Lecture 2 - Environment and Climate change Flashcards
At what pH do rain and snow become problematic?
pH of 5 (see pH scale).pH < 5
**Rain and snow are already naturally acidic
What is the major cause of acid depositions?
Sulphur dioxide –> sulfuric acid
**Current government regulations and
changes in industrial practices are expected to reduce the rate of these emissions from the electricity sector
What are the effects of acid rain on materials?
Acidic particles corrode metal and cause paint and stone to deteriorate more quickly.
Consequences:
◦ damaged materials that need to be repaired or replaced
◦ increased maintenance costs
◦ loss of detail on stone and metal statues, monuments and tombstones
What are the effects of ocean acidification on marine organisms and ecosystems?
Different for all species: some algae and seagrass may benefit (increase their photosynthetic and growth rates).
A more acidic environment will harm other marine species such as molluscs, corals and some varieties of plankton. Coral reefs may become vulnerable to storm damage and slow the recovery rate.
What causes ozone depletion and where is it most pronounced?
Release of chemical compounds containing gaseous chlorine or bromine from industry and other human activities. Most pronounced in polar regions.
What is a major source of chlorine in the stratosphere?
human-produced chlorofluorocarbons (CFCs)
What action was done to preserve the ozone layer?
The 1987 Montreal Protocol on Substances That Deplete the Ozone Layer began the phaseout of CFCs in
1993 (goal: reduce global consumption by 50%)
Define water pollution
Water pollution is mainly due to the release of substances into groundwater or into lakes, rivers, and oceans. These substances can impact the quality of water and interfere with the natural functioning of ecosystems. May also include the release of energy, in the form of radioactivity or heat, into bodies
of water.
What are the major water contaminants?
Pathogens, organic waste, nutrients, toxic organic chemicals, toxic metals, sediments, acidity, salts, and heat.
Define pathogens and their source
Mostly caused by domestic sewage. Pathogens can enter waterways from untreated sewage, runoff from naturally vegetated areas, malfunctioning septic systems, stormwater drains and others.
What are the health issues provoked by pathogens?
range from mild impacts to serious
life-threatening illnesses, such as typhoid, and cholera.
Define organic waste and their source
Large quantities of organic compounds are released into water courses.
They can lead to oxygen depletion in surface waters. Organic pollutants consist of proteins, carbohydrates, fats and
nucleic acids. They originate from domestic sewage (raw or treated), urban
run-off, industrial (trade) effluents and farm wastes.
Define 2 major nutrients in aquatic ecosystems and the harms associated to them
Nitrogen and phosphorus are nutrients that are natural parts of aquatic ecosystems. They support the growth of algae and aquatic plants (food and habitat for different water organisms).
What are the harms associated to Nitrogen and Phosphorous?
- Infants are vulnerable to nitrates in drinking water
- Excess nitrogen in the atmosphere can produce pollutants such as ammonia and ozone, which can impair our ability to breathe, limit visibility and alter plant growth. The excess nitrogen that comes back to earth from the atmosphere, harms the health of forests, soils and waterways.
What are the primary sources of excess nitrogen and phosphorus?
◦ Agriculture
◦ Stormwater
◦ Wastewater
◦ Fossil Fuels
What are the different types of toxic organic chemicals?
Synthetic organic chemicals like chlorine, an important organ. chem. is PESTICIDES. VOCs: used as industrial or household solvents and as ingredients in
chemical manufacturing processes
