lecture 9 - technological hazards Flashcards
example of a technological hazards being a hybrid disaster
an earthquake that causes an oil spill from a pipeline
example of technological disaster involving the environment
the sinking of the titanic and explosion of the challenger space shuttle
vulnerability to technological hazards
death toll is low
vulnerability is greatest for those involved in specific industries or transportation systems
workers in resource industries in hinterlands are at higher risk (miners)
categories of technological hazards
widespread; long term (hazard that lead to cumulative effects)
rare events: airplane crashes, mine collapses, shipwrecks
relatively common; automobile accidents, poisons
cumulative effects of technological hazards
conditions that worsen slowly over time as exposure to a concentration
concentration reaches a threshold critical to human health
hazards that cumulative effects include exposure to radiation, toxic chemical, acid precipitation and groundwater contamination
calculating risk of infrastructure, transportation and industry
infrastructure (bridges, dams, pipelines); risk is defined as the probability of failure during the lifetime of the structure
transportation (by road, sea, rail); risk is the probability of death or injury per km travelled
industry (manufacturing, energy production); risk is probability of death or injury per person per numbers of hours exposed
what is radon?
primary source of radon GAS is from natural decay or uranium in rock and soil
becomes a hazard when released
what happens when radon gas is inhaled?
when inhaled it decays to polonium and lodges in the lungs where it damages tissues
2nd leading cause of lung cancer in North America
why is radon difficult to detect?
difficult to detect because its odourless, colourless and tasteless
how does radon move?
can move quickly through non saturated soil and seep into homes, basements are at higher risk in winter due to reduced air circulation
genetically modified organisms
have had changes made to their DNA by transfer of genes
crops are modified to increase yields
some of the crops have been genetically engineered to have greater resistance to: extreme change in temp or precipitation, herbicides, pests and acidic soil
most common genetically modified organisms
corn, soybeans, canola and wheat
examples of feats in genetic modifications
chickens that lay low cholesterol eggs
tomatoes that reduce risk of cancer
bananas & potatoes to treat viral disease in developing countries
rice that contains more vitamin A
bacteria that can clean up oil and toxic spills
citrus trees producing fruit in their first year (when take 6)
how safe are genetically modified foods?
benefits outweigh the risks
great benefits in developing countries
impacts of radiation
can be direct (effects seen within days of exposure) or delayed and chronic (cancer)
can be indirect in the form of genetic effects
example: person may not experience effects but pass them onto their children in the form of birth defects
2 potential sources of radiation
mining of uranium; produce wastes know as tailing that can be a radioactive hazard
production of electricity; uranium is used in nuclear power plants
nuclear power plants
most in North American are in the eastern half of the continent
must be near water source aka coolant
must be located near a market for electricity
considered a clean source on energy because does not emit greenhouse gases that cause climate change
nuclear accidents
nuclear meltdown is an informal term for an accident that results in damage from overheating
occurs when heat is generated by nuclear plant exceeds the heat removed by its cooling systems
in meltdown, fuel rods turn liquid and the wall of the plant could melt from extreme heat
hot liquid could melt through the bottom of the plant and seep into the soil
three mile island nuclear accident
the worst nuclear disaster in the U.S. in 1979
one of the two power plants on the island that experienced in a partial meltdown
caused by failure of a valve that controlled cool water entering the plant
no direct injuries but minor amount of radiation released and plant closed
chernobyl nuclear accident
nuclear disaster occurred in 1986
the accident was result of a flawed design, operator error and disregard of safety regulations
killed 3 workers due to radiation exposure, thousands developed thyroid cancer
nuclear energy
over 3 mile island and chernobyl slowed nuclear development for a time
concern over greenhouse gas has created high demand for cleaner sources of energy
when did he last coal plant in Ontario close?
2014
titanic shipwreck
hit an iceberg in 1912
wreckage was found by SONAR in 1985
the carpathia arrived at 4:10 and picked up survivors
oil spill impacts
most common in water but occur on land due to pipeline bursts
clean up can take months to years
oil penetrates bird feathers and mammal fur reducing the ability to insulate
birds and animals left vulnerable to changes and become less buoyant in water
exxon valdez oil spill
caused by an oil tanker ship striking a rocky reef of the coast of Alaska (1989)
region is important habitat for salmon, seals, sea otters, killer whales and seabirds
75 mil L of oil spilled; the remote location made recovery efforts difficult
