INTERNATIONAL PROGRAMME ON CHEMICAL SAFETY
WORLD HEALTH ORGANIZATION
SUMMARY OF TOXICOLOGICAL DATA OF CERTAIN FOOD ADDITIVES
AND CONTAMINANTS
WHO FOOD ADDITIVES SERIES NO. 13
The data contained in this document were examined by the
Joint FAO/WHO Expert Committee on Food Additives*
Rome, 3-12 April 1978
Food and Agriculture Organization of the United Nations
World Health Organization
* Twenty-second Report of the Joint FAO/WHO Expert Committee on Food
Additives, Geneva, 1978, WHO Technical Report Series No. 631
ASBESTOS
Explanation
Asbestos was evaluated by the Joint FAO/WHO Expert Committee on
Food Additives in 1974. Additional data have become available since
the last evaluation and are summarized below.
BIOLOGICAL DATA
Long-term studies
Rat
In two studies containing 10 and 40 animals/group respectively,
male rats were fed 0 and 1% chrysotite asbestos for their lifetime. In
the first study, six malignant tumours were found in the treated
animals compared to one malignant tumour in the controls. In the
second study, 11 malignant tumours were observed in each group. Two of
the tumours in the treated animals were associated with the
gastrointestinal tract. A third study was performed in which two
groups of 10 male rats were fed 0 end 1% asbestos for six weeks. At
the time of sacrifice tissues were analysed for asbestos fibres. All
tissues of the treated animals showed higher levels of fibres than the
controls. The highest level was found in the omentum (Cunningham et
al., 1978).
Epidemiology
Twenty-two municipalities in Quebec, grouped by evidence of
exposure to asbestos fibres in their municipal water supplies (known
high, probable high and probable low exposures), were evaluated in
respect to mortality experience. The expected number of cancer deaths
were calculated by applying the Quebec age-specific (five-year
groups), sex-specific, site-specific and period-specific (1965-1967,
1970-1972) mortality rates to the 1966 or 1971 census populations for
each municipality. Excess mortality due to cancer of the stomach and
lungs in males, and pancreas in females, was observed in the two
asbestos mining municipalities with known high exposures. The excess
mortality among males was probably due to occupational exposure to
asbestos. The absence of excess mortality due to pancreatic cancer in
the male would suggest that the excess among females was not due to
waterborne asbestos. The author concluded that the evidence derived
from this study would indicate that the excess mortality due to cancer
could not be attributed to exposure to asbestos in the drinking-water
(Wigle, 1977).
REFERENCES
Cunningham, H. M., Moodie, C. A., Lawrence, G. A. and Pontefract, R.
D. (1978) Chronic effects of ingested asbestos in rats, Arch. Environ.
Contamination and Toxicol. (In press)
International Agency for Research on Cancer (1973) IARC Monographs
on the evaluation of carcinogenic risk of chemicals to man. Some
inorganic and organometallic compounds, vol. 2, p. 17, Lyon, IARC
International Agency for Research on Cancer (1977) IARC Monographs
on the evaluation of carcinogenic risk of chemicals to man.
Asbestos, Vol. 14, Lyon, IARC
Wigle, M.D. (1977) Cancer mortality in relation to asbestos in
municipal water supplies, Arch. environm. Hlth, 32, 185