Transcript A Small Dose of Bioethics Precautionary Principle and Ethical Issues in Toxicology and Risk Assessment Department of Civil and Environmental Engineering Rice University – February 18,

A Small Dose of Bioethics
Precautionary Principle and
Ethical Issues in Toxicology and
Risk Assessment
Department of Civil and Environmental
Engineering
Rice University – February 18, 2005
Steven G. Gilbert, PhD, DABT
www.asmalldoseof.org
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Current Bioethical Issues
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Check the local news paper
Stem cells (state, national, international)
Genetically Engineered Organisms
Knowing your genes
In vetro fertilization – choosing your child's
genes and characteristics
Global warming
Nanotechnology
Environmental health
Chemicals exposures – human health
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Child Health
A Small Dose of Toxicology
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Convergence of Issues
• Vision of Child Health
• Knowledge of Reproductive and
Developmental Toxicology
• Policy Approach within an
ethical framework
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Social responsibilities
No technical solutions
Restriction of freedoms
Precautionary Principle
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
WHO Vision for Child Health
A World Fit for Children
• Promoting healthy lives
• Providing quality education
• Protecting against abuse,
exploitation and violence
• Combating HIV/AIDS.
http://www.unicef.org/why/why_worldgoals.html
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CDC Vision for Child Health
“Environmental Health at CDC
strives to promote health and
quality of life by preventing or
controlling those diseases or
deaths that result from
interactions between people
and their environment.”
http://www.cdc.gov/node.do?id=0900f3ec8000e044
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American Academy of Pediatrics
Mission and vision
To attain optimal physical,
mental and social health and
well-being for all infants,
children, adolescents and young
adults.
http://www.aap.org/member/memcore.htm
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American Academy of Pediatrics
The APA goes on to state: “To this
purpose, the AAP and its members
dedicate their efforts and resources.
The vision: 1) to advocate for
infants, children, adolescents, and
young adults and provide for their
care; 2) to collaborate with others to
assure child health; and ….
http://www.aap.org/member/memcore.htm
A Small Dose of Toxicology
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Vision for Child Health
“Children can develop
and mature in an
environment that allows
them to reach and
maintain their full
potential.”
A Small Dose of Toxicology
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Environmental & Human Health
“Conditions that ensure that all
living things have the best
opportunity to reach and maintain
their full genetic potential.”
S. Gilbert (1999)
A Small Dose of Toxicology
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Susceptibility of Children
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Dose Response Issues
Higher metabolic rate
Different nutritional requirements
Rapidly dividing & migrating cells
Immature organs
A Small Dose of Toxicology
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Socially responsible white guys?
A Small Dose of Toxicology
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Socially Responsibility
What is social responsibility?
What are our responsibilities
to society?
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The First Bioethicist
Aldo Leopold
"A thing is right when it tends to
preserve the integrity, stability, and
beauty of the biotic community. It is
wrong when it tends otherwise." Aldo Leopold, 1949, A Sand County
Almanac
---------- 1887 - 1948 ---------A Small Dose of Toxicology
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Limits on Freedom
“An ethic, ecologically, is
a limitation on freedom of
action in the struggle for
existence”
Aldo Leopold
A Small Dose of Toxicology
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“The Commons”
The Tragedy of the Commons
By Garrett Hardin, Science, 1968
A Small Dose of Toxicology
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Technical Solutions
“It is our considered
professional judgment that
this dilemma has no
technical solution.”
The Tragedy of the Commons
By Garrett Hardin, Science, 1968
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Problems – Solutions?
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A Small Dose of Toxicology
Lead and kids
Fetal alcohol syndrome
Nuclear disarmament
Bioterrorism
Ocean Fisheries
Persistent chemicals
The Commons
Ethics & Prec Prin 2/18/05
Case Studies
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A Small Dose of Toxicology
Thalidomide
Methylmercury
Lead
Ethanol (Alcohol)
PBDEs
Ethics & Prec Prin 2/18/05
Thalidomide
 Introduced in 1956 as
sedative (sleeping pill) and to
reduce nausea and vomiting
during pregnancy
 Withdrawn in 1961
 Discovered to be a human teratogen
causing absence of limbs or limb
malformations in newborns
 5000 to 7000 infants effected
 Resulted in new drug testing rules
A Small Dose of Toxicology
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Fetal Effects of MeHg
A Small Dose of Toxicology
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The Mercury Cycle
A Small Dose of Toxicology
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WA State Advisory
Limit the amount of canned tuna you
eat, based on your bodyweight.
