| Co-Investigator(Kenkyū-buntansha) |
OMAE Kazuyuki Keio University, School of Medicine, Professor, 医学部, 教授 (60118924)
KIKUCHI Yuriko Keio University, School of Medicine, Instructor, 医学部, 助手 (10383720)
YOSHIOKA Noriyuki Keio University, School of Medicine, Instructor, 医学部, 助手 (70365229)
TANAKA Akiyo Kyushu University, School of Medicine, Assistant Professor, 大学院医学研究院, 専任講師 (10136484)
HIRATA Miyuki Kyushu University, School of Medicine, Instructor, 大学院医学研究院, 助手 (30156674)
|
|---|
| Budget Amount *help |
¥8,100,000 (Direct Cost: ¥8,100,000)
Fiscal Year 2006: ¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 2005: ¥5,000,000 (Direct Cost: ¥5,000,000)
|
|---|
| Research Abstract |
During the study period (April 2005-March 2007), a research team visited a total of 44 times to 21 indium plants or head quarters (3 in Kyushu area, 2 in Chugoku area, 1 in Kinki area, 12 in Kanto area, and 3 in Tohoku area), and base-line studies, follow-up studies, negotiation for joining our study, exposure information exchanges and risk communication were carried out After the epidemiological studies, the results of individual medical examinations or overall results in the plants were informed to each worker or to company medical staff/plant managers.
In epidemiological studies, indium in serum and whole blood, and job history were measured as an exposure index. Medical history, subjective symptoms on respiratory tracts, spirometry, chest HRCT, KL-6, SP-D, SP-A, etc. were examined as effect indices. In a few plants, immunological and collagen-diseased-related parameters in serum and renal cortex functions were also determined to rule out the possibility of hypersensitive / collagen-
… More
disease-related pneumonitis and cadmium-like health effects (An atomic number of the indium is the next to the cadmium).
We found 3 new indium lung cases in the base-line studies. Total number of indium-exposed workers examined was ca. 530 and that of referent workers was ca. 150. Results of base-line studies indicated that KL-6 of more than a quarter exposed workers exceeded the reference value ( 500 U/mL) and chest HRCT of ca. one-tenth exposed workers showed interstitial changes of the lung. Both exposure-effect and exposure-response relationships were very sharp between indium exposure indices and effect indices. We concluded that a cause-effect relationship was firmly established.
We think that number of workers examined is enough to establish the exposure limit value for indium and preparation of documentation for an occupational biological exposure limit (OEL-B) of indium is now ongoing.
(On April 25, 2007, the Japan Society for Occupational Health proposed OEL-B of indium in serum as 3 ng/ml at General Meeting of JSOH.) Less
|
