Unit 6 –Health, Risk, Toxicology Ch.15

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Unit
6

Health, Risk, Toxicology

Risks & Hazards

Ch.15


Risk is a measure of the
likelihood that you will suffer
harm from a hazard.



We can suffer from:

Biological hazards
: from
more than 1,400
pathogens.

Chemical hazards
: in air,
water, soil, and food.

Physical hazards
: fire,
earthquake, volcanic
eruption…

Cultural hazards
:
smoking, poor diet,
unsafe sex, drugs,
unsafe working
conditions, and poverty.

7 deadliest infections kill 13.6
million people worldwide
every year

Global HIV/AIDS Epidemic:

AIDS has reduced the life
expectancy of sub
-
Saharan
Africa from 62 to 47 years


40
years in the seven countries
most severely affected by AIDS.

Projected age structure of
Botswana's population in
2020.

Figure 18
-
2

Unit
6

Health, Risk, Toxicology

Chemical Hazards &
Pollutants

Ch.15

Point Source

Non
-
Point Source (Area Source)

Mobile Source

Unit
6

Health, Risk, Toxicology

Ch.15

Toxic Heavy Metals:



Mercury


Lead


Cadmium


Nickel


Gold


Platinum


Silver


Bismuth


Arsenic


Selenium*


Vanadium


Chromium


Thallium

*Not classified as a metal

Figure 18
-
2

Interactive Periodic Table

Each are:


Found in nature


Used in industry


By
-
products mining for
other elements

Metals tend to be stored in fatty
tissue (sometimes permanently)
creating a
body burden
(content of heavy metals in our
bodies)



We all live with metals stored in
our tissues

Unit
6

Health, Risk, Toxicology

Toxic Pathway &

Biomagnification

Ch.15

Figure 18
-
2

Unit
6

Health, Risk, Toxicology

Ch.15

Volatile Organic Compounds:
(VOC’s)

Carbon compounds that evaporate easily at room temperature.


Found in many household and industrial items:

paints, paint strippers, and other solvents; wood preservatives;
aerosol sprays; cleansers and disinfectants; moth repellents
and air fresheners; stored fuels and automotive products;
hobby supplies; dry
-
cleaned clothing.


Usually VOC levels are 2
-
5% greater indoors than outdoors

Figure 18
-
2

Short
-
Term (Acute) effects


Eye, nose and throat irritation


Headaches


Nausea / Vomiting


Dizziness


Worsening of asthma symptoms

Long
-
Term (Chronic) effects

Increased risk of:


Cancer


Liver damage


Kidney damage


Central Nervous System damage

Organic Compounds:

Carbon compounds

Synthetic Organic Compounds:

100,00 chemicals have been commercially available.

Wide range of adverse environmental effects

Persistent Organic Pollutants (POP):

Often contains volatile chlorine

Resistant to environmental degradation

Can be transported long distances by wind, water and
sediments


Many POPs are currently or were in the past used as
pesticides. Others are used in industrial processes and in
the production of a range of goods such as solvents,
polyvinyl chloride, and pharmaceuticals.

Unit
6

Health, Risk, Toxicology

Ch.15

Figure 18
-
2

Hormonally Active Agent (HAA)

A type of POP that effects the endocrine system

Unit
6

Health, Risk, Toxicology

Ch.15

Figure 18
-
2

Radiation

Thermal Pollution

Unit
6

Health, Risk, Toxicology

Ch.15

Figure 18
-
2

Thermal Pollution

Directions


Examine the data in the table below. It shows the concentration of dissolved oxygen
available in water at different temperatures. The oxygen available to fish is in units
marked
ppm

or "parts per million."

Water
Temperature

(Degrees
Celsius)

Concentration
of Dissolved
Oxygen

(
ppm
)

30

7.8

20

9.0

10

10.5

0

14.1

1.
Construct a line graph of the data on the left.


2.
A certain species of fish normally live in a pond
that never exceeds the temperature of 10
degrees Celsius. this species of fish
requires a
dissolved oxygen level 9.5
ppm
. Industrial
development has the potential of increasing the
pond's temperature by releasing hot water
produced during necessary process. Answer the
questions below based on your knowledge of
biology and using your graph.



(a)
According to your graph, at what temperature would the dissolved oxygen level
in the pond drop below the required level?
(b)
What impact would the change in
temperature have on the fish. Explain your reasoning in complete sentences.


