Radiation Protection Bureau / Bureau de la radioprotection Environment and Health Dr. Jack Cornett...

Radiation Protection Bureau / Bureau de la radioprotection

Environment and Health

Dr. Jack CornettDirector,

Radiation ProtectionHealth Canada

[email protected] 954 6647


Environmental Health

Goals• Increase awareness of influence of environmental

factors in disease and health• Develop an approach to identify the problems

Approach• Environmental Health Policy Framework• Discuss some common environmental exposures• Examples of Case histories - questions and tools.


Environment and Environmental Exposures

• Environment: • External to the individual human body

• Environmental exposure:• Broad sense: includes all non-genetic factors• Narrow sense: exogenous to and nonessential for the

normal function of body

• Key Points• Exposures alter patterns of disease and health• Largely involuntary


Environmental Health - Case

Patient• 40 year old man works as an accountant• Headaches over past ~ 3 yrs• Difficulty concentrating & remembering detail • Fatigue, stuffy noise and blocked ears• No other family members with these symptoms

What Questions and Case History

information would help with the diagnosis?


“The area of environmental impacts on health has been seriously neglected in Canada and requires

urgent investment.”

National Advisory Committee on

SARS and Public Health 2003

Environmental Health Policy


Concerns have a factual basis

• Air pollution causes thousands of premature deaths, tens of thousands of hospitalizations, and hundreds of thousands of days absent from work and school annually

• Dramatic increase in childhood asthma• High profile water contamination events• Increases in cancers with known environmental

connections (skin, lung)• Thousands of cases of poisoning


Canadians are worried

• 90% of Canadians believe that environmental pollution is harming their health or the health of their children

• “Pollution” ranks second after “stress” when Canadians are asked to rank the main factors negatively affecting their health


Costs are high

• OECD estimates direct health care costs at 0.5-1.0% of GDP, or $5-10 billion annually for Canada

• Ontario government estimates health care costs of air pollution in that province alone at more than $3 billion annually

• Canada has not conducted a national burden of disease study to assess the magnitude of environmental impacts on health


Impacts are inequitably distributed

• Certain groups are particularly vulnerable• Children• Aboriginal people• Low income Canadians

• Inequitable burden of environmental health hazards has a major impact on public policy

• Different susceptibility


Focus• Past: Biologic agents and factors:

• water distribution systems• sewage collection• food handling

• Current: Chemical and physical agents:• volatile organic compounds• metals• particulate matter• pesticides• radiation


Other Factors in Environmental Health

• Social factors frequently affect the exposure to environmental agents.

• Life-style and behavioural factors are important determinants of some diseases that also are related to environmental pollution.

• Workplace pollution and ambient environmental pollution are sometimes correlated.

• These sub-disciplines use similar epidemiological, statistical and toxicological techniques


Environmental Health - Case

Patient• 8 year old boy accompanied by mother• Stomach pain, some flu-like symptoms• Sporadic problem over past ~2 months• No other family members with these

symptoms

What Questions and Case Historyinformation would help with the diagnosis?


The EH Paradigm

Contaminant Exposure Pathways: How des a contaminant travel through the environment from its source to humans or other living organism?

• Source of contamination• Environmental media (water, soil, air, food product)• Point of exposure• Receptor (person or population)• Route of exposure


Source of Contamination

• Exhaust from vehicles• Emissions from smokestacks• Waste water released by factories and mills• Waste disposal sites• Closed factories and storage sites• Consumer products• Natural sources


Environmental Media

Once released from its sources, a contaminant will travel through environmental media to points where human exposure can occur:

• Water - Groundwater (water below ground,

- Surface water• Soil - Important carriers of contaminants

- Act as a contaminant reserve• Air - Capable of transporting

contaminants widely and quickly • Food -Imported food may contain new strains


Point of Exposure and Receptor Person/Population

Point of exposure: The location where contact with a contaminant

occurs• Home• Office• Playground• Lakes, rivers• ……Receptor person/Population: People who are

exposed the contaminant at the point of exposure:


Route of Exposure

The exposure route is the final link in the chain from the contaminant source through the exposure pathway to people:

• Ingestion: The mouth, throat, stomach, and intestines absorb ingested materials

• Inhalation: Breathing in a contaminant• Dermal (skin) contact: Absorbed through skin


Environmental Health -Case

Patient• 10 year old girl accompanied by mother• Large blisters and red skin on back of both hands

especially deep between fingers• 2nd and 3rd degree burns but girl healthy and well

tanned and states emphatically that she was not scalded or burned.

• No other family members with these symptoms

What Questions and Case History information would help with the diagnosis?


How Can You Assess Exposure?

InterviewsQuestionnaire, and structured diaries• Other approaches ????


Examples of Exposure Assessment

Interviews Questionnaire, and structured diaries• Measurements in external media (macro

environment) • - Metals e.g. (Arsenic) in soil• - POPC in food• - particulate matter in air• - UV index for sun burn


Examples of Exposure Assessment

• Concentrations in the personal or micro environment

• Radiation dosimeters in clinics• Concentrations in human tissues

• Lead in blood• Markers of physiologic effects

• Kidney function for uranium toxicity• Individual doses

• Radiation ingestion at work


Everyone is Exposed to LeadBlood Lead Concentrations Considered to be

Elevated

0

20

40

60

80

1950

1960

1970

1980

1985

1990

2000

2010

Year

Blo

od L

ead

Con

cent

rati

ons

(ug/

dl)


Identifying Individuals at Risk to PbWhat questions should a physician use to

decide whether to order a blood lead test?

• Environment?• Behaviour?• Subpopulation?

Pb was ubiquitously used in paint, cosmetics, gasoline …



Patient• Male 40 in good health at check up• Mentions that two close neighbours

recently were diagnosed with lung cancer• His mother died two years previously of

lung cancer.• All NON smokers and no smokers in family

What questions / information might help ?


Radon: Where Do the Risks Come From?

Swallowing0.1 %

Breathing

95 %0.8 %

0

00

0

00

00

0

00

00

Outdoors

4 %


What are the health effects of radon?

• The only known health effect associated with exposure to radon is an increased risk of developing lung cancer.

• In confined spaces like mines or household basements, radon gas can accumulate to relatively high levels.

• In the open air, the amount of radon gas is very low.


Radon Mitigation

MitigationHow Radon Problems Are Fixed

Radon Mitigation System – Active Soil Depressurization (ASD)

Suction created by fan draws radon from beneath the foundation and safely vents radon outdoors

Most common type of radon mitigation system

FanAttic

DepressurizationPiping System

Discharge



Patient• 45 year old scientist visiting CDN university• Staying with a family he has visited in the past• Sever headaches since he arrived• Dizziness and Nausea• No other people in home he is visiting have these

symptoms

What Questions and Case Historyinformation would help with the diagnosis?


CAUSES OF DEATH IN CANADA -- 1997All lung cancers 15,439

Motor vehicle accidents 3026

Accidental falls 2622

Lung cancers attributable to radon 1589

Accidental poisonings 703

Homicides 440

Drowning 283

Fires 272

Air transport accidents 73

Lightening 6


Summary• Environment is a strong determinant of health• Environmental exposures are often involuntary• Some populations are more vulnerable or

susceptible• Usually effects are proportional to exposure &

frequency of exposure • Use case history and context to ID environmental

components• Lots of tests available – consult specialists• Exposure control is effective at prevention

Radiation Protection Bureau / Bureau de la radioprotection Environment and Health Dr. Jack Cornett...

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