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Biomedical subjects

J Burger

Publications and source records attributed to J Burger.

At least 73 records · Page 4Linked to original sources
PubMed1999

Animals as sentinels of human health hazards of environmental chemicals.

A workshop titled "Using Sentinel Species Data to Address the Potential Human Health Effects of Chemicals in the Environment," sponsored by the U.S. Army Center for Environmental Health Research, the National Center for Environmental Assessment of the EPA, and the Agency for Toxic Substances and Disease Registry, was held to consider the use of sentinel and surrogate animal species data for evaluating the potential human health effects of chemicals in the environment. The workshop took a broad view of the sentinel species concept, and included mammalian and nonmammalian species, companion animals, food animals, fish, amphibians, and other wildlife. Sentinel species data included observations of wild animals in field situations as well as experimental animal data. Workshop participants identified potential applications for sentinel species data derived from monitoring programs or serendipitous observations and explored the potential use of such information in human health hazard and risk assessments and for evaluating causes or mechanisms of effect. Although it is unlikely that sentinel species data will be used as the sole determinative factor in evaluating human health concerns, such data can be useful as for additional weight of evidence in a risk assessment, for providing early warning of situations requiring further study, or for monitoring the course of remedial activities. Attention was given to the factors impeding the application of sentinel species approaches and their acceptance in the scientific and regulatory communities. Workshop participants identified a number of critical research needs and opportunities for interagency collaboration that could help advance the use of sentinel species approaches.

Animals↗
PubMed1998

Effects of lead on behavior, growth, and survival of hatchling slider turtles.

In this study the effects of lead on behavioral development of hatchling slider turtles (Trachemys scripta) from the Savannah River Site, near Aiken, SC, were examined. It was of interest to determine whether dose or size affects survival, growth, or behavior. Hatchlings from 1995 showed no significant differences in growth, survival, or behavior between control and lead-injected animals at a dose of 0.05 and 0.1 mg/g (n = 10 per group). In 1996, 48 hatchlings were divided into four groups injected with 0 (control), 0.25, 1, or 2.5 mg/g lead. Few significant differences occurred in growth or size as a function of lead treatment at 4 mo of age, but survival declined markedly as a function of lead dose. Righting response was significantly impaired by lead; time to right was directly related to lead dose. Size also affected behavior; larger hatchlings turned over more quickly and reached cover sooner than did smaller hatchlings.

Animals↗
PubMed1998

Fishing and risk along the Savannah River: possible intervention.

Fishing is often perceived as an enjoyable activity, and eating fish is viewed as safe and healthful. However, with recent increases in consumption advisories because of contamination, the public is faced with whether to eat fish or not. In this article I examine the knowledge base of people fishing along the Savannah River, where South Carolina has issued consumption advisories because of mercury and radionuclides. Over 250 people fishing from the Augusta lock and dam to south of the Department of Energy's Savannah River Site (SRS) were interviewed from early April until late November 1997. Overall 82% of the fishermen thought the fish were safe to eat, even though 62% had heard some warnings about eating the fish. There were significant differences in whether people thought the fish were safe to eat as a function of income, age, education, and whether they were employed at the Savannah River Site. Significantly more fishermen thought the fish were safe who made more than $20,000/year, were over 34 yr of age, worked at SRS, and had no college or technical training, compared to others. Significantly fewer blacks had heard of consumption advisories than whites, fewer low-income people had heard, and fewer people who had not worked at SRS had heard, compared to others. Most people heard about the advisories from television, newspapers, and other people, although more blacks than whites heard about advisories from the radio. There were also significant ethnic differences in distance traveled, and in whether specific fish were frozen for later consumption. These data can be used to design an information program to target the people who may be most at risk from eating fish obtained from the Savannah River.

Adolescent↗
PubMed1998

Environmental attitudes and perceptions of future land use at the Savannah River Site: are there racial differences?

