Causality levels

Type of causality Causality Level of required regulation... 

The primary evaluation (in our system at the end of the hospital stay) for such cases must be checked again by a secondary or even a further evaluation in connection with the specific characteristics of the problem studied. This final or secondary evaluation has to be independent from the causality level originally attributed (Inman 1982). Assessing the causality of adverse drug reactions, even with standardized approaches, should remain an activity under control of physicians (Venulet 1982). 

The construction of a causal factor chart usually starts on the first causal level and proceeds to lower ones. A formalized start inside the process multicomponents may be required in order to assure that no exception from this natural procedure will occur. 

Evidence for chemically mediated disruption of thyroid function in wild reptile populations includes the finding of elevated thyroxine levels in male alligators from Lake Apopka, although a causal relationship with specific chemicals has not been established. ... 

In addition to these formal studies of human error in the CPI, almost all the major accident investigations in recent years, for example, Texas City, Piper Alpha, the Phillips 66 explosion, Feyzin, Mexico City, have shown that human error was a significant causal factor at the level of design, operations, maintenance or the management of the process. 

In addition to the proactive uses of the SRK model described in the two previous sections, it can also be employed retrospectively as a means of identifying the underlying causes of incidents attributed to human error. This is a particularly useful application, since causal analyses can be used to identify recurrent vmderlying problems which may be responsible for errors which at a surface level are very different. It has already been indicated in Section 2.4.1 that the same observable error can arise from a variety of alternative causes. In this section it will be shown how several of the concepts discussed up to this point can be combined to provide a powerful analytical framework that can be used to identify the root causes of incidents. 

A specific example of a causal model is the root cause tree described in Section 6.8.4 and Figure 6.8. This is a very elaborate model which includes several levels of detail for both equipment and human causes of incidents. The root causes tree is a generic causal model, and may require tailoring for application to specific plants and processes (e.g., in the offshore sector) where other error causes may need to be considered. 

Stmcture-property relations usually have a qualitative character (words, causal relations) and can be expressed as if-then clauses by this is an existing property, then it is caused by this type of stmcture or Hf this is the existing stracture, then probably this property can be expected . Stmcture-property relations at the same scale (horizontally) were not found all relations were links between two different (meso-) levels. Stmcture-property relations are different for the different tasks, and even within the same domain (e.g. ceramics) may well be different when the type of requirements is different (e.g. unbreakable versus resistant to certain chemicals). The relations will be specific for specific stmctures and specific properties, e.g. the strength of a jacket, a set of mats, one mat, a cluster of fibres, or one fibre. 

The book takes a bottom-up approach, describing the mechanisms by which pollutants have harmful effects on living organisms and how these effects are translated into adverse changes at the population level. This mechanistic approach supplies the basis for development of new mechanistic biomarker assays, which in turn provide measures of toxic effect and not merely of exposure, and subsequently provide evidence of causality between pollutant levels and ecological changes. 

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