Refractories, fibers, aluminosilicate

Epidemiological data

Administrative data

Endpoint:

epidemiological data

Type of information:

other: Epidemiological survey of exposure and health

Adequacy of study:

supporting study

Study period:

1994-1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study done to the highest standards by independent institute with international colaboration

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Study type:

cross sectional study

Endpoint addressed:

repeated dose toxicity: inhalation

Test guideline

Qualifier:

no guideline required

Test material

Test material information

Constituent 1

Reference substance name:

oxo[(oxoalumanyl)oxy]alumane; silanedione

EC Number:

604-314-4

Cas Number:

142844-00-6

Molecular formula:

amorphous glass Si(n)O(3n+1) polymeric anions bonded to Zr and Al(3+)

IUPAC Name:

oxo[(oxoalumanyl)oxy]alumane; silanedione

Details on test material:

- Name of test material (as cited in study report):RCF

Method

Type of population:

occupational

Ethical approval:

confirmed and informed consent free of coercion received

Details on study design:

METHOD OF DATA COLLECTION
- Type: Questionnaire, Work history and Clinical tests.
- Details: Target population comprised all current workers associated with RCF production plus others, who had left the industry (774 workers 90% of current workers and 37% of leavers). Information was collected on personal characteristcs, chest radiographs, lung function, respiratory symptoms, smoking, and full occupational history. Regression analysis was used to study relations between indices of health and cumulative exposure to airborne dust and fibres and likely past exposure to asbestos.

STUDY PERIOD:1994-1998

Exposure assessment:

measured

Details on exposure:

TYPE OF EXPOSURE: airbourne dust

TYPE OF EXPOSURE MEASUREMENT: Personal sampling for fibre concentration and total inhalable and total respirable dust (including silica) and fibres.
Results Fibres : <0.1 f/ml up to 0.4 f/ml depending on occupational groups and plant. Secondary conversion and finishing gave higher concentrations with results ranging from 0.3 f/ml up to 1.25 f/ml. Total inhalable dust was low when compared to current occupational hygiene standards. Respirable quartz was seldom detected, the highest recorded result from 200 samples was only 0.015 mg/m3, consequently no further action was taken on quartz measurements.

EXPOSURE PERIOD: 1995-1996

POSTEXPOSURE PERIOD:varies by worker but was documented - ongoing programme of sampling to same standards

Statistical methods:

Regression analysis

Results and discussion

Results:

The individual cumulative exposure was calculated for each worker and regressed against clinical results.

Radiology: Prevalence of small opacities -760 individuals provided x-rays for this survey it was difficult to find any coherent pattern in the results. Small opacities of profusion 1/0+ were not associated to life time accumulated exposures to fibres and dust however a positive association was suggested with exposures up to 1971. There was little or no evidence of a positive association with later exposures.

Pleural changes of any kind were seen on 11% of radiographs with pleural plaques on 5% . Pleural plaques and pleural changes more generally were both associated with age and exposure to asbestos there was no evidence that exposure to RCF was additionally associated with pleural changes on the chest radiographs.

Lung function : There was no association between cumulative exposure to respirable fibres and lung function in the study population overall. Among men FEV1 and FVC decreased with increased exposure but only in current smokers .On average the effect on male smokers was mild (100ml for average life time exposure to RCF).

Respiratory symptoms- Breathlessness did not show any association with exposure but reports of recurrent chest illness were associated with cumulative exposure to both fibres and dust.

Summary

The authors concluded that it was premature to speculate on the nature of any response if indeed there is any adverse effect of RCF.

Confounding factors:

Asbestos and smoking were the major confounding factors.

Strengths and weaknesses:

The study population represents most of the wokers exposed but this is still a small population and exposures are low.

Any other information on results incl. tables

The full report may be down loaded form the Institute of Occupational Medicine (IOM) web site (www.iom-world.org)

Cowie et al (2001) Epidemiological Research in the European Ceramic Fibre Industry 1994 -1998 A study of the respiratory Health of Workers in the European RCF Industry; Occupational and Environmental medicine,Volume 58, pages 800 -810

Applicant's summary and conclusion

Conclusions:

If there is any adverse effect of RCF it will only become apparent after further cross sectional studies on workers who have been exposed for longer.