People make subjective judgments about the severity of environmental problems and on future land use relying on certain information, and on their experiences with the problem. This article examines perceptions of the severity of environmental problems, willingness to expend future funds to solve these problems, and future land use for the Department of Energy's Savannah River Site (SRS) in South Carolina as a function of race. The null hypothesis that there are no racial differences in perceptions was tested. Of those interviewed, 23% of the 399 people were black, 75% were white, and 2% identified themselves as other. Blacks were significantly more willing than whites to spend federal funds to solve environmental problems such as cleaning up the SRS and Superfund sites, fixing ozone depletion, and reducing the threats from radon and high-tension power lines. There were statistically significant racial differences in preferences for future land use at the SRS, with blacks having a higher preference for using it as a preserve, and whites having a higher preference for a research park, camping, hiking, and hunting. These results indicate that the environmental concerns of the blacks interviewed were equal to or stronger than those of the whites. This is in contrast to much of previously published work that shows that blacks exhibit lower concerns and actions than whites for environmental problems.

Attitude↗
PubMed1998

Gender differences in attitudes about fish safety in a coastal population.

Behavioral approaches to reducing the adverse health effects of consuming fish with high contaminant levels benefit from understanding attitudes and perceptions about the relative safety of fish. Gender differences in attitudes about fish safety were investigated by interviewing 197 men and 94 women who attended a Duck Decoy show at Tuckerton, NJ. There were significant gender differences in perceptions of the safety of fish, ducks, and deer, with women generally believing that it was less safe to eat these foods than did men. Although people correctly perceived that ocean fish were safer than bay-caught fish from a chemical contaminant perspective, perceptions were less clear with respect to consuming predatory or herbivorous, or large versus small fish. Although men significantly perceived small fish as safer than large fish, women did not. However, people correctly believed that bluefish (a predaceous fish) were less safe than flounder (an herbivore). People uniformly believed it was safer to eat fish they caught themselves or bought in a fish store than those from a supermarket. These results suggest that any program to inform the public about the potential dangers from contaminated fish should take into account gender differences in perceptions.

Animals↗
PubMed1998

Antipredator behaviour of hatchling snakes: effects of incubation temperature and simulated predators.

All animals that are exposed to predators must distinguish dangerous from nondangerous threats and respond correctly. In reptiles, emerging hatchlings are vulnerable to a wide range of predators, particularly if they emerge during daylight. In these experiments I tested the response of pine snake, Pituophis melanoleucus, hatchlings incubated at 22-23, 27-28, or 32-33 degreesC to visual and vibratory stimuli to examine antipredator behaviour. Emerging hatchlings were exposed to one of five conditions: (1) hawk model, (2) white head model with no facial features, (3) white head model with black eyes, (4) a person, or (5) a vibration without a visual stimulus. I tested the null hypotheses of no differences in response as a function of predator type or incubation temperature. Emergence behaviour when undisturbed was affected by incubating temperature, and antipredatory behaviour was affected by both predator type and incubation temperature. Pine snake hatchlings responded more protectively (withdrawal into tunnels) than defensively (striking), responded with less intensity to a vibration compared with visual predator stimuli, and required longer to respond to a head model without eyes than to all other predator types. Given the relatively small size of hatchlings, it is adaptive for them to withdraw into the nest rather than attack a predator. Hatchlings from eggs that were incubated at medium temperatures required less time to emerge from their underground nests when undisturbed, and had stronger protective responses than snakes incubated at other temperatures. These results suggest that hatchlings incubated at medium temperatures are generally less vulnerable to predators than hatchlings incubated at higher or lower temperatures. Copyright 1998 The Association for the Study of Animal Behaviour.

Journal Article↗
PubMed1998

Evidence for social facilitation of preening in the common tern.

Social facilitation of reproductive behaviour has been studied extensively in gulls and terns, but social facilitation of preening has been reported only anecdotally, and has not been previously quantified. We studied a common tern, Sterna hirundo, colony during the summers of 1996 and 1997 to test for socially facilitated preening. Scan sampling provided evidence of spatial and temporal synchrony of preening behaviour. Preening occurred more often than expected in groups of three or more neighbours. Breeding pairs also preened simultaneously more often than expected. In loafing (resting) areas, the proportion of preeners present increased with tern density. Behavioural observations suggest that preening spread from neighbour to neighbour. The observed clumping in preening behaviour could not be explained by differences in date, time of day or weather. Social facilitation of preening and other maintenance behaviour may be an important aspect of group living that is often overlooked. Copyright 1998 The Association for the Study of Animal Behaviour.

