BEIR VII: “The very error of the moon.” Othello, Act II Herbert L.Abrams
Blast Thermal & Shock Radiation Initial Nuclear Residual Nuclear Radiation Radiation Nuclear Weapons Effects
Thermal Heat Wave A one-second “heat flash” travels at the speed of light: vaporizing, melting, starting fires at a distance.
Blast The Wave Travels at Supersonic Speed, Killing People & Destroying Buildings in its Path.
RADIATION: The Mystery Nausea, Vomiting, Loss of Appetite, Diarrhea, WBC Drops.
Radiation Effects High radiation doses tend to kill cells, while low doses tend to damage the genetic code (DNA). The higher the dose, the sooner the effects of radiation will appear & the higher the probability of death.
Radiation Effects • “Radiation Sickness” • 5 Sieverts or Above Marrow Death • 10 Sieverts or Above GI Death • 20 Sieverts or Above Neurologic Death
ABCC (47), RERF (75) • Life Span Study: 120,000 • Adult Health Study: 20,000
The Cancer Risk From Low Level Radiation
Our Committee Report: the 700 page BEIRVII advisory recently issued by the National Research Council. The last previous report on this subject: 1990.
The BEIR series of seven reports is widely accepted in many nations as a primary source of radiation risk estimates and protective regulations.
The 16 member BEIR VII international Study Committee consisted of scientists & educators with expertise in: • Epidemiology • Radiation Biology • Cancer Biology • Genetics • Radiology • Physics
Submissions & Presentations: • University & governmental entities such as the EPA, NRC, DOE • NGO, public interest, activist & industry groups
THE ISSUE Higher risk estimates: smaller permissible doses Lower risk: relaxation of protection standards Stakes: $millions vs. health
Why “low level” radiation? Are we all exposed?
We defined “low level” radiation as a range from near zero up to 100 milliSieverts (mSv). • 30-40 times annual natural background exposure • 10 times that of a CT Scan • 1000 times that of a chest film.
Background: radiation from the natural environment represents 82% of human exposure. • Outer space • The Ground • Basic Activities such as eating, drinking & breathing
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 Data Source: Los Alamos, 1995 Photo Credit: Procare4U
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 menin the solid tumors
Excess Cases of Cancer per 100,000 Exposed Persons(Exposed at 30, Attained Age 60) ALL SOLID CANCER
Small Children Exposure in infants, as compared to adults, produces 3-4 times the cancer risk. Photo: Stepin.org Female infants have almost double the risk of males.
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.
Areas Identified for Further Research: • Adverse genetic impacts of radiation, emphasizing hereditary effects • Health impacts of radiation usage in medical practice • Epidemiology of high risk occupations, persons in key areas of former Soviet Union & atomic bomb survivors
Areas Identified for Further Research: • Molecular markers of radiation caused DNA damage • Specific role of radiation in development of cancer (tumors) • Correlation between radiation & conditions such as heart disease & stroke
“A star, however willing, • cannot help the moon.” • Chinese proverb