Radiation Protection Bureau / Bureau de la radioprotection
Environment and Health
Dr. Jack CornettDirector,
Radiation ProtectionHealth Canada
[email protected] 954 6647
Radiation Protection Bureau / Bureau de la radioprotection
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.
Radiation Protection Bureau / Bureau de la radioprotection
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
Radiation Protection Bureau / Bureau de la radioprotection
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?
Radiation Protection Bureau / Bureau de la radioprotection
“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
Radiation Protection Bureau / Bureau de la radioprotection
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
Radiation Protection Bureau / Bureau de la radioprotection
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
Radiation Protection Bureau / Bureau de la radioprotection
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
Radiation Protection Bureau / Bureau de la radioprotection
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
Radiation Protection Bureau / Bureau de la radioprotection
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
Radiation Protection Bureau / Bureau de la radioprotection
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
Radiation Protection Bureau / Bureau de la radioprotection
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?
Radiation Protection Bureau / Bureau de la radioprotection
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
Radiation Protection Bureau / Bureau de la radioprotection
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
Radiation Protection Bureau / Bureau de la radioprotection
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
Radiation Protection Bureau / Bureau de la radioprotection
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:
Radiation Protection Bureau / Bureau de la radioprotection
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
Radiation Protection Bureau / Bureau de la radioprotection
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?
Radiation Protection Bureau / Bureau de la radioprotection
How Can You Assess Exposure?
InterviewsQuestionnaire, and structured diaries• Other approaches ????
Radiation Protection Bureau / Bureau de la radioprotection
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
Radiation Protection Bureau / Bureau de la radioprotection
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
Radiation Protection Bureau / Bureau de la radioprotection
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)
Radiation Protection Bureau / Bureau de la radioprotection
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 …
Radiation Protection Bureau / Bureau de la radioprotection
Environmental Health -Case
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 ?
Radiation Protection Bureau / Bureau de la radioprotection
Radon: Where Do the Risks Come From?
Swallowing0.1 %
Breathing
95 %0.8 %
0
00
0
00
00
0
00
00
Outdoors
4 %
Radiation Protection Bureau / Bureau de la radioprotection
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.
Radiation Protection Bureau / Bureau de la radioprotection
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
Radiation Protection Bureau / Bureau de la radioprotection
Radiation Protection Bureau / Bureau de la radioprotection
Environmental Health -Case
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?
Radiation Protection Bureau / Bureau de la radioprotection
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
Radiation Protection Bureau / Bureau de la radioprotection
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