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At least 253 records · Page 14Linked to original sources
USGS2000

Organochlorine and metal contaminant exposure and effects in hatching Black-Crowned Night Herons (Nycticorax nycticorax) in Delaware Bay

Pea Patch Island in Delaware Bay is the site of the largest heronry north of Florida. From 1989–93, the population of nine species of wading birds numbered approximately 12,000 pairs, but has recently declined to about 7,000 pairs. Because Delaware Bay is a major shipping channel and receives anthropogenic releases of toxic substances from agricultural, industrial, and municipal point and nonpoint sources, contaminant exposure and effects to the heronry have been an ongoing concern. In 1997, pipping (early hatching stage) black-crowned night herons ( Nycticorax nycticorax ) were collected from separate nests at Pea Patch Island and from a coastal reference site, Middle Island in Rehoboth Bay, Delaware. There was no evidence of malformations or hepatic histopathological lesions in embryos, and their body and liver weights did not differ between sites. Biomarkers of petroleum hydrocarbons, polyhalogenated contaminant, and metal exposure (cytochrome P450 induction and oxidative stress responses) did not differ (p > 0.05) between sites, although activities of benzyloxy- O -dealkylase and ethoxyresorufin- O -dealkylase were somewhat elevated in 3 of the 15 embryos collected from Pea Patch Island. Concentrations of 21 organochlorine pesticides and metabolites were relatively low at both sites, with p,p′ -DDE values well below the threshold associated with eggshell thinning. Although total PCB concentration was modestly elevated (p < 0.05) in Pea Patch Island heron embryos, levels of arylhydrocarbon receptor-active PCB congeners, polychlorinated dibenzodioxins and dibenzofurans, and toxic equivalents were low and did not differ between sites. Concentrations of Cd and Mn in pipping embryos from Pea Patch Island were slightly greater (p < 0.05) than values observed in Middle Island embryos, but levels of these and the other metals and metalloids ( e.g. , Hg and Se) were below values associated with toxicity. In conclusion, it seems unlikely that chlorinated hydrocarbon and metal contaminant exposure constitutes a direct threat to the reproductive success of black-crowned night herons at Pea Patch Island. However, low-level exposure to these contaminants may constitute one of many stressors that in combination could adversely affect the stability of the wading bird population at this large heronry.

Delaware↗
USGS2000

Field evaluation of lead effects on Canada geese and mallards in the Coeur d'Alene River Basin, Idaho