Guidelines are: Women of childbearing age should limit the amount
of canned tuna they eat to about one can per week (six ounces.) A
woman who weighs less than 135 pounds should eat less than one
can of tuna per week. Children under six should eat less than one
half a can of tuna (three ounces) per week. Specific weekly limits for
children under six range from one ounce for a twenty pound child,
to three ounces for a child weighing about sixty pounds.
http://www.doh.wa.gov/fish/FishAdvMercury.htm
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Lead In Homes
A Small Dose of Toxicology
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Agency Blood Lead Levels
Blood Lead (ug/dl)
Acceptable Childhood Blood Lead Levels
40
35
30
25
20
15
10
5
0
40
30
25
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15
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CDC
1973
CDC
1975
CDC
1985
WHO
1986
EPA
1986
CDC
1990
Agency and Year
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Small Dose of Toxicology
FASAChild
Ethics & Prec Prin 2/18/05
FAS & FAE
Most common preventable cause of
adverse CNS development
Fetal Alcohol Syndrome (FAS)
4,000-12,000 infants per year in US
Fetal Alcohol Effect (FAE)
7,000-36,000 infants per year in US
1 to 3 infants per 1,000 world wide??
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Fetal Alcohol Effect (FAE)
Milder form of FAS
7,000-36,000 infants per year in US
1 to 3 infants per 1,000 world wide??
Characteristics
Growth deficiency
Learning dysfunction
Nervous systems disabilities
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Policy Approaches
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1981 - U.S. Surgeon General first advised that
women should not drink alcoholic beverages
during pregnancy.
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1988 - U.S. requires warning labels on all
alcoholic beverages sold in the United States.
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1990 - U.S. Dietary Guidelines state that women
who are pregnant or planning to become
pregnant should not drink alcohol.
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1998 - 19 states require the posting of alcohol
health warning signs where alcoholic beverages
are sold
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Structure of PBDEs
PolyBrominated Diphenyl Ether
O
Brx
Br
y
X & Y are number of Bromine atoms
Common Penta, Octa, and Deca
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
PBDEs in House Dust (ppb)
From EWG - Toxic Fire Retardants Contaminate American Homes - http://www.ewg.org/reports/inthedust/summary.php
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
PBDEs in Breast Milk (ppb)
From EWG - Toxic Fire Retardants in Breast Milk from American Mothers - http://www.ewg.org/reports/mothersmilk/es.php
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
“The Commons”
The Tragedy of the Commons
By Garrett Hardin, Science, 1968
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Bioethics
Van Rensselaer Potter
"Biology combined with diverse
humanistic knowledge forging a
science that sets a system of
medical and environmental
priorities for acceptable survival.“
Global Bioethics (1988)
-------- 1911 - 2001 -------A Small Dose of Toxicology
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Genomic and Ecological Bioethics
The challenge
To develop an individual and
societal ethical framework for
decision making that supports the
long term maintenance of a globally
sustainable ecology
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Knowledgeable Bioethics
The challenge
“the knowledge of how to
use knowledge for the social
good”
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Sir Austin Bradford Hill
"All scientific work is incomplete - whether it
be observational or experimental. All
scientific work is liable to be upset or
modified by advancing knowledge. That
does not confer upon us a freedom to
ignore the knowledge we already have or
postpone the action that it appears to
demand at a given time. "
Sir Austin Bradford Hill (1965)
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Determining Causation
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Strength of association
Consistency of findings
Biological gradient
Temporal sequence
Biologic or theoretical plausibility
Coherence with established knowledge
Specificity of association
Sir Austin Bradford Hill (1965)
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Safety & Efficacy vs Harm
 FDA regulations of Drugs (1938)
 FDA regulations of Dietary
Supplements (Dietary Supplement
Health and Education Act of 1994
(DSHEA))
 Ephedra present an unreasonable risk
of illness or injury (Dec, 2003)
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Precautionary Principle
“When an activity raises threats of harm to
human health or the environment,
precautionary measures should be take even if
some cause and effect relationships are not
fully established scientifically.”
