International Agency for Research on Cancer (IARC) - Summaries & Evaluations

(Group 3)

For definition of Groups, see Preamble Evaluation.

Supplement 7: (1987) (p. 88)

CAS No.: 309-00-2

A. Evidence for carcinogenicity to humans (inadequate)

Specific mention of aldrin in analytical epidemiological studies is limited to reports of follow-up of two cohorts of men employed in its manufacture in plants where dieldrin and endrin (and, in one, telodrin) were also manufactured [ref: 1-4]. In the most recent report of the first of these cohorts [ref: 3], 232 of 233 exposed workers were successfully followed from four to 29 (mean, 24) years, with duration of exposure to pesticides varying between four and 27 (mean, 11) years. There were nine deaths from cancer with 12 expected (standardized mortality ratio [SMR], 75; 95% confidence interval, 25-125). In the second cohort [ref: 4], 90% of 1155 men were followed for 13 years or more. Mortality from all cancers was not increased (SMR, 82; 56-116), although there were apparent increases in mortality from cancers of the oesophagus, rectum and liver, based on very small numbers.

B. Evidence for carcinogenicity to animals (limited)

Aldrin was tested for carcinogenicity by the oral route in mice and rats. In mice, it produced malignant liver neoplasms [ref: 1,5]. In rats, the incidence of thyroid tumours was increased in exposed animals in one study ref: 5], but this could not be clearly associated with treatment; three other studies in rats gave negative results [ref: 1,6] and one was inadequate [ref: 1].

C. Other relevant data

No data were available on the genetic and related effects of aldrin in humans. It did not induce dominant lethal mutations in mice. In single studies, it induced chromosomal aberrations in bone-marrow cells of rats and mice, but no micronuclei in bone-marrow cells of mice treated in vivo. It induced chromosomal aberrations in cultured human lymphocytes; studies of DNA damage in human and rodent cells in vitro were inconclusive. Aldrin inhibited intercellular communication in both human and rodent cell systems. It did not induce sex-linked recessive lethal mutations in Drosophila but was mutagenic to yeast. It was not mutagenic to bacteria and did not induce breakage of plasmid DNA [ref: 7].

Overall evaluation

Aldrin is not classifiable as to its carcinogenicity to humans (Group 3).

For definition of the italicized terms, see Preamble Evaluation.

Also see previous evaluation: Vol. 5 (1974)


1. IARC Monographs, 5, 25-38, 1974

2. Van Raalte, H.G.S. (1977) Human experience with dieldrin in perspective. Ecotoxicol. environ. Saf., 1, 203-210

3. Ribbens, P.H. (1985) Mortality study of industrial workers exposed to aldrin, dieldrin and endrin. Int. Arch. occup. environ. Health, 56, 75-79

4. Ditraglia, D., Brown, D.P., Namekata, T. & Iverson, N. (1981) Mortality study of workers employed at organochlorine pesticide manufacturing plants. Scand. J. Work Environ. Health, 7 (Suppl. 4), 140-146

5. National Cancer Institute (1978) Bioassays of Aldrin and Dieldrin for Possible Carcinogenicity (Tech. Rep. Ser. No. 21; DHEW Publ. No. (NIH) 78-821), Bethesda, MD, US Department of Health, Education and Welfare

6. Deichmann, W.B., Macdonald, W.E. & Lu, F.C. (1979) Effects of chronic aldrin feeding in two strains of female rats and a discussion on the risks of carcinogens in man. In: Deichmann, W.B., ed., Toxicology and Occupational Medicine, New York, Elsevier/North-Holland, pp. 407-413

7. IARC Monographs, Suppl. 6, 57-59, 1987


Last updated: 9 March 1998

    See Also:
       Toxicological Abbreviations
       Aldrin (ICSC)
       Aldrin (PIM 573)
       Aldrin (FAO Meeting Report PL/1965/10/1)
       Aldrin (FAO/PL:CP/15)
       Aldrin (FAO/PL:1967/M/11/1)
       Aldrin (IARC Summary & Evaluation, Volume 5, 1974)