Nickel-exposed workers in China: a cohort study.

There are more than 50 000 workers in Jinchuan Group Co, Ltd (JNMC). Since all staff in JNMC are eligible for a medical examination every two years, only 23 484 nickel-exposed subjects who participated in medical examination were included in this study. Their data, collected from June 22, 2011 to September 28, 2012, in a comprehensive epidemiological survey and during medical examinations, permitted an extensive evaluation of the relation between metal exposure, gene, epigenetics and risk of human diseases.