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Toxicological information

Health surveillance data

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Administrative data

Endpoint:
health surveillance data
Type of information:
other: human case
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
Entry adopted from the OECD SIAR on sulfur dioxide without modification.Study meets generally accepted scientific principles, sufficient documentation of test results with statistical evaluation; less well characterisation of worker and control group, sulphite pulp mill workers with exposure to sulphur dioxide were compared to workers engaged in other processes; consideration of smoking habit; less well characterisation of exposure conditions, no data on exposure concentration and possible co-exposure to clastogenic substances; study acceptable for assessment.

Data source

Reference
Reference Type:
publication
Title:
Is exposure to sulphur dioxide clstogenic?
Author:
Nordenson, I. et al.
Year:
1980
Bibliographic source:
Hereditas 93: 161-164

Materials and methods

Study type:
biological exposure monitoring
Endpoint addressed:
genetic toxicity
Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Study reports exposure- related observations in humans.
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
no data

Method

Type of population:
occupational
Ethical approval:
not specified
Details on study design:
Report of the results of a preliminary study of chromosomal aberrations among workers at a sulphite pulp factory in northern Sweden.
TEST GROUP:
- Number: N=19 males
- Working history: individuals working at the same sulphite pulp factory with employment for more than 15 years
SULPHUR DIOXIDE-EXPOSED GROUP (Subgroup A):
- Number: N=7
- Working history: chronically exposed to sulphur dioxide from boiling of pulp and handling of sulphuric acid, concentration not specified
- Characterisation: 1 smoker, 6 non-smokers
PULP BLEACHING GROUP (Subgroup B):
- Number: N=6
- Working history: bleaching of pulp with exposure to chlorine,
- Characterisation: 1 smoker, 5 non-smokers
PAPER MILL GROUP (Subgroup C):
- Number: N=6
- Working history: exposure to dust in the paper mill
- Characterisation: 3 smokers, 3 non-smokers
CONTROL GROUP:
- Number: N=15 males
- Characterisation: healthy subjects (no further information), N=5 smokers

GENOTOXICITY TESTS: isolation of peripheral lymphocytes and investigation of the following endpoints: chromosomal aberrations after 72 h culture. In 8 workers a second blood sample was taken one month after the first sample in order to see whether aberrations varied with time.

STATISTICAL METHODS: chi square test

Results and discussion

Results:
TEST RESULTS:
- Frequency of chromosomal aberrations: values for subgroups A (SO2 exposed), B (bleaching) and C (paper mill), control group:
total aberrations: 0.075 %, 0.031 %, 0.039 %, 0.027 %
gaps: 0.038 %, 0.013 %, 0.027 %, 0.021 %
chromatid aberrations: 0.021 %, 0.006 %, 0.006 %, 0.006 %
chromosome aberrations: 0.016 %, 0.011 %, 0.006 %, 0.001 %
Repeatability of results: in 8 workers within 1 month of post-observation the difference was 0.88 aberrations/100 cells, not significant
STATISTICAL RESULTS: in the sulphur dioxide exposed group (A) all types of aberrations were significantly increased in comparison to the control group with p<0.01 or p<0.001; in contrast no significant increases for groups B and C.

Applicant's summary and conclusion

Conclusions:
An investigation of workers in a sulphite pulp factory with employment for more than 15 years demonstrated a significant increase of structural chromosomal aberrations (CA) only in those workers with exposure to sulfur dioxide (N=7) but not in those at other workplaces. Frequencies of CA in the unexposed workers (2 groups with N=6 employed in pulp bleaching with chlorine or in the paper mill) were similar to a control group (N=15, higher frequency of smokers).