Hatch year (HY) mallards ( Anas platyrhynchos ) in the Coeur d'Alene (CDA) River Basin had higher concentrations of lead in their blood than HY Western Canada geese ( Branta canadensis moffitti ) (geometric means 0.98 versus 0.28 μg/g, wet weight). The pattern for adults of both species was similar, although geometric means (1.77 versus 0.41 μg/g) were higher than in HY birds. HY mallards captured in the CDA River Basin in 1987 contained significantly lower lead concentrations in their blood than in 1994–95 (0.36 versus 0.98 μg/g); however, some very young mallards were sampled in 1987, and concentrations in adults were not significantly different in 1987, 1994, or 1995 (1.52, 2.07, 1.55 μg/g, respectively). Both species in the CDA River Basin in 1994–95 showed significantly reduced red blood cell delta-aminolevulinic acid dehydratase (ALAD) activity compared to the reference areas: Canada geese (HY −65.4 to −86.0%, adults −82.3%), and mallards (HY −90.7 to −95.5%, adults −94.1%). Canada goose goslings were divided into size classes, and the two smaller classes from the CDA River Basin had significantly elevated free erythrocyte protoporphyrin (protoporphyrin) levels compared to the reference area (15.2× and 6.9×). HY and adult mallards both had significantly elevated protoporphyrin (5.9× and 7.5×). Recognizing that interspecific differences exist in response and sensitivity to lead, it appears (at least for hemoglobin and hematocrit) that Canada geese were more sensitive to lead than mallards, i.e ., adverse hematologic effects occur at lower blood lead concentrations. Only Canada geese from the CDA River Basin, in spite of lower blood lead concentrations, had significantly reduced mean hemoglobin and hematocrit values. No euthanized Canada geese (all HYs) from CDA River Basin were classified as clinically lead poisoned, but 38 Canada geese found dead in the CDA River Basin during a concurrent study succumbed to lead poisoning between 1992 and 1997. Only 6 (15.8%) of these 38 contained ingested lead shot, which contrasts greatly with the 75–94% incidence of ingested lead shot when mortality was due to lead shot ingestion. Lead from other contaminated sources ( i.e ., sediments and vegetation) in the CDA River Basin was strongly implicated in most Canada goose deaths. Based on the 31 live mallards and Canada geese collected in the CDA River Basin, which were representative of the live populations blood sampled only, the prevalence of subclinical and clinical lead poisoning (as determined by liver lead concentrations, excluding birds with ingested lead shot) was higher in mallards: subclinical (4 of 8, 50% HYs and 6 of 11, 55% adults); clinical (0% HYs and 4 of 11, 36% adults), with less data available for Canada geese (only 1 of 9, 11% HYs marginally subclinical). The clinically lead-poisoned mallards had extremely high concentrations of lead in blood (2.69–8.82 μg/g) and liver (6.39–17.89 μg/g). Eight mallards found dead in the CDA River Basin during a concurrent study were diagnosed as lead poisoned, and only one (12.5%) contained ingested lead shot, which again strongly implicates other lead sources. The finding of dead lead poisoned Canada geese together with the high percentage of live mallards classified as subclinically or clinically lead poisoned, in combination with the low incidence of ingested lead shot causes us concern for both of these species, which live in association with lead-contaminated sediment in the CDA River Basin.

Idaho↗
USGS2000

Developmental toxicity of lead-contaminated sediment to mallard ducklings

Sediment ingestion has been identified as an important exposure route for toxicants in waterfowl. The toxicity of lead-contaminated sediment from the Coeur d'Alene River Basin (CDARB) in Idaho was examined on posthatching development of mallard ( Anas platyrhynchos ) ducklings for 6 weeks. Day-old ducklings received either untreated control diet, clean sediment (24%) supplemented control diet, CDARB sediment (3,449 μg/g lead) supplemented diets at 12% or 24%, or a positive control diet containing lead acetate equivalent to that found in 24% CDARB. The 12% CDARB diet resulted in a geometric mean blood lead concentration of 1.41 ppm (WW) with over 90% depression of red blood cell ALAD activity and over threefold elevation of free erythrocyte protoporphyrin concentration. The 24% CDARB diet resulted in blood lead of 2.56 ppm with over sixfold elevation of protoporphyrin and lower brain weight. In this group the liver lead concentration was 7.92 ppm (WW), and there was a 40% increase in hepatic reduced glutathione concentration. The kidney lead concentration in this group was 7.97 ppm, and acid-fast inclusion bodies were present in the kidneys of four of nine ducklings. The lead acetate positive control group was more adversely affected in most respects than the 24% CDARB group. With a less optimal diet (mixture of two thirds corn and one third standard diet), CDARB sediment was more toxic; blood lead levels were higher, body growth and liver biochemistry (TBARS) were more affected, and prevalence of acid-fast inclusion bodies increased. Lead from CDARB sediment accumulated more readily in duckling blood and liver than reported in goslings, but at given concentrations was generally less toxic to ducklings. Many of these effects are similar to ones reported in wild mallards and geese within the CDARB.

