Chronic Toxicity of Environmental Contaminants: Sentinels and Biomarkers

Abstract

Due to the use of a limited number of species and subchronic exposures, current ecological hazard assessment processes can underestimate the chronic toxicity of environmental contaminants resulting in adverse responses of sentinel species. Several incidences where sentinel species have responded to the effects of chronic exposure to ambient levels of environmental contaminants are discussed, including the development of neoplasia in fish, immunosuppression in marine mammals, pseudohermaphrodism in invertebrates, teratogenicity in amphibians, and aberrations in the sexual development of fish and reptiles. Biomarkers of chronic toxicity, including DNA mutations, alterations in specific protein and mRNA levels, and perturbations in metabolism, are presented. The incorporation of appropriate surrogate species and biomarkers of chronic toxicity into standard toxicity characterizations is proposed as a means of significantly refining the ecological hazard assessment process. -Environ Health Perspect 105(Suppl 1): 65-80 (1997)

Histopathologic and histochemical biomarker responses of Baltic clam, Macoma balthica, to contaminated Sydney Harbour sediment, Nova Scotia, Canada.

“…Neoplastic changes or histopathologic alterations of gonad cells have been observed in shellfish collected from contaminated areas or exposed to contaminated sediments in the laboratory (14,16,19,21,(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36). The observed lesions ranged from dilation of reproductive follicles in mussel, Mytilus edulis (33), to gonadal neoplasms in soft-shell clam, Mya arenaria (21), and the American oyster, Crassostrea virginica.…”

Characterization of Microbial Communities Found in the Human Vagina by Analysis of Terminal Restriction Fragment Length Polymorphisms of 16S rRNA Genes

“…In studies of quite different ecosystems, the term "sentinel species" has been used to refer to particular species of organisms that are indicative of an impending or existing upset caused by some disturbance or change in conditions (6,28,37). A sentinel species is commonly an indigenous species that has been found to be particularly sensitive to changes in biological, physical, or chemical characteristics of the environment and responds through either an increase or (more commonly) a decrease in population size.…”

Risk Assessment of Food Coloring Agents on DNA Damage Using RAPD Markers

“…Most substances which have been found to be mutagenic, also seem to have a carcinogenic action for example, carmoisine (E122), amaranth (E123), Sunset Yellow (E110), Tartrazine (E102) and Allura red (E129). Furthermore, some of them have been found to cause mutations in some bacteria, implying that they may also act as mutagenic and/or carcinogenic agents in humans [1,5] Hence, they may affect genome integrity due to mutations in germinal and/or somatic cells, leading to an increase in the incidence of different types of tumours [6] The OCDE Guidelines [7] list a series of widely used techniques, both in vivo and in vitro, for use in risk assessment procedures associated with genotoxins for humans. However, the application of these traditional techniques to the detection in DNA of both macro-and micro-damage (sis-ter chromatid exchange, chromosomal aberrations, etc.)…”