Dr. Nadia Aziz C.A.B.C.M.
Department of Community Medicine
Baghdad Medical College
Objectives
Define
Environment
&
Environmental Health
Describe
outdoor air pollutants
Explain the
effects of air pollution
Describe methods of
control
of air pollution
Environment
In nature, the
totality of surrounding conditions
.
The world around you is your environment; air,
sun, ground, sky, house and woods -- whatever
you live within is your environment.
Environmental Health
Definition
It refers to the theory and practice of
assessing,
correcting, controlling
, and
preventing
those
factors
in the environment that can potentially
affect adversely the health
of present and future
generations.
Environmental Health
Environmental health comprises those aspects of
human health, including
quality of life
, that are
determined by
physical, biological, social and
psychosocial factors
in the environment.
Environmental Health
The
atmosphere and water
of this earth
although extensive are
not limitless
world and cannot with safety be used as
disposal dumps.
Environmental Health
Air, water and consequently food cannot
continue to be mistreated in this way without
rapidly increasing danger to a rapidly increasing
population in a limited world.
The
average person
consumes each day 4 pounds
of waters and 3.5 pounds of food.
Air Pollution
The presence of
chemicals
in the atmosphere in
quantities
and
duration
that are harmful to human
health and the environment
Types of air pollutants
Primary pollutants
- products of
natural events
(like fires and volcanic eruptions) and human
activities added directly to the air
Secondary pollutants
- formed by
interaction of
primary pollutants
with each other or with normal
components of the air
Air Pollutants outdoor
Individual outdoor air pollutants typically exist as part of
a
complex mixture
of multiple pollutants.
Sources of Outdoor air pollution
Large industrial facilities.
Smaller industrial operations e.g. dry cleaner and gas
stations.
Sources of Outdoor air pollution
Natural sources e.g. wildfires.
Sources of Outdoor air pollution
Transportations e.g. gasoline based transportation like
highway vehicles ( major source)
Others like pesticides, smoking etc..
The effects of air pollution
1-
Ecological
: global warming, acid rain deposition,
contamination of water and food
2-
Biological
: irritation, increase risk of respiratory
diseases and cancers or pass into systemic circulation
causing systemic disease e.g. Lead poisoning.
3-
Economical
: losses of animals or plants, increase
sickness absenteeism and medical cost.
Air Pollutants outdoor
The 6 Criteria pollutants:
Ozone (O
3
)
Respiratory particulate matter( PM
10
, PM
2.5
)
Lead (Pb)
Sulfur dioxide (SO
2
)
Carbon monoxide (CO)
Nitrogen oxides (NO
x
)
Ozone (O
3
)
Ozone is the
most pervasive
outdoor air pollutant.
It is the
principal component of urban smog
.
Ozone
and other photochemical oxidants
formed
in the atmosphere from a chemical reaction
between
volatile organic compounds
and
( NO
x
)
in
the presence of
heat
and
sunlight
.
Ozone (O
3
)
Atmospheric movement of these
precursor
pollutants
can affect ozone levels hundreds of
miles downwind from the sources of these
pollutants.
Ozone (O
3
)
Ozone is also
formed
from oxygen
by the action of
ultraviolet light
.
Is present in low concentrations throughout the Earth's
atmosphere.
It is a
powerful oxidant
and has many
industrial
applications
related to oxidation.
Ozone (O
3
)
As a powerful oxidant ozone is a
potent
respiratory hazard
and pollutant
near ground
level.
It causes
damage
to mucus and respiratory
tissues in
animals
, and also tissues in
plants.
Ozone (O
3
)
Ozone layer
; a portion of the
stratosphere
with
a higher concentration of ozone
Is beneficial,
preventing damaging
ultraviolet
light
from reaching
the Earth's surface, to the
benefit of both plants and
animals
..
.
Respiratory particulate material
(PM
10
, PM
2.5
)
Respiratory particulate material is of
solid particles
and
liquid droplets
.
Particulates
smaller than 2.5 µm
are referred to as
fine particles
e.g. Particles result from motor
vehicles, power planet and industrial operations.
Respiratory particulate material
(PM
10
, PM
2.5
)
Fine particles
can
remain suspended
in the
atmosphere for
long period
Fine particles
are
transported
over longer
distances
compared with
coarse particles
.
Respiratory particulate material
(PM
10
, PM
2.5
)
Particles
between 2.5-10 µm
are referred to as
coarse particles
result from
mechanical breakdown
of solid matter such as rocks, soil and windblown
dust.
Particles
larger than 10 µm
are too large to be
inhaled beyond the nasal passages.
Lead (Pb)
Industrial operations
such as ferrous and non
ferrous smelters, battery manufacturers, and
other sources of lead emissions
can generate
potentially harmful air emission of lead
.