3.
Using complete sentences, suggest two (2) ways of preventing the thermal
pollution and still have the industrial development occur.


Unit
6

Health, Risk, Toxicology

Ch.15

Figure 18
-
2

Thermal Pollution

1.
Construct a line graph of the data on the left.


2.
A certain species of fish normally live in a pond
that never exceeds the temperature of 10
degrees Celsius. this species of fish
requires a
dissolved oxygen level 9.5
ppm
. Industrial
development has the potential of increasing the
pond's temperature by releasing hot water
produced during necessary process. Answer the
questions below based on your knowledge of
biology and using your graph.



(a)
According to your graph, at what temperature would the dissolved oxygen level
in the pond drop below the required level?
(b)
What impact would the change in
temperature have on the fish. Explain your reasoning in complete sentences.


3.
Using complete sentences, suggest two (2) ways of preventing the thermal
pollution and still have the industrial development occur.


Electromagnetic Fields (EMF)

Unit
6

Health, Risk, Toxicology

Ch.15

Figure 18
-
2

Radiation

Thermal Pollution

Particulates

Asbestos

Noise Pollution

Cultural

Smoking Epidemic Stages

Dust, soot asbestos
fibers released into
the air

From: dust storms,
volcanic eruption,
combustion

Unit
6

Health, Risk, Toxicology

Ch.15

Figure 18
-
2

Unit
6

Health, Risk, Toxicology

Ch.15

Figure 18
-
2

Dose response curve.


Low concentrations may
be harmful to life. As the
concentration increases, it
may be beneficial to life.

Unit
6

Health, Risk, Toxicology

Ch.15

Figure 18
-
2

Dose response curves.

LD
-
50:

Lethal Dose

The dose at
which 50% of
the population
dies

ED
-
50:

Effective Dose

The dose that
causes an effect
in 50% of the
population

TD
-
50:

Toxic Dose

The dose that is
toxic to 50% of
the population

Unit
6

Health, Risk, Toxicology

Ch.15

Figure 18
-
2

Unit
6

Health, Risk, Toxicology

Ch.15

Figure 18
-
2

Unit
6

Health, Risk, Toxicology

Ch.15

Figure 18
-
2

Unit
6

Health, Risk, Toxicology

Ch.16

Figure 18
-
2

Natural Hazards
:
Potential for property
damage & a threat to human well being

Natural Disasters
:
Significant loss of
life & property over a short time & in a
specific location

Catastrophe
:
Massive disaster
requiring significant time and
money for recovery

Unit
6

Health, Risk, Toxicology

Ch.16

Figure 18
-
2

Natural Hazards Fundamentals:
Natural Hazards…

…provide service functions

… are predictable

… can be linked to other
hazards

… severity is linked to the
biological and physical
environment

… are creating more
damage and loss of life than
in the past

… risk can be estimated

… negative effects can be
minimized

Unit
6

Health, Risk, Toxicology

Ch.16

Figure 18
-
2

Natural Hazards Fundamentals:
Natural Hazards…

…provide service functions

… are predictable

… can be linked to other
hazards

… severity is linked to the
biological and physical
environment

… are creating more
damage and loss of life than
in the past

… risk can be estimated

… negative effects can be
minimized

Unit
6

Health, Risk, Toxicology

Ch.16

Figure 18
-
2

… are predictable

Unit
6

Health, Risk, Toxicology

Ch.16

Figure 18
-
2

… can be linked to other
hazards

… severity is linked to the
biological and physical
environment

Unit
6

Health, Risk, Toxicology

Ch.16

Figure 18
-
2

… are creating more
damage and loss of life than
in the past

Due to:

Poor land
-
use planning &
exponential human
population growth

Unit
6

Health, Risk, Toxicology

Ch.30

Figure 18
-
2

Solid Waste Management:

EQ’s (ch.30):

1.
What are the advantages and disadvantages of:


Recycling?
Composting?
Onsite disposal?
Incineration?
Open
dumps?

2.
How do the physical and hydrologic conditions at a site effect
its suitability as a sanitary landfill?

3.
What are the multiple barriers used in landfills and how are
they monitored?

4.
Why is the disposal of hazardous chemicals one of our most
pressing environmental issues?

5.
How are chemical wastes managed?

6.
What problems are related to ocean dumping and why are
they likely to persist for some time?

Unit
6

Health, Risk, Toxicology

Ch.30

Figure 18
-
2

Integrated Waste Management:
current dominant concept of waste
management meant to manage municipal (MSW) and industrial solid
wastes we produce and reduce or prevent their production.


