EESA10H3 Lecture Notes - Tap Water, Lake Ontario, Disinfectant

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Published on 19 Apr 2013
School
UTSC
Department
Environmental Science
Course
EESA10H3
Page:
of 7
Life Support EESA10H3 S
Human Health and the Environment
Lecture 3: Waterborne Hazards and Human Health
Announcements
There have been numerous questions regarding the dates for the midterm and final exam. These dates
have yet to be finalized by the registrar’s office. The professor has requested that we have the gym for
one room to write in. If this is the case, the midterm examination will take place the week after the
reading week. This is just preliminary information as we do not know a day or time. As soon as the date
for the midterm is finalized it will be posted on the intranet. The video for lecture one will be posted
tomorrow for us to watch. Remember late submissions of assignments will not be accepted period.
Assignment 1
Read through the assignment carefully in detail. Ask the TA questions. Give your idea and ask if it is
correct. You can ask basically anything you want. After that, if you still do not know what to do, you are
not clear, you want to learn more, professor is available from 4PM to 6PM to answer questions
regarding the assignment. Go to TA first for the TA is fully responsible for the assignments. The
assignment is to be done single-spaced. Question 3 is a maximum of two pages including the references.
It could be shorter than two pages. The major idea is important. Find scientific papers published in
scientific journals to support your opinion or get more information regarding the question. You can use
other books and internet resources to elaborate if you like. Make sure you are getting reliable
information from the web. Try to be original and do not be repetitive.
Question 1: Discuss environmental risks to your health. Explain: this is the risk; I have that risk that will
affect my health, what will happen to me, are you going to potentially experience some lung damage or
is it cancerous say why and how you know that. Did you learn that in lecture, read it in a book, is it
from the internet, how do you know that risk is associated with that health affect. Make sure that you
explain. What type of risks or hazards? The hazards include chemical, physical, social, biological, cultural
or environmental hazards. Is this a season of flu? Do you take TTC, drink tap water, smoke, drink, and/or
drive a car (indoor environment) many different risks. Do you eat breakfast, does your roommate
smoke. Can we have an overlapping of the risks? It could be but try not to do it because if you have idea
for five you do not have to repeat it.
Question 2: An explanation is needed. If you start right away you can get help from TA.
Liquid natural capitol
Water generally is a liquid capitol, natural capitol
Why is it natural? Water is available everywhere in nature, we are surrounded by water
Even our body is mostly consisted of water
Earth is a water planet 71% of our surface is covered with water
Not all of this water is available for us for our consumption
Why? Mostly salty water we are surrounded by huge oceans and huge seas
Not much fresh water that we can use for human consumption and animal consumption
Why is water so important? No living species (animals, plants, or humans) can survive and live
without water
We always think about drinking though water is not just for drinking
Everything in household from cleaning to cooking, industrial purposes, agriculture (for watering
plants and crops)
Life Support EESA10H3 S
There is a science called geomorphology that discusses sculpting the Earth’s surface
Water is one of the factors that changes the shape of planet Earth this is called water erosion
One of the types of erosion is water soil erosion - changes, moving of the soil by water water
streams, surface runoff
Moderating climate mild winter, hot summers (not that hot)
Water is a universal solvent solve many different chemicals, same is the thing in nature
Water is involved in dissolving and diluting particles can be good and something that we might not
want
Water also dilutes wastes and pollutants what happens is move water together with water
stream/flow and reach rivers, lakes, ponds, oceans
How much fresh water is available?
Not much fresh water is available on Earth
97.4% of all water is found in oceans and saline lakes
2.6% in fresh water is available
Of the 2.6% in fresh water most of it is captured as ice caps and glaciers (1.984%)
Water from ice caps and glaciers is not readily available (might be if global warming continues)
Groundwater composes of a significant amount of the fresh water
Groundwater is available for us but we need to pump it out to use it and consume it and also not
use it more than it is replenished
There is only 0.014% of readily available fresh water
Of this, 0.007% is found in lakes, 0.005% as soil moisture, some significant amount of water is in
atmosphere as water vapour and some as biota (all living organisms)
