Calcium acetylide

Epidemiological data

Administrative data

Endpoint:

epidemiological data

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Research publication. Reasonably documented meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

publication

Title:

Incidence of cancer among workers producing calcium carbide

Author:

Kjuus H, Andersen A, Langård

Year:

1986

Bibliographic source:

British Journal of Industrial Medicine 43: 237-242

Materials and methods

Study type:

cohort study (retrospective)

Endpoint addressed:

carcinogenicity

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

The paper reports a cohort study on mortality and incidence of cancer in workers in a calcium carbide plant

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Calcium acetylide

EC Number:

200-848-3

EC Name:

Calcium acetylide

Cas Number:

75-20-7

Molecular formula:

C2Ca

IUPAC Name:

calcium acetylene

Constituent 2

Reference substance name:

Calciumcarbid

IUPAC Name:

Calciumcarbid

Details on test material:

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

Method

Type of population:

occupational

Ethical approval:

not specified

Details on study design:

HYPOTHESIS TESTED (if cohort or case control study): Not clearly stated in publication.

METHOD OF DATA COLLECTION
- Type: other: worker information obtained from personnel records; incidence of cancer from cancer registry of Norway
- Details:

STUDY PERIOD:

SETTING:

STUDY POPULATION
- Total population (Total no. of persons in cohort from which the subjects were drawn): 1055
- Selection criteria: adequate employment data; total time of employment (> 18 months); women excluded because of low numbers and absence of relevant occupational exposures
- Total number of subjects participating in study: 790
- Sex/age/race: male; no age or race data included
- Smoker/nonsmoker: both
- Total number of subjects at end of study: 556
- Matching criteria: no information

COMPARISON POPULATION
- Type: National registry
- Details: Cancer registry of Norway

HEALTH EFFECTS STUDIED
- Disease(s): Cancer, classified by site
- ICD No.: 140-207
- Year of ICD revision: unknown: 8th revision
- Diagnostic procedure: not specified - information drawn from registry
- Other health effects: Mortality

OTHER DESCRIPTIVE INFORMATION ABOUT STUDY: The cohort was drawn from those working in 1953; former employees who were no longer working at that date were lost to the cohort as personnel records prior to that date had been destroyed. The workforce was stable: 60% of those employed in period 1953-1969 had been employed for 10 years or more.
Ten occupational categories were defined, and each cohort member was allocated to the category in which he had been employed for the longest time.

Exposure assessment:

not specified

Results and discussion

Results:

EXPOSURE
- Number of measurements: none

FINDINGS

INCIDENCE / CASES
- Incidence/ Number of cases for each disease / parameter under consideration: All deaths: observed: 234, expected: 250-263; all cancer: observed: 92, expected: 76-80


STATISTICAL RESULTS
- SMR (Standard mortality ratio): 0.93
- SIR (standard incidence ratio) all cancer 1.20

Confounding factors:

Retrospective smoking information for the total cohort was not available, but a smoking survey was performed in 1977, 59% of 458 subjects were daily smokers, compared with 44% in the general male population for that year.
Asbestos exposure: asbestos had in regular use in the plant.
Polycyclic aromatic hydrocarbons (PAH): low grade exposure to PAH as from the electrodes used cannot be excluded
Cadmium exposure: another plant in the village has produced cadmium for many years, and interchange of workers between the two plants is traditional

Strengths and weaknesses:

All those who had worked at the plant should have been eligible for the study, and the preferred cohort formation would be that of an inception cohort, where all participants start their exposure at the time of admission to the cohort. These could not be fulfilled in this study, and the potential bias may have influenced the results.
An uncertain number of former employees were lost to follow up, so both primary and secondary healthy worker effects may have been present. This is not supported by the mortality figures.

Any other information on results incl. tables

Respiratory cancer: SIR 1.15 95% CI** (0.55 -2.11)

Cancer of the colon: SIR 2.09* 95% CI (1.08 -3.66)

Prostate cancer: SIR 1.78* 95% CI (1.16 -2.63)

Stomach cancer: SIR 0.49 95% CI (0.16 -1.4 .14)

* p< 0.05

** CI: confidence interval

Applicant's summary and conclusion

Conclusions:

A study of workers at a single calcium carbide plant showed a decrease in stomach cancer and a significant excess of colonic cancer (standardised incidence ration (SIR) 2.09) and prostatic cancer (SIR 1.56).

Executive summary:

A study of workers at a single calcium carbide plant showed a decrease in stomach cancer and a significant excess of colonic cancer (standardised incidence ration (SIR) 2.09) and prostatic cancer (SIR 1.56). In view of the confounding factors, the lack of compositional and exposure information, and the lack of any mechanisms, it is not considered that this study is evidence for carcinogenicity. IARC have reviewed these data in consideration of possible carcinogenicity of PAHs and found that they are not classifiable as to their carcinogenicity to humans (Group 3).