Can reduce solid waste making it to a landfill by 50%

Includes:

Unit
6

Health, Risk, Toxicology

Ch.30

Figure 18
-
2

Composting

Using organic waste as fertilizer

Unit
6

Health, Risk, Toxicology

Ch.30

Figure 18
-
2

Incineration:

“Waste to Energy”

Releases:

Dioxins (a POP)

Heavy Metals

Particulates

Inorganic Acidic Gases
(
HCl
,
SO
x
,
NO
x
)

But…

Vastly reduces waste
volume (75%
-
95%) and
creates energy


Unit
6

Health, Risk, Toxicology

Ch.30

Figure 18
-
2

Landfills

Open dumps:
are fields or holes in the ground where
garbage is deposited and sometimes covered with soil.
Mostly used in developing countries.

Sanitary landfills
: solid wastes are spread out in thin
layers, compacted and covered daily with a fresh layer of
clay or plastic foam.

Unit
6

Health, Risk, Toxicology

Ch.30

Figure 18
-
2

Landfills

Geomembrane

Sanitary landfills
: solid wastes are spread out in thin
layers, compacted and covered daily with a fresh layer of
clay or plastic foam.

Unit
6

Health, Risk, Toxicology

Ch.30

Figure 18
-
2

8 Ways pollutants from
sanitary landfill may
enter the environment

Noxious liquid that
percolates from the
surface or through the
waste via groundwater
movement

Methane,
ammonia,
hydrogen
sulfide and
NO
X

Heavy Metals

Figure 18
-
2

No open burning

Trade
-
Offs

Eventually leaks and can
contaminate groundwater

Discourages recycling,
reuse, and waste reduction

Slow decomposition

of wastes

Groundwater contamination

Releases greenhouse
gases (methane and CO2)

unless they are collected

Air pollution from toxic
gases and volatile organic

compounds

Dust

Noise and traffic

No shortage of landfill
space in many areas

Filled land can be used
for other purposes

Can handle large amounts
of waste

Can be built quickly

Low operating costs

Low groundwater

pollution if sited
properly

Little odor

Sanitary Landfills

Advantages

Disadvantages

Dust

Noise and traffic

Figure 18
-
2

Unit
6

Health, Risk, Toxicology

Ch.30

Hazardous Materials:

material that is toxic, ignitable, corrosive,
or reactive enough to explode or release toxic fumes.


The two largest classes of hazardous wastes are organic
compounds (e.g. pesticides, PCBs, dioxins) and toxic heavy
metals (e.g. lead, mercury, arsenic).

Figure 18
-
2

Unit
6

Health, Risk, Toxicology

Ch.30

Hazardous Waste Legislation:

Two major federal laws regulate the management and disposal
of hazardous waste in the U.S.:


Resource Conservation and Recovery Act (RCRA)


Cradle
-
to
-
the
-
grave system to keep track waste.


Comprehensive Environmental Response, Compensation,
and Liability Act (CERCLA)


Commonly known as
Superfund

program.


The Superfund law was designed to have
polluters pay for cleaning up abandoned
hazardous waste sites.


Only 70% of the cleanup costs have come
from the polluters, the rest comes from a trust
fund financed until 1995 by taxes on
chemical raw materials and oil.


Figure 18
-
2

Unit
6

Health, Risk, Toxicology

Ch.30

Hazardous Waste Storage:

Deep
-
well disposal
: liquid hazardous
wastes are pumped into dry porous rock
far beneath aquifers.

Surface impoundments
: ponds, pits, or
lagoons into which liners are placed and
liquid hazardous wastes are stored.

Long
-
Term Retrievable Storage
: Some
highly toxic materials cannot be
detoxified or destroyed. Metal drums are
used to stored them in areas that can be
inspected and retrieved.

Secure Landfills
:
Sometimes
hazardous waste are put into drums and
buried in carefully designed and
monitored sites.

Figure 18
-
2

Unit
6

Health, Risk, Toxicology

Ch.30

Ocean Dumping:

Marine debris on the coast of Hawaii

Figure 18
-
2

Unit
6

Health, Risk, Toxicology

Ch.30

“There is no away”