Conrad D. Volz

An updated weight of evidence approach to the aquatic hazard assessment of Bisphenol A and the derivation a new predicted no effect concentration (Pnec) using a non-parametric methodology.

An aquatic hazard assessment establishes a derived predicted no effect concentration (PNEC) below which it is assumed that aquatic organisms will not suffer adverse effects from exposure to a chemical. An aquatic hazard assessment of the endocrine disruptor Bisphenol A [BPA; 2, 2-bis (4-hydroxyphenyl) propane] was conducted using a weight of evidence approach, using the ecotoxicological endpoints of survival, growth and development and reproduction. New evidence has emerged that suggests that the aquatic system may not be sufficiently protected from adverse effects of BPA exposure at the current PNEC value of 100 μg/L. It is with this background that; 1) An aquatic hazard assessment for BPA using a weight of evidence approach, was conducted, 2) A PNEC value was derived using a non parametric hazardous concentration for 5% of the specie (HC(5)) approach and, 3) The derived BPA hazard assessment values were compared to aquatic environmental concentrations for BPA to determine, sufficient protectiveness from BPA exposure for aquatic species. A total of 61 studies yielded 94 no observed effect concentration (NOEC) and a toxicity dataset, which suggests that the aquatic effects of mortality, growth and development and reproduction are most likely to occur between the concentrations of 0.0483 μg/L and 2280 μg/L. This finding is within the range for aquatic adverse estrogenic effects reported in the literature. A PNEC of 0.06 μg/L was calculated. The 95% confidence interval was found to be (0.02, 3.40) μg/L. Thus, using the weight of evidence approach based on repeated measurements of these endpoints, the results indicate that currently observed BPA concentrations in surface waters exceed this newly derived PNEC value of 0.06 μg/L. This indicates that some aquatic receptors may be at risk for adverse effects on survival, growth and development and reproduction from BPA exposure at environmentally relevant concentrations.

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.

Heavy metals in Pacific cod (Gadus macrocephalus) from the Aleutians: location, age, size, and risk.

Considerable attention has been devoted to the risks from mercury (Hg) and polychlorinated biphenyls (PCB) to high-level predators (including humans) who consume freshwater fish. Although the U.S. Food and Drug Administration (FDA) issued advisories because of Hg for four marine fish species, there are few data on lead (Pb), cadmium (Cd), or other metals in Bering Sea fish generally, or on the risk these levels pose to the fish themselves or to consumers of marine fish. Levels of arsenic (As), Cd, chromium (Cr), Pb, Hg, and selenium (Se) levels were examined in muscle and liver of 142 Pacific Cod (Gadus macrocephalus) collected in 2004 at Nikolski, Adak, Amchitka, and Kiska Islands in the Aleutian Chain (Alaska) in the Bering Sea/North Pacific Ocean, a major source of commercial fishing. One key objective was whether there were location, age, gender, and size effects on tissue concentration that might pose a risk to the fish or their predators (including humans). All fish were measured and weighed, and a subset was aged by examining otolith layers. As was higher in liver than in muscle (geometric mean 2420 versus 1590 ng/g or ppb wet weight), as were Cd (GM 224 versus 1.92) and Se (GM 1380 versus 165). Conversely, Cr was higher in muscle (76.8 versus 45 ppb), as were Pb (23.7 vs 12 ppb) and surprisingly Hg (128 versus 82 ppb). Adak, until recently a large military base, had the highest levels of As, Hg, and Se, while Amchitka had the highest Pb levels, but Nikolski, which generally had the lowest levels, had relatively high Pb in liver. In general, interisland differences were significant for most metals in muscle, but only for Cr in liver. Weight and length were positively related to age, but age tended to explain more of the variance in metal levels. The multiple regression relationships differed by tissue in an unanticipated manner. Location contributed significantly to the models for muscle Cd, Pb, Hg, and Se, but not for liver levels. Conversely the length by weight interaction entered all of the liver models but none of the muscle models. Se and Hg were positively but weakly correlated in both liver (tau = +0.16) and muscle tissue (tau = 0.12). Hg was positively correlated with length, weight, and age in muscle, but not in liver. As showed a significant negative correlation with size variable in both tissues, and Cr was negatively correlated in muscle. Cd was positively correlated with Hg, Se, and As. Between liver and muscle there were significant positive correlations for Hg (tau = .24), As (tau = .407), and Cr (tau = 0.17), but not for Pb, Cd, or Se. In this study, the only metals that might pose a risk to cod-eating predators is Hg, as well as some of the higher values of Pb at Amchitka and Nikolski . The U.S. Environmental Protection Agency (EPA) reference dose (RfD) (not available for lead) was used to evaluate the risk to people consuming an 8-ounce (228g) meal of cod once per day and once per week, and to calculate risk using the levels found in this study. If a subsistence fisher from one of the Aleut villages ate one meal of cod per week for As, or one meal per day for Hg, they would exceed the U.S. EPA reference dose for As and Hg (set at a level to be without adverse effect for any person with this average daily exposure).