Idaho↗
USGS2014

A comparison of selected diversity, similarity, and biotic indices for detecting changes in benthic-invertebrate community structure and stream quality

Implementation of advanced wastewater treatment at the two municipal wastewater-treatment plants for Indianapolis, Indiana, resulted in substantial improvement in the quality of the receiving stream and significant changes in the benthic-invertebrate community. Diversity, similarity, and biotic indices were compared to determine which indices best reflected changes in the composition of the biota in the river. None of the indices perfectly reflected the changes in river quality or community structure. Similarity indices, especially percentage similarity, exhibit the most promise of the three classes of indices. Diversity indices were least useful, wrongly indicating that water quality deteriorated after the upgrade of the wastewater-treatment plants. The most descriptive tool in analyzing the data was the percentage of Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa present. Using a mixture of indices and other analytical tools, such as EPT, in the analysis of biological data will ensure the most effective investigations of water quality.

Archives of Environmental Contamination and Toxico↗
USGS2001

Behavioral dysfunctions correlate to altered physiology in rainbow trout (Oncorynchus mykiss) exposed to cholinesterase-inhibiting chemicals

We selected four metrics of swimming behavior (distance swam, speed, rate of turning, and tortuosity of path) and the commonly used biochemical marker, brain cholinesterase (ChE) activity, to assess (1) the sensitivity and reliability of behavior as a potential biomarker in monitoring work, (2) the potential for these endpoints to be used in automated monitoring, and (3) the linkage between behavior and its underlying biochemistry. Malathion-exposed fish exhibited large decreases in distance and speed and swam in a more linear path than control fish after 24 h exposure. By 96 h exposure, fish still swam slower and traveled less distance; fish fully recovered after 48 h in clean water. Diazinon-exposed fish exhibited decreases in distance, speed, and turning rate compared to controls. After 48 h recovery in clean water, fish exposed to diazinon had not recovered to control levels. The behavioral responses provided measures of neurotoxicity that were easily quantifiable by automated means, implying that the inclusion of behavior in monitoring programs can be successful. Furthermore, correlations between behavior and biochemical endpoints, such as ChE inhibition, suggest that this approach can provide a meaningful link between biochemistry and behavior and can provide useful information on toxicant impacts.

Archives of Environmental Contamination and Toxico↗
USGS2001

Organochlorine contaminants and biomarker response in double-crested cormorants nesting in Green Bay and Lake Michigan, Wisconsin, USA

Double-crested cormorant ( Phalacrocorax auritus ) eggs at pipping and sibling 10-day-old chicks were collected from two colonies in Green Bay, WI, one colony in Lake Michigan, WI, and reference colonies in South Dakota and Minnesota. Egg contents and chicks were analyzed for organochlorine contaminants including polychlorinated biphenyl (PCB) congeners. Livers of embryos and chicks were assayed for hepatic microsomal ethoxyresorufin- O -dealkylase (EROD) activity. Eggshell thickness and the physical dimensions of embryo brains were measured. Concentrations of organochlorines, including p,p′-DDE (p,p′-dichlorodiphenyldichloroethylene), PCBs, and PCB congeners were generally an order of magnitude higher in eggs and chicks from Wisconsin than from reference locations. Total PCBs averaged 10–13 μg/g wet weight in eggs from three Wisconsin colonies compared to 0.9 μg/g PCBs from reference locations. Double-crested cormorant chicks accumulated on average 33–66 μg PCBs/day and 7–12 μg p,p′-DDE/day in the Wisconsin colonies compared to 0 μg PCBs/day and 1 μg p,p′-DDE/day in the reference colonies. At pipping, EROD activity in the livers of cormorant embryos was significantly higher in the Wisconsin colonies and significantly correlated with PCBs and the toxic equivalents (TEQs) of aryl hydrocarbon-active PCB congeners relative to 2,3,7,8-tetrachlorodibenzo- p -dioxin. However, in 10-day-old chicks EROD activity was not consistently different among colonies and was not correlated with PCBs or TEQs. A significant negative relationship between embryo brain asymmetry and the size of the egg suggested that physical constraint might be an important factor influencing the response of this bioindicator. Thinner eggshells in two colonies located near Door County, Wisconsin, suggested that historic p,p′-DDE residues associated with orchards are still an important source of p,p′-DDE in the local environment.

