Biological effects techniques assessment methods

Level 1 sampling provides a single set of samples acquired to represent the average composition of each stream. This sample set is separated, either in the field or in the laboratory, into solid, liquid, and gas-phase components. Each fraction is evaluated with survey techniques which define its basic physical, chemical, and biological characteristics. The survey methods selected are compatible with a very broad spectrum of materials and have sufficient sensitivity to ensure a high probability of detecting environmental problems. Analytical techniques and instrumentation have been kept as simple as possible in order to provide an effective level of information at minimum cost. Each individual piece of data developed adds a relevant point to the overall evaluation. Conversely, since the information from a given analysis is limited, all the tests must be performed to provide a valid assessment of the sample. 

Before embarking upon the design for a ventilation system, it is necessary to assess the extent of the problem, that is, the amount of airborne pollution to be encoimtered in a workplace, and/or the degree of discomfort or stress expected from a thermal environment. Measmement and analysis techniques need to be devised and criteria and standards applied to the environment imder consideration. Where measurement and analysis are concerned, the physics and the chemistry of the properties of the pollutant and its mode of emission need to be studied in such a way that a reliable and accmate assessment of the exposure of a worker can be made. As far as criteria and standards are concerned, medical evidence, biological research and epidemiological methods need to be applied to establish the relationship between the exposure and the long- and short-term effect upon the human body of the worker taking into account the duration of exposure and the work rate. It can be seen, therefore, that many scientific skills... 

It is more diflBcult to secure conclusive evidence of the specificity of a chemical method, when applied to a biological system (B7). Since the constituent will almost certainly have to be determined as one component in a mixture, the possible interfering effects of some (ideally all) of these other substances need to be determined, each over the range of concentrations liable to be met with in practice. Whereas the accuracy of a method can best be determined by recovery experiments, which depend on the availability of a pure sample of the compound under investigation, the specificity of a technique and the effects of possible interfering factors can be more readily investigated by experiments involving radioactive isotopes these isotopic assessments of specificity have so far not been widely applied in clinical chemistry. 

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