OBJECTIVESPrevious types of rock wool has been recently replaced with high-temperature wool (HT wool). HT wool is characterized by a chemical composition with a higher concentration of Al(2)O(3) and a lower concentration of SiO(2), lower biopersistence, and a higher melting point than previous types of rock wool. To evaluate the safety of HT wool, an asbestos substitute, we examined the biopersistence of HT wool in the lungs, based on changes in fiber count according to the length and fiber size (length and width), by performing a nose-only inhalation exposure study in rats.

METHODSMale Fischer 344 rats were exposed to fibers at the target exposure concentration of 30 mg/m(3) continuously for 3 hours daily for 5 consecutive days. Rats were sacrificed shortly after exposure, and 1, 2, and 4 weeks after exposure, and their lung tissues were incinerated at a low temperature. Then, fiber counts and sizes in the lungs were analyzed using a phase contrast microscope.

RESULTSThe fiber count in the lungs 4 weeks after exposure significantly decreased from the baseline value (shortly after exposure). The half-life of fibers calculated from the approximation curve was 34 days for all fibers and 11 days for fibers longer than 20 μm.

CONCLUSIONSBoth the length and width significantly decreased 4 weeks after exposure, probably because fibers were ingested by alveolar macrophages, discharged to outside of the body by mucociliary movement, or lysed by body fluid. In future studies, it is necessary to examine the long-term persistence of fibers in the lungs.

OBJECTIVESThe objective of this study was to evaluate factors associated with turnover intention among nurses in small and medium-sized medical institutions.

METHODSA self-administered questionaire survey was performed in 293 registered nurses, licensed practical nurses, and assistant nurses working full-time in various medical institutions. Multiple linear regression analysis was conducted, with turnover intention as the dependent variable, and nurses' basic attributes and job satisfaction as independent variables.

RESULTSAs for nurses' basic attributes, turnover intention was significantly associated with registered nurses, younger nurses and those with low satisfaction with sleep. As for nurses' job satisfaction, the number of nurses with turnover intention was significantly higher for those with low satisfaction with salary, low satisfaction with welfare, poor implementation of fair salary raise and poor cooperation among nurses.

CONCLUSIONTurnover intention may be reduced by the enhancement of trust in the organization, giving appropriate advice to young nurses and registered nurses, and developing measures for addressing sleep disorders.