Minnesota, South Dakota, Wisconsin↗
USGS2001

Cyclodiene insecticide, DDE, DDT, arsenic, and mercury contamination of big brown bats (Eptesicus fuscus) foraging at a Colorado Superfund site

Rocky Mountain Arsenal (RMA) National Wildlife Area, near Denver, Colorado, is a Superfund site contaminated by past military and industrial uses, including pesticide manufacturing. From an ecosystem standpoint, the most critical contaminants at RMA are certain cyclodiene insecticides and metabolites, p,p ′-DDE, p,p ′-DDT, arsenic, and mercury. Bats are important ecosystem components that can be impacted by persistent contaminants because of their position in the food chain and their potential longevity and thus duration of exposure. Big brown bats ( Eptesicus fuscus ) were captured (n = 51) while foraging at RMA in the summers of 1997 and 1998 for determination of concentrations of contaminants of concern in carcasses, brains, and stomach contents. Adult females (n = 15) were also tracked by radiotelemetry to determine locations of nearest maternity roosts for sampling of guano for contaminant analysis and inspection for potential contaminant-induced mortality. Bats captured while foraging at RMA had measurable quantities of dieldrin and DDE in masticated insect samples from stomach contents and significantly higher concentrations of dieldrin, DDE, DDT, and mercury (juveniles) in carcasses than big brown bats (n = 26) sampled at a reference area 80 km to the north. Concentrations of dieldrin and DDE in brains of bats captured while foraging at RMA were also greater than in bats from the reference area, but not high enough to suggest mortality. Maximum concentrations of DDE, DDT, and cyclodienes in brains of big brown bats were found in adult males from RMA. Guano from the two closest known roosts had significantly higher concentrations of dieldrin, DDE, and mercury than guano from two roosts at the reference area. Dieldrin concentrations in carcasses of bats from RMA were highest in juveniles, followed by adult males and adult females. DDE concentrations in carcasses were lowest in adult females at both sites and highest in adult males at RMA. No contaminant-related mortality was obvious at the small maternity colonies near RMA. Big brown bats show higher contamination than most other mammals previously sampled at this site. Concentrations and proportions of samples with detectable residues of dieldrin in carcasses of big brown bats from RMA were similar to or exceeded reports for this species from elsewhere in the United States some 25 years ago, prior to or just following restrictions on use of this compound.

Archives of Environmental Contamination and Toxico↗
USGS2001

Distribution of inorganic mercury in Sacramento River water and suspended colloidal sediment material

The concentration and distribution of inorganic Hg was measured using cold-vapor atomic fluorescence spectrometry in samples collected at selected sites on the Sacramento River from below Shasta Dam to Freeport, CA, at six separate times between 1996 and 1997. Dissolved (ultrafiltered, 0.005 μm equivalent pore size) Hg concentrations remained relatively constant throughout the system, ranging from the detection limit (< 0.4 ng/L) to 2.4 ng/L. Total Hg (dissolved plus colloidal suspended sediment) concentrations ranged from the detection limit at the site below Shasta Dam in September 1996 to 81 ng/L at the Colusa site in January 1997, demonstrating that colloidal sediment plays an important role in the downriver Hg transport. Sequential extractions of colloid concentrates indicate that the greatest amount of Hg associated with sediment was found in the “residual” (mineral) phase with a significant quantity also occurring in the “oxidizable” phase. Only a minor amount of Hg was observed in the “reducible” phase. Dissolved Hg loads remained constant or increased slightly in the downstream direction through the study area, whereas the total inorganic Hg load increased significantly downstream especially in the reach of the river between Bend Bridge and Colusa. Analysis of temporal variations showed that Hg loading was positively correlated to discharge.

