You are here

Study finds increases in birth defects near CANDU reactor

Nuclear Monitor Issue: 

(November 8, 1991) A report on an independent study released in July has found evidence that Ontario Hydro's Pickering nuclear power station in Canada has caused significant increases in five types of birth defects.

(361.3568) WISE Amsterdam - The defects are typical of the known effects of radiation exposure. "About 33% of Pickering birth defects may be due to the nuclear plant," says the report's author, David McArthur, a former Canadian Nuclear Association re-searcher. McArthur is also the author of an earlier report, "Fatal birth defects, newborn infant fatalities and tritium emissions in the Town of Pickering, Ontario: A preliminary examination", released in December 1988 by Durham Nuclear Awareness.

His new report ("Possible Repro-ductive Effects of Radioactive Emissions from the Pickering Nuclear Power Station: Statistically Significant Birth Defects in Pickering, Ontario from July 1985 to December 1986") analyzes data from the birth defect registry of the Ontario Ministry of Health. Based on an 18-month period (the only data released for inde-pendent analysis), the report finds the birth defects listed in the accompanying chart (see table) as statistically significant.

The report links the first five of these birth defects to known effects of radiation exposure in either of two time periods: 1) exposure during embryonic development, which is known to cause cleft palate and lip, spinal and sex abnormalities; or 2) damage to egg or sperm chromosomes before or about the conception period, when Patau's syndrome is caused.


Medical Name of Birth Defect Cases Observed in Pickering Cases Expected (@ Ont. rate) Statistical Significance (Poisson test)
(1) Patau's syndrome 2 0.30 95%
(2) Indeterminate sex and pseudohermaphroditism 2 0.25 95%
(3) Cleft palate 4 1.13 95%
(4) Cleft palate with cleft lip 4 1.08 95%
(5) Anomolies of the spine 3 0.42 99%
(6) Hyperchylomicronemia 1 1.01 99%
(7) Other hyperlipidaemia 1 0.02 95%
Total 17 3.21  
(1) to (5) are linked to radiation exposure;
(1) is a chromosomal abnor-mality similar to Down's syndrome;
(2) is abnormal gender develop-ment;
(6) and (7) are diseases of tat metabolism.

The 17 statistically significant birth defects occurred in 12 children -- 19% of the 65 children with birth defects recorded in the period covered and 0.8% of the 1,513 births in Pickering. Yet, says McArthur, the 12 children had 29 other birth defects as well, making a total of 46. He estimates that if this same increase occurred from 1973 to 1990, some 57 birth defects in 93 Pickering children may be due to CANDU radiation.

The report argues that the radioactive isotopes tritium and carbon-14 are the most likely cause of the seven types of defects. CANDU reactors routinely release large amounts of both isotopes -- more than other reactor types -- and the Pickering station has exceeded its short-term radiation release guidelines. Both isotopes accumulate in locally-grown food, which is a major pathway to reproductive damage. It accumulates in chromosomes, increasing damage to genetic material during atomic decay and, says McArthur, inevitably causes genetic damage in Pickering. "This in itself adequately explains the seven types of defects."

Source and Contact: Both McArthur's current report and the 1988 study are available from Conception Research, Postal Station "B" Box One, Toronto, Ontario, Canada M5T 2T2; tel: +1-416-598-0146; fax: 416-928-0243.