Environment and Health
Dr. Jack Cornett
Director,
Radiation Protection
Health Canada
Jack_cornett@hc-sc.gc.ca
613 954 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
Environmental Health Policy
“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
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 0.51.0% 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
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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
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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 History
information 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
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•
•
•
•
•
•
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
•
Soil
•
Air
•
Food
- Groundwater (water below ground,
- Surface water
- Important carriers of contaminants
- Act as a contaminant reserve
- Capable of transporting
contaminants widely and quickly
-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?
 Interviews
 Questionnaire,
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
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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 Lead
Year
Radiation Protection Bureau / Bureau de la radioprotection
10
20
00
20
90
19
85
19
80
19
70
19
19
19
60
80
60
40
20
0
50
Blood Lead
Concentrations
(ug/dl)
Blood Lead Concentrations Considered to be
Elevated
Identifying Individuals at Risk to Pb
What 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
R a d o n : W h e re D o th e R is k s C o m e F ro m ?
O u td o o rs
0
0
0
0
0
0 0
0
0
0
0
0
4 %
0
0 .8 %
95
%
S w a llo w in g
0 .1 %
Radiation Protection Bureau / Bureau de la radioprotection
B re a th in g
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
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 History
information would help with the diagnosis?
Radiation Protection Bureau / Bureau de la radioprotection
CAUSES OF DEATH IN CANADA -- 1997
All 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
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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