Archives of Environmental Contamination and Toxico↗
USGS2001

Predictions of sediment toxicity using consensus-based freshwater sediment quality guidelines

The objectives of this study were to compare approaches for evaluating the combined effects of chemical mixtures on the toxicity in field-collected sediments and to evaluate the ability of consensus-based probable effect concentrations (PECs) to predict toxicity in a freshwater database on both a national and regional geographic basis. A database was developed from 92 published reports, which included a total of 1,657 samples with high-quality matching sediment toxicity and chemistry data from across North America. The database was comprised primarily of 10- to 14-day or 28- to 42-day toxicity tests with the amphipod Hyalella azteca (designated as the HA10 or HA28 tests) and 10- to 14-day toxicity tests with the midges Chironomus tentans or C. riparius (designated as the CS10 test). Mean PEC quotients were calculated to provide an overall measure of chemical contamination and to support an evaluation of the combined effects of multiple contaminants in sediments. There was an overall increase in the incidence of toxicity with an increase in the mean quotients in all three tests. A consistent increase in the toxicity in all three tests occurred at a mean quotient > 0.5, however, the overall incidence of toxicity was greater in the HA28 test compared to the short-term tests. The longer-term tests, in which survival and growth are measured, tend to be more sensitive than the shorter-term tests, with acute to chronic ratios on the order of six indicated for H. azteca . Different patterns were observed among the various procedures used to calculate mean quotients. For example, in the HA28 test, a relatively abrupt increase in toxicity was associated with elevated polychlorinated biphenyls (PCBs) alone or with elevated polycyclic aromatic hydrocarbons (PAHs) alone, compared to the pattern of a gradual increase in toxicity observed with quotients calculated using a combination of metals, PAHs, and PCBs. These analyses indicate that the different patterns in toxicity may be the result of unique chemical signals associated with individual contaminants in samples. Though mean quotients can be used to classify samples as toxic or nontoxic, individual quotients might be useful in helping identify substances that may be causing or substantially contributing to the observed toxicity. An increase in the incidence of toxicity was observed with increasing mean quotients within most of the regions, basins, and areas in North America for all three toxicity tests. The results of these analyses indicate that the consensus-based PECs can be used to reliably predict toxicity of sediments on both a regional and national basis.

Archives of Environmental Contamination and Toxico↗
USGS2001

Organochlorine contaminant exposure and reproductive success of Black-Crowned Night Herons (Nycticorax nycticorax) nesting in Baltimore Harbor, Maryland

The declining size of the Baltimore Harbor black-crowned night-heron ( Nycticorax nycticorax ) colony has been hypothesized to be linked to polychlorinated biphenyl (PCB) exposure. In 1998, a “sample egg” was collected from 65 black-crowned night-heron nests (each containing ≥ three eggs) for contaminant analysis, and the remaining eggs in these 65 nests, plus four two-egg nests, were monitored for hatching and fledging success. Eggs were also collected from 12 nests at Holland Island, a reference site in southern Chesapeake Bay. Samples were analyzed for 26 organochlorine pesticides and metabolities and 145 PCB congeners. Pesticide and metabolite concentrations, including p,p '-DDE, were well below thresholds associated with adverse reproductive effects at both sites. Average concentration of total PCBs, 12 Ah receptor–active PCB congeners, and toxic equivalents in eggs from Baltimore Harbor were greater (up to 35-fold) than that observed in Holland Island samples. Overall nest success at the Baltimore Harbor heronry was estimated by the Mayfield method to be 0.74, and the mean number of young fledged/hen was 2.05, which is within published productivity estimates for maintaining a stable black-crowned night-heron population. Using logistic regression, no significant relationships were found between organochlorine contaminant concentrations in sample eggs and hatching, fledging, or overall reproductive success. Processes other than poor reproduction ( e.g. , low postfledging survival, emigration, habitat degradation) may be responsible for the declining size of the Baltimore Harbor colony.