There are huge amounts of water stored in leaves and vegetation
How do we use the world’s fresh water?
There is a comparison between three countries Canada, U.S. and China
There is a significant difference in the use of fresh water between these three countries
We are most interested in Canada 64% of the fresh water is used for power plant cooling, 15% in
industry, 12% in public and 9% in agriculture
If you look at the graph of the U.S. much more water is used in the agricultural sector (41%)
United States uses much more water for irrigation in agriculture; China uses even much more (61%)
More specifically how do we use water in households? Too much water is used for conventional use
flushing toilet (30%), showering (35%), laundry (20%), drinking 10% and cleaning (5%)
Hydrological poverty
Canada has plentiful water available but what about the people in some areas of the world
People in many developing countries just don’t have enough water for basic things such as drinking
or cooking
One out of six people do not have regular access to clean water (safe water to drink)
In many areas such as North Africa and Western Asia people travel far distances to just get a couple
of litres of water (they spend half of the day doing it)
They need to do it just to survive (often use polluted water because that is all they can find)
As a result of this diarrheal deaths is very common in developing countries
It is the number one cause of death in children younger than five years old
The biggest risk 2 million kids die every year due to diarrheal death
Life Support EESA10H3 S
Adults are also under high risk but definitely children are at a huge risk
Water and Your health
We are in desperate need for help drinking water and swimming water
Drinking Water
It is our right to know what it is that we drink what other chemicals that we have in a glass of
water that we consume today
Our municipals must provide us with record they are checking our tap water everyday
Provide us with annual reports on local drinking water quality
On water bottles it says naturally pure water water cannot be 100% pure because water naturally
has to have some minerals
We need calcium, potassium, magnesium, sodium and salts
There is no such thing as naturally pure water
Distillate water is water without salts our body needs salts
Our tap water comes from Lake Ontario, an example of surface water
Surface water in urban areas mostly from rivers, lakes and reservoirs
Ground water can also be used for water supply wells are very common in rural areas
Ground water reservoirs can be very small or extremely huge
There is one ground water reservoir in the U.S. thousands of metres deep underground that runs in
6 states
If we withdraw all this water more than can be naturally replenished that water reservoir will shrink
and it will not last forever
How is drinking water treated?
What do the municipalities do after they take water from rivers, lakes and reservoirs?
They need to clean it, it is not for drinking
First they leave water in tanks to settle down it is easier later to purify
Then they add coagulants agents (some specially designed chemicals) for this purpose
The chemicals make clumps that settle down the smaller particles it is easy to remove them from
the water in that way
Water then goes through mechanical filtering and some types of chemical filtering
There are different types of filters to filter bacteria, viruses and protozoa (some microbes that are
possibly found in water)
Filters are very good for filtering bacteria but not very good for filtering viruses
There is such a tiny and very small special techniques that need to be used for this types of germs
Water then goes for disinfection (addition of chemicals)
Question 2 on your assignment is about addition of chlorine (one type of disinfectant that can be
added to water)
More new and advanced techniques are now often implemented and slowly replace convention
disinfection
One is granulated activated charcoal chemical cleaning mostly of organic contaminants
Ion exchange resins better with heavy metals (mercury, lead)
Reverse osmosis is a good technique for metals and inorganic contamination
Ground water is cleaner with less concentration of toxic chemicals

Document Summary

There have been numerous questions regarding the dates for the midterm and final exam. These dates have yet to be finalized by the registrar"s office. The professor has requested that we have the gym for one room to write in. If this is the case, the midterm examination will take place the week after the reading week. This is just preliminary information as we do not know a day or time. As soon as the date for the midterm is finalized it will be posted on the intranet. The video for lecture one will be posted tomorrow for us to watch. Remember late submissions of assignments will not be accepted period. Give your idea and ask if it is correct. After that, if you still do not know what to do, you are not clear, you want to learn more, professor is available from 4pm to 6pm to answer questions regarding the assignment.