Indicator species biomarkers

The relationship between biomarker responses and effects at the population level can be tested in both field experiments and more controlled experiments in mesocosms. It may be possible to define thresholds for biomarker assays performed on indicator species, above which population effects have been shown to occur. Indicator species may be either free living or deployed. The advantage of the latter is... 

Apart from the use of this approach to study the ecotoxicology of neurotoxic pollutants in the field, it also has potential for use during the course of environmental risk assessment. An understanding of the relationship between biomarker responses to neurotoxic compounds and effects at the population level can be gained from both field studies and the use of mesocosms and other model systems. From these it may be possible to define critical thresholds in biomarker responses of indicator species above which population effects begin to appear. In the longer term, this approach... 

In the housefly, the protein carbonyl content rather than chronological age was found to be associated with life expectancy. Exposure of flies to sublethal hy-peroxia (100% oxygen) irreversibly enhanced the carbonyl content of the flies and decreased their rate of oxygen consumption. Results of this study were suggested to indicate that protein carbonyl content may be a biomarker of aging (S40, S52, Y6). The average life-span potential of several insect species is inversely correlated with the level of protein carbonylation (S43). The white-footed mouse (.Peromyscus leucopus) has more than a twice as long a life span as the house mouse (Mus musculus), and tissues of the white-footed mouse also have lower levels of... 

Metabolomics has made remarkable inroads into the environmental research community. Here, a major emphasis is to understand the impact that environmental stress, such as pollution and climate change, has on wildlife. Indeed, many government organizations monitor the prevalence of pollutants in certain species of wildlife as indicators of the exposure risk within the environment. Studies of Japanese medaka have been conducted to investigate the effects of trichloroethylene, a common environmental pollutant, and the pesticide dinoseb, on the development of fish embryos (44, 45). Similarly, cadmium toxicity has been examined in the bank vole and rat and has revealed changes in lipid metabolism that preceded classical nephrotoxicity (46, 47). Another study investigated the effects of environmental toxins on earthworms (48). In particular, the analysis of earthworm tissue extracts by NMR spectroscopy identified maltose as a potential biomarker for ecotoxicity within a metal-contaminated site. 

Human health biomonitoring may also use animal surrogates in the environment to assess potential health hazards to humans - the proverbial canary in the coal mine . For example, chemical and biomarker analysis of bodily fluids or tissue biopsies from family pets, especially dogs, are sometimes used to assess potential chemical exposure and effects in children. This is because dogs often accompany children in the outdoor environment, and both have a tendency to (accidentally or intentionally) consume environmental media such as soil and surface water There has also been an increasing trend to use native animals as sentinel species, that is, fish, wildlife, or invertebrates that are indicators of possible human health risks from environmental hazards. For example, increased incidences of tumors or endocrine disruption in fish may indicate the presence of compounds in the water that may cause cancer or reproductive dysfunction in humans. Concern has also been raised over the increased incidence of deformities in frogs, because these may indicate an increased level of chemicals in the environment, which can cause birth defects in humans. 

---