Maryland↗
USGS2001

Development of marine toxicity data for ordnance compounds

A toxicity database for ordnance compounds was generated using eight compounds of concern and marine toxicity tests with five species from different phyla. Toxicity tests and endpoints included fertilization success and embryological development with the sea urchin Arbacia punctulata ; zoospore germination, germling length, and cell number with the green macroalga Ulva fasciata ; survival and reproductive success of the polychaete Dinophilus gyrociliatus ; larvae hatching and survival with the redfish Sciaenops ocellatus ; and survival of juveniles of the opossum shrimp Americamysis bahia (formerly Mysidopsis bahia ). The studied ordnance compounds were 2,4- and 2,6-dinitrotoluene, 2,4,6-trinitrotoluene, 1,3-dinitrobenzene, 1,3,5-trinitrobenzene, 2,4,6-trinitrophenylmethylnitramine (tetryl), 2,4,6-trinitrophenol (picric acid), and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). The most sensitive toxicity test endpoints overall were the macroalga zoospore germination and the polychaete reproduction tests. The most toxic ordnance compounds overall were tetryl and 1,3,5-trinitrobenzene. These were also the most degradable compounds, often being reduced to very low or below-detection levels at the end of the test exposure. Among the dinitro- and trinitrotoluenes and benzenes, toxicity tended to increase with the level of nitrogenation. Picric acid and RDX were the least toxic chemicals tested overall.

Archives of Environmental Contamination and Toxico↗
USGS2001

Lead poisoning of waterfowl by contaminated sediment in the Coeur D'Alene River

The Coeur d'Alene River basin in Idaho has been contaminated by mine tailings that have impaired the health of wildlife since the early 1900s. In other parts of the world, virtually all lead poisoning of waterfowl is caused by the ingestion of manmade lead artifacts, primarily spent lead shotshell pellets or, occasionally, fishing sinkers. However, in the Coeur d'Alene River basin in Idaho, nonartifactual lead poisoning was the ultimate cause of death of most of 219 (77%) of 285 waterfowl carcasses that had been found sick or dead from 1992 through 1997. The majority of these 219 waterfowl (172 tundra swans [Cygnus columbianus], 33 Canada geese [Branta canadensis], and 14 other species) were poisoned by ingesting river sediment that was contaminated with lead. The next most common cause of death (20 instances, 7%) was lead poisoning accompanied by ingested shotshell pellets. The remaining 46 waterfowl succumbed to trauma, infectious diseases (aspergillosis, avian cholera, tuberculosis), or miscellaneous problems, or the cause of death was not determined.

Idaho↗
USGS2014

The occurrence and distribution of selected trace elements in the upper Rio Grande and tributaries in Colorado and Northern New Mexico

Two sampling trips were undertaken in 1994 to determine the distribution of trace elements in the Upper Rio Grande and several of its tributaries. Water discharges decreased in the main stem of the Rio Grande from June to September, whereas dissolved concentrations of trace elements generally increased. This is attributed to dilution of base flow from snowmelt runoff in the June samples. Of the three major mining districts (Creede, Summitville, and Red River) in the Upper Rio Grande drainage basin, only the Creede District appears to impact the Rio Grande in a significant manner, with both waters and sediments having elevated concentrations of some trace elements considerably downriver. For example, dissolved zinc concentrations upriver of Willow Creek, which primarily drains the Creede District, were about 2-3 μg/L; immediately downstream of the Willow Creek confluence, concentrations were above 20 μg/L; and elevated concentrations occurred in the Rio Grande for the next 100 km. The Red River District does not significantly impact the Upper Rio Grande for most trace elements. Because of current water management practices, it is difficult to assess the impact of the Summitville District on the Upper Rio Grande. There are, however, large increases in many dissolved trace element concentrations as the Rio Grande passes through the San Luis Valley, coincident with elevated concentrations of those same trace elements in tributaries. Among these elements are As, B, Cr, Li, Mn, Mo, Ni, Sr, U, and V. None of the trace elements exceeded U.S. EPA primary drinking water standards in either survey, with the exception of cadmium in Willow Creek. Secondary drinking water standards were frequently violated, especially in tributaries draining areas where mining has occurred. Dissolved zinc (in Willow Creek in both June and September) was the only element that exceeded the EPA Water Quality Criteria for aquatic life of 120 μg/L.

