Transcript Environmental Epidemiology on little areas

Environmental
Epidemiology
on small
areas
Agenzia Regionale Prevenzione Protezione
Ambientale Veneto ( Italy ) www.arpa.veneto.it,
email : [email protected]
Ph. D. Alessandro Menegozzo
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Background
Environmental epidemiology studies
environmental risk factors and their impact on
the health of exposed people;
These factors may be natural or
anthropogenic
The risk factors derive from the people’s
exposure to chemical, physical or biological
stressors.
The stressors come from point, line or area
sources and reach the population by way of
matrices ( air, water, soil, foods and space for
electomagnetic waves ).
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Background (cont.)
The environmental risk adds or synergically
interacts with the basic risk of contracting an
illness.
The environmental risk is as great as is exposure
and individual physiological and anamnestic
susceptibility.
The exposure to environmental risk factors may
occur in an external environment (outdoor air )
or an internal environment (indoor air ).
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Environmental Epidemiology
Objectives
Environmental Epidemiology
assesses the added risk
( real or potential ) to the population
exposed to environmental pollutants
with the purpose of identifying the
sources responsible for the
pollution.
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Risk factors
interaction
The added risk from environmental factors
interacts with non environmental risk factors:
Behavioural (smoking, drugs, alcohol abuse)
Socio-health (hygiene, nutrition, stress)
Genetic (hereditary susceptibility)
Anamnestic (previous diseases and
medication)
Physiological ( age, sex, pregnancy,
weight, height and respiration)
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Professional exposure
Why environmental
epidemiology on small areas?
The complexity of interaction among risk factors
hinders the risk assessement with conventional
statistic tools used for large populations.
We have to study the disaggregate non sampled
and territory related data to indentify a clusters of
increased incidence of disease and then filter from
them cases with non environmental risk factors.
This is only possible for small populations living
on small areas concerned with a small number of
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risk factors.
Problems
The small areas considered must be sufficiently
populated for the clusters significance, especially for
stochastic damages.
We have to make use of all computerised databases :
territorial, private, health, and environmental.
During data transfer and assessement, privacy must
be guaranteed
The health data needs to include family,
physiological, pathological, behavioural
and occupational exposure and mobility
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data .
Solutions
In low population density areas, the health
stochastic environmental damages is very
little.
All the institutions have adequate
computerized database systems.
It is possible to use the private data without
access to subjects names on screen.
We may obtain the informations on the
environmental risk factors from
questionnaires administered by the family
doctor.
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Necessary resources
and collaborations
Territorial, health and environmental
institutions have to form a coordinated
operative team.
The databases have to be to coordinated on
work station capable of building, to
managing and to querying the geodatabases.
The clusters filtering process requires the
elaboration and administration of
questionnaires through family doctors.
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Operative process
A)Identify the suspicious sources and risk areas
from emissions register, environmental data and
modeling
B) Choose a study area, including risk areas, with a
population of suitable dimensions
C) Build the thematic map of the study area
D) Acquiring and georeference the road, sociohealth and personal databases
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Operative process
( continuation )
E) Identify possible health damage and
environmental diseases
F) Show evidence of the environmental
disease clusters associated with selected
factors
G) Filter the clusters from non
environmental risk factor cases
H) Verify the filtered clusters by
biochemical methods on tissue
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A+B ) Study area identification
Examine the emissions registers and
environmental data in air, soil, foods, water and
space.
Identify the hazardous substances and stressors
carried by matrices.
Fate and diffusion modeling of hazardous
substances and stressors.
Risk areas identification.
Link the risk areas with synergic stressors.
Choose a study area including risk and stressor
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free areas.
C+D) Geodatabase building
Acquire raster map of study area
Map vectorialization for residential,
production and service structure and
sensitive sites
Acquire personal and health databases on
the map layers for geodatabase building
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E) Possible
environmental diseases
Reduced fertility, spontaneous abortion
Lower birth weight, malformations
Respiratory, gastroenteric and kidney diseases
Immune, endocrine and neoplastic diseases
Nervous and mental diseases
Dermatological and sense organ diseases
Infectious and parasitic diseases
Cardiocirculatory and muscle-skeleton diseases
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F) clusters identification
Health data layer may show clusters with a
greater incidence of disease caused by the
environment causes
G) clusters purification
Patients ( or at relatives in case of death ) of
these clusters have to be given a questionnaire
to identify and exclude non prevalent
environmental cases
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G) Anamnestic
questionnaire for cluster filtering
Family anamnesis ( disease cases in relatives
not living in the cluster )
Work and behavioural anamnesis ( exposure to
professional and behavioural risk factors )
socioeconomic, pathologic and pharmacological
anamnesis ( factors modifying exposure,
susceptibility or prognosis )
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H) Clusters biochemical check
Even the most careful cluster purification
not confirm the relationship between
environmental factors and diseases
Therefore we must research metabolic
markers, i.e.matabolites of pollutants, in
tissues ( hairs or nails ) or biological fluids
( blood, urine, saliva and mother’s milk ) in
affected people or in random sample for
comparison with subjects outside the
cluster.
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Latency problems
The neoplastic, reproductive and development
diseases begin a long time from exposure.
therefore the emission sources have to be
considered taking latency time into account.
The affected subjects have verified for
different exposure for home changes.
In the course of latency time, the health risks
cannnot be prevented, therefore a risk estimation
of possible exposure and effects is better than the
epidemiological survey of disease cases.
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Environmental risk
communication
The communication should be sincere,
jargon-free, in time and with preventive
value :
Communication should include: method
description, uncertainty factors and
scientific bibliography.
The assessement receivers who manage the
environmental risk take responsability for
using the assessement in environmental
protection and health prevention decisions.
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