Animals as Sentinels of Environmental Health Hazards (1991) / Chapter Skim
Currently Skimming:
5. Fish and Other Wildlife as Sentinels
5. Fish and Other Wildlife as Sentinels
Pages 81-102
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 81... ...
In this manner, in situ studies might now be used to determine the efficacy of cleanup regulations aimed at hazardous-waste sites. DESCR1~7VE EPIDEMIOLOGIC STUDIES The literature is replete with reports documenting the presence of residues of environmental contaminants in the tissues of fish, shellfish, and wildlife.
|
From page 82... ...
High concentrations of PCB residues appear to be related to population and industrial trends. The NS&T program includes histopathologic evaluations of fish liver, kidney, gill, and skin, in addition to measurement of tissue residue concentrations.
|
From page 83... ...
Nevertheless, it is reasonable to consider whether human consumption of tissues of fish with liver tumors will result in ingestion of large amounts of carcinogens large enough eventually to induce similar tumors in the consumers. Mussel Watch Bivalves, such as mussels and oysters, accumulate many chemicals to concentrations much higher than those in the ambient water; bioconcentration factors range up to 104 or even 1Os for some chemicals.
|
From page 84... ...
Data have been used to identify temporal and geographic trends in the occurrence of chemical residues so as to improve understanding of the magnitude of existing and potential threats to fish and wildlife resources and to monitor the success of failure of regulatory actions related to environmental contaminants. In addition to revealing trends in contaminant concentrations, the data collected have been used by EPA in identifying exposures to some hazardous substances and hence in regulating the release of some of these substances into the environment.
|
From page 85... ...
Va., were analyzed by EPA for chlorinated dibenzopdioxins to document the historical contamination of that site by a chemical-manufacturing facility. The NCBP has shown that removal of persistent chemicals from the marketplace has decreased environmental contaminants to more acceptable concentrations.
|
From page 86... ...
Examples of fish from polluted waterways with epizootic liver cancer include English sole from Puget Sound; Seattle, Washington; and Vancouver, British Colombia; winter flounder from Boston Harbor, white sucker from Hamilton Harbor in Lake Ontario; white croaker from Long Beach, California; white perch from the Chesapeake and Delaware bays; mummichog from the Elizabeth River, Virginia; brown bullhead from the Black River, Ohio, and many other sites; sauger and walleye from Torch Lake, Upper Peninsula, Michigan; and AtIantic tomcod from the Hudson River. Although v~rtuady all fish cell types appear to have the capacity for neoplastic transformation, liver cancer is the most clearly correlated to a chemical causation and thus is the strongest sentinel for carcinogens in the aquatic environment for the following reasons: · Epidemiologic evidence.
|
From page 87... ...
Neoplastic and non-neoplastic pathologic changes involving various organs and in winter flounder appeared to be related to chemical contaminants, inasmuch as PCBs, chlorinated pesticides, PAHs, and mercury were concentrated in their habitat. All these animals that display adverse health effects continue to provide data about the status of their environment and indicate trends in environmental contamination, In addition to signaling potential risks associated with their consumption.
|
From page 88... ...
Data analysis revealed several clusters of particular cancer types that drew suspicion to carcinogenic agents in the environment. For example, a cluster of lung cancers in seven families of mammals and four families of birds from the Philadelphia Zoo collection was reported in 1966 (Snyder and Ratcliffe, 1966~.
|
From page 89... ...
Later, the effects of chronic exposure to complex mixtures of persistent lipophilic environmental contaminants were also measured eggshell thinning, embryotoxicity, teratogenicity, genotoxicity, behavioral toxicity, and demographic changes (Fox and Weseloh, 1987~. Similar effects have since been documented in cormorants nesting in the Great Lakes as opposed to colonies in nonpolluted lakes in Canada (Langenberg et al., 1989~.
|
From page 90... ...
Animal sentinel systems seem to require much more development and validation before they will be used as more than a qualitative underpinning for conventional procedures in human-risk characterization. Chesapeake Bay The Chesapeake Bay program is one of the best examples of a comprehensive ecologic monitoring program for an entire estuary.
|
From page 91... ...