Archives of Environmental Contamination and Toxico↗
USGS2002

Relating body condition to inorganic contaminant concentrations of diving ducks wintering in coastal California

One egg from each of 114 red-breasted merganser (Mergus serrator) nests in 1977 and 92 nests in 1978 was collected and later analyzed for organochlorines, polybrominated biphenyls (PBBs), polychlorinated styrenes (PCSs). and metals. One egg was also collected from each of the dabbling duck nests located: Twenty-nine of these eggs were analyzed for organochlorines and metals in 1977; 10 eggs were analyzed in 1978. All merganser eggs contained DDE, polychlorinated biphenyls (PCBs), and dieldrin; all but one egg collected in 1978 contained DDT. DDE and PCB levels had declined since 1975 to a geometric mean of 7.4 ppm DDE and 20 ppm PCBs in 1977 and 7.6 ppm DDE and 19 ppm PCBs in 1978. Dieldrin residues in eggs had not declined from 1975 Ievels; the geometric mean was 0.78 ppm in 1977 and 0.76 ppm in 1978. Other organochlorines were present at low levels. Mercury residues averaged >0,50 ppm in merganser eggs and had not declined since 1975. Other metals were present at low levels. Dabbling ducks generally had much lower organochlorine and Hg residues than mergansers; DDE and PCBs were the only organochlorines present in the majority of eggs. Geometric means of PCBs and DDE in dabbling duck eggs did not exceed 2.0 ppm and 1.0 ppm, respectively. PBBs and PCSs were detected only in a few merganser eggs, at low levels. Eggshell thickness for red-breasted merganser eggs averaged 0.359 mm in 1977 and 0.355 mm in 1978, which is only 2%-3% below pre-1946 thicknesses. Mallard (Anas platyrhynchos) eggshell thicknesses averaged 0.331 mm in 1977 and 0.337 mm in 1978.

Archives of Environmental Contamination and Toxico↗
USGS1996

Trihalomethane and nonpurgeable total organic-halide formation potentials of the Mississippi river

Trihalomethane and nonpurgeable total organic-hallide formation potentials were determined for water samples from 12 sites along the Mississippi River from Minneapolis, MN, to New Orleans, LA, for the summer and fall of 1991 and the spring of 1992. The formation potentials increased with distance upstream, approximately paralleling the increase of the dissolved organic- carbon concentration. The pH and the dissolved organic-carbon and free- chlorine concentrations were significant variables in the prediction of the formation potentials. The trihalomethane formation potential increased as the pH increased, whereas the nonpurgeable total organic-halide formation potential decreased. All formation potentials increased as the dissolved organic-carbon and free-chlorine concentrations increased, with the dissolved organic-carbon concentration having a much greater effect.

Archives of Environmental Contamination and Toxico↗
USGS1996

Comparison of gas chromatography/mass spectrometry and immunoassay techniques on concentrations of atrazine in storm runoff

Gas chromatography/mass spectrometry (GC/MS) and enzyme-linked immunosorbent assay (ELISA) techniques were used to measure concentrations of dissolved atrazine in 149 surface-water samples. Samples were collected during May 1992&ndash;September 1993 near the mouth of the White River (Indiana) and in two small tributaries of the river. GC/MS was performed on a Hewlett-Packard 5971 A, with electron impact ionization and selected ion monitoring of filtered water samples extracted by C-18 solid phase extraction; ELISA was performed with a magnetic-particle-based assay with photometric analysis. ELISA results compared reasonably well to GC/MS measurements at concentrations below the Maximum Contaminant Level for drinking water set by the U.S. Environmental Protection Agency (3.0 &mu;g/L), but a systematic negative bias was observed at higher concentrations. When higher concentration samples were diluted into the linear range of calibration, the relation improved. A slight positive bias was seen in all of the ELISA data compared to the GC/MS results, and the bias could be partially explained by correcting the ELISA data for cross reactivity with other triazine herbicides. The highest concentrations of atrazine were found during the first major runoff event after the atrazine was applied. Concentrations decreased throughout the rest of the sampling period even though large runoff events occurred during this time, indicating that most atrazine loading to surface waters in the study area occurs within a few weeks after application. Use of brand names is for identification purposes only and does not constitute endorsement by the U.S. Geological Survey, the Uniroyal Chemical Company, or Wichita State University.

