The goal this study is to provide the basic data for health management of workers who are working in the dust emissing process and for improving the quality of working enviroment of manufacturing industries. The author selected 32 dust emissing
processes (8 as the first class of dust, 22 as the second class of dust, 2 as the third class of dust) from 10 types of industries which placed in an Industrial Complex of Kyungsangnam-Do, Korea. The level of total dust was measured as
atmospheric
concentration and personal exposure concentration by low volume air sampler and personal air sampler and personal air sampler, respectively. This study was performed from March 1 to December 31, 1991. The permissible value of dust used in this
study was
that of Korean Ministry of Labour-2mg/㎥ in the first class of dust, 5mg/㎥ in the second class of dust, 10mg/㎥ in the third class of dust.
@ES The results of this study were as follows:
@EN 1. Geometric mean of atmospheric concentration exceeded the permissible value at the 5 (15.6%) of the 32 processes desanding (3.75mg/㎥) in gray iron foundries industry, pulverization (2.35mg/㎥) and ball mill (2.04mg/㎥) in manufacture of
sanitary
ceramic wares industry, ingot molding (2.15mg/㎥) in manufacture of basic steel industry as the first class of dust, and gausing (5.36mg/㎥) in forging of metal industry as the second class of dust.
2. Geometric mean of personal exposure concentration exceeded the permissible value at the 11 (34.4%) of the 32 processes molding (2.69mg/㎥) and desanding (2.99mg/㎥) in gray iron foundries industry, pulverization (2.55mg/㎥) and forming
(2.55mg/㎥) in
manufacture of sanitary ceramic wares industry, and ingot molding (2.44mg/㎥) in manufacture of basic steel industry as the first class of dust, grinding (5.10mg/㎥) and gausing (12.40mg/㎥) in forging of metal industry, parts-welding (7.94mg/㎥)
in
manufacture of parts for railway rolling stock industry, welding (7.63mg/㎥) in gray iron foundries industry, melting (7.01mg/㎥) in manufacture of basic steel industry, welding (5.69mg/㎥) in manufacture of metal cutting machinery industry as
the
second class of dust.
3. Regardless of within the permissible value as atmospheric concentration, there showed exceeding the permissible value as personal exposure concentration at the process of forming in manufacture of sanitary ceramic wares industry, melting in
manufacture of basic steel industry, grinding in forging of metal industry, welding in manufacture of metal cutting machinery industry, molding and welding in gray iron foundries industry, parts-welding in manufacture of parts for railway rolling
stock
industry.
4. Personal expoure concentration (B) was higher than atmospheric concentration (A) in 28 (87.5%) of the 32 processes, and the ratio (B/A) of personal exposure concentration to atmospheric concentration was above 2.0 at the process of melting
(2.37) in
manufacture of basic steel industry, grinding (2.36) and gausing (2.31) in forging of metal industry, welding (2.52) in manufacture of metal cutting machinery industry, welding (2.11) in gray iron foundries industry, parts-welding (4.62) in
manufacture
of parts for railway rolling stock industry.
In conclusion, it is considered that the dust control program might be focused on the processes which have the relatively higher personal exposure concentration than atmospheric concentration, and lowering personal exposure level by exhausting
ventilation system and personal protective equipment is very important for protecting the health of workers who are working in the processes.
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