BEIR VII: “The very error of the moon.”
Othello, Act II Herbert L. Abrams
30-40 times annual natural background exposure
10 times that of a CT Scan
1000 times that of a chest film.
We defined “low level” radiation as a range from near zero up to 100 milliSieverts (mSv).
Outer space
The Ground
Basic Activities such as eating, drinking & breathing
Background: radiation from the natural environment represents 82% of human exposure.
CONTRIBUTION OF MAN-MADE RADIATION SOURCES (18%) RELATIVE TO BACKGROUND RADIATION (82%)
Medical & Dental X-Ray Diagnostic Procedures Examinations &
Dose Averages 1985-1990 Average Annual Total Medical Exams: 1200 per 1000
1985-1990 Average Annual Total Dental Exams: 400 per 1000
1980 Average Annual Effective
Dose Per patient examined:
50 millirem
Photo Credit: Procare4U Data Source: Los Alamos, 1995
Effective Doses From Diagnostic X-Ray Procedures Data Source: Los Alamos, 1995
Nuclear Medicine Procedures
Per Annum 1985-1990 Average Number of Procedures
26 per 1000 persons
1982 Average Effective Dose Per Patient
500 millirem
Data Source: Los Alamos, 1995
Effective Doses Per Diagnostic Nuclear Medicine Procedures CSPmedical.com Data Source: Los Alamos, 1995
Mechanism of Cancer Induction
Damage to DNA
Single strand breaks
Double strand breaks
Oxidative changes in nucleotide bases
DNA deletions; gene and chromosome damage
BEIR VII Committee
Conclusions Linear Non-Threshold model of cancer risk prediction validated
No evidence of a threshold below which no cellular damage occurs
Radiation Related Cancer Risk ______ Linear No Threshold Model
BEIR VII Committee
Conclusions Significant lifetime excess risks were determined for 12 cancers, including lung, liver, breast, prostate, stomach, colon, thyroid and leukemia
Women Radiation related cancer mortality risks for woman averaged 37.5%
higher than for men in the solid tumors
Excess Cases of Cancer per 100,000 Exposed Persons (Exposed at 30, Attained Age 60) 17,500 22,100 Number of Deaths in the Absence of Exposure 610 410 Excess deaths from Exposure 36,900 45,500 Number of Cases in the Absence of Exposure 1300 800 Excess Cases from Exposure to 100 mSv Females Males ALL SOLID CANCER
Exposure in infants, as compared to adults, produces 3-4 times the cancer risk. Small Children Photo: Stepin.org Female infants have almost double the risk of males.
Unlike BEIR V, BEIR VII contained both incidence & mortality figures.
At low doses, the risk, though increased, is small, one excess cancer in 100 exposed persons during their lifetime. Mortality, as opposed to incidence, would be about one-half.
Likelihood of Excess Cancer Vs. Cancer Incidence in 100 Unexposed Persons over Lifetime
No impact of low levels on heart
disease, in contrast to high doses.
No definite genetic effects in the
offspring of A-bomb survivors.
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