PT  - JOURNAL ARTICLE
AU  - Y Kusaka
AU  - K Yokoyama
AU  - Y Sera
AU  - S Yamamoto
AU  - S Sone
AU  - H Kyono
AU  - T Shirakawa
AU  - S Goto
TI  - Respiratory diseases in hard metal workers: an occupational hygiene study in a factory.
AID  - 10.1136/oem.43.7.474
DP  - 1986 Jul 01
TA  - British Journal of Industrial Medicine
PG  - 474--485
VI  - 43
IP  - 7
4099  - http://oem.bmj.com/content/43/7/474.short
4100  - http://oem.bmj.com/content/43/7/474.full
SO  - Br J Ind Med1986 Jul 01; 43
AB  - A hygiene study of a hard metal factory was conducted from 1981 to 1984. All workers exposed to hard metal were medically examined and their exposure to cobalt measured. Eighteen employees had occupational asthma related to exposure to hard metal, a prevalence rate of 5.6%. Nine had a positive bronchial provocation test to cobalt and reactions of the immediate, late, or dual type were elicited. Exposure measurements suggest that asthma may be caused by cobalt at a mean time weighted average concentration below 0.05 mg/m3. Only two of the nine individuals with cobalt asthma had a positive patch test to cobalt. Chest radiographs of three workers showed diffuse shadows of category 1 or over. X ray microanalysis of lung biopsy specimens from two of these three workers showed the presence of tungsten, titanium, cobalt, nickel, and some minerals. One of the two was diagnosed as having pneumoconiosis due to exposure to silica in a steel industry and the other was suspected of having pulmonary fibrosis caused by dust generated from the carborundum wheels used to grind hard metal. There were no cases with interstitial pneumonitis in the factory.