Outer 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. 

At this time, the volunteer exits the dressing room and is provided with a clean air monitoring pump which is hooked to the belt or outer dosimeter of the volunteer. The volunteer is now ready to move to the test site. If multiple volunteers are to be prepped and dressed, volunteers who are ready to go to the field site are set back in the chairs to wait for all volunteers to be dressed. 

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. 

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. 

The skin exposure is first calculated by correcting the outer whole-body dosimeter residues by the penetration factor. The penetration factor is derived from dividing the total outer torso residues into the total residues on the combined tee-shirt and brief... 

Sum the micrograms chlorpyrifos on the arms and legs and torso section of the coverall (outer whole-body dosimeter) and multiply by the percentage penetration of the chlorpyrifos through the coverall. 

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... 

The amount of chlorpyrifos deposited on the passive dosimeters such as outer whole-body dosimeters (coveralls) was determined as described... 

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 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. 

In 900MWe units, the capsules are irradiated along the outer surface of the thermal shield assembly. In 1300 and 1450 MWe units, the capsules are directly attached to the core barrel. In the case of Chooz-A, the thermal shield assembly was removed in 1970 and the surveillance capsules were then located under the core. The capsules are equipped with neutron dosimeters and thermal monitors, with some variations according to the reactor series. In all cases, activation dosimeters of nickel, copper and cobalt, as well as fissile dosimeters of uranium-238 and neptunium-237 are used. This instrumentation is complemented by iron and cadmium-shielded cobalt dosimeters in most cases and, in the most recent plants, also by niobium dosimeters. Each capsule contains temperature detectors based on eutectic alloys with melting points generally of 304 and 310 °C. 

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