Exposure modes

Huckins JN, Fairchild JF, Boyle TP. 1991. Role of exposure mode in the bioavailability of triphenyl phosphate to aquatic organisms. Arch Environ Contam Toxicol 21 481-485. 

In this case, the exposure mode is called equilibrium sampling . When kj <short exposure times and/or highly hydrophobic compounds), the group between... 

Because of their physiological property of concentrating primarily in bone and the low penetrating power of the a particle, internal deposition from ingestion and inhalation intakes are the most important exposure modes to man. Most of the actinides show low water solubilities and consequently drinking water typically will not dominate over diet with respect to ingestion. 

Both patients and medical staff are understandably concerned about the health effects of exposure to radiation and radioactive contamination. There are two distinct types of radiation exposure, acute and chronic, and two primary exposure modes, radiation and radioactive contamination. Each exposure type and mode is slightly different and must be treated differently by medical staff (see Table 27.2). In addition, there are concerns about the reproductive effects of radiation exposure. In this section, these concerns will be discussed. 

Ranking Unit. "Ranking unit" refers to an environmental issue at a facility. The definition of a ranking unit is derived directly from its use in the Environmental Survey. A ranking unit is a composite of similar and related environmental problems located in approximately the same geographic location. There can be, and often are, multiple ranking units at each DOE site. Each ranking unit may have multiple exposure modes (e.g., multiple release locations, different release methods, different pathways). 

Even under the best of circumstances in which all possible exposure modes are controlled, it would be foolhardy to make a conclusion of zero exposure. Numerous industrial chemical accidents have occurred. One particularly catastrophic incident occurred in Bhopal, India, in 1984 in which the extremely toxic gas methyl isocyanate leaked out of a closed and contained system resulting in the deaths of perhaps tens of thousands of people. The Bhopal incident dramatically demonstrates that zero exposure (and therefore zero risk) can never be concluded, but it is also possible to go too far in the direction of concluding that all toxic chemicals must be banned for all applications, which is sometimes referred to as the precautionary principle . This important nuance is discussed later in this chapter. 

The comparison of the results of different investigations that examine the outcome of similar exposures must always be evaluated in light of factors that may influence the outcome of the study. Afewofthese factors include study design, potential confounding factors and exposures (extraneous factors or exposures that relate to both outcome and exposure, such as age), biases that affect the selection and participation of the study population, differential exposure misclassiHcation, variation in age of the study population, different conditions of exposure (mode, intensity, duration, and route), and differences in methods used to assess outcomes of interest. Such differences may result in some variation in the results of the compared studies. Given that the studies are well conducted and the variations noted, what is important is the within-study consistency of the results. 

Applications of industrial photopolymer technology can be divided into two general classifications based on the exposure mode of the applied radiation. 

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