The New Millennium: Values, Perceptions of Risk and the Key Roles of Science and Technology Ionizing Radiation Science and Protection In the 21st Century Gilbert S. Omenn, MD, PhD Executive Vice President for Medical Affairs and CEO, University of Michigan Health System National Council on Radiation Protection and Measurements April 5-6, 2000 Arlington, Virginia
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The New Millennium: Values, Perceptions of Risk and the Key Roles of Science and Technology Ionizing Radiation Science and Protection In the 21st Century.
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The New Millennium: Values, Perceptions of Risk and the Key
Roles of Science and Technology
Ionizing Radiation Science and Protection In the 21st Century
Gilbert S. Omenn, MD, PhD
Executive Vice President for Medical Affairs and CEO, University of Michigan Health System
National Council on Radiation Protection and Measurements
April 5-6, 2000 Arlington, Virginia
AMERICAN VALUES FOR THIS MILLENNIUM
• Sustainable development: Robust economy,
environmental protection, inter-dependent world
• Freedom of speech, freedom of religion, freedom from
want, freedom from fear (FDR, 1941)
• Transparency of decision-making in an internet-
informed or misinformed, more empowered populace
• High expectations and benefits and tolerance for risks
from science and technology
SOURCES OF IONIZING RADIATION EXPOSURES
• Nature background; radon progeny• Medical Diagnostic and Therapeutic Uses• Industrial Radionuclides• Radioactive Liquid and Solid Wastes• Nuclear Power Plant Operations /
Emissions Risk• Decommissioning of Nuclear Reactors
“I know no safe depository of the ultimate powers of society but the people themselves; if we think them not enlightened enough to exercise their control with a wholesome discretion, the remedy is not to take it away from them, but to inform their discretion.”
- Thomas Jefferson
NOT OBSERVABLE
• Unknown to those exposed
• Effect delayed• New risk• Risks unknown to
science
OBSERVABLE
• Known to those exposed
• Effect immediate• Old risk• Risks known to
science
RISK PERCEPTION
CONTROLLABLE
• Not dread• Not catastrophic• Not fatal• Equitable• Low risk to future
Uses and limitation of risk assessment in decision-making
Appropriate exposure scenarios
Uncertainty and risk communication
Risk management policy issues
Consistency across agencies
EXPOSURE
• Sources
• Pathways
• Environmental transformations
• Routes of entry
• Time course of exposures
• Concept of total exposure
• Need for translation from ambient levels to target
tissue effective dose
• New methods for tissue burdens and dosimetry
MIXTURES
Test real world mixturesdiesel exhausturban smogactual effluentspesticide combinationsworkplaces
Assume additivity of risks as default; use mechanisms, if known
Pay attention to radiation and microbial exposures/risks
PUTTING ENVIRONMENTAL RISKS INTO CONTEXT
• Multi-Source
• Multi-Media
• Multi-Chemical / Multi-Agent
• Multi-Risk
CONTEXT
Multi-Source
Multi-Media
Multi-Agent
Multi-Risk
Public Health
Status/Trends
Ecological Health
Social & Cultural
Environmental Justice Considerations
Reducing risk by orders of magnitude is not equivalent to linear reductions
0
200
400
600
800
1000
1 x 10-3 1 x 10-4 1 x 10-5 1 x 10-6
Level of risk
Risk Commission, Final Report, 1997
RISK COMMISSION RECOMMENDATION (1997 REPORT, p. 82)
A concerted effort should be made to evaluate and relate the methods, assumptions, mechanisms, and standards for radiation risks to those for chemicals to clarify and enhance the comparability of risk management decisions, especially when both types of hazards are present.
LACK OF COLLABORATION ON CHEMICAL AND RADIATION
HAZARDS
• Different models of carcinogenesis• Different regulatory laws and
agencies• Different disciplines and scientific
meetings• Smaller margin of exposure tolerated
for IR• Despite common waste streams and
co-existing contamination
POLICY AND PUBLIC INTEREST IN COMPARISONS OF RISK
Discrepancy between levels of risk considered negligible forradiation exposures and for chemical exposures
Workers General Population Comments
Chemicals 10-3 10-6 Single chemicals
Radiation 50 mSV/yr 1mSV/yr Integrated Dose 10-1 / 10-2 Ratio of 50 vs 300+
Importance of interactions of radiation and chemicals, of
radiation and infectious disease risks.
BEIR VII - Phase 1 Letter---21 January, 1998
• Continued reliance on epidemiological studies• Lots of laboratory studies• OPPORTUNITY FOR REALLY BIG BREAKTHROUGH
- Patterns of gene expression on microarray
and protein expression in proteomics
readouts that reflect carcinogenesis: key to
resolving long-festering questions about risks of
low-level exposures
OUR GENETIC FUTURE
“Mapping the human genetic terrain may rank with the great expeditions of Lewis and Clark, Sir Edmund Hillary, and the Apollo Program.”