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22 Cards in this Set
- Front
- Back
- 3rd side (hint)
Water Facts
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-A human can live up to a month without food but can survive for about a week without water
-Average requirement for human consumption of water per day is approximatley 2.5 liters (about 2 1/2 quarts). -About two-thirds of the human body is made up of water |
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Hydrological (Water) Cycle
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-"The natural cycle by which water evaporates from oceans and other water bodies, accumulates as water vapor in clouds, and returns to oceans and other water bodies as precipitation."
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Water Availability Facts
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-Although the earth's surface (about 70%) is covered largely by water, most of this water is unusable ocean water.
-Approximately 3% of all water is freshwater, of which the majority is unavailable for human use (e.g., frozen icecaps and glaciers) -Remaining 1% of readily accessible water comes from surface freshwater; sources includes lakes, riers, and shallow underground aquifers. |
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Water that flows across the ground
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-Potential contaminants include:
-chemicals and nutrients (e.g., fertilizers and nitrates from agricultural lands) -rubber, heavy metals, sodium (from roads) -Petroleum byproducts and organic chemicals (from dry cleaners, service stations, and leaking underground storage tanks) |
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The urban water cycle:
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Man's impact on groundwater
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Chemicals in the Water Supply
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Some chemicals that have been reported to cause adverse health effects:
-Aluminum -disinfection by-products -Flouride -lead -Pesticides -Radon |
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Two causes of viral gastroenteritis
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1. noroviruses
2. adenoviruses |
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Norovirus
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infection with norovirus produces nausea, vomitting and cramping and is normally brief (1 to 2 days)
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Adenoviruses
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most common way of spreading adenoviruses is person to person contact but can also be spread by waterborne transmission
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Viral Hep A
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linked to the consumption of raw or incompletely cooked clams and other mollusks
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Viral Hep E
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has occurred in developing countries and has been associated with drinking contaminated water
-travelers to South Asia and north africa need to take care that their water supply is safe |
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Diseases reportable within one week
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-AIDS and HIV
-Amebiasis -Legionellosis -Arbovirus infection -Asbestosis -Listerosis -Botulism, infant, wound and other -Lyme Disease -Campylobacteriosis -Malaria -Chickenpox (varicella) -Mumps -Chlamydia Trachomatis infection -Creutzfeldt-Jakob disease -relapsing fever -cryptosporidiosis -salmonellosis, including typhiod fever |
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Health Effects of chemicals in the water supply
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-reported health effects have included:
-various cancers -adverse reproductive outcomes -cardiovascular disease -neurological disease |
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Another source of water contamination
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-Pharmaceutical and personal care products (PPCPs) represent another source of water contamination
-They are washed off or excreted from the body -examples include: analgesics, oral contraceptive agents, drugs for lowering cholesterol, and anticonvulsants. |
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Water Disinfection Byproducts (DBPs)
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-Chemicals used to disinfect water include chlorine, chloramines, chlorine dioxide, and ozone.
-These chemicals are associated with by-products of chlorination called DBPs. -Chlorine is associated with trihalomethanes (THMs, CHX3) which are among the most common DBPs. |
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Chlorination of Water and Risk of Birth Defects
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Consumption of chlorinated water
Frequency of late adverse pregnancy outcomes -congenital anomalies -birth defects -stillbirths -neonatal death |
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Beach and Coastal Pollution
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-The approximately 1 billion people who live near coastal areas cause great stress on coastal ecosystems.
-coastal areas are threatened by over-development, poor planning, and economic expansion -world's coastal regions are the recipients of billions of gallons of treated and untreated wastewater |
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effects of beach and coastal pollution
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excessive amounts of nutrients that enter the oceans may cause harmful blooms of algae, resulting in reduced levels of oxygen in the water (anoxic conditions)
-an anoxic ocean environment can bring about fill kills and damage other forms of ocean life. -urban runoff and sewage contamination of the ocean expose swimmers to waterborne disease |
The destruction of many wetlands has had a negative impact on beach pollution
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Petroleum spills
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oil spills from tankers and off-shore drilling platforms can have a devastating impact on the shorline, aquatic life, mammals, and birds.
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-On March 24th, 1989, the tanker Exxon Valdez ran aground in Alaska and caused the largest oil spill in U.S. waters as of that time
-On April 20, 2010, the Deepwater Horizon oil platform exploded, causing history's largest accidental marine oil spill as of mid-2010 |
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Legionnaires' disease (Legionellosis) and Pontiac Fever
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Legionnaire's disease
clinical features: pnuemonia, cough, fever, chest pain Radiographic pneumonia-yes incubation period- 2 to 14 days after exposure Etiologica agent= legionella species attack rate- less than 5% isolation of organism- possible outcome: hospitalization common, case-fatality rate: 5 to 30% |
Pontiac fever:
clinical features- flu-like illness (fever, chills, malaise) without pneumonia Radiographic pneumonia-no incubation period- 24 to 48 hours after exposure isolation of organism-greater than 90% Hospitalization uncommon case-fatality=0% |
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Why is Legionnaires' disease called legionnaires' disease?
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1976 meeting of the American Legion Convention 34 deaths
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low levels of the L. pneumophila are found in freshwater lakes, streams, and rivers.
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Pontiac Fever
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is a milder form of legionnaires' disease
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