Search

This paper provides an overview of the exposure-response relationship for the vascular component of the hand-arm vibration syndrome, called vibration-induced white finger (VWF). Over the past two decades, several epidemiological studies have shown a poor agreement between the risk for VWF observed in various occupational groups and that predicted by models included in annexes to International Standard ISO 5349 (ISO 5349:1986, ISO 5349-1:2001). Either overestimation or underestimation of the occurrence of VWF have been reported by investigators. It has been argued that the current ISO frequency-weighting curve for hand-transmitted vibration, which assumes that vibration-induced adverse health effects are inversely related to the frequency of vibration between 16 and 1250 Hz, may be unsuitable for the assessment of VWF. To investigate this issue, a prospective cohort study was carried out to explore the performance of four alternative frequency weightings for hand-transmitted vibration to predict the incidence of VWF in groups of forestry and stone workers. The findings of this study suggested that measures of vibration exposure which give relatively more weight to intermediate and high frequency vibration produced better predictions of the incidence of VWF than that obtained with the frequency weighting currently recommended in International Standard ISO 5349-1:2001.

Noise measurements were performed in eight patients' rooms, three intensive care units (ICUs) and one operating theatre at a large hospital (1300 beds). Daytime and nighttime LAeq in patients' rooms and in ICUs were higher than the recommended standards. The measured noise levels could interfere with normal sleep and could be dangerous for patients at greatest risk. The laminar flow ventilation system was the main source of noise in the operating room. The LAeq recorded during a surgical procedure was sufficiently high to mask speech communication.The measurement of A-weighted sound pressure levels disclosed that staff activities were responsible for the loudest noises. Air-conditioning systems and electro-mechanical instruments were also important contributors to noise pollution in the hospital.