distribution of technical chlordane in riverine environments may be due in part to resuspension and aqueous transport of contaminated bed sediment. To test this hypothesis, the Mississippi River was sampled for suspended sediment five times over a two-year period, at up to 17 sites from St. Louis to below New Orleans, including major tributaries. The ratio of chlordane to nonachlor concentrations averaged 3.6 during May–June 1988 for the Mississippi River below its confluence with the Ohio River. During March–April 1989, the ratio was 0.6, suggesting weathered technical chlordane contributions to the suspended sediment. During June 1989, the ratio averaged 1.1, indicating some input of less weathered technical chlordane. During February–March and May–June 1990, the ratios again shifted, from 0.8 to 1.3. This shifting ratio is likely due to resuspension of weathered technical chlordane associated with bed sediment during spring runoff. Annual transport by suspended sediment from the Mississippi River to the Gulf of Mexico was estimated to be 110 kg of chlordane and 100 kg of nonachlor.
Organochlorine Pesticides and Polychlorinated Biphenyls (PCBs) in Sediments and Biota from Four US Arctic Lakes by S. M. Allen-Gil; C. P. Gubala; R. Wilson; D. H. Landers; T. L. Wade; J. L. Sericano; L. R. Curtis (pp. 378-387).
Organochlorine (OC) concentrations in surface sediment, snails (Lymnea sp.), and two freshwater fish species (grayling, Thymallus arcticus; and lake trout, Salvelinus namaycush) from four lakes in the US Arctic were determined. In surface sediment, chlorinated benzenes (including hexachlorobenzene, HCB), and p,p′-DDT were the primary analytes detected (max = 0.7 ng/g dry wt), while individual polychlorinated biphenyl (PCB) congeners were always below 0.1 ng/g. A wider range of compounds and higher concentrations were found in lake trout, the top predatory fish species in the same lakes. The concentration ranges for hexachlorocyclohexanes (HCHs), chlordane-related compounds (CHLORs), DDTs, and PCBs in lake trout and grayling were similar to those reported for other arctic freshwater fish (1–100 ng/g wet wt), but one to two orders of magnitude lower than Great Lakes salmonids. Nitrogen isotope analysis confirmed that differences in OC concentrations between grayling and lake trout are explained partly by differences in food web position.
Comparative Bioaccumulation of Chlorinated Hydrocarbons from Sediment by Two Infaunal Invertebrates by J. P. Meador; N. G. Adams; E. Casillas; J. L. Bolton (pp. 388-400).
Bioaccumulation of chlorinated hydrocarbons (CHs) from field-contaminated sediments by two infaunal invertebrates, Rhepoxynius abronius (a non–deposit feeding amphipod) and Armandia brevis (a nonselective, deposit-feeding polychaete), was examined and species responses were compared. Sediments were selected over a large geographical area of the Hudson-Raritan estuary to assess the potential for bioaccumulation from a typical urban estuary. Unlike polycyclic aromatic hydrocarbons (PAHs) from these sediments, concentrations of CHs in interstitial water (IW) indicated that partition coefficients (Koc) were generally as expected, especially when based on predicted, nonsorbed, interstitial water CH concentrations (IWfree). Correlations between amphipod and polychaete tissue residues revealed that these species were responding similarly to a gradient of CH concentrations in sediment. While tissue residues and BAFloc (lipid/organic carbon normalized bioaccumulation factor) values for the trichlorobiphenyls were similar for both species, accumulation in the polychaete was three to 10 times higher for the more hydrophobic PCBs, which was attributed to differences in the route of exposure. A negative correlation between the bioaccumulation factor (BAF) and total organic carbon (TOC) was found for both species, which was expected according to equilibrium partitioning theory. Because it was assumed that the amphipod was not feeding in these tests and the polychaete was ingesting sediment, comparison of their tissue residues and bioaccumulation factors was useful for highlighting the importance of sediment ingestion, especially for short-term, nonequilibrium exposures. These results may also help elucidate the limitations associated with assessing bioaccumulation and the resultant toxic response in standard 10-day toxicity tests with similar invertebrates.
