title: Investigation of rare chronic lipoid pneumonia associated with occupational exposure to paraffin aerosol.
abstract: OBJECTIVE
  Occupational exposure to paraffin is an infrequent cause of lipoid pneumonia (LP) and related data are scare. We investigated the possible relationship between three rare cases of chronic LP and occupational exposure to paraffin aerosol in an iron foundry.
  
  
  METHODS
  The three cases of LP and their workplaces were investigated using data from field investigations, air monitoring, pulmonary radiological examinations, cell staining, and lung biopsies.
  
  
  RESULTS
  The patients had long-term occupational exposure to paraffin. X-ray diffraction testing revealed that the raw material from the workshop was paraffin crystal. The air concentrations of paraffin aerosol in workplaces were significantly higher than outdoor background levels. Small diffuse and miliary shadows with unclear edges were observed throughout the whole lungs via radiography. Computed tomography revealed diffuse punctate nodules and a high density of stripe-like shadows in both lungs (ground-glass opacity in a lower lobe, and a mass-like lesion and high translucent area near the bottom of the lung). Lipid-laden macrophages were found in the sputum and bronchial lavage. A broadened alveolar septum and local focal fibrosis were also discovered via lung biopsy. The inflammatory reaction in the lung tissues appeared to resolve over time.
  
  
  CONCLUSIONS
  These three rare cases of chronic LP in workers during molding and repair processes were associated with occupational paraffin aerosol exposure. Therefore, primary prevention is essential for molding or repairing workers in the iron foundry, and a differential diagnosis of occupational chronic LP (vs. pneumoconiosis) should be considered when treating these workers.
authors.affiliation: Lishui Center for Disease Control and Prevention.
authors.forename: Chenghong
authors.initials: C
authors.lastname: Han
authors.forename: Lihai
authors.initials: L
authors.lastname: Liu
authors.forename: Shiping
authors.initials: S
authors.lastname: Du
authors.forename: Jianhua
authors.initials: J
authors.lastname: Mei
authors.forename: Ling
authors.initials: L
authors.lastname: Huang
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.forename: Yongliang
authors.initials: Y
authors.lastname: Lei
authors.forename: Junwen
authors.initials: J
authors.lastname: Qian
authors.forename: Jianyong
authors.initials: J
authors.lastname: Luo
authors.forename: Meibian
authors.initials: M
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000336:Aerosols / Q000009:adverse effects; D002681:China; D005260:Female; D006801:Humans; D000072499:Manufacturing and Industrial Facilities; D008875:Middle Aged; D009784:Occupational Diseases / Q000139:chemically induced*; D016273:Occupational Exposure / Q000009:adverse effects* / Q000032:analysis; D010232:Paraffin / Q000009:adverse effects* / Q000032:analysis; D011017:Pneumonia, Lipid / Q000139:chemically induced* / Q000000981:diagnostic imaging / Q000473:pathology
chemical_list: D000336:Aerosols; D010232:Paraffin