Sensitizer biological effects

One of the most sensitive biological effects of ionizing radiation is to increase the frequency of normally observed chromosome aberrations (but not to induce qualitatively special abnormalities). Peripheral blood lymphocytes are the most feasible cells for chromosome investigations, as blood samples are easy to obtain and the techniques to stimulate the lymphocytes to proliferate within a culture medium and to prepare suitable chromosome slides for microscopic analyzation have their routine protocoil (e. g. Yunis, 1965 Lloyd et al, 1982). 

Examples of differences in the responses of wildlife organisms to EDCs include the differences in sensitivity to phthalates and bisphenols among mollusks, crustaceans, and amphibians compared to fish. In invertebrates, biological effects are observed at exposures in the ng/L to low pg/L range, compared to high pg/L for most effects in fish (reviewed in Oehtmann et al. 2008). In addition, aquatic mollusks tend to bioconcentrate and bioaccumulate pollutants to a greater level than hsh, possibly owing to poorer capabilities for metabolic detoxification (see Chapter 4, Section 4.3). 

Methods for Determining Biomarkers of Exposure and Effect. Analytical methods with satisfactory sensitivity and precision are available to determine the levels of americium in human tissues and body fluids. However, improved methods are needed to assess the biological effects of americium in tissues. 

A bioassay which is generally accepted in the discipline as representative and sensitive for the biological effect. 

M.J. Schoning and A. Poghossian, Recent advances in biologically sensitive field-effect transistors. Analyst 127, 1137-1151 (2002). 

Acute biological effects of the Chernobyl accident on local natural resources were documented by Sokolov et al. (1990). They concluded that the most sensitive ecosystems affected at Chernobyl were the soil fauna and pine forest communities and that the bulk of the terrestrial vertebrate community was not adversely affected by released ionizing radiation. Pine forests seemed to be the most sensitive ecosystem. One stand of 400 ha of Pirns silvestris died and probably received a dose of 80 to 100 Gy other stands experienced heavy mortality of 10- to 12-year-old trees and up to 95% necrotization of young shoots. These pines received an estimated dose of 8 to 10 Gy. Abnormal top shoots developed in some Pirns, and these probably received 3 to 4 Gy. In contrast, leafed trees such as birch, oak, and aspen in the Chernobyl Atomic Power Station zone survived undamaged, probably because they are about 10 times more radioresistant than pines. There was no increase in the mutation rate of the spiderwort, (Arabidopsis thaliana) a radiosensitive plant, suggesting that the dose rate was less than 0.05 Gy/h in the Chernobyl locale. 

The risk that exists from the use of antibiotics in animals arises through a complicated series of events. When an antibiotic is fed to an animal, it comes in contact with the vast and complex bacterial population in the digestive tract. If present in biologically effective amounts, it affects the sensitive bacteria, which may include pathogens but, the total number of living bacteria remains about the same. The sensitive bacteria destroyed or inhibited, and the resistant bacteria multiply to take their place. These resistant bacteria may contaminate animal products used by humans as food. 

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