Environmental Health Toxicology APES 2009 http news nationalgeographic

Environmental Health & Toxicology APES 2009 http: //news. nationalgeographic. com/news/2009/01/090116 -poison-video-wc. html

Some Vocab… • WHO- World Health Organization • Health- state of complete physical, mental, and social well being (not just the absence of disease) • Disease- change in the body’s condition in response to an environmental factor – Ex: nutritional, chemical, biological or psychological • • • Morbidity- illness Pathogen- disease-causing Vector- organism that spreads disease Emergent- new, not identified or absent for last 20 years Zoonotic- transmitted from animal host to humans

PATHOGENIC VS. -PATHOGENIC • 43% of all diseaserelated deaths are from pathogens (insects, bacteria, virus, worms) • 57% from cardiovascular disease, cancer, lung disease, injuries, etc. NON

Morbidity & Quality of Life • Not everyone dies from disease, but still can cause severe suffering and debilitation • When sick… – – Crops not planted/harvested Animals not tended Work not done Kids not fed • Poorest people are most affected because they live in unhealthiest environments & don’t have $ for health care. • Lack of adequate housing, sanitation, safe drinking water causes most cases of diarrhea which is made worse by malnutrition.

PATHOGENIC THREATS TO HUMAN HEALTH

Infectious Diseases • Onchocerciasis (river blindness) – Vector: Black fly – Many roundworms get into eyes & die causing blindness – Control with insecticide sprays – Merck & Co. are providing free ivermectin to help eradicate.

Infectious Diseases • Elephantiasis – Vector: Mosquitoes – Roundworm gets into lymph system and blocks lymph vessels causing fluid build up in the extremities. – Smith. Kline Beecham is supplying free albendazole to kill worms in body to help prevent spread.

Infectious Diseases • Drancunculiasis– Guinea worm – Vector: Drinking Water contaminated with Cyclops – 3 meter long worm that lives under skin. Forms blister & must be wound out of skin to remove

Infectious Diseases • Hemorrhagic Fever – Some Types… • Ebola: Vector- unknown • Lassa: Vector- Mastomys rat species • Hanta: Vector- Deer mice – All cause tissue deterioration, bleeding, pulmonary edema. – Ebola has 90% mortality rate. – Highly contagious

Infectious Diseases • Malaria – Vector: Anopheles Mosquitoes transmits Plasmodium protist into host blood stream – 3 million die each year, 90% of them in Africa – In 1950’s & 60’s, sprayed DDT & knocked down from millions cases each year to thousands, now back to 2. 5 million new cases – Mosquitoes are developing resistance – Fever, chills, flu-like symptoms

Infectious Diseases • Cholera – Cause: Bacteria in unclean drinking water – Severe stomach cramping, severe diarrhea, vomiting – Thought eradicated in many places but has made comeback in some due to ships dumping bilges in harbors of cities with inadequate water treatment

Infectious Diseases • Tuberculosis – Cause: bacteria – Eliminated but has returned stronger than ever – Some strains drug resistant – Spreads rapidly by respiratory droplets (coughing, sneezing, mucus) – EX: Russian prisons

EMERGING DISEASES

Infectious Diseases • West Nile Virus – Vector: mosquitoes or blood transfusions, mother to child via nursing – Symptoms: nerve problems, stiff neck, headache, high fever, etc. – Mammals are the “dead end” infection as the virus cannot multiple in mammals – Prevention: scan blood donations; mosquito prevention

Infectious Diseases • SARS – Severe Acute Respiratory Syndrome – Vector: can be passed directly from animals (usually birds) to humans, also passed human to human – Highly contagious! – Passed via respiratory droplets (cough, mucus, sneeze) from human to human – Prevention: wash hands, destroy infected animals, keep distance from animals, quarantine infected people.

SARS vs. Bird Flu Similarities • • • Both are potentially fatal viruses. Both are respiratory diseases. Both have first affected animals and then made the jump to humans. Both have similar symptoms, including fever and difficulty breathing. At present, there is no known cure for either virus. Differences • Bird flu is caused by a flu virus while the SARS virus is more closely related to the common cold. • SARS can be transmitted from person to person. So far, MOST CASES of bird flu have only been transmitted from birds to humans.

H 1 N 1 (Swine Flu) • First showed in 2009 • First thought to be genetically similar to flu virus seen in pigs • Now know it has similarities to viruses seen in pigs, birds, and humans • Very contagious- spread from human to human • Same symptoms of flu with high fever

Difference between Endemic, Epidemic & Pandemic • Endemic- disease exists permanently in a region or population. EX: malaria • Epidemic is localized outbreak of disease. EX: west nile • Pandemic is worldwide outbreak of disease. EX: H 1 N 1, small pox

Methods of disease prevention Insect-born diseases: • Reduce mosquito population – Use biological control- frogs, fish, bats, birds – Wear more clothing in mosquito infested areas – Use insect repellant – Insecticides – Mosquito netting – Eliminate standing water Water-born diseases (cholera): • Wash hands • Boil water • Shut down shellfish beds • Provide clean drinking water • Introduce sanitation for sewage Other diseases (tuberculosis, hemorrhagic fever) • Quarantine infected individuals • Use antibiotics on bacteria (tuberculosis)

What causes disease to spread so rapidly? • Population density , so contact • Moving into remote areas for agriculture exposure. • Deforestation, pollution causing local & global climate change ( in temp = in mosquito pop. And in mosquito range) • Eliminating predators so in rodent, roach, mosquito pop. • in speed & frequency of travel (airplanes, ships) to other countries • in resistance (Malaria) = “Superbugs” • Taking medication improperly leads to “superbugs” • Antibiotics given to farm animals increases their resistance.