Lead (Pb)
Paint
and
soil
generally are the most common
sources of lead exposure in children.
In developing countries the use of
leaded
gasoline
in motor vehicles is an important source
of
lead exposure
.
Sulfur dioxide (SO
2
)
The primary source of SO
2
is from the
burning of
coal
and
sulfur containing oil
thus major emitters
of SO
2
include coal- fired power plants, smelters
and paper mills.
Sulfuric acid aerosol
is formed in the atmosphere
from the
oxidation of SO
2
in the presence of
moisture.
Carbon monoxide (CO) &
Nitrogen dioxide (NO
2
)
Motor vehicle
emissions contribute to
outdoor levels of (CO) and (NO
2
).
Another important source of NO
x
is
fuel
combustion from power plants
.
Toxic Air Pollutant
Also known as air toxics or hazardous air pollutants, that
are known or suspected to cause
cancer
or other
serious
health effect
, including:
1.
volatile organic compounds(VOCs)
2.
heavy metals
3.
solvents
4.
combustion by- products(such as dioxin)
Toxic Air Pollutant
Volatile organic compounds
(VOCs): are
Hydrocarbon
compounds that have low boiling points, usually less
than 100ºC, and therefore evaporate readily. Some
are gases at room temperature.
Propane
,
benzene
,
and other components of
gasoline
are all volatile
organic compounds.
Toxic Air Pollutant
Some toxic air pollutants, such as
benzene
,
1,3- butadiene
&
diesel
exhaust, are emitted primarily from
mobile
sources.
Other toxic air pollutants
chlorofluorocarbons
(CFC's) come
primarily from large,
stationary industrial facilities
.
Smaller area sources (such as dry cleaners) and
indoor
sources
also can release toxic air pollutants.
Indoor
concentrations of
VOCs
often
exceed outdoor
concentrations.
Mercury
Mercury
occurs naturally in the earth’s crust
. Most
people and wildlife can tolerate the extremely low
levels of this naturally occurring substance.
When mercury enters the body it becomes
concentrated in tissue, an effect known as
bioaccumulation
.
Mercury
Because this element is toxic at very low
concentrations, even slight increases in the minute
concentrations naturally present in the environment
can have serious effects on humans and wildlife.
Once mercury enters the water it can be converted to
its most toxic form,
methyl mercury
Traffic- Related Pollutants and
Diesel Exhaust
Increased incidence of
wheezing
,
bronchitis
, and
asthma
hospitalizations have been linked
to residence
near areas of high
traffic density.
Traffic- Related Pollutants and
Diesel Exhaust
Diesel particles
may enhance allergic and
inflammatory responses and may
facilitate
development of new allergies.
Routes of exposure
1- Inhalation
: Is the primary route of exposure to air
pollution.
2-Ingestion
: The material that was originally released
into the atmosphere can be ingested as a result of
subsequent
contamination
of
water, soil, or vegetation
or the consumption of fish from contaminated waters.
Routes of exposure
Some toxic air pollutants (
mercury ,lead,
polychlorinated biphenyls and dioxins
) degrade
very slowly or not at all and thus
persist or
accumulate
in soil and the sediments of lakes
and streams.
Systemic effects
1.
Respiratory system
: most of the common
outdoor air pollutant are recognized irritants
,with
ozone being the most potent irritant.
2.
Other systemic effect
: Cancer and impaired
neurologic development.
Clinical effects
1-
Acute health effects
Increased respiratory symptoms
such as
wheezing,
cough
and
transient decrements in
lung function.
More serious
lower respiratory tract infections,
and increase
absenteeism
due to respiratory
illness.
Clinical effects
2-
Long term exposure
to outdoor air pollution
particularly ozone and related co-pollutants, is
associated with
decrements in lung function
among children and increases in prevalence of
chronic obstructive lung disease.
Control of air pollution
1- Engineering methods
: by
altering the process
substitution
by non pollutant substance
but this is not always possible so..
Control of air pollution
2-Other methods:
Isolation
of heavy industries away from cities
Use very
tall stacks
Shielding
of the dangerous process e.g. Radioactive
substances
Appropriate
collection
of harmful particles, gases
and industrial waste
Continuous
monitoring
of the process
Education
and
legislation
Control of air pollution
3- Medical methods
:
Health education
; the benefit of safe environment
Supervision
of sanitary collection and disposal of
human wastes
Continuous environmental
monitoring
Summary
Environment is totality of surrounding conditions.
The atmosphere and water though extensive are not limitless
The 6 Criteria pollutants
Some toxic air pollutants
Systemic effects
Respiratory particulate material
Control of air pollution
Thank you
&
Good Luck