Biological Hazards
Download
Report
Transcript Biological Hazards
Biological
Hazards
Chapter 20 Section 2
Global Warming Affects
Wide
Spread of global warming allows
mosquitoes to flourish in regions of the
world they never could before.
The mosquitoes bring a variety of diseases
with them .
The Environment’s Role in
Disease
Infectious
diseases are caused by
pathogen, organisms that cause disease.
These diseases spread through person to
person contact through the air or drinking
water.
A host is an organism in which a
pathogen lives all or part of its life.
Waterborne Disease
About ¾ of infectious diseases are transmitted
through water.
In developing countries, there is a shortage of
water so the water supply is used for drinking,
washing and sewage disposal.
These are good breeding grounds for
pathogens.
Organisms that transmit diseases are called
vectors.
Cholera
Deadliest
waterborne diseases come from
drinking polluted water by human feces.
Cholera causes the body to lose water by
diarrhea and vomiting.
It causes the most infant mortality.
Malaria
Once
the world’s leading cause of death.
Caused by parasitic protists and is
transmitted by a bite from female
mosquitoes.
No vaccine for malaria exists but there
are preventative measures to control
mosquitoes.
Environmental Change and
Disease
We
alter the environment to make it more
suitable for pathogens to live and
reproduce.
Many organisms spread through soil that is
contaminated with feces. Ex. Hookworm
People are infected by walking
barefooted and contaminated food.
Antibiotic Resistance
Antibiotics
cause pathogens to evolve
Large quantities of antibiotics are feed to
live stock to speed growth causing
Salmonella and E.Coli to evolve.
Treating human illnesses has also caused
diseases such as pneumonia and
tuberculosis to evolve
Emerging viruses
Viruses
that were unknown 100 years ago.
Ex. HIV/AIDS, ebola virus, West Nile virus.
We do not have any effective drugs to
treat viral diseases.
Vaccines are only effective to a virus that
is already present.
Cross Species Transfers
When
pathogens cross over from its
original host to a new host.
Ex. HIV, West Nile
Recent Examples include the bird flu and
the swine flu.