Journal Article↗
PubMed1998

Temporal trends in metal levels in eggs of the endangered roseate tern (Sterna dougallii) in New York.

Female birds sequester certain organic and inorganic compounds in their eggs which have been widely used as a bioindicator for examining the body burdens of contaminants and therefore the temporal and spatial trends of the contaminants in the environment. The same analyses can also reflect the status or vulnerability of the indicator species. Extensive bridge de-leading activities in the New York Bight (Cape May to Montauk) in the early 1990s coincided with a long-term study of the endangered roseate tern (Sterna dougallii) on Long Island, New York, affording the opportunity to test the utility of such fish-eating species as bioindicators of lead contamination, as well as the potential impact on the bird population itself. In this paper we test the null hypothesis that there were no temporal trends between 1989 and 1994 in metal levels in eggs of roseate terns nesting at Cedar Beach, Long Island, where the birds have been declining since the late 1980s. We report levels and trends for cadmium, chromium, manganese, mercury, and selenium as well as lead in abandoned eggs collected each year. There were significant interyear differences for all metals, with 1990 to 1992 generally having higher levels than 1989 and 1994. The yearly differences were particularly prominent for lead, where the 10-fold increase may have been partially due to the increased removal of leaded paint from bridges in the early 1990s, leading to increased lead in the aquatic environment. Cadmium and chromium are also released during de-leading. The causes for the higher levels in the other metals in the early 1990s are unclear. Metal levels in roseate tern eggs are several times higher than the median reported for most birds, and the possible impact on the population requires study.

Animals↗
PubMed1998

Fishing, consumption, and risk perception in fisherfolk along an east coast estuary.

Increasingly public and governmental agencies are concerned about the safety of fish and shellfish that recreational fishermen consume. Fishing behavior, consumption patterns, and risk perceptions were examined for people flashing and crabbing in Barnegat Bay, NJ. Women fished in significantly larger groups than men, and their groups included more children. Subjects fished an average of seven times per month and crabbed three times per month; they caught fish on most outings, and 80% ate their catch. Subjects consumed fish an average of five times a month, eating just under 10 oz (ca. 280 g) per meal. Only 25% of the fish consumed by women, and 49% of the fish consumed by men, are self-caught. Nearly 90% of the people believe the fish and crabs from Barnegat Bay are safe to eat, although about 40% have heard some warnings about their safety. Most people heard about advisories from newspapers or television. Most subjects believe that saltwater fish are safer than freshwater fish and that fish they catch themselves or buy in a bay store are safer than those from a supermarket. People generally do not have a clear understanding of the relationship between contaminants and fish size or trophic level, suggesting an avenue for risk reduction.

Adolescent↗
PubMed1998

Effects of lead on sibling recognition in young herring gulls.

Lead exposure early in life affects physiology, behavior, and cognitive development in humans and other animals. In gulls, lead also disrupts parental recognition, leading to potential decreases in survival in wild populations. In this paper, young herring gulls, Larus argentatus, were used to examine the effect of lead on sibling recognition. Each of 80 one-day-old herring gull chicks was randomly assigned to either a control group or a lead treatment group that received a single dose of lead acetate solution (100 mg/kg) at day 2. Matched controls were injected with isotonic saline at the same age. At 10 days of age, there was no demonstrable sibling recognition in control chicks, but recognition was clearly developed by 15 days of age. Lead disrupted sibling recognition, and there still was no evidence of sibling recognition in lead-injected chicks by 26 days of age. Time to respond initially increased and then decreased with age in both control and lead-injected chicks. Control chicks that correctly reached their siblings did so in significantly less time than did lead-injected chicks, and they remained closer to their siblings at the end of the test. These experiments clearly demonstrate that lead disrupts sibling recognition in herring gull chicks, delays the time to respond and to reach their siblings, and increases the final distance chicks are from their calling siblings. In nature, lead-impaired chicks would be unable to use siblings as a cue enabling them to find their nests and might suffer higher mortality from territorial adults and chicks, as well as from cannibalistic adults.

