Download Environmental Factors Affecting Disease Transmission

Introduction
 The environment plays a
big role on human
health.
 Public health agencies
decide policy based on
the environmental
factors at play in their
area of jurisdiction.
Introduction
 Environmental factors
can influence the
macroenvironment that
is a person’s city,
province, country or
continent OR the
microenvironment that
is a person’s home,
vehicle and
workplace/school.
1) Climate Change
 As the world is becoming
warmer due to the
runaway greenhouse
effect, the tropical
regions of the world are
expanding into what was
once known as a
temperate climate zone
(James Cook University
2009 Study).
1) Climate Change
 With this push outward from
the equator comes with it
tropical pathogens and the
diseases they bring.
 The majority of tropical
diseases are passed through
insect vectors which need a
humid climate, high
temperatures and lots of
precipitation (for their
larvae).
 Once previously temperate
areas now meet these criteria
(i.e. Southern USA,
Mediterranean Coast)
2) Air Pollution
 The human health effects
of air pollution are far
reaching, but mainly affect
the respiratory and
circulatory systems.
 The negative health effects
depend on the
time/frequency of
exposure, the type of
pollutant and the person’s
overall general health.
2) Air Pollution
 The respiratory system is
particularly affected by
pollutants because it is
made up of mostly thinwalled tissue.
 Many pollutants can break
down these tissues and
over time, damage them
permanently.
 Pollutant effects can be
amplified by the
respiratory system and
spread to other areas of the
body.
2) Air Pollution
 The inhalation of
pollutants eventually
puts them into the blood
stream and brings them
eventually to the heart.
 Many pollutants can
break down heart
muscle, lead to irregular
heartbeats or worse.
2) Air Pollution
 This weakening of two of
the main systems in the
body will generally lower
the body’s immune
system and leave them
open to attack by
pathogens.
Hospitalization and Mortality
3) Water Pollution
 No matter where we live, our
drinking water originates in a
watershed, a land area that drains
to a single body of water that may
be surface water or groundwater.
 These watersheds are constantly
under siege from multiple
threats.
 As rain washes over roofs,
pavement, farms, and grassy
areas, and as snow melts and
soaks into the ground, it picks up
pollution and deposits it into
surface water and groundwater.
3) Water Pollution
 The pollutants may be
chemical or biohazardous
in nature.
 The may be put directly
into the water table (i.e. a
pipe from a factory or
storm sewer drain in a city)
or accumulate over time
(i.e. storm runoff or the
gradual leaching of
fertilizer into the
groundwater below).
3) Water Pollution
 Examples:
 Fertilizer runoff
 Fats and grease from
food processing
 Insecticides
 Heavy metals from cars
 Any number of lovely
pathogens from
mismanaged sewage
treatment or farming
operations
3) Water Pollution
 Poor water quality is the
leading cause of
sickness/illness in the
world!
 Polluted water leads to
increased public health
risks.
4) Radiation
 Thankfully, radiation is
not as much of a health
factor in Canada as in
some countries.
 The adverse health
effects caused by
radiation are usually not
seen until long after the
exposure.
4) Radiation
 Massive radiation
exposure or continual
exposure over the long
term cause serious public
health issues.
 It can have a lasting
effect on a population
due to the genetic effects
and increased cancer
risks.
1) Air Quality
 One way to ensure
health is maintained in
the home is the avoid
lowering the quality of
air the circulates.
1) Air Quality
 Things that deteriorate
air quality:
 Cigarette smoke
 Dust
 Mould
 Chemicals (paint
thinner, gasoline, etc…)
1) Air Quality
 Poor air quality leads to an
increase in cases of asthma
and allergies.
 These are public health
issues because increased
allergies can lead to
sensitivities to
medications, while asthma
can lead to an increased
risk of future respiratory
illness (i.e. H1N1 flu).
2) Clean Drinking Water
 In the United States, 91%
of the people have drinking
water that meets their
federal clean water
standards.
 In Canada, the guidelines
have been updated in
2008, so now, no one on
Municipal water in Canada
will be drinking
substandard water.
2) Clean Drinking Water
 Clean drinking water
lowers the occurrence of
water borne pathogens and
their diseases.
 This lowers the cost to
public health and has
many positive health
benefits.
3) Existing Hazardous
Substances
 Many older homes,
workplaces and even
vehicles were made
before the health
hazards of many of the
products used to build
them were known.
3) Existing Hazardous Substances
 Asbestos in the insulation
of older houses.
 Lead in piping and in
paints.
3) Existing Hazardous Substances
 Radon/Carbon monoxide
released from older
appliances.
 All lead to public health
issues and all, thankfully,
have been reduced in
Canada.
PHAC lead initiatives
 http://www.phac-
aspc.gc.ca/publicat/2008/cphorsphcrespcacsp/cphorsphc-respcacsp07d-eng.php