Population Growth Kinetics of Tetrahymena pyriformis Exposed to Selected Nonpolar Narcotics by A. P. Bearden; B. W. Gregory; T. W. Schultz (pp. 401-406).
This study describes effects of selected nonpolar narcotics of varying hydrophobicity (quantified by the 1-octanol-water partition coefficient, log Kow) and molecular structure on the population growth kinetics of the freshwater ciliate Tetrahymena pyriformis. The response of Tetrahymena exposed to different nonpolar narcotics varied from a change in generation time to a change in lag phase with similar generation time compared to control. Two narcotics with high (>3.00), intermediate (>0.00 and <3.00), and low log Kow (<0.00) values were tested. Growth of Tetrahymena inhibited up to 85% by the high log Kow toxicants (2-decanone and butylbenzene) grew with similar rates as the control, but exhibited increased lag time, suggesting that the protozoan became acclimated to toxicant stress. Results from growth of Tetrahymena in the low log Kow toxicants (ethanol and acetone) indicate an increased generation time with increasing concentration. Cells inhibited by the intermediate log Kow chemicals, 1-pentanol and anisole, exhibited a response that was a combination of the previously mentioned two contrary responses. Cells inhibited <35% with 1-pentanol and <50% with anisole grew with similar generation times as control flasks, whereas in cells inhibited >35% or >50%, respectively, the doubling times were longer than control growth.
Evaluation of Three Larval Instars of the Midge Chironomus petiolatus as Bioassay Tools Using a Computationally Intensive Statistical Algorithm by A. Larrain; A. Riveros; E. Bay-Schmith; R. Roa (pp. 407-414).
Sensitivity to toxicants is a major criterion for selecting organisms for bioassay testing. If a sensitive species is also abundant and occupies a role as prey for many other species within a community, then the species become a valuable tool in environmental monitoring. These features apply to larval midge Chironomus petiolatus in freshwater environments of central Chile. The youngest larval instar is the most sensitive and presents the additional feature of lower survival within control arenas, making it more difficult to discern toxicant-related mortality from background mortality. In this work, we perform acute bioassays with the three larval stages of C. petiolatus and K2Cr2O7 as reference toxicant, with the goal of selecting a particular instar as the best bioassay tool using two criteria: sensitivity and background mortality. Sensitivity is evaluated through Monte Carlo estimation of LC50 and background mortality through bootstrap resampling, and a final Bioassay Performance Index as the product of LC50 and background mortality. For this task we developed a new computationally intensive statistical algorithm. Results show that the best bioassay tool is not the youngest and most sensitive instar but an intermediate one.
Effects of Sublethal Copper Exposure on Copper Accumulation, Food Consumption, Growth, Energy Stores, and Nucleic Acid Content in Common Carp by G. De Boeck; A. Vlaeminck; R. Blust (pp. 415-422).
Juvenile common carp were exposed for 28 days to three different sublethal copper concentrations (0.20 μM, 0.55 μM, and 0.80 μM). Food consumption was monitored on a daily basis during the exposure period, while growth, copper accumulation, energy stores, and nucleic acid contents were assessed weekly. Copper exposure to 0.80 μM affected both growth and feeding behavior in common carp. At 0.55 μM, growth was affected despite normal food consumption. Even at the lowest copper concentration (0.20 μM), metabolic demand for the fish increased, challenging the carp with an increased demand for food. Copper accumulation mainly occurred in the liver, reaching an equilibrium between uptake and excretion after 1 month of exposure. Substantial biochemical changes were observed at the two highest copper exposure concentrations, but the correlation between growth rate and RNA:DNA ratio was poor considering the substantial differences in growth rate. The use of the RNA:DNA ratio as a sensitive biomarker is questioned.
