Japanese Indium Cohort Study: 5-year follow-up
该研究对104名铟暴露工人进行了5年随访，发现高暴露组血清铟、间质性肺炎生物标志物和肺功能指标显著下降，但肺功能异常率变化不显著，提示需更长期随访。
<h3>Objectives</h3> 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. <h3>Methods</h3> 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. <h3>Results</h3> 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. <h3>Conclusions</h3> It is difficult to judge the discrepancy between prevalence and GM of %FVC and FEV1/FVC. Longer follow-up is necessary.