A Small Dose of ToxicologyEthics & Prec Prin 2/18/05 A Small Dose of Bioethics Precautionary...

A Small Dose of Toxicology Ethics & Prec Prin 2/18/05

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, DABTwww.asmalldoseof.org

Ethics & Prec Prin 2/18/05 A Small Dose of Toxicology

Current Bioethical Issues

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


Child Health


• Vision of Child Health

• Knowledge of Reproductive and Developmental Toxicology

• Policy Approach within an ethical framework• Social responsibilities• No technical solutions• Restriction of freedoms• Precautionary Principle

Convergence of Issues


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


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


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


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


“Children can develop and mature in an

environment that allows them to reach and maintain their full

potential.”

Vision for Child Health


“Conditions that ensure that all living things have the best opportunity to reach and maintain their full genetic potential.”

S. Gilbert (1999)

Environmental & Human Health


• Dose Response Issues

• Higher metabolic rate

• Different nutritional requirements

• Rapidly dividing & migrating cells

• Immature organs

Susceptibility of Children


Socially responsible white guys?


Socially Responsibility

What is social responsibility?

What are our responsibilities to society?


"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

The First Bioethicist

---------- 1887 - 1948 ----------

Aldo Leopold


“An ethic, ecologically, is a limitation on freedom of action in the struggle for

existence”Aldo Leopold

Limits on Freedom


“The Commons”

The Tragedy of the CommonsBy Garrett Hardin, Science, 1968


Technical Solutions

“It is our considered professional judgment that

this dilemma has no technical solution.”



Problems – Solutions?

Lead and kids Fetal alcohol syndrome Nuclear disarmament Bioterrorism Ocean Fisheries Persistent chemicals The Commons


Case Studies

Thalidomide Methylmercury Lead Ethanol (Alcohol) PBDEs


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


Fetal Effects of MeHg


The Mercury Cycle


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.

WA State Advisory

http://www.doh.wa.gov/fish/FishAdvMercury.htm


Lead In Homes


Agency Blood Lead Levels

40

30

25

20

15

10

0

5

10

15

20

25

30

35

40

Blo

od

Lea

d (

ug

/dl)

CDC1973

CDC1975

CDC1985

WHO1986

EPA1986

CDC1990

Agency and Year

Acceptable Childhood Blood Lead Levels

Ethics & Prec Prin 2/18/05 A Small Dose of ToxicologyFAS Child


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??


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??

CharacteristicsGrowth deficiency

Learning dysfunctionNervous systems disabilities


• 1981 - U.S. Surgeon General first advised that women should not drink alcoholic beverages during pregnancy.

• 1988 - U.S. requires warning labels on all alcoholic beverages sold in the United States.

• 1990 - U.S. Dietary Guidelines state that women who are pregnant or planning to become pregnant should not drink alcohol.

• 1998 - 19 states require the posting of alcohol health warning signs where alcoholic beverages are sold

Policy Approaches


Structure of PBDEs

X & Y are number of Bromine atomsCommon Penta, Octa, and Deca

PolyBrominated Diphenyl Ether

O

BrxBry


PBDEs in House Dust (ppb)

From EWG - Toxic Fire Retardants Contaminate American Homes - http://www.ewg.org/reports/inthedust/summary.php


PBDEs in Breast Milk (ppb)

From EWG - Toxic Fire Retardants in Breast Milk from American Mothers - http://www.ewg.org/reports/mothersmilk/es.php


“The Commons”



"Biology combined with diverse humanistic knowledge forging a

science that sets a system of medical and environmental

priorities for acceptable survival.“Global Bioethics (1988)

Bioethics

-------- 1911 - 2001 --------

Van Rensselaer Potter


The challenge

To develop an individual and societal ethical framework for

decision making that supports the long term maintenance of a globally

sustainable ecology

Genomic and Ecological Bioethics


The challenge

“the knowledge of how to use knowledge for the social

good”

Knowledgeable Bioethics


"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)

Sir Austin Bradford Hill


1. Strength of association

2. Consistency of findings

3. Biological gradient

4. Temporal sequence

5. Biologic or theoretical plausibility

6. Coherence with established knowledge

7. Specificity of association

Sir Austin Bradford Hill (1965)

Determining Causation


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)

Safety & Efficacy vs Harm


“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.

Precautionary Principle


• 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.

Central components


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.

Values of the precautionary principle


Improve decision making Promote integrated assessments Promote transparency Promote sharing of information Examine alternatives Examine uncertainties Encourage discussion among

stake holders

Purpose/Objectives


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.

Seattle Initiative


• 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

Knowledge - Responsibility


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.

Citizen Toxicologist

Socially Responsible Toxicologist


• Testifying

• Writing review papers

• K-12 class room teaching

• Adding expertise to community groups

• Education

• Mentoring

• Speakers Bureau

Socially Responsible Actions


• 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

SOT - ESLI Specialty Section

http://www.toxicology.org/memberservices/specsection/specsection.html


The Potential of Children


Ethics and the Precautionary Principle

Questions or Comments?

Download Presentation from www.asmalldoseof.org


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


Authorship Information

For Additional Information ContactSteven G. Gilbert, PhD, DABT

E-mail: [email protected]: www.asmalldoseof.org

This presentation is supplement to “A Small Dose of Toxicology”


Socially Responsible


Scientific Process

VariabilityUncertainty


• Statistical

• Model

• Fundamental

Types of Uncertainty


• Easiest to examine & reduce

• Not knowing the exact value of a variable (inter and intra subject variance)

• Sample size

Statistical Uncertainty

Reducing Variability


• Not fully understanding the relations between variables (mechanism of action)

• Which variables are most important (high dose vs low dose)

Model or System Uncertainty


• Not knowing the right questions to ask

• Most sensitive end point

• “we don’t know what we don’t know”

Fundamental Uncertainty

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