Mercury Distribution in Sediments and Bioaccumulation by Fish in Two Oregon Reservoirs: Point-Source and Nonpoint-Source Impacted Systems by J.-G. Park; L. R. Curtis (pp. 423-429).
Mercury pollution was compared in two Oregon reservoirs of similar size and age, located within the same ecoregion. Cottage Grove Reservoir was distinguished by a history of mercury mining and processing within its watershed, while Dorena Reservoir was not. Mercury concentrations in sediments of the reservoirs, tributary streams, and three species of fish were measured. Sediment mercury concentrations in the main tributary of Cottage Grove Reservoir, which drains the subbasin where past mercury mining occurred, was tenfold higher than mercury in sediments from other reservoir tributaries. There were no significant differences between sediment mercury concentrations in the tributaries of Dorena Reservoir. The average mercury concentration in the basin sediment of Cottage Grove Reservoir (0.67 ± 0.05 μg/g dry wt) was higher than for Dorena Reservoir (0.12 ± 0.01 μg/g dry wt). At Cottage Grove Reservoir, maximum mercury concentrations were near or exceeded 1 μg/g wet wt for largemouth bass (Micropterus salmonides) and bluegill (Lepomis macrochirus) epaxial muscle. Muscle mercury concentrations in largemouth bass and crappie (Pomoxis nigromaculatus) from Cottage Grove Reservoir were significantly higher than from the same species from Dorena Reservoir. Numbers of bluegill of the same age available from both reservoirs were too small for statistical comparisons. Mercury concentrations in largemouth bass muscle fluctuated annually in both reservoirs. Fish ages were consistently positively correlated with muscle mercury concentrations in only the point-source-impacted reservoir. These results indicated that a point source, Black Butte Mine, contributed amounts of mercury greatly in excess of mobilization from natural deposits, atmospheric deposition, and small-scale uses of the metal as an amalgamating agent in gold mining.
Organochlorine and Heavy Metal Residues in Breast Muscle of Known-Age Thick-Milled Murres (Uria lomvia) from the Canadian Arctic by G. M. Donaldson; B. M. Braune; A. J. Gaston; D. G. Noble (pp. 430-435).
Thick-billed murres (Uria lomvia) originating from breeding colonies in the Canadian Arctic were collected on their wintering grounds off the coast of Newfoundland. Murres had been previously banded such that the age of each bird could be determined upon collection. This allowed us to explore the possible relationships between age and contaminant levels in the thick-billed murre. Samples of breast muscle were analyzed for organochlorines (chlorobenzenes, hexachlorocyclohexanes, DDTs, chlordanes, mirex, dieldrin, and PCBs) and metals (selenium, cadmium, mercury, and lead). Levels of both organochlorine and metal residues were sufficiently low so that toxic effects were unlikely. First-year birds contained lower levels of DDTs, mirex, dieldrin, and PCBs compared with older birds, reflecting lower levels of contamination of these compounds in food chains at breeding colonies located at higher latitudes. Higher levels of chemical residues in older birds may reflect greater direct input of those organochlorines into the wintering grounds via the highly contaminated St. Lawrence River. Levels of chlorobenzenes, hexachlorocyclohexanes, and chlordanes, which reflect atmospheric deposition, were not detected at higher levels in older birds. Of the metals, only cadmium was detected at higher levels in older birds.
Age Differences in Metals in the Blood of Herring (Larus argentatus) and Franklin's (Larus pipixcan) Gulls by J. Burger; M. Gochfeld (pp. 436-440).
