Workplace, personal monitoring

Borders RA, Gluck SJ, Sowle WF, et al. 1986. Development and validation of personal monitoring methods for low levels of acrylonitrile in workplace atmosphere II. Thermal desorption and field validation. Am Ind Hyg Assoc J 47 158-163. 

The calibration procedure provides a body of data about how the personal monitor responds to the various irradiation conditions. These data are converted into formulas or algorithms that generate a value for Hp(lO) for the irradiation conditions assumed in the workplace. The formulas or algorithms apply to the personal monitor system calibrated, and do not change unless there is a modification in the design or types of radiation detectors used in the personal monitor. An example of such a body of data for a particular monitoring device is provided by Ehrlich and Soodprasert (1994). 

They may differ, however, from the actual irradiation conditions experienced in the workplace. The disparity of irradiation conditions results in differences in response that cannot be fully simulated and represent basic limitations in the accuracy of personal monitors. Some of these limiting conditions are ... 

In practice, if one knows that the actual conditions in the workplace can be reasonably simulated by these idealized irradiation geometries and locations of the personal monitor, and the photon energy is within the indicated range, Hp(lO) can be used directly as a surrogate for He even if the precise conditions are not known. The most frequently encountered condition of AP irradiation with the personal monitor located on the front of the body is well within this region for photon energies above 40 keV, and use of Hp(lO) would not overestimate He by more than a factor of three for photon energies as low as 30 keV. 

Occupational pesticide exposure holds a peculiar status within the field of occupational health and safety, both from a scientific and regulatory perspective. Methods for personal monitoring of dermal exposure first arose in the context of pesticide applications in agriculture, pioneered by scientists in the USA Public Health Service (Batchelor and Walker, 1954 Durham and Wolfe, 1962). These methods gained worldwide recognition in the early 1960s, and remain a component of exposure assessment practice today. This work pre-dated most personal monitoring methods that were developed for industrial workplaces. 

See also Air Analysis Sampling Workplace Air. Lipids Fatty Acids. Personal Monitoring Passive. Pesticides. Polycyclic Aromatic Hydrocarbons Determination. 

Coultas DB, Samet JM, McCarthy JF, Spengler JD. A personal monitoring study to assess workplace exposure to environmental tobacco smoke. Am J Public Health 1990 80 988-990. 

Action Levels. The scheme requires that the exposures of one or more potentially-exposed workers be monitored periodically. If all of the air concentrations measured are below the "action level (AL), which is of the "permissible exposure limit" (PEL), then no further action is required unless the process is changed. The workplace is deemed to be in compliance with the standard. If a value exceeds the PEL, the workplace is declared to be out of compliance and some form of remedial action is required, e.g., a process change, engineering controls or personal protective equipment. Finally, if the sample value is between the AL and the PEL further sampling is required until two values in a row are observed below the AL (workplace in compliance) or one value is observed above the PEL (workplace out of compliance). 

Exposure Levels in Humans. Although relatively recent estimates of the size of the population occupationally exposed to 1,1-dichloroethane are available from NIOSH, monitoring data on workplace exposures are generally limited, with a few observations about 1,1-dichloroethane included in detailed studies of 1,2-dichloroethane. A study of the levels of 1,1-dichloroethane in the inhaled and exhaled air and drinking water of college students in Texas and North Carolina found low levels (<0.49 ppb) of 1,1 - dichloroethane in the personal air quality monitors of the Texas students, whose campus bounded a petrochemical manufacturing area, but none in samples of their exhaled breath. Additional information on the availability of biomarkers that could be used to indicate human exposure to 1,1-dichloroethane would be helpful. 

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