title: [Nested case-control study of chrysotile and lung cancer].
abstract: OBJECTIVE
  To investigate the relationship between simple exposure to chrysotile and lung cancer.
  
  
  METHODS
  The nested case-control study method was used. All of lung cancer cases collected from a male fixed prospective cohort with follow-up of 30 years served as cases and a 1:4 matched proportion was used to select non-cancer case as controls. Controls matched for sex age (+/-5 years old), work time (+/-5 years) and smoking were collected in the same cohort.
  
  
  RESULTS
  Forty cases died of lung cancer in the study cohort, and the incidence was higher than the average incidence (SMR =1.77). The top four work types of death density were raw material (741.5), combing and spinning (424.3), weaving (365.0), and repairing (285.5), which was consistent with exposed level. According to the exposed level of chrysotile, the research objects were divided into the high level group and the low level group. The result demonstrated that lung cancer incidence of the high exposed level group of chrysotile was higher (OR = 3.7 95% CI 2.30 approximately 8.16), compared with the low exposed level group.
  
  
  CONCLUSIONS
  Simple exposure to chrysotile can increase the risk of lung cancer for workers who are exposed to chrysotile.
authors.affiliation: West China School of Public Health, Sichuan University, Chengdu 610041, China.
authors.forename: Ding-lun
authors.initials: DL
authors.lastname: Zhou
authors.forename: Ya-jia
authors.initials: YJ
authors.lastname: Lan
authors.forename: Zhi-ming
authors.initials: ZM
authors.lastname: Wang
authors.forename: Mian-zhen
authors.initials: MZ
authors.lastname: Wang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017632:Asbestos, Serpentine / Q000009:adverse effects*; D016022:Case-Control Studies; D006801:Humans; D008175:Lung Neoplasms / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*
chemical_list: D017632:Asbestos, Serpentine