Chromium

Epidemiological data

Administrative data

Endpoint:

epidemiological data

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Read-across: exposure to varoius chromium species. Acceptable, well-documented study report which meets basic scientific principles.

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Incidence of cancer among ferrochromium and ferrosilicon workers: an extended observation period.

Author:

Langård, S., A. Andersen, et al.

Year:

1990

Bibliographic source:

Br J Ind Med.47(1): 14-9.

Reference 2

Reference Type:

publication

Title:

A survey of respiratory symptoms and lung function in ferrochromium and ferrosilicon workers.

Author:

Langård, S.

Year:

1980

Bibliographic source:

Int Arch Occup Environ Health.46(1): 1-9.

Materials and methods

Study type:

cohort study (retrospective)

Endpoint addressed:

carcinogenicity

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Cohort study of incidence of cancer and total mortality in 1953-1985 in a study population of 976 male ferrochromium and ferrosilicon workers emplyed at a ferrochromium plant for more than one year, starting in 1928-1959, and an extended cohort covering all those who were first employed between 1928-1965, covering 1235 workers. The Cancer Register of Norway was used for data collection.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

exposure to various Cr-compounds

IUPAC Name:

exposure to various Cr-compounds

Details on test material:

Exposure to Cr(III) and Cr(VI) compounds in ferrochromium manufacturing. No details available.

Method

Type of population:

occupational

Ethical approval:

not specified

Details on study design:

Cohort study of incidence of cancer and total mortality in 1953-1985 in a study population of 976 male ferrochromium and ferrosilicon workers emplyed at a ferrochromium plant for more than one year, starting in 1928-1959, and an extended cohort covering all those who were first employed between 1928-1965, altogether 1235 workers.
The Cancer Register of Norway was used for cancer data collection.
Data on personal work conditions were collected from a) personnel lists provided by the company, which included job categories for about 40% of the cohort members; b) detailed work history for those emplyed between 1946 and 1952 as recoded by the company's industrial physician; and c) supplementary information from 10 independent, old workers, some of whom had been employed from the early 1930s.

Exposure assessment:

measured

Details on exposure:

TYPE OF EXPOSURE: air


TYPE OF EXPOSURE MEASUREMENT: Area air sampling, exposure measurements started in 1975. No measurements before this.


EXPOSURE LEVELS: Total chromium concentrations:
ferrochromium furnace operators: 0.04-0.29 mg/m3
charge floor: 0.05 mg/m3 (of which 11-33% was water soluble, hexavalent Cr)


EXPOSURE PERIOD: At least one year from the beginning of employment.



DESCRIPTION / DELINEATION OF EXPOSURE GROUPS / CATEGORIES: Job categories (various jobs / ferrosilicon / ferrochromium / internal maintenance / quartz quarry / office / electric shops / external maintenance / internal transport

Statistical methods:

95% confidence intervals were presented on the basis of an assumed Poisson distribution of the cases of cancer. Standardised mortality ratios (SMR) and Standardised incidence ratios (SIR) were used for the presentation of results.

Results and discussion

Results:

A significant excess risk for cancer among the ferrochromium workers, in comparison with the non-ferrochromium workers, could be observed. The standardised incidence rate ratio (SIR) for ferrochromium workers when using all non-ferrochromium workers as a reference group was 3.0 (99% CI 1.1-6.4). An excess of lung cancer (SIR=154) and prostate cancer (SIR=151) was observed among ferrochromium workers. cancer of the kidney was also increased (SIR=273) in the ferrochromium group, with a mean "latency time" of 39 years.

Confounding factors:

Measurements conducted in the plant in 1975 indicated the presence of both trivalent and hexavalent chromium, as well as high concentrations of fumes and dust particles. Therefore no conclusions on the carcinogenic potential of chromium(III) can be made based on these results.

Strengths and weaknesses:

Strengths: large study group.
Weakness: co-exposure to hexavalent chromates.

Applicant's summary and conclusion

Conclusions:

The incidence of cancer and total mortality in 1953-1985 was studied in a study population of 1235 male ferrochromium and ferrosilicon workers emplyed at a ferrochromium plant for more than one year, starting in 1928-1964. A significantly increased risk for cancer among the ferrochromium workers, in comparison with the non-ferrochromium workers, could be observed. However, measurements conducted in the plant in 1975 indicated the presence of both trivalent and hexavalent chromium, as well as high concentrations of fumes and dust particles. Therefore no conclusions on the carcinogenic potential of chromium(III) can be made based on these results.

Executive summary:

The incidence of cancer and total mortality in 1953-1985 was studied in a study population of 1235 male ferrochromium and ferrosilicon workers emplyed at a ferrochromium plant for more than one year, starting in 1928-1964. A significantly increased risk for cancer among the ferrochromium workers, in comparison with the non-ferrochromium workers, could be observed. However, measurements conducted in the plant in 1975 indicated the presence of both trivalent and hexavalent chromium, as well as high concentrations of fumes and dust particles. Therefore no conclusions on the carcinogenic potential of chromium(III) can be made based on these results.