Article Text


Poster-discussion: Respiratory effects 1
Japanese Indium Cohort Study: 5-year follow-up
  1. Makiko Nakano1,
  2. Akiyo Tanaka2,
  3. Miyuki Hirata2,
  4. Noriyuki Yoshioka1,
  5. Takehiro Michikawa1,
  6. Satoko Iwasawa1,
  7. Kazuyuki Omae1
  1. 1Keio University, Tokyo, Japan
  2. 2Kyushu University, Fukuoka, Japan


Objectives Since the demand for manufacturing flat panel display expands, we are ongoing an indium cohort study and followed up 104 indium exposed workers for 5 years to assess the changes on lung parameters.

Methods Follow-up rate is 66.2% (104/157). According to BEI by the Japan Society for Occupational Health, workers with indium in serum (In-S, ng/ml) < 3 and with In-S ≥ 3 at a baseline study were defined as lower (n=53) and higher (n=51) exposure workers. Interstitial pneumonia biomarkers (KL-6, SP-D) and spirometry were examined for assessing the effects on the lung. Some potential confounders were also checked.

Results During the follow-up, intensive efforts for improvement of working environments were made in all 7 factories. In higher exposure workers, geometric means (GM) of In-S, KL-6 (U/ml), SP-D (ng/ml), %FVC (%),and FEV1/FVC (%) significantly decreased from 13.7 to 9.33 (p<0.001), from 702 to 422 (p<0.001), from 90.0 to 57.7 (p<0.001), from 96.7 to 94.7 (p=0.047), from 82.3 to 81.0 (p=0.020), respectively. Prevalence exceeding the reference values of KL-6 and SP-D significantly reduced from 62.7% and 37.3% to 27.5% and 19.6%, respectively. However, prevalence of %FVC and FEV1/FVC was from 14.3% to 8.2% (p=0.375) and from 4.1% to 6.1% (p=1.000), respectively. During the 5-year-follow-up, 1 lung and 1 renal cancer were disclosed.

Conclusions It is difficult to judge the discrepancy between prevalence and GM of %FVC and FEV1/FVC. Longer follow-up is necessary.

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.