Heavy Metals in the Eggs and Muscle of Horseshoe Crabs (Limulus Polyphemus) from Delaware Bay

Lead, mercury, cadmium, chromium and manganese concentrations were measured in the eggs of horseshoe crabs (Limulus polyphemus) from 1993, 1994 and 1995; and from chelicera muscle in 1995 from Delaware Bay. Metal concentrations in the eggs represent levels derived from females. In eggs, mercury levels were below 100 ppb or were non-dectable; cadmium levels were generally low in 1993 and 1995 but were relatively higher in 1994; lead levels in eggs decreased from 558 ppb in 1993 to 87 ppm in 1995; selenium increased from 1993 to 1995; chromium decreased from 1993 to 1995; and manganese generally decreased. Leg muscles had significantly lower levels of all metals than eggs, except for mercury.     

Mercury and other metals in eggs and feathers of glaucous-winged gulls (Larus glaucescens) in the Aleutians

Levels of mercury and other contaminants should be lower in birds nesting on isolated oceanic islands and at high latitudes without any local or regional sources of contamination, compared to more urban and industrialized temperate regions. We examined concentrations of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in the eggs, and the feathers of fledgling and adult glaucous-winged gulls (Larus glaucescens) nesting in breeding colonies on Adak, Amchitka, and Kiska Islands in the Aleutian Chain of Alaska in the Bering Sea/North Pacific. We tested the following null hypotheses: 1) There were no differences in metal levels among eggs and feathers of adult and fledgling glaucous-winged gulls, 2) There were no differences in metal levels among gulls nesting near the three underground nuclear test sites (Long Shot 1965, Milrow 1969, Cannikin 1971) on Amchitka, 3) There were no differences in metal levels among the three islands, and 4) There were no gender-related differences in metal levels. All four null hypotheses were rejected at the 0.05 level, although there were few differences among the three test sites on Amchitka. Eggs had the lowest levels of cadmium, lead, and mercury, and the feathers of adults had the lowest levels of selenium. Comparing only adults and fledglings, adults had higher levels of cadmium, chromium, lead and mercury, and fledglings had higher levels of arsenic, manganese and selenium. There were few consistent interisland differences, although levels were generally lower for eggs and feathers from gulls on Amchitka compared to the other islands. Arsenic was higher in both adult feathers and eggs from Amchitka compared to Adak, and chromium and lead were higher in adult feathers and eggs from Adak compared to Amchitka. Mercury and arsenic, and chromium and manganese levels were significantly correlated in the feathers of both adult and fledgling gulls. The feathers of males had significantly higher levels of chromium and manganese than did females. The levels of most metals in feathers are below those known to be associated with adverse effects in the gulls or their predators. However, levels of mercury in some gull eggs are within a range suggesting that several eggs should not be eaten in one day by sensitive humans.     

Metal Levels in Raccoon Tissues: Differences On and Off the Department of Energy's Savannah River Site in South Carolina

Levels of arsenic, cadmium, chromium, copper, lead, manganese, selenium, and strontium⁸⁸ were examined in heart, kidney, muscle, spleen and liver of raccoons (Procyon lotor) from four areas on the Department of Energy's Savannah River Site (SRS), including near a former reactor cooling reservoir and a coal ash basin, and from public hunting areas within 15 km of the site. Mercury is mentioned briefly because it is discussed more fully in another paper. We test the hypotheses that there are no differences in metal levels between raccoons on SRS and off the SRS (off-site), and among different locations on the SRS. Although raccoons collected off-site had significantly lower levels of mercury and selenium in both the liver and kidney, there were few consistencies otherwise. There were significantly higher levels of cadmium in liver of on-site compared to off-site raccoons, and significantly higher levels of chromium and strontium⁸⁸ in kidney of on-site compared to off-site raccoons. Copper and manganese were highest in the liver; cadmium, lead, mercury and selenium were highest in the liver and kidney; chromium was highest in the spleen and muscle; arsenic was highest in the heart, and strontium⁸⁸ was slightly higher in the kidney than other organs. Where there were significant differences on site, chromium, manganese were highest in raccoon tissues from Steel Creek; arsenic, lead and selenium were highest in the Ash Basin; cadmium was highest at Upper Three Runs; and strontium⁸⁸ was highest at Upper Three Runs and Steel Creek. The patterns were far from consistent.     

Metal levels in feathers of cormorants, flamingos and gulls from the coast of Namibia in southern Africa

Arsenic, cadmium, chromium, lead, manganese, mercury, selemium,and tin concentrations were measured in the feathers of Capecormorant (Phalacrocorax capensis), Hartlaubs gull(Larus hartlaubii), kelp gull (Larus dominicanus), andlesser flamingo (Phoeniconaias minor) from the coast ofNamibia in southern Africa. Metal concentrations in feathers represent the concentrations in the blood supply at the time offeather formation. Cape Cormorants are piscivores; kelp gullsare primarily piscivores; Hartlaubs gull is an omnivore; and lesser flamingos eat primarily blue-green algae and invertebrates filtered from the water and sediment ofhypersaline lagoons. We predicted that metal concentrationswould reflect these trophic level differences. There weresignificant species differences in the concentrations of allmetals, with flamingos having the lowest levels, and cormorantshaving the highest levels of 4 metals but not mercury. The gulls hadthe highest levels of mercury, perhaps reflecting their morescavenging behavior.     

