Safe ocular levels for IR occupational exposures.
Duke University Eye Center, Durham, North Carolina, Final Report 1978 Nov; :1-21
The effects of exposure to elevated temperatures or to infrared radiation (IR) on lens proteins were investigated in-vitro in rabbit and calf lenses and in-vivo in rabbits. Calf lens homogenates were incubated at temperatures ranging from 37 to 45 degrees-C. Isoelectric focused gel analysis of the lenses incubated for 30 minutes at 45 degrees showed a definite loss in the lowest points of the alpha crystallin components. Similar changes occurred at lower temperatures, but at slower rates. The loss of alpha crystallin from the isoelectric focusing pattern was due to aggregation to higher molecular weight particles which could not enter the gel. A very high molecular weight fraction contained alpha crystallin material. Rabbit lenses were exposed in-vitro and in-vivo to IR from a Raychem-IR 500 infrared hand tool with a total irradiance of 65 milliwatts/square centimeter. In-vivo exposures were for 1 hour/day for several months. The concentration of beta crystallin proteins was reduced by in-vivo exposures. In in-vitro studies, the beta crystallin was more resistant to degradation than were mixtures of alpha and gamma crystallins. The findings support the theory that changes in some lens proteins can occur by direct absorption of IR by the lens, and that these changes are different from those seen in the early stages of ultraviolet cataract formation.
NIOSH-Grant; Laboratory-animals; Eye-damage; Eye-disorders; Radiation-hazards; Radiation-exposure; Infrared-radiation; Nonionizing-radiation
Ophthalmology Department of Ophthalmology Duke University Med Ctr Durham, N C 27710
Final Grant Report
NTIS Accession No.
Duke University Eye Center, Durham, North Carolina, Final Report
Duke University, Durham, North Carolina