Non-malignant consequences of decreasing asbestos exposure in the Brazil chrysotile mines and mills
- E Bagatin1,
- J A Neder2,
- L E Nery2,
- M Terra-Filho3,
- J Kavakama4,
- A Castelo5,
- V Capelozzi6,
- A Sette2,
- S Kitamura1,
- M Favero1,
- D C Moreira-Filho1,
- R Tavares7,
- C Peres8,
- M R Becklake9
- 1Area of Occupational Health, State University of Campinas (UNICAMP), Campinas, SP, Brazil, and Jundiai School of Medicine, Jundiai, SP, Brazil
- 2Pulmonary Function and Clinical Exercise Physiology Unit (SEFICE), Division of Respiratory Diseases, Federal University of Sao Paulo (UNIFESP), São Paulo, SP, Brazil
- 3Division of Respiratory Diseases, University of Sao Paulo (USP), São Paulo, SP, Brazil
- 4Department of Radiology, USP, São Paulo, SP, Brazil
- 5Division of Infectious Diseases, UNIFESP, São Paulo, SP, Brazil
- 6Department of Pathology, USP, São Paulo, SP, Brazil
- 7Department of Radiology, UNIFESP, São Paulo, SP, Brazil
- 8Department of Preventive and Social Medicine, UNIFESP, São Paulo, SP, Brazil
- 9Respiratory Epidemiology and Clinical Research Unit, Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, QC, Canada
- Correspondence to: Dr E Bagatin Occupational Health Area, State University of Campinas (UNICAMP), Av Vital Brasil, 100–CIPOI–3° piso, Cidade Universitária “Zeferino Vaz”, Campinas, São Paulo, Brazil;
- Accepted 15 December 2004
Aims: To investigate the consequences of improvement in the workplace environment over six decades (1940–96) in asbestos miners and millers from a developing country (Brazil).
Methods: A total of 3634 Brazilian workers with at least one year of exposure completed a respiratory symptoms questionnaire, chest radiography, and a spirometric evaluation. The study population was separated into three groups whose working conditions improved over time: group I (1940–66, n = 180), group II (1967–76, n = 1317), and group III (1977–96, n = 2137).
Results: Respiratory symptoms were significantly related to spirometric abnormalities, smoking, and latency time. Breathlessness, in particular, was also associated with age, pleural abnormality and increased cumulative exposure to asbestos fibres. The odds ratios (OR) for parenchymal and/or non-malignant pleural disease were significantly lower in groups II and III compared to group I subjects (0.29 (0.12–0.69) and 0.19 (0.08–0.45), respectively), independent of age and smoking status. Similar results were found when groups were compared at equivalent latency times (groups I v II: 30–45 years; groups II v III: 20–25 years). Ageing, dyspnoea, past and current smoking, and radiographic abnormalities were associated with ventilatory impairment. Lower spirometric values were found in groups I and II compared to group III: lung function values were also lower in higher quartiles of latency and of cumulative exposure in these subjects.
Conclusions: Progressive improvement in occupational hygiene in a developing country is likely to reduce the risk of non-malignant consequences of dust inhalation in asbestos miners and millers.
Supported by a Research Grant from FAPESP-Brazil (1996/10415-6).
Funds from the SAMA SA company have also been available to the Area of Occupational Health, UNICAMP, Campinas, SP, Brazil
Competing interests: EB, LEN, and MTF received support from SAMA (Institutional Grant to State University of Campinas, no. 2P-04559–98) for travelling and lodging to data collection in the mines and also to attend international conferences. EB, LEN, and MTF have a healthcare company which performs disability and medicolegal evaluations in occupational lung diseases: SAMA is one of their clients.
JK, VC, AS, SK, MF, DCM, and RT received support from SAMA (Institutional Grant to State University of Campinas, no. 2P-04559–98) for travelling and lodging to data collection in the mines and also to attend international conferences.
M Favero is deceased