Wingspread Conference, 1998.
A Small Dose of Toxicology
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Central components
• Taking preventive action in the face of
uncertainty
• Shifting the burden of proof/responsibility
to the proponents of an activity
• Exploring a wide range of alternatives to
possibly harmful actions
• Increasing public participation in decision
making
Wingspread Conference, 1998.
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Values of the precautionary principle
1) Respect - for the needs and rights of this and future
generations as well as others who cannot speak for
themselves
2) Humility - towards the natural world and our ability to
understand it through science
3) Democracy - giving people a voice in matters that affect
their lives
4) Responsibility
- government’s public trust responsibility to manage the
commonwealth for this and future generations.
- Individuals’ including industry, obligation to take
responsibility for their actions in the world.
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Purpose/Objectives
 Improve decision making
 Promote integrated assessments
 Promote transparency
 Promote sharing of information
 Examine alternatives
 Examine uncertainties
 Encourage discussion among
stake holders
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Seattle Initiative
City Comprehensive Plans
• Every citizen of Seattle has an
equal right to a healthy and safe
environment.
• Seattle sees the Precautionary
Principle approach as its policy
framework to develop laws for a
healthier and more just Seattle.
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Knowledge - Responsibility
• Children have a right to a safe, fair
and healthy environment
• Ethical Responsibility to share
and use of knowledge
• Duty to promote health and well
being of children
• Thoughtful public health advocate
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Citizen Toxicologist
Socially Responsible Toxicologist
The citizen toxicologist is a thoughtful
advocate for human and environmental
health, who strives to share their
scientific knowledge with the public,
speaking to public interests rather than
private or special interests.
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Socially Responsible Actions
• Testifying
• Writing review papers
• K-12 class room
teaching
• Adding expertise to
community groups
• Education
• Mentoring
• Speakers Bureau
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SOT - ESLI Specialty Section
• Forum in which to discuss the
ethical implications of results
from our science as well as
the resulting legal and social
implications.
• 2005 SOT meeting – workshop
on Conflict of Interest
http://www.toxicology.org/memberservices/specsection/specsection.html
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
The Potential of Children
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Ethics and the Precautionary Principle
Questions or Comments?
Download Presentation from
www.asmalldoseof.org
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Additional Information
 The Science and Environmental Health Network
(SEHN) (www.sehn.org)
 Late lessons from early warnings: the
precautionary principle 1896-2000 – European
Environment Agency (free)
 Garrett Hardin - The Tragedy of the Commons
(Science, 1968)
 Ethics and Environmental Health – Mini
Monograph - Environmental Health Perspectives
(November 2003)
 Ethical, legal, and social issues: our children's
future. Steven G. Gilbert. Neurotoxicology, in
press, 2005
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Authorship Information
This presentation is supplement to
“A Small Dose of Toxicology”
For Additional Information Contact
Steven G. Gilbert, PhD, DABT
E-mail: [email protected]
Web: www.asmalldoseof.org
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Socially Responsible
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Scientific Process
Variability
Uncertainty
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Types of Uncertainty
• Statistical
• Model
• Fundamental
A Small Dose of Toxicology
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Statistical Uncertainty
Reducing Variability
• Easiest to examine & reduce
• Not knowing the exact value
of a variable (inter and intra
subject variance)
• Sample size
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Model or System Uncertainty
• Not fully understanding the
relations between variables
(mechanism of action)
• Which variables are most
important (high dose vs low
dose)
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05
Fundamental Uncertainty
• Not knowing the right
questions to ask
• Most sensitive end point
• “we don’t know what we
don’t know”
A Small Dose of Toxicology
Ethics & Prec Prin 2/18/05