Lecture 11 Review Questions and Answers (h2o and waste sanitation) Flashcards
What is e-waste and what are some major sources?
Electronics (computer, mobile phone, keyboards, computer displays, hardcopy devices, televisions. They consist of precious metal, base and special metals, toxic/hazardous metals, halogens, organics including plastics, glass and ceramics
What did we learn about regulation (or not) of e-waste
No federal regulation–>
states regulation in 25 states: prohibit electronics from being disposed , take back program.
50-80% us export to developing countries where there is open air burning, riverside acid baths and dumping
Why does it pose a health problem?
Health effects: contains various hazardous substances like mercury, beryllium, cadmium and children are exposed to theses toxic wastes when scavenging dumps. There is also secondary exposure in the home, contaminated food and water.
What part of the population is most at risk to e-waste exposure?
Children. They get exposed to cadmium, mercury and beryllium when they dig through the waste in search of heavy metals.
What is the hierarchy of waste management?
Pollution prevention: green chemistry policy to reduce hazardous substances in the design, manufacture and use of chemical products
Waste minimization: eliminates packaging, extends product life, places electrical equipments on lead, cadmium and mercury.
Recycling, re-use and recovery
Treatment, storage, disposal (TSD) –> regulation to ensure it does not leak to underground.
What laws govern waste management and are there problems with them? Problems for recycled materials?
Before ‘65, waste disposal largely unregulated.
Solid waste disposal act of 1965: better management of solid waste and financial support for state to develop waste management plant.
Resource Recovery Act of 1970: focus on recycling and energy recovery, requires EPA to regulate waste disposal.
Resource Conservation and recovery Act of 1976 RCRA: changes requirement for control of hazardous waste, storage treatment and disposal
Hazardous and solid waste amendment of 84
Problems with recycled material: not the same quality, prices fluctuate, purity is not uniform, lack of market development.
Know historical epi data that showed the relationship between drinking water source and diarrheal disease.
John Snow’s studies of London: did statistical mapping, analyzed deaths from cholera according to the areas served by the water companies and found that cholera rates varied according to water supplier.
what are the best strategies for preventing transmission of infectious diseases through the water supply?
Shift from drinking river water to ground water
Filtration of water supply
Regulate the water system
Filter the river water
Sanitation
Explain the steps of water treatment and which is the most important (aggregation, settling, filtering and chlorinating)
Aggregation: (put coagulants in water to attract impurities)
settling: impurities will settle to the bottom
Filtering: separation and filter out the impurities: through funnel cone separating from the bottom or by pumping air bubbles to get the surface and skimming the floc off.
Chlorination (best solution): natural solar disinfection occurs, chlorination killing fecal cloakrooms and giardia
Explain how to build a better well
Well must be dug into the ground well, use a liner dug in a stream bed, well must have a protecting wall to protect contaminants from entering, make sure its built on a slope and finally, a covered well is the best.
What are a few ways to keep feces from entering our mouths?
Put distance/time between poop and people
Filtration of water
Hand washing, food hygiene, keep food covered, sterile packaging, putting barriers, personal hygiene, cleaner water.
What factors influence water quantity?
number of people at filling point
Ability to store water
Safety
Access to water containers
Distance to water source
What are three simple and inexpensive ways for individuals to treat water for consumption?
Chlorination: cost efficient but not sustainable
Natural disinfectant from the sun
Filtration
