Humans causes

Fig. 2. Frequency of fatalities owing to human-caused events (—) and those caused by nucleai leactoi accidents (-) togethei with proposed nuclear...

Saline waters, including seawater, contain, besides a variety of inorganic salts, also organic materials and various particles. They differ in composition from site to site, and also change with time as a result of both natural and human causes. Design and operation of desalination plants requires good knowledge of the saline water composition and properties (41,44). 

The ICS is designed to be used in response to emergencies caused by fires, floods, earthqu es, hurricanes, riots, hazardous materials, or other natural or human-caused incidents. 

Insights into the human causes of accidents for a specific category of process plant installations are provided by the Oil Insurance Association report on boiler safety (Oil Insurance Association, 1971). This report provides a large number of case studies of human errors that have given rise to boiler explosions. 

For the sake of completeness, it is also useful to define at this stage the category of errors known as violations. Violations occur when a worker carries out actions that are either prohibited or are different from those which are prescribed by the organization and carry some associated risks. Since violations are deliberate acts, they are not, strictly speaking, errors. However, the violations category is useful when classifying human caused failures. 

From a human reliability perspective, a number of interesting points arise from this example. A simple calculation shows that the frequency of a major release (3.2 x lO"" per year) is dominated by human errors. The major contribution to this frequency is the frequency of a spill during truck unloading (3 X10" per year). An examination of the fault tree for this event shows that this frequency is dominated by event B15 Insufficient volume in tank to imload truck, and B16 Failure of, or ignoring LIA-1. Of these events, B15 could be due to a prior human error, and B16 would be a combination of instrument failure and human error. (Note however, that we are not necessarily assigning the causes of the errors solely to the operator. The role of management influences on error will be discussed later.) Apart from the dominant sequence discussed above, human-caused failures are likely to occur throughout the fault tree. It is usually the case that human error dominates a risk assessment, if it is properly considered in the analysis. This is illustrated in Bellamy et al. (1986) with an example from the analysis of an offshore lifeboat system. 

Another danger of an inadequate appreciation of human causes of hazards is that the HAZOP analyst may consider a particular high risk event (identified by a guide word and deviation) to be noncredible, because he or she only takes into accoimt the hardware failures (with an extremely low probability) that could give rise to the event. When human causes are taken into accoimt, the likelihood of the event may actually be quite high. 

Accidents do not arise from a single cause but from a combination of conditions which may be human caused (active or latent failures), characteristics of the environment, or operating states of the plant (see Chapter 2). 

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. 

Normally, circulating glucocorticoids (of which cortisol is the most prominent in humans) cause feedback inhibition of ACTH release so that cortisol secretion is, to some extent, self-limiting. However, many patients suffering from major depression have an increased concentration of plasma cortisol but reduced ACTH secretion. The latter abnormality seems to be partly due to a reduction in the number of CRF receptors in the pituitary, although it is thought that decreased ACTH secretion could provoke the adrenal hyperplasia which is common in depression. This would result in excessive secretion of cortisol and contribute to the inhibition of ACTH release (Musselman and Nemeroff 1993). 

FIGURE 1.2 Estimated contributions of natural and human-caused emissions to global mercury emissions. (Source From USEPA 2004b.)... 

Another definition of an evaluation-case event is "that incident outcome for which an engineered solution or a management system solution could be found that would reasonably prevent its occurrence," or more simply put, an event that could be preventable. All human-caused accidents and the consequences of some natural occurrences (earthquake, wind, waves) can be defined as preventable. However, we are only interested in events where engineering and management system parameters could have prevented the accident provided they are within reasonable control of plant personnel. 

Symptoms of intoxication in humans caused by accidental ingestion of Kou-Wen plants have been described as follows. The effect on the digestive system starts with loss of appetite and turn of the stomach, and continues to severe abdominal pain and intestinal bleeding. The effect on the respiratory system presents as breathing difficulties which finally lead to death by respiratory failure. The effect on muscle innervation usually results in generalized muscular weakness and paralysis of the limbs. The effect on the circulatory system starts with heartbeat disorders and a drop in blood pressure, but heart failure is not a common cause of death. In addition to dilation of pupils, a drop in body temperature and proliferation of white blood cells have also been obseryed (70). 

Over the last centuries, climate change has been raised as a very important issue all over the world. The change in climate results from an increase in the earth s average atmospheric temperature, which is usually referred to as global warming. It may be due to both natural and human causes, especially greenhouse gas (GHG) emissions. 

In studies of acute effects on humans caused by exposure to Pb, nephrotoxic effects as well as gastrointestinal effects have been observed [40], Encephalopathy can affect both children and adults. Acute encephalopathy has been shown to increase the incidence of neurological and cognitive impairments. 

Lotito SB and Frei B. 2006. Consumption of flavonoid-rich foods and increased plasma antioxidant capacity in humans cause, consequence, or epiphenomenon Free Radic Biol Med 41(12) 1727—1746. 

Listeria monocytogenes, a bacterium that, when transmitted to humans, causes listeriosis. Listeriosis is characterized by flu-like symptoms, but can cause swelling of the brain and induce abortions. 

Poole GC, Berman CH (2001) An ecological perspective on in-stream temperature natural heat dynamics and mechanisms of human-caused thermal degradation. Environ Manage 27 787-802... 

Skin dermatitis in humans caused by chemicals used in nickel plating 5... 

Little is known specifically about the effects of mescaline compared to LSD. Much information about it relies upon its similarities with other monoamine hallucinogens. The majority of attention is given here to mescaline, but some brief mention of the diverse effects of other peyote alkaloids (of which little is known) is deserved. Often, their effects are very different from mescaline. Many alkaloids are present in sufficent concentrations to alter human physiology after oral consumption of peyote. Lophophorine in humans causes a "sickening feeling in the back of... 

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