Reaction mass of Limestone and dicalcium silicate

Health surveillance data

Administrative data

Endpoint:

health surveillance data

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Study period:

no data available

Reliability:

other: high

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Well-documented publication on cancer risks due to exposure to Portland cement dust. Local effects in the respiratory tract following inhalation of lime dust are attributed to the alkaline reaction of lime in contact with water (in this case the humidity of mucous membranes). Addition of water to cement or Portland cement can raise the pH to values exceed 13, thus giving a more alkaline mixture than that from CaO and Ca(OH)2. Since pH change is the primary adverse effect leading to irritation of the mucosa and impaired ventilatory function, (Portland) cement can be used as a surrogate to predict effects and safe exposure levels for lime. The following additional information should be considered: (Portland) cement contains hexavalent chromium which is, however, not contained in lime at significant concentrations. Until the addition of ferrous sulphate became a common procedure, cement contained about 5-10 mg Cr(VI)/kg of cement; a content of 20 mg Cr(VI)/kg has also been reported . After the addition of ferrous sulphate, the level of Cr(VI) decreased to less than 2 mg/kg. This reasoning was also used by the Scientific Committee on Occupational Exposure Limits (SCOEL) in their recommendation occupational exposure limits for calcium oxide (CaO) and calcium hydroxide (Ca(OH)2) (see 7.5.3, Repeated dose toxicity: inhalation). The current paper was considered by SCOEL for establishing the STEL and the 8 h TWA OEL for lime, employing read-across from (Portland) cement to lime.

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

publication

Title:

Exposure to cement dust at a Portland cement factory and the risk of cancer

Author:

Vestbo, J.; et al.

Year:

1991

Bibliographic source:

Br. J. Ind. Med. 48, 803- 807

Materials and methods

Study type:

health record from industry

Endpoint addressed:

repeated dose toxicity: inhalation

carcinogenicity

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

Cross-sectional study on mortality from all cancers, respiratory cancer, and stomach cancer in Portland cement workers

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

cement dust

IUPAC Name:

cement dust

Details on test material:

- Name of test material (as cited in study report): Cement dust
No further details are given.

Method

Type of population:

occupational

Ethical approval:

not specified

Details on study design:

The cohort for analysis sampled in 1973 in Aalborg (Denmark) consisted of 1401 male subjects aged 46-69 (546 Portland cement workers and 858 randomly sampled men of similar age and area of residence). All subjects were examined with lung function tests and interviews including the BMRC questionnaire, questions on lifelong occupational and smoking histories. No regular dust measurements were conducted before 1974. Personal dust sampling during the 1st half of 1974, however, showed 9 % of respirable dust measurements above 5 mg/m³.
Information on all incident cancer cases from the time of examination in 1974 to 15 June 1985 was obtained from the Danish Cancer Registry.

Results and discussion

Results:

No increased risk of overall cancer was found among cement workers. Among men with more than 20 years of exposure to cement dust, 14 cases of respiratory cancer (including cancer of the larynx and trachea) were observed (ratio observed/expected 1.52; 95 % CI: 0.90-2.57) when compared with all Danish men. Men with 1-20 years of exposure had a ratio observed/expected of 1.14 (95 % CI: 0.59-2.19) based on nine cases of cancer. No increased risk of stomach cancer was observed.
After excluding all men with documented exposure to asbestos during an employment in an asbestos cement factory no increased risk of overall cancer or respiratory cancer was found among cement workers compared with white collar workers from the local reference population, using a Cox regression model controlling for age and smoking habits. Relative risks were 0.5 (95 % CI: 0.1-1.5) and 1.0 (95 % CI: 0.4-2.6) for men with 1-20 and more than 20 years of exposure to cement dust, respectively, compared with white collar workers.

Applicant's summary and conclusion

Conclusions:

See section "results".
This study was used by SCOEL for establishing OELs for lime dust. Data on Portland cement as a surrogate were used as supportive information, based on the reasoning of similar pH, being the causative factor for respiratory effects in both lime and Portland cement dust.