Establishment Of Exposure Limits Research Articles

Embryo/fetal radiation protection: a possible model for comprehensive occupational reproductive health programs

Modern work activities may necessitate the use of a wide variety of potentially hazardous physical, chemical, biological, or radiological agents. The risks associated with exposure to these agents may not be limited to the worker, and in some cases can extend to the offspring of exposed individuals. Potential exposures to such agents introduce a number of interesting health and safety considerations, including the possible establishment of exposure limits that address reproductive health concerns, and the determination of the extent to which an organization will go to accommodate occupationally exposed persons. The radiation safety profession has considered this issue in part through the promulgation of a specific, lowered occupational dose limit for the embryo/fetus in the workplace. Because ionizing radiation is certainly not the only known or suspected teratogenic agent that may be occupationally encountered, the approach used by the radiation protection profession may be used as a model upon which comprehensive occupational reproductive health programs can be developed. The essential elements of such programs include: the initial disclosure of potential reproductive hazards to all employees upon employment, a mechanism for formal voluntary declaration of reproductive status, a codified institutional decision process that establishes the extent to which accommodations will be made, and formal recognition of the rights of the employee regarding all final work-related decisions.

Particle Loading in the Human Lung—Human Experience and Implications for Exposure Limits

ABSTRACT Timbrell's analyses of fiber burdens in the post-mortem lungs of workers with long-term inhalation exposures to a variety of amphiboles have shown that the clearance of fibers is strongly dependent on lung burden and its associated lung fibrosis, with a small percentage of very heavily exposed workers having little, if any clearance from parts of the lung. The extent of lung fibrosis is proportional to the total surface of retained mineral particles for both fibers and more compact particles. The human data base from the asbestos workers can provide a sound basis for the development of more generic models describing the influence of lung burden of mineral dust on particle deposition in, and clearance from, human lungs. The implications of the results obtained to the pathogenesis of chronic lung diseases and the evaluation and/or establishment of exposure limits are also discussed, along with some research needs to facilitate interspecies extrapolation of fiber toxicity data.