title: Pneumoconiosis after sericite inhalation.
abstract: BACKGROUND
  Between 1997 and 1999 three sericite plant workers in Parana, Brazil, were diagnosed with pneumoconiosis.
  
  
  OBJECTIVE
  To investigate and describe the radiological, clinical, and pathological changes in miners and millers exposed to sericite dust with mineralogical characteristics of inhaled dust.
  
  
  METHODS
  The working premises were visited to examine the sericite processing and to classify the jobs according to make qualitative evaluation. Respirable dust was collected and the amount of crystalline silica and particle size distribution were measured. Forty four workers were examined by a standard questionnaire for respiratory symptoms, spirometry, and chest x ray. Material from an open lung biopsy was reviewed for histopathological and mineralogical analysis, together with sericite samples from the work site to compare the mineral characteristics in lung lesions and work area.
  
  
  RESULTS
  Respirable dust contained 4.5-10.0% crystalline silica. Particle size distribution showed a heavy burden of very fine particles (23-55%) with a mean diameter of <0.5 microm. Mean age of sericite miners was 41.0 (11.9) and mean number of years of exposure was 13.5 (10.1). In 52.3% of workers (23/44), chest radiographs presented a median category of 1/0 or above, and 18.2% (8/44) had a reduced FEV1. There was a significant association between exposure indices and x ray category. Histological studies of the lung biopsy showed lesions compatible with mixed dust fibrosis with no silicotic nodules. x Ray diffraction analysis of the lung dust residue and the bulk samples collected from work area showed similar mineralogical characteristics. Muscovite and kaolinite were the major mineral particle inclusions in the lung.
  
  
  CONCLUSIONS
  Exposure to fine sericite particles is associated with the development of functional and radiological changes in workers inducing mixed dust lesions, which are distinct histologically from silicosis.
authors.affiliation: Division of Medicine, FUNDACENTRO, Sao Paulo, Brazil. eduardo@fundacentro.gov.br
authors.forename: E
authors.initials: E
authors.lastname: Algranti
authors.forename: A M
authors.initials: AM
authors.lastname: Handar
authors.forename: P
authors.initials: P
authors.lastname: Dumortier
authors.forename: E M C
authors.initials: EM
authors.lastname: Mendonça
authors.forename: G L
authors.initials: GL
authors.lastname: Rodrigues
authors.forename: A M A
authors.initials: AM
authors.lastname: Santos
authors.forename: T
authors.initials: T
authors.lastname: Mauad
authors.forename: M
authors.initials: M
authors.lastname: Dolhnikoff
authors.forename: P
authors.initials: P
authors.lastname: De Vuyst
authors.forename: P H N
authors.initials: PH
authors.lastname: Saldiva
authors.forename: M A
authors.initials: MA
authors.lastname: Bussacos
mesh_terms: D000328:Adult; D000538:Aluminum Silicates / Q000032:analysis / Q000633:toxicity*; D004391:Dust / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods; D005541:Forced Expiratory Volume; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis; D008297:Male; D008875:Middle Aged; D008906:Mining; D016273:Occupational Exposure / Q000032:analysis; D010316:Particle Size; D011009:Pneumoconiosis / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D011658:Pulmonary Fibrosis / Q000209:etiology / Q000473:pathology; D011859:Radiography; D012822:Silicon Dioxide / Q000032:analysis; D014797:Vital Capacity
chemical_list: D000538:Aluminum Silicates; D004391:Dust; D012822:Silicon Dioxide; C011934:mica
references.citation: Lab Invest. 1979 May;40(5):576-82
references.pmid: 439858
references.citation: Am J Roentgenol Radium Ther Nucl Med. 1952 Mar;67(3):375-82
references.pmid: 14903282
references.citation: Am J Pathol. 1979 Jul;96(1):149-70
references.pmid: 223447
references.citation: Thorax. 1978 Apr;33(2):219-27
references.pmid: 663882
references.citation: Rev Clin Esp. 1989 Jun;185(1):45-6
references.pmid: 2772339
references.citation: Br J Ind Med. 1983 Feb;40(1):22-7
references.pmid: 6824595
references.citation: Am Rev Respir Dis. 1991 Sep;144(3 Pt 1):718-21
references.pmid: 1892315
references.citation: Lancet. 1982 Jan 2;1(8262):45-6
references.pmid: 6119435
references.citation: Scand J Work Environ Health. 1985 Apr;11(2):65-74
references.pmid: 3890162
references.citation: Am J Ind Med. 1984;6(3):231-40
references.pmid: 6475967
references.citation: Scanning Microsc. 1991 Mar;5(1):95-104; discussion 105-8
references.pmid: 1647058
references.citation: Hum Pathol. 1992 Oct;23(10):1098-105
references.pmid: 1398639
references.citation: Am J Med Sci. 1966 Feb;251(2):215-24
references.pmid: 4285806
references.citation: Environ Health Perspect. 1994 Oct;102 Suppl 5:257-9
references.pmid: 7882946
references.citation: Hum Pathol. 1992 Dec;23(12):1344-54
references.pmid: 1468771
references.citation: Am J Ind Med. 1997 Sep;32(3):309-14
references.pmid: 9219663
references.citation: Am J Ind Med. 2002 Feb;41(2):139-44
references.pmid: 11813219