Animals↗
PubMed1998

Trace elements in egg contents and egg shells of slider turtles (Trachemys scripta) from the Savannah River Site.

In this paper we examine the levels of trace elements in the egg contents and egg shells of slider turtles (Trachemys scripta) from the Savannah River Site, near Aiken, South Carolina. Trace elements have seldom been examined in the tissues or eggs of reptiles, although some turtles and large snakes occupy a high trophic level. Lead, mercury, cadmium, selenium, chromium, and manganese levels were examined in one egg and its egg shell collected from each of 16 females that laid in late May and June 1996. We were interested in determining background levels, whether certain metals were sequestered in the egg shells, and whether levels were higher in contents or shells. Concentrations were higher in egg contents than in shells for lead, mercury, and selenium, while chromium was higher in the shell. There were no differences for cadmium and manganese. Compared to eggs from other reptiles, levels in slider turtles were generally similar for cadmium and selenium, lower for chromium and lead, and higher for manganese.

Animals↗
PubMed1998

Apparent paralytic shellfish poisoning in captive herring gulls fed commercial scallops.

This report describes an acute poisoning event observed in captive herring gull (Larus argentatus) chicks fed a batch of store-bought scallops. They developed a characteristic acute syndrome, that has not hitherto been reported in birds and the cause of which remains to be identified. We suggest that it is a variant of paralytic shellfish poisoning (PSP) insofar as it was paralytic and caused by shellfish. However, analyses by the U.S. Food and Drug Administration to identify known toxins (saxitoxins, brevetoxins, domoic acid) in the scallops were negative.

Animals↗
PubMed1998

A risk assessment for consumers of mourning doves.

Recreational and subsistence hunters and anglers consume a wide range of species, including birds, mammals, fish and shellfish, some of which represent significant exposure pathways for environmental toxic agents. This study focuses on the Department of Energy's (DOE's) Savannah River Site (SRS), a former nuclear weapons production facility in South Carolina. The potential risk of contaminant intake from consuming mourning doves (Zenaida macroura), the most popular United States game bird, was examined under various risk scenarios. For all of these scenarios we used the mean tissue concentration of six metals (lead, mercury, cadmium, selenium, chromium, manganese) and radiocesium, in doves collected on and near SRS. We also estimated risk to a child consuming doves that had the maximum contaminant level. We used the cancer slope factor for radiocesium, the Environmental Protection Agencies Uptake/Biokinetic model for lead, and published reference doses for the other metals. As a result of our risk assessments we recommend management of water levels in contaminated reservoirs so that lake bed sediments are not exposed to use by gamebirds and other terrestrial wildlife. Particularly, measures should be taken to insure that the hunting public does not have access to such a site. Our data also indicate that doves on popular hunting areas are exposed to excess lead, suggesting that banning lead shot for doves, as has been done for waterfowl, is desirable.

Adult↗
PubMed1998

Plasma prostaglandin E2 concentrations after single dose administration of ketorolac tromethamine (Toradol) in dogs.

Ketorolac tromethamine (Toradol) is a relatively new, potent, non-narcotic analgesic with cyclooxygenase (COX) inhibitory activity and has been associated with gastric and renal toxicity in people and dogs. The objectives of this study were to establish whether endogenous PGE2 exists in the plasma of healthy dogs and to determine if, and to what magnitude, ketorolac alters PGE2 plasma concentrations after administration. Enzyme immunoassay measurement of a stable PGE2 derivative, bicyclo PGE2, showed that after i.v. administration of 0.5 mg/kg ketorolac tromethamine, 1 and 24 h plasma samples contained significantly (P < or = 0.01) less PGE2 than did plasma samples collected from dogs before the drug treatment. After p.o. administration, 1 h plasma samples contained significantly (P < or = 0.01) less PGE2 than did pretreatment samples, and the 24 h post-drug administration samples contained significantly (P < or = 0.01) less plasma PGE2 than the 96 h plasma samples. The results of this study suggest that a clinically effective single i.v. or p.o. dose of ketorolac tromethamine to healthy dogs causes a significant but reversible decrease in endogenous PGE2 production which may partially explain the drug's low therapeutic index.

