粉塵衛生のあゆみ(第2報)1960年(昭和35年)以降

摘要

Subsequent to the previous report, the studies on occupational hygiene of dust exposures reported in the Journal of Science of Labour from 1960 onwards were reviewed. These reports demonstrated that the development of research in dust exposure levels was a prerequisite for the progress in anti-dust measures. Until around 1960, Roken-type dust counters used to be mainly employed in industrial workplaces, and the exposure limits were indicated in terms of particle counts. In the 1960s, mass-based dust meters were developed and, as a result, exposure limits started to be expressed in terms of collected dust weight per unit air volume. The importance of the concentrations of respirable dust particles was also taken into account. This was followed by the development of individual dust samplers for determining the individual exposures to dust. A notable breakthrough was the development of a "T-R sampler" that made it possible to measure simultaneously the total dust concentrations and respirable dust concentrations. Further, continuous measurement of temporal changes of individual dust exposure levels became possible by means of continuous recording devices. The improvement of anti-dust facilities was greatly facilitated by comparing dust exposures determined by these various dust meters. This close link between dust measurement methods and anti-dust measures was typical in the overall development of occupational hygiene in the country.