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Toxicological information

Epidemiological data

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Administrative data

Endpoint:
epidemiological data
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference
Reference Type:
publication
Title:
Occupational exposure to wood dust and formaldehyde and risk of nasal, nasopharyngeal, and lung cancer among Finnish men
Author:
Siew S.S., et al.
Year:
2012
Bibliographic source:
Cancer Management and Research 2012:4 223-232

Materials and methods

Study type:
cohort study (retrospective)
Endpoint addressed:
carcinogenicity
Principles of method if other than guideline:
A cohort of all Finnish men born between the years 1906 and 1945 and in employment during 1970 was followed up through the Finnish Cancer Registry for cases of cancers of the nose (n = 292), nasopharynx (n = 149), and lung (n = 30,137) during the period 1971- 1995. The subjects' occupations, as recorded in the population census in 1970, were converted to estimates of exposure to wood dust, formaldehyde, asbestos, and silica dust through the Finnish job-exposure matrix.
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: no additional information
Specific details on test material used for the study:
Name of test material (as cited in study report): Formaldehyde

Method

Type of population:
occupational
Ethical approval:
not specified
Details on study design:
The study cohort consisted of all 1.2 million economically active Finnish men born between 1906 and 1945 who participated in the national population census on December 31, 1970. Data on the occupations held for the Iongest time during 1970 were obtained from the census records. The incident cases of respiratory cancers diagnosed between 1971 and 1995 among Finnish men born between 1906 and 1945 were identified from the FCR for linkage with the population census data from 1970. Cancer patients who had no record in the census (2.2% or 676 cases) were excluded.
Exposure assessment:
estimated
Details on exposure:
The Finnish job-exposure matrix (FINJEM) was used to calculate occupational exposure estimates for the study cohort. The FlNJEM covers major occupational exposures in bnland since 1945, and it addresses exposure by occupation and calendar time.
The proportion of exposed persons and the mean level of exposure in each occupation were used to characterize exposure. The exposure estimates are based on exposure measurements, hazard surveys, and assessments by industrial hygienists of the Finnish Institute ofüccupational Health. Smoking data (percentage ofworkers who were daily smokers) by occupation are also included in the FlNJEM.

Exposure to fomaldehyde is defined as occupational inhalation exposure to formaldehyde as gas, mist, or dust or to formaldehyde on a dust carrier. Occupations with more than 5% of persons exposed to the individual agent at any time between 1945 and 1984 are considered as exposed occupations in the FINJEM.
Statistical methods:
The expected numbers of cases for every occupation were calculated for each 5-year birth cohort and 5-year calendar period by multiplying the number of person-years in each stratum by the corresponding cancer incidence rate of the entire study cohort. The standardized incidence ratio (STR) was defined as the ratio of the observed to the expected number of cases. The 95 % confidence intervals for each SIR were estimated assuming that the observed number of cases followed the Poisson distribution.

Results and discussion

Results:
This study found no increase in portal-of-entry cancer at low FA concentrations in occupational settings.

Any other information on results incl. tables

- The risks of nasal cancers (1.1 (0.6–1.9), nasal squamous cell carcinoma (1.0 (0.4–2.0)) and nasopharyngeal cancer (0.9 (0.3–2.2)) were not increased. The risk was slightly increased for lung cancer (1.2 (1.1–1.3)). However, the risk in the highest exposure group (≥ 1 ppm) was not increased.

- The authors considered the increased risk to be due to residual confounding effects of smoking and co-exposures, including asbestos and crystalline silica.

- FA exposures were below 1 ppm in most occupations.

- Only floor layers, and varnishers and lacquers had average exposures at 1 ppm.

Applicant's summary and conclusion