Sample harmful effects

The method was extended from plants to include soils and waters by Milham ef al. (1970). They point out that nitrate reductase activity in fresh plant samples often causes a rapid decline in nitrate content, so samples collected from remote sites should be frozen in dry ice. A trace of chloroform was used to protect soil and water samples before freezing. We are now more aware of the harmful effects of chloroform inhalation and suggest immediate freezing without preservative and analysis within a few days as a safer alternative - especially with student projects. 

There are a few other precautions specific to the type of survey used. The effects of the induced seismic waves used in seismic surveys should be carefully analyzed, for potentially harmful effects on wildlife and nearby human structures. Also, when conducting radiometric surveys, drilling fluids and drill cuttings not removed as samples should be disposed of properly. These materials should not be placed into surface waters. They should be placed in stable configurations, with embankments and diversions provided to prevent contamination of runoff water where necessary. 

Whilst many chemical-specific tests are fast and effective for detecting known toxicants, some are too slow and/or expensive [1]. They are also unable to answer the more general or the more important question is the sample toxic , and how toxic is it , even when recourse can be made to good sources of information (see also chapter by Cowie and Richardson). To answer such questions, living organisms, typically fish, invertebrates, algae, plants, etc., are exposed to the sample and then after a period of time examined for harmful effects caused by that sample. 

Radioiodine plays an important role in the diagnosis and treatment of various thyroid disorders. Production methods for various iodine isotopes, namely, and are briefly described in this paper. The chemistry of iodine and radiation effects in aqueous solutions and isotopic exchange reactions are also reviewed. An understanding of the chemistry of iodine is essential in isotope production, and for developing the procedure to prepare the radioactive iodine labeled pharmaceuticals. In radiochemical analysis of iodine, most environmental and biological samples can be accurately analyzed by neutron activation at trace levels. The use of potassium iodide (KI) has become an important remedy to prevent the harmful effects of radioiodine exposure under nuclear accident conditions. The inhibitory effect of KI administration on thyroid radioactive iodine uptake is discussed. 

Results are reported as percentage inhibition and expressed as Gl, EC20 or EC50 (Table 7.5). The higher the percentage inhibition of the light emission, the more harmful is the sample s effect on the microorganisms. 

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