Inner dosimeters

After donning the outer dosimeter or clothing, the volunteer will then put on his/her socks and shoes. Usually clean, unworn socks are provided to avoid crosscontamination of the inner dosimeter with the socks from prior workdays. New shoes are also provided to the volunteer, again to avoid cross-contamination issues. On occasion, regular pre-worn shoes and socks may be used for the volunteer if crosscontamination of samples is not an issue. 

Many types of matrices have been used in the past to measure the field stability of the test substance. Cotton gloves, cellulose patches, face wipe handkerchiefs and/or gauze face wipe matrices, long underwear (inner dosimeters), pants, shirts, coveralls (outer dosimeters), sorbent tubes, urine, and other matrices are common matrices that have been used for this purpose. 

Inner dosimeter sections should be covered with outer dosimeter material to simulate the environment of the inner dosimeter on the volunteer, which would normally be covered by the outer dosimeter. This procedure can be accomplished by pinning the outer dosimeter material over the inner dosimeter section using straight pins. Outer dosimeter sections, patches, or other exposed matrices should not be covered. 

CA, outer whole-body dosimeter = coveralls dosimeters (arms, legs, torso) FL and AZ (short sleeve with arm band) inner dosimeter = t-shirt and brief head patch, face and neck... 

Among the first dermal dosimeters used in exposure research were 4 x 4-in cellulose or gauze patches which were pinned to the outer and inner surfaces of clothing or vests which farm workers would wear during the application or re-entry phase of the smdy. These patches were easy to manufacture and when pinned to the shirt or pants of the worker made for an easily used dosimeter pad. The major advantage to the use of the patch to estimate worker exposure was this method s ability to differentiate the relative contributions of pesticide residues to different parts of the worker s body. This sampling technique in turn could lead to recommendations (i.e., the use of... 

Both inner and outer whole-body dosimeters are common tools to measure successfully dermal exposure to pesticide workers and are employed in a variety of ways in mixer-loader/applicator or re-entry studies. 

Selection of the type of whole-body dosimeter is important. Inner whole-body dosimeters are usually white, 100% cotton, long underwear purchased from a variety of clothing outlets and stores. One- or two-piece inner whole-body dosimeters are common. Outer whole-body dosimeters can range from hand-made cotton coveralls to shirts and pants bought directly off the shelf at local retail stores. Outer whole-body dosimeters can also be purchased from wholesale clothing outlets. Outer whole-body dosimeters may be any color and may also be 100% cotton or mixed materials, depending on the purpose for which the outer whole-body dosimeter is to be used. For example, one may want to use a coverall as an outer whole-body dosimeter. This would be acceptable even if the coverall were not white and not 100% cotton provided that the fabric did not contain interfering analytical components. 

Pre-exposure proeessing and preparation of the inner and outer whole-body dosimeters for use in the field should be eonsidered. The analytieal laboratory should determine if the fabric of the dosimeter of choice contains any analytical interference, which may be a problem in subsequent analysis of the fabric. If such analytical interferences are present in the fabric of the dosimeter, they may be reduced by pre-washing the dosimeter material prior to use in the field. The dosimeter is usually pre-washed (sometimes more than once) and rinsed several times prior to thorough drying. The washing detergent of choice should be as free as possible from additive brighteners and other chemicals, which may cause analytical interferences. 

Patches should be fortified in a similar fashion to the dosimeter sections. Care should be taken when designing a patch to make sure the patch has backing made of aluminum foil or other nonpenetrable material so as not to lose fortification solution during the fortification process. Patches representing inner exposure can also be covered with a cotton/chambray material after fortification. 

Penetration of chlorpyrifos through the outer whole-body dosimeter to the inner-body dosimeter... 

In order to determine the dermal exposure of volunteers to chlorpyrifos, the penetration of chlorpyrifos through the outer whole-body dosimeter (coveralls) to the inner body dosimeter (t-shirt and briefs) was measured. The penetration factor was calculated for each volunteer in the study from the experimental data by dividing the amount of chlorpyrifos on the t-shirt and brief sample by the amount of chlorpyrifos on the torso section of the coveralls. This method of calculation assumes that the surface area of the torso section of the coveralls is nearly the same as the surface area of the t-shirt and briefs worn directly under the torso section of the coveralls. A mean penetration factor for each worker type was calculated by averaging all the worker volunteer... 

The mean radon concentrations determined by the passive detectors are based on calibrations using NBS standard radium-226 solutions and also from participation in the OECD (Nuclear Energy Agency)/CEC radon dosimeter intercomparisons (Commission of the European Communities, 1986) held at the U.K. National Radiological Protection Board (NRPB). Recent calibrations of the new LR-115 based detectors, in terms of response to radon concentrations and F factors have been carried out at the NRPB, which assistance is greatly appreciated. For the etching and track counting procedures used the inner LR-115 piece in the detectors has a mean sensitivity of approximately 1.6 tracks cm 2 kBq l m hr l. 

Experimental approaches to measure the radial dose distribution are also in progress [119], and it was found that the distribution follows r law in the inner region of a critical distance and obeys r law outside of that region. LaVerne and Schuler reported the considerable decrease in the radiation chemical yield for ferric production in the Fricke dosimeter, suggesting a model of a deposited energy density in an ion track, which depends on the LET and the atomic number of an irradiation particle [120,121]. 

Product analysis of y-R was carried out in a Pyrex tube with an inner diameter of 1.0 cm at room temperature (r.t.). After y-R, the reaction mixtures were directly analyzed by GC and GC-MS. The G values were calculated from the product yields, and the absorbed dose measured by the ferrous sulfate dosimeter (Fricke dosimeter). 

The requirement to access cells for maintenance purposes and to transfer full product containers to the vitrified product store offers the potential for >1-Sv doses to operators under fault conditions. In order to prevent such incidents, entries to cells are controlled via inner and outer shield doors that are interlocked to gamma monitors. Additionally Operating Rules and Instructions place requirements on operators with regard to man entries to cells and prohibit the presence or introduction of active product containers to specified cells. Personal Alarmed Dosimeters are routinely worn during cell entries to provide an immediate indication of high dose rates. 

On July 8 and 9, 1992, with the unit at no greater than 10% power, work crews at Limerick Unit 1 were performing troubleshooting on a main steamline sample flow isolation valve inside the drywell. The crews were unaware that a narrow, intense beam of radiation passed from a reactor water level instrumentation penetration to the inner drywell wall near the work area. The beam measured 6" at the penetration to 1 -2 at the drywell wall. The beam was discovered when the dosimeter of one worker alarmed. 

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