potable water
what is Leptospirosis
bacteria in urine (rats urban legend)
bottled vs tap
bottle more likely to develop bacteria faster and more abundant once opened in comparison to tap
how to disinfect water
chlorine (most common), Ozone, UV light
problem with chlorine and ozone disinfection
chlorine: chlorinated organics Ozone: chlorinated organics, no residual
Examples of fecal oral route disease
cholera, typhoid fever, hepatitis A, salmonellosis, bacterial dysentery (shigellosis), amoebic dysentery (amoebiasis)
how can people ingest a waterborne disease
drink, food preparation, and fecal-oral route
3 routes of infection for waterborne diseases
ingestion, contact, and inhalation
example of inhalation of contaminated waterborne disease
legionnaires disease
what contaminants to MCLs restrict
microorganisms, disinfectants, disinfection byproducts, inorganic chemicals, organic chemicals, radionuclides
are home filters effective?
pesticides and taste/odor- good solvents- some lead- moderate microbes- no
cost of water $1
pint bottle or gallon bottle or 200 gallons of tap
what are primary MCLs and Secondary based on
primary based on health and secondary based on aesthetic and economic
schematic process of general water treatment procedure
raw water, screen, rapid mix, flocculation (slow mix), settling, sand filter, activated carbon, add chlorine, to storage
how is fecal to oral possible
sewage contaminates water supply and travels to water of next town (down stream)
how do home filters work?
small filter and activated carbon adsorption
what is Schistosomiasis
topical disease caused by flatworm in standing water. (contact)
Sand Filtration
trenches with sand filtration deem resourceful to filter cleaner water supply
describe southwark and vauxhall company vs lambeth company
two competing private water suppliers. the untreated water from Thames was different for each co. SVC got polluted water from London and LC got water from upstream in london (clean)... SVC much higher cholera death rate
Ways of water contact and potential diseases
washing, swimming, wading, splashing schistosomiasis, swimmers itch, leptospirosis, primary amebic meningocephalitis
what is potable water
water suitable for drinking
what is dermatitis
"swimmer's itch" bird poop infects water... eggs to parasite inhabits host (snail) to human exposure
Chain of events for waterborne disease
1. sick people excrete large # pathogens 2. poor sanitation puts pathogens in water 3. poor water treatment doesn't remove pathogens 4. bad water=sick people
Safe Drinking Water Act
1974; amended 1986. created public water systems (15 service connections for greater than or at least 60 days a yr). National Interim Primary Drinking Water Standards. Max contaminant level and MCL goals. establish secondary MCLs
describe broad street pump incident
London, 1854; cholera; john snow, red and black dots to mark pumps and deaths, public health measure taken to remove pump handle