Assessing Risks and Benefits

Risk vs. Benefit:

Tipping the Scales

We make choices everyday…

How can risk-benefit assessment help us make better choices?

• What are the risks to health?

• What are the benefits to our every day living?

WHAT IS ENVIRONMENTAL HEALTH RISK ASSESSMENT?

A process that evaluates the

likelihood that adverse health effects

may occur as a result of

exposure to a chemical,

physical, or biological agent.

Risk Assessment

Risk Characterization

Data collection and evaluation

Toxicity Assessment

Exposure Assessment

Toxicology is the study

of toxicants and their

adverse effects.

Adverse effects = Any change from an organism’s normal functioning.

Toxicity Assessment

The Dose Makes a Difference

• Different chemicals have different concentrations at which they are harmful.

• Different people (depending on age, size, genetics, and other health factors) may be more sensitive to chemicals than others.

• Toxicologists study the adverse effects of toxicants at many levels: organism, organ, cell, organelle, molecule

• Toxicants may interfere with the normal functioning of proteins, lipids, and DNA.

Areas of concern when

studying exposure: • Frequency• Duration• Routes of entry• Distribution/storage in the body• Probability that exposure will cause

adverse effects

Exposure Assessment

Risk Characterization

Risk Characterization

Toxicity Assessment Exposure

Assessment

Risk Characterization

• Is an estimate of the likelihood that exposure to a toxicant may cause harm.

Risk is only part of the picture

Benefits• As part of our society, you must make

decisions which assess risks, costs, benefits, and trade-offs.

– Thalidomide: Leprosy treatment vs. birth defects

– Pesticides: Mosquito abatement vs. toxicity

Tradeoffs

• Planning to reduce risks to take advantage of the benefits offered by use of a particular ‘product.’

– BOTOX: Neurotoxin vs. wrinkles

– Sunlight: Vitamin D and skin cancer

• The decisions of this generation may choose tradeoffs that benefit them but pose risks for future generations.

– Fossil fuels use vs. global warming

– DES vs. reproductive system cancer

– Hazardous waste disposal vs. increase of groundwater pollutants

PRECAUTIONARY PRINCIPLE

If the consequences of an action are unknown, butjudged to have some potential for negative consequences, then it is better to avoid that action.

“Better safe than sorry.”

“The first principle of science is that you must not fool yourself - and you are the easiest to fool.” - Richard Feynmanwww.hoagiesgifted.org/brain_research.htm

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