Radionuclides in marine fishes and birds from amchitka and Kiska Islands in the aleutians : Establishing a baseline

Amchitka Island (51o N lat, 179o E long) was the site of three underground nuclear tests from 1965–1971. There have been no substantive studies of radionuclides in marine fishes and birds in the area since the mid-1970’s. In this study, levels of 60Co, 52Eu, 90Sr, 99Tc, 129I, 137Cs, and the actinides (241Am, 238Pu, 239,240Pu, 234U, 235U, 236U, and 238U) were studied in ten marine fish species (including Pacific Cod Gadus macrocephalus and Pacific Halibut Hippoglossus stenolepis) and five marine bird species (including Glaucous-winged Gulls Larus glaucescens, Tufted Puffins Fratercula cirrhata, and Common Eider Ducks Somateria mollissima) from Amchitka. The same species were collected at a reference site, Kiska Island (52o N lat; 177o E long), about 130 km west of Amchitka. Each sample was a composite of edible muscle from five or more individual fish or birds of similar size (±15%) from the same sampling station. The null hypotheses of no differences among species or between Amchitka and Kiska were tested. Most analytic results were below the minimum detectable activity (MDA), even when 1,000 g sizes and 72 h counting times were used. The only radionuclides detected above the MDA were 137Cs, 241Am, 239,240Pu, 234U, 235U, and 238U. There were significant differences in 137Cs as a function of species, but not location, for top predatory fishes. Of the fishes, eight of ten species had 137Cs values above the MDA for some samples; only one bird, Glaucous-winged Gull, had 137Cs values above the MDA. The highest concentrations of 137Cs were in Dolly Varden [Salvelinus malma, 0.780 (Bq kg−1 wet weight)] and Pacific Cod (0.602 Bq kg−1). In aggregate for any actinides, 73 of 234 (31%) composites for fish were above the MDA, compared to only 3 of 98 (3%) for birds. 234U and 238U, radionuclides that are primarily natural in origin, were routinely detected in these biological samples, but there were no significant differences in mean concentrations between Amchitka and Kiska. The concentrations of all radionuclides examined at Amchitka are similar to those of other uncontaminated Northern Hemisphere sites, and are lower than those reported for fishes and birds from the Irish Sea in the vicinity of the Sellafield nuclear reprocessing facility, an area with known contamination.

Conceptual Site Models as a Tool in Evaluating Ecological Health: The Case of the Department of Energy'S Amchitka Island Nuclear Test Site

Managers of contaminated sites are faced with options ranging from monitoring natural attenuation to complete removal of contaminants to meet residential health standards. Conceptual site models (CSMs) are one tool used by the U.S. Department of Energy (DOE) and other environmental managers to understand, track, help with decisions, and communicate with the public about the risk from contamination. CSMs are simplified graphical representations of the sources, releases, transport and exposure pathways, and receptors, along with possible barriers to interdict pathways and reduce exposure. In this article, three CSMs are created using Amchitka Island, where the remaining contamination is from underground nuclear test shot cavities containing large quantities of numerous radionuclides in various physical and chemical forms: (1) a typical underground nuclear test shot CSM (modeled after other sites), (2) an expanded CSM with more complex receptors, and (3) a regional CSM that takes into account contaminant pathways from sources other than Amchitka. The objective was to expand the CSM used by DOE to be more responsive to different types of receptors. Amchitka Island differs from other DOE test shot sites because it is surrounded by a marine environment that is highly productive and has a high biodiversity, and the source of contamination is underground, not on the surface. The surrounding waters of the Bering Sea and North Pacific Ocean are heavily exploited by commercial fisheries and provide the United States and other countries with a significant proportion of its seafood. It is proposed that the CSMs on Amchitka Island should focus more on the pathways of exposure and critical receptors, rather than sources and blocks. Further, CSMs should be incorporated within a larger regional model because of the potentially rapid transport within ocean ecosystems. The large number of migratory or highly mobile species that pass by Amchitka provide the potential for a direct pathway to the local human population, known as Aleut, and commercial fisheries, which are remote from the island itself. The exposure matrix for receptors requires expansion for the Amchitka Island ecosystem because of the valuable marine and seafood resources in the region. CSMs with an expanded exposure/receptor matrix can be used effectively to clarify the conceptualization of the problem for scientists, regulators, and the general public.

Developing a Health and Safety Plan for Hazardous Field Work in Remote Areas

Developing health and safety plans (HASPs) is a common feature of occupational safety and health for many workplaces. Formal HASPs are a requirement for hazardous waste work, requiring the anticipation and identification of hazards and embodying the training, equipping, and evaluation of workers. Aside from OSHA, there are relatively few manuals or examples and virtually no papers that provide practical guidance in what a HASP should cover or how to create and implement one. Moreover, existing guidance refers to spatially circumscribed worksites. This article details development of a HASP to cover field researchers and ship personnel conducting scientific research in a remote area of the world (Amchitka Island in the western Aleutians), hundreds of kilometers from the nearest emergency room. It required characterizing the kinds of work to be performed and anticipating the hazards that could be encountered. It illustrates the meshing of a general HASP with a ship safety plan, a dive safety plan, and specialized topics, including stop-work authority, rock climbing, firearms, vehicle safety, and communication strategy. Remote area operations are a growing challenge facing the profession. An expedition of this sort requires extensive planning and experienced safety personnel and cannot rely on luck to ensure the safe return of participants.