Those programs measure contaminant concentrations in tissues of shellfish, fish, and wildlife, including marine mammals. Some of the most comprehensive long-term information on contaminant concentrations in marine mammals has been collected in the Puget Sound area, including data on organochlorine pesticides and heavy metals in fur seals and harbor seals (Anas and Wilson, 1970a,b; Anas, 1974a,b; Calambokidis et al., 1984, 1985~.
|
From page 92... ...
The memorandum of agreement grew out of a desire to meet environmental requirements regarding fish and wildlife and to design and operate the State Water Project and Federal Central Valley Project so as to minimize detrimental effects on fish and wildlife. The plan includes a water-quality program and a program to monitor fish abundance, movements, and health (including tissue residues of organochlorines, heavy metals, and selected PAHs)
|
From page 93... ...
. In only a few cases were the warnings provided by sentinel animals distinctive and decisive enough to trigger control measures before human exposure took place.
|
From page 94... ...
However, it is not clear that the results can be used other than qualitatively to infer a potential for human exposure. Wild animals have been used widely to assess the bioavailability of metals, such as lead, from soil and hence to determine patterns of contamination and potential exposure (Williamson and Evans, 1972; Gish and Christensen, 1973; Goldsmith and ScanIon, 1977; Clark, 1979; Ash and Lee, 1980; Hutton and Goodman, 1980; Ohi et al., 1981)
|
From page 95... ...
Using animals to monitor the health of the ecosystem—that is, to look at effects of pollution, as well as potential exposure to it has recently been considered but has not yet been widely adopted into monitoring programs. The International Joint Commission is considering such monitoring in the Great Lakes basin, and several studies have recently been funded by the Interagency Ecological Studies Program for the Sacramento-San Joaquin Estuary.
|
From page 96... ...
More alarming, abrupt decreases in numbers of peregrine falcons, bald eagles, ospreys, Cooper's hawks, and brown pelicans in the United States were noted from the mid-19SOs to the late 1960s (Hickey, 1968~. The population declines were determined to be the result of reproductive decreases due to breeding delays, failure to lay eggs, and, most notably, drastic thinning and weakening of eggshells; the latter had led to breakage and decreased hatchability (Peakall, 1970~.
|
From page 97... ...
Anton of Julian Food Chad Many national, regional, and local programs are designed to monitor human exposure to contaminants in the food chain by sampling fish, game, or other nonmarketed food animals (Schmitt et al., 1985, Bunck et al., 1987~. Calculation of intakes from contamination measurements is not always straightforward, however.
|
From page 98... ...
The reindeer provide continuous data on radioactivity in northern Sweden; the data have been used to regulate human exposure. Food-monitoring programs are in effect monitoring animals that are acting as sentinels of environmental contamination.
|
From page 99... ...
They exhibit a sublethal array of acute neurotoxic signs that can be recognized by a min~mally trained observer for example, screw shape, convulsions, hyperkinesis, vomiting (with pharynx protruding) , roll shape, banana shape, and pharynx out or Belly up.~ Planarians are more cost-effective, need less testing time, and are more sensitive to pollutants than are traditional laboratory species (Brigham, 1981; Barndt and Bohn, 1985~; their use also requires minimal equipment.
|
From page 100... ...
sites (NAS Whidbey Island has been nominated for addition to the NPL3 (Johnston and Kendall, 1990~. Much of the area is forest, grassland, and marsh that provide habitat for upland game birds, waterfowl, various mammals, and the endangered peregrine falcon and bald eagle.
|
From page 101... ...
Comparisons of sediment concentrations with earthworm body burdens have confirmed that laboratory-reared earthworms accumulated as many chemicals and heavy metals and were as sensitive when placed in the field as when contaminated soil was brought into the laboratory for exposure of earthworms under controlled conditions. Preliminary studies also showed that earthworms collected from the site had reduced immunologic functions, as measured by E-rosette formation and macrophage function (Rodriguez et al., 1989; Fitzpatrick et al., 1990~.
|
From page 102... ...
The study of cancer in fish and amphibians not only would provide new insights into the origins of human cancers, but would provide numerous other benefits, because these animals would serve as sentinels of environmental contaminants and as models for studying neoplasia and basic mechanisms in oncology. Despite the obvious advantages of monitoring animals that live in an environment in question, substantial difficulties are associated with designing and executing such monitoring programs.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.