Human performance effects fundamentals

Abstract Adsorption and desorption of indoor air pollutants to and from indoor surfaces are important phenomena. Often called sink effects, these processes can have a major impact on the concentration of pollutants in indoor environments and on the exposure of human occupants to indoor air pollutants, Basic theories are used to describe the processes using fundamental equations. These equations lead to models describing sink effects in indoor environments. Experimental studies have been performed to determine the important parameters of the sink models. Studies conducted in dynamic, flow-through environmental test chambers have quantified adsorption and desorption rates for many combinations of indoor air pollutants and interior surfaces. Sink effects have been incorporated into indoor air quality (lAQ) models to predict how adsorption and desorption processes affect... 

While risk assessment in the context of protecting public health has been performed for many years, it is the 1983 U.S. National Academy of Sciences Report (Committee on the Institutional Means for Assessment of Risks to Public Health Commission on Life Sciences National Research Council 1983) that has served as the tenet for practicing risk assessors (see Chapter 1). Risk assessment was defined as the characterization of the potential adverse health effects of human exposures to environmental hazards. The predictive aspect of risk assessment was set by the use of the word potential. A fundamental expectation of the risk assessment process was that it should attempt to accm-ately predict adverse effects before there is evidence of disease in the population. Thus, risk assessment goes beyond the mere description of epidemiological and clinical case-control studies. In that report, the committee defined logical components of a risk assessment which still serve as guiding principles today. They were and are (a) hazard assessment or the qualitative determination that a stressor poses a hazard as evidence by causal evidence of an ill effect,... 

Baseline Risk Assessment. The risk assessment is the foundation upon which site remediation goals are determined and is developed following two fundamental assessments. A toxicity assessment is performed to collect the most recent and pertinent toxicity data for carcinogenic and noncarcinogenic effects of chemical contaminants detected in site media. An exposure assessment is performed to quantify human intake of contaminated media. Subsequently, by measuring the concentrations of chemicals detected in the site media, the dose of chemical intake can then be quantified to complete the exposure assessment. Risk characterization is the final step, performed by coupling the results of the toxicity assessment with those of the exposure assessment to obtain an overall cumulative site risk. 

The fundamental purpose of all allowances is to add enough time to normal production time to enable the average worker to meet the standard when performing at standard performance. Even when the most practical, economical, and effective method has been developed, the job will still require the expenditure of human effort, and some allowance must therefore be made for recovery from fatigue and for unavoidable delays. Allowance must also be made to enable a worker to attend to his personal needs. Other special allowances may also have to be added to the basic time in order to arrive at a fair standard. 

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