Indiana↗
USGS1997

Organochlorine contaminants in double-crested cormorants from Green Bay, Wisconsin: II. Effects of an extract derived from cormorant eggs on the chicken embryo

White Leghorn chicken ( Gallus domesticus ) eggs were injected prior to incubation with one of four concentrations (0.001, 0.01, 0.1, and 1.0 egg-equivalent) of an extract derived from 1,000 double-crested cormorant ( Phalacrocorax auritus ) eggs collected at Spider Island adjacent to Green Bay in Lake Michigan. One egg-equivalent corresponded to the concentration of contaminants present in an average cormorant egg. This was approximately 322 pg toxic equivalents (TEQs)/g, ww egg with polychlorinatedbiphenyl congener 126 (3,3′,4,4′,5-pentachlorobiphenyl) accounting for over 70% of the TEQs. Injection of 1.0 egg-equivalent resulted in 77% mortality at hatch. The incidence of developmental abnormalities (structural defects or edema) was not affected by injection of the extract. Body weight gain of chicks was reduced in the 1.0 egg-equivalent dose group in the first, second, and third week's post-hatch. Relative brain weights were greater and relative bursa weights were less in the 1.0 egg-equivalent dose group than in the vehicle control at three weeks of age. There were no significant differences in the relative weights of the heart, liver, spleen, testes, or comb among treated and control birds.

Wisconsin↗
USGS1997

Comparative sensitivity of Selenastrum capricornutum and Lemna minor to sixteen herbicides

Aquatic plant toxicity tests are frequently conducted in environmental risk assessments to determine the potential impacts of contaminants on primary producers. An examination of published plant toxicity data demonstrates that wide differences in sensitivity can occur across phylogenetic groups of plants. Yet relatively few studies have been conducted with the specific intent to compare the relative sensitivity of various aquatic plant species to contaminants. We compared the relative sensitivity of the algae Selenestrum capricornutum and the floating vascular plant Lemna minor to 16 herbicides (atrazine, metribuzin, simazine, cyanazine, alachlor, metolachlor, chlorsulfuron, metsulfuron, triallate, EPTC, trifluralin, diquat, paraquat, dicamba, bromoxynil, and 2,4-D). The herbicides studied represented nine chemical classes and several modes of action and were chosen to represent major current uses in the United States. Both plant species were generally sensitive to the triazines (atrazine, metribuzin, simazine, and cyanazine), sulfonureas (metsulfuron and chlorsulfuron), pyridines (diquat and paraquat), dinitroaniline (trifluralin), and acetanilide (alachlor and metolachlor) herbicides. Neither plant species was uniformly more sensitive than the other across the broad range of herbicides tested. Lemna was more sensitive to the sulfonureas (metsulfuron and chlorsulfuron) and the pyridines (diquat and parequat) than Selenastrum. However Selenastrum was more sensitive than Lemna to one of two thiocarbamates (triallate) and one of the triazines (cyanazine). Neither species was sensitive to selective broadleaf herbicides including bromoxynil, EPTC, dicamba, or 2,4-D. Results were not always predictable in spite of obvious differences in herbicide modes of action and plant phylogeny. Major departures in sensitivity of Selenastrum occurred between chemicals within individual classes of the triazine, acetanilide, and thiocarbamate herbicides. Results indicate that neither species is predictively most sensitive, and that a number of species including a dicot speciessuch as Myriophyllum are needed to perform accurate risk assessments of herbicides.

Archives of Environmental Contamination and Toxico↗