Lecture 5: One Health & water, Land, & Air (Exam 1) Flashcards
How long can a person live w/o water
3 Days
What % of the earth’s surface is covered in water
71%
T/F: Water is probs the most poorly managed natural resource
True
What % of the earths water is ava as fresh, accessible, liquid water
- 3%
- Only 1% comes from rives & lakes
Describe the global water resources
- Globally there is enough freshwater for all
- Canada has 0.5% of the world’s pop but 20% of the world’s liquid freshwater
- China has 20% of the world’s pop but only 7% of the freshwater supply
Describe water withdrawal
- 70% of the water is withdrawn from the surface & groundwater sources is not returned theses sources
Across the globe what is the biggest user of water
- Irrigation
- Produces 40% of the world’s food
What is the difference btw/ consumptive & non-consumptive water
- Consumptive use does not return the water to its original source
- Non-consumptive use does not remove or only temporarily removes water from the original source & then returns it
How much water does it take to produce, soy, eggs, chickens, pork, & beef
The bigger the animal the more water it takes
What are the impacts of livestock production on water quality
- Have an impact b/c of the nutrient loading of nitrogen & phosphorus from animal & feed waste (bio oxygen demand, BOD, eutrophication of aquatic systems)
- Bio contamination like water-borne bacteria, viruses, & parasites
- Drug residue contamination in surface runoff (antimicrobials & hormones)
- Heavy metal feed additives in surface runoff (copper, zinc, iron, & others)
Describe soil erosion
- The breakdown, detachment, transport, & redistribution of soil particles by wind, water, or gravity
- Soil erosion effects water quality, air quality, & soil productivity
- We are gaining our ground back in the US
Describe global soil erosion
- Mid west US - fairly high severity
- Sub sahara, south africa, india, & chine = severity, poorest livestock owners, & highest zoonotic disease burden
- Big prob globaly
What are the causes of soil degradation
- 63% - overgrazing
- Agri activities
Describe desertification
- Dryland regions become increasingly arid, losing their bodies of water, vegetation, & wildlife
- Drylands occupy nearly half of the earths area & are home to 1/3 of the human population
- Experience water scarcity which limits the production of crops, forage, wood, & ecosystem services needed for survival
- Globally expanding
Describe histoplasmosis
- Chronic, noncontagious, disseminated, granulomatous disease of people & other animals
- Caused by dimorphic fungus
Where is histoplasma capsulatum commonly found
Soil that contains bird & bat manure
Describe how soil is a reservoir for anthrax
- Just cuz animals eat the spore doesn’t mean when they get sick
- Bacillus anthracis produce spores that are dormant & they live in the envi
- When spores enter an animals body they can become activate & turn into active growing cells
- Once active they can become bacteria & multiply
What is the sources of anthrax - bacillus anthracis infection
- Outbreaks occur when livestock are grazing on neutral or slightly alkaline soil
- Infection in cattle, sheep, or horses is b/c of grazing on infected pasture land
- Organisms enter through the mouth, & less often via nose or skin injury
- Organism spreads rapidly through out the body
- Dead animals that are opened & not burned or buried provide a source
- low lying ground or marshy areas are readily contaminated by flooding & resultant stagnant water holes
Describe tetanus found in soil reservoirs
- Tetanus toxemia is caused by a neurotoxin produced by clostridium tetani found in necrotic tissue
- Almost all mammals are susceptible
- Dogs & cats are rel more resistant than others
- Birds are quite resistant
- Horses & lambs seem to be the most sensitive of all species w/ the possible exception of people
- Minor stimulation of affected can trigger tetanic muscular spasms
- Sx in dogs: Furrowed brow, ears pulled together, lips drawn up, eyelids drawn, wound (may not be obvious), & warn nails
What is the Tx for tetanus
- Curariform agents, tranquilizers, or barbiturate sedatives 300,000 IU of tetanus antitoxin IV twice daily
- Penicillin or broad spec antibiotics
Describe blackleg from clostridium chauvoei
- C. chauvoei is found naturally in the GI tract of animals
- Spores remain viable in the soil for years & are purported to be a source of infection
- Outbreaks have occurred in cattle on farms in which recent excavations have occurred or after flooding
- Organisms probably ingested, pass through the wall of the GI tract to gain access to the BS, then deposited in the muscle & other tissues where they may remain dormant indefinitely
- Sx: acut severe lameness & marked depression
- Edematous & crepitant swelling dev in the hip, shoulder, chest, back, neck, or elsewhere
What is hypomagnesemic (grass) tetany
- A complex metabolic disturbance characterized by hypomagnesemia
- Sx: hyperexcitability, muscular spasms, convulsions, resp distress, collapse, & death
Who is most susceptible to hypomagnesemic tetany & why
Adult lactating animals b/c of the loss of Mg in milk (rare in nonlactating cattle but can occur when undernourished cattle when intro to green cereal crops
When does hypomagnesemic tetany occur
When animals are grazed on lush grass pastures or green cereal crops