A paradigm for ecological risk assessment

The 1983 National Academy of Sciences paradigm for conducting human health risk assessment is considered with respect to ecological risk assessment. This four-step paradigm fails to capture key intrinsic differences between the two types of analysis, specifically: identity of risk targets and receptors; identity of the appropriate level of ecological organization at which the risk is expressed; variability of endpoint with respect to risk receptor; and the existence ofrisk cascades through ecological feedback loops. We propose an alternative paradigm that includes a preliminary step,receptor identification, in which chemical partitioning is combined with a conceptual model of the ecosystem to identify appropriate risk targets. In addition, we propose formal inclusion ofendpoint identification and explicit consideration of risk cascades in arelationship assessment in which interactive feedback loops are considered in an iterative process. The proposed paradigm preserves the steps of hazard identification, exposure assessment, dose-response assessment (renamedresponse assessment) and risk characterization, although specific modifications are recommended.     

Restoration,stewardship, environmental health,and policy: understanding stakeholders' perceptions

In recent years there has been considerable interest in the health of humans and the environment, restoration of contaminated or otherwise degraded lands, and in long-term stewardship of public lands. Unfortunately, it is unclear whether governmental agencies and the public hold similar views about the meanings of these concepts, making policy decisions about restoration and stewardship difficult. In this paper, I explore how the public conceptualizes restoration and stewardship by examining the relative rating of several attributes of restoration, stewardship, environmental health, ecological health, environmental restoration, and ecological restoration. People were interviewed in Santa Fe, New Mexico, USA, near the Department of Energy's Los Alamos National Laboratory. The ratings of attributes of environmental health and ecological health reported in this paper can be used to understand how the public understands these concepts. The attributes rated most highly by the subjects were more similar to definitions in the scientific literature for these terms than they were to those used by the Department of Energy. For environmental health, the highest rating related to human sanitation, while for ecological health the highest rating was for maintaining functioning ecosystems. Reduction of exposure to hazardous substances was rated the second highest for both environmental and ecological health. The wise use of natural resources, preservation of natural resources, and hazardous waste site cleanup were rated the highest attributes of stewardship. These data suggest that both expert and nonexpert perceptions about restoration and stewardship should be incorporated into environmental management decisions.     

Use of Central Stonerollers (Cyprinidae: Campostoma anomalum) from Tennessee as a Bioindicator of Metal Contamination

We compared the levels of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in a small species of fish (Central stonerollers, Campostoma anomalum) collected from East Fork Poplar Creek (EFPC) and a reference site in eastern Tennessee. Stonerollers are minnows in the Cyprinidae family that serve as prey for many carnivores in aquatic systems. Fish were collected from East Fork Poplar Creek within the U.S. Department of Energy's Y-12 National Security Complex, part of the Oak Ridge Reservation, and from a reference stretch of the Little River in East Tennessee. Whole fish were homogenized for analysis. Concentrations of all metals (except arsenic) were significantly higher in stonerollers from EFPC compared to the reference site. Mercury levels in minnows from EFPC averaged 0.4 ppm (μg/g), four times higher than the average for fish in the U.S. in general. This was higher than levels in fish from the nearby Clinch River and higher than fillets of white bass (Morone chrysops) from the same creek. Most metal levels were inversely related to size and weight of the stonerollers, perhaps due to growth dilution.     

A Comparison of On-site Hunters,Sportsmen and the General Public about Recreational Rates and Future Land Use Preferences for the Savannah River Site

Management of ecosystems has been improved both by our understanding of how ecosystems function, as well as by what people consider to be suitable future land uses. This is particularly true with contaminated lands where decisions must be made about clean-up and future land use. In this paper I synthesize several surveys of public recreational rates and preferences for future land use of the Savannah River Site (SRS), a Department of Energy (DoE) facility located in South Carolina. Four groups of people were interviewed: on-site hunters; sportsmen; local residents attending an event near Aiken, South Carolina; and the general public attending a festival in Columbia, South Carolina. The general public that engaged in recreational activities averaged 20 days/ year or more for hunting and fishing, while sportsmen averaged over 50 days/year. All four groups rated maintaining SRS as a National Environmental Research Park (NERP) and using it for recreation as the highest preferred land uses. The general public rated hiking and camping higher than hunting and fishing, while sportsmen rated hunting higher than hiking and camping. All groups rated using SRS for homes as the lowest, or second lowest, preferred land use. There was disagreement on the ratings for industrial development, with people living closer to the site rating it higher than the general South Carolina population. These data can be used by local planners and managers in decision making regarding clean-up levels and future land use. The relative unanimity of views for cleaning up DoE sites, continued use of the site as a NERP and increased recreational use suggests that different groups of people share similar preferences for future use of SRS, and provides a useful paradigm for considering future land use decisions at other DoE sites nationwide. The relatively low ranking for housing and factories suggests that clean-up levels could be geared to future land use, such as recreation, which are less stringent than residential levels.     

Consumption Advisories and Compliance: The Fishing Public and the Deamplification of Risk

Managers and regulators have recognized that the fishing public often ignores fish consumption advisories, and the reasons for non-compliance are explored in this paper. Risk assessors acknowledge that there is a social amplification (intensification) of risk where the public perceive a risk as much more severe than do the 'experts' or scientists, and this social amplification is a function of the interaction of hazards with social, psychological and cultural processes. I propose that non-compliance of consumption advisories occurs because of the deamplification of risk in hazards that are familiar and enjoyed, such as fishing and fish consumption. Although the public are generally aware of consumption advisories, they continue to believe the fish are safe to eat, and a high percentage eat the fish they catch. Unlike the amplification of risk, the deamplification of risk from fishing in the face of consumption advisories is partly legitimized by the actions of some governmental agencies, as well as by society at large. It is suggested that a variety of economic benefits and social institutions lead to a discounting of consumption advisories, and the delayed nature of adverse health effects allows for additional disregard. Further, it is suggested that co-management of the risk from contaminated fish would increase public involvement, and therefore compliance.