Worker exposure data issues

The replacement of asbestos fibers by other fibrous materials has raised similar health issues in relation to substitute materials. However, since lung cancer has a latency period of approximately 25 years, and since the fiber exposure levels in contemporary industries is far lower than those which prevailed half a century ago, the epidemiological data on most substitutes is insufficient. A possible exception is slag fibers for which several studies on worker populations are available over extended periods (44) some results show a substantial increase in lung cancer occurrence. Consequentiy, the toxicity of asbestos substitute fibers remains a subject of active investigation. 

Certain LMW agents will cause OA via a poorly defined mechanism. Only about 20% of workers with OA to toluene diisocyanate (TDI) have IgE detectable to TDI indicating that IgE antibody may be more an indicator of exposure rather than a mediator of the disease [10], Similar data exist for workers with asthma caused by plicatic acid from western red cedar [11], The inability to detect IgE antibody in the majority of these workers may be based in technical issues such as the nature of the chemical-protein... 

This chapter discusses issues relevant to assessing exposure of military personnel to jet-propulsion fuel 8 (JP-8). The chapter begins with a description of various scenarios under which military personnel are exposed to JP-8, followed by a brief discussion of the challenges of quantifying human exposure to this distillate fuel. The next section contains a summary of data from studies that have measured concentrations of several components of JP-8 in ambient air at Air Force aircraft maintenance sites. Studies measuring body burden of several JP-8 components in workers involved in aircraft maintenance are also presented. The final section of this chapter describes how the physical and chemical properties of JP-8 affect uptake into the body from exposure by the inhalation, dermal, and oral routes. This last section also serves as a prelude to interpretation of animal toxicity studies conducted with distillate fuels (e.g., JP-8) that are described in later chapters. 

The EPD uses infrared links to interface with a computer, thus providing the data to authorized persons who can read the dose received, add up previous exposures, and establish dose-alarm threshold settings. A custom lithium battery that lasts for a year powers the EPD. Each unit will be issued to a radiation worker for a full year. 

One of the primary shortcomings of the standard data package with regard to worker/bystander risk assessment as It exists today is the emphasis on the oral route of exposure. Others are the limited data on kinetics of the chemical, lack of attention to determining the effect of the route of exposure on toxicity and the Inability to test combinations of pesticides In a manner which would approximate the type of nilxed exposure that applicators receive. These Issues complicate the risk assessments for applicators, for whom the primary route of exposure Is dermal and generally Is Intermittent. 

---