Analysis of Variance↗
PubMed1997

Paradigms for ecological risk assessment.

Ecological risk assessment developed from the convergence of human health risk assessment, ecology, and ecotoxicology to provide data for environmental management and decision making. There has been an emphasis on using the health risk paradigm. However, ecological systems are much more complex than the single-species, single-lifetime approach used in human health risk assessment; hence several modifications are necessary, as ecological risk assessment evolves for particular uses. The advancement of ecological risk assessment is particularly timely, given competing considerations for cleanup of a variety of hazardous-waste sites, including the huge Department of Defense and Department of Energy sites, as well as the 1000+ Superfund sites. Sufficient resources are not available to clean up all sites completely, much less at the same time. Some sites pose no current identifiable risk to human receptors, but may be unusable for human habitation. Where human receptors are not the targets, ecological risk assessment can be used not only to evaluate the risks to ecosystems, but to help determine the degree of cleanup required to restore degraded environments to functioning ecosystems that provide valuable ecological services, and to rank sites for possible cleanup.

Ecology↗
PubMed1997

Recreation and risk: potential exposure.

The Department of Energy and other federal facilities are reclaiming land through the process of remediation and restoration, and this land will eventually be turned over for future land uses that may involve recreation. Understanding the amount of recreation that is likely (and thus individual exposure) is an essential element in decisions about cleanup standards. In this article the number of days people engage in different recreational activities as a measure of potential exposure is examined. People attending a Mayfest celebration (n = 399) and the Palmetto Sportsmen's Classic (n = 285) in Columbia, SC, were interviewed regarding their recreational activities. In most cases reported in the literature, recreational activities are examined as the mean number of days people engage in each activity per year, but to determine risk it is essential to know the distribution of these activities. In descending order of frequency, people attending the Mayfest reported their activities as birdwatching, photographing, fishing, hiking, camping, and hunting. There were significant gender differences in the frequency of activities, with men spending more days in every activity except birdwatching and photography. There were ethnic differences in recreation, with whites engaging in higher levels of most recreational activities than blacks, but the percentage of black men who reported fishing more than 100 d per year was greater than for white men. Most people reported their participation in most activities less than 30 d per year; however, a higher percentage of people reported participating in photography, birdwatching, and fishing more than 30 d per year compared to the other activities. Further, individuals at the Sportsman's Classic reported far higher rates of hunting and fishing per year than the general public. These data can be used to examine potential exposure of recreationists on remediated and restored land. The data clearly indicate that over 25% of the people engage in at least one recreational activity over 20 d per year, and thus exceed the Department of Energy's 14-d recreation assumption in its future land use document.

Cohort Studies↗
PubMed1997

Attitudes toward environmental hazards: where do toxic wastes fit?

The public is continually faced with making decisions about the risks associated with environmental hazards, and, along with managers and government officials, must make informed decisions concerning possible regulation, mitigation, and restoration of degraded sites or other environmental threats. We explored the attitudes regarding several environmental hazards of six groups of people: undergraduate science majors, undergraduate nonscience majors, and graduate students in environmental health, in ecological risk assessment, and in nonscience disciplines, as well as nonstudents over 35 yr of age. We had predicted that there would be significant differences in attitudes between science and nonscience majors and as a function of age. Relative concerns could be divided into three discrete classes (in descending order of concern): (1) general ecological problems (cutting tropical forests, polluting groundwater, trash along the coasts, lead in drinking water, and acid rain), (2) radon and nuclear wastes, and finally (3) specific nuclear waste facilities, chromium, fertilizers and pesticides, and electromagnetic waves. For any hazard, attitudes were consistent across groups with regard to ranking the severity of the environmental problem and willingness to expend funds to solve the problems. Attitudes about spending money to develop methods to evaluate risk fell in the middle level of concern. There were no major differences among classes of college-age students, or between them and older nonstudents.

Adult↗