Concentrations of heavy metals and selenium were measured in the blood of adult and young herring (Larus argentatus) and Franklin's (Larus pipixcan) gulls collected during the same breeding season in colonies in the New York Bight and in northwestern Minnesota, respectively. Concentrations were expected to be higher in young herring gulls collected in an urban, industrialized area, compared to young Franklin's gulls collected in a relatively pristine prairie marsh. Exposure is similar for the fledgling and adult gulls because by the time the blood of young gulls is drawn both adults and young have been eating foods from the surrounding region for two months; leading to the prediction that metal levels should be similar in adults and young. However, young Franklin's gulls had significantly higher levels of arsenic, cadmium, and manganese than adults; adults had significantly higher levels of mercury and selenium. Young herring gulls had significantly higher concentrations of arsenic and selenium, but lower levels of lead than adult herring gulls. Interspecific comparisons indicated that young Franklin's gulls had significantly higher levels of cadmium than young herring gulls, and adult Franklin's gulls had higher levels of selenium and chromium than adult herring gulls, but for all other comparisons herring gulls had higher levels of metals in their blood. Young herring gulls chicks had higher arsenic, manganese, and selenium levels and lower cadmium and lead levels in 1993 than in 1994. Overall, the levels in the two species were usually within an order of magnitude.
A Comparison of Mercury Levels in Feathers and Eggs of Osprey (Pandion haliaetus) in the North American Great Lakes by K.D. Hughes; P.J. Ewins; K.E. Clark (pp. 441-452).
Osprey (Pandion haliaetus) eggs and chick feathers were collected for mercury analysis from nests at four Great Lakes study areas in Ontario (three “naturally formed” lakes in southern Ontario and one reservoir in northern Ontario) and two New Jersey study areas in 1991–1994. Adult osprey feathers were sampled from three Great Lakes study areas in 1991. Feathers sampled from chicks (approximately 28–35 days old) appear to be better indicators of local contaminant conditions since spatial patterns of mercury in known prey, yellow perch (Perca flavescens), also collected in these areas, were more similar to chick feathers than to eggs. Mercury levels were less variable in chick feathers than in eggs. Estimates of biomagnification factors using prey of known size at these areas were also less variable in feathers than in eggs. At naturally formed lakes, no significant correlation in mercury levels between eggs and chick feathers from the same nest was apparent, suggesting that the source of mercury contamination was not the same in these two tissues: mercury levels in eggs reflect mercury acquired on the breeding grounds, wintering grounds, and migratory route; mercury levels in chick feathers reflect local dietary conditions on the breeding grounds. Mercury levels in both osprey eggs and chick feathers were higher at the Ogoki Reservoir than at naturally formed lakes. Adult osprey feathers had higher mercury concentrations than chick feathers. Mercury levels in osprey eggs, chick feathers, and adult feathers did not approach levels associated with toxic reproductive effects.
Blood Levels of DDT and Breast Cancer Risk Among Women Living in the North of Vietnam by A. Schecter; P. Toniolo; L. C. Dai; L. T. B. Thuy; M. S. Wolff (pp. 453-456).
A positive association has been reported between elevated tissue organochlorines (p,p′-DDT/p,p′-DDE, PCBs, dioxins) and breast cancer in some case–control studies and occupational cohort studies. We previously reported high serum levels of p,p′-DDT and its metabolite p,p′-DDE in women living throughout Vietnam. We report here the results of a small hospital-based case–control study examining the association between blood levels of p,p′-DDT/p,p′-DDE and the risk of invasive breast cancer among residents of the north of Vietnam—an area where insecticides such as p,p′-DDT have been heavily used in the recent past. The study was conducted among patients admitted to a single hospital in the capital city of Hanoi in 1994. Study subjects were 21 women newly diagnosed with invasive adenocarcinoma of the breast, who served as cases, and 21 women of similar age with fibrocystic breast disease, who served as controls. No increase was evident in the relative risk of breast cancer with increasing tertiles of serum concentration of the compounds of interest, even after adjustment for major potential confounders, such as age at menarche, parity, history of lactation, and body weight. These results suggest that recent and past exposure to p,p′-DDT does not play an important role in the etiology of breast cancer among women living in a country with a tropical climate where insecticide use for mosquito control is common.