Methane

Epidemiological data

Administrative data

Endpoint:

epidemiological data

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Non-GLP, Non-guideline human population study, fully adequate for assessment

Data source

Reference

Reference Type:

publication

Title:

Breath methane and large bowel cancer risk in contrasting African populations

Author:

Segal I, et al.

Year:

1988

Bibliographic source:

Gut, 29, 608-613

Materials and methods

Study type:

cohort study (retrospective)

Endpoint addressed:

not applicable

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Breath methane was measured in 1016 people from four populations with different risks of bowel cancer and other colonic diseases

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Reference substance 003

Cas Number:

74-82-8

Molecular formula:

C H4

Constituent 2

Reference substance name:

74-82-0

IUPAC Name:

74-82-0

Details on test material:

Methane was sampled from exhaled breath

Method

Type of population:

other: 1016 people from four populations resident in South Africa with different risks of bowel cancer and other colonic disease (rural black, urban black, white, Indian)

Ethical approval:

not specified

Details on study design:

Breath was sampled using a Wiggins end expiratory breath sampler. Methane concentration was determined by gas chromatography using a Pye Unicam PU-4500 equipped with a hydrogen ionisation detector.

Exposure assessment:

measured

Details on exposure:

See above

Statistical methods:

No data

Results and discussion

Results:

Highly significant differences in the proportion of subjects with detectable methane in breath were found; % producers - rural black 84, urban black 72, white 52, Indian 41.Bowel cancer risk determined from a variety of sources was lowest in rural blacks, greatest in whites, with intermediate rates for urban blacks and Indians.

Applicant's summary and conclusion

Conclusions:

Methane production in the human colon shows significant interethnic differences but shows no relationship to bowel cancer risk.

Executive summary:

Breath methane was measured in 1016 people from four populations with different risks of bowel cancer and other colonic diseases.

Highly significant differences in the proportion of subjects with detectable methane in breath were found; % producers - rural black 84, urban black 72, white 52, Indian 41. Bowel cancer risk determined from a varietary of sources was lowest in rural blacks, greatest in whites, with intermediate rates for urban blacks and Indians. Methane production in the human colon shows significant interethnic differences but shows no relationship to bowel cancer risk in these populations.