Lecture 2-___ Flashcards
___% of water is in oceans, glaciers, and polar ice caps
97.2%
___% of water is in oceans, glaciers, and polar ice caps
97.2%
Differentiate between the progressive, regressive, and flat rate of water pricing?
Progressive: The higher quantities you use, the higher your rate
Regressive: Those using high quantities generally pay less (ex. businesses subsidized by municipal/provincial taxes)
Flat rates: Same price per unit water regardless of how much is used
About ___% of the adult human body is water
70%
What are some of the long term impacts of substances carried by drinking water?
Influencing immunity, behaviour, IQ, reproduction, life expectancy
What are examples of some groups in Canada that may not have access to safe drinking water?
Aboriginal communities, rural residents, and northern communities
People generally use (more or less) water when they have a water meter
Less!
____% of all disease is spread by unsafe water
80%
Why was the new Winnipeg water treatment plant developed?
To deal with Cryptosporidium, a protist which grows from fecal contamination and is found in shoal lake. It cannot be killed by chlorination but instead only filtration
How does water quality influence deforestation?
When people need to boil their water, they often use wood, which contributes to global pollution and deforestation
Approximately _____L per day is considered to be what you need for daily life (adequate standard of living). How does this differ from urban areas and why?
50L.
100L in urban areas for effective sewer transport
____% of the global population has no access to safe water
26%
Average residential water consumption per person per day in Winnipeg is approximately
approximately 300L/person/day
Why was the new Winnipeg water treatment plant developed?
To deal with Cryptosporidium, a protist which grows from fecal contamination and is found in shoal lake. It cannot be killed by chlorination but instead only filtration
What are the primary things that domestic water use is related to?
Household income/property value, and climate
Approximately _____L per day is considered to be what you need for daily life (adequate standard of living). How does this differ from urban areas and why?
50L.
100L in urban areas for effective sewer transport
____/___ of the world’s food is grown on irrigated land
1/3rd
Average residential water consumption per person per day in Winnipeg is approximately
approximately 300L/person/day
How does Canada rank globally in terms of per capita water usage?
2nd to the U.S.
In Winnipeg the costs of water went up after the installment of what?
The installment of the new water treatment plant
How does Canada rank globally for water prices?
One of the lowest rates in the developed world.
What is the primary reason why some cities around the world are running short on water?
Groundwater depletion.
What are some measures to cut back on water consumption?
Ask consumer to cut back voluntarily (ha).
Rotate restrictions (ex. every second street can water their lawn on every second day)
Restrict size of surface area
Provide service only at certain hours of the day
Arrange to import water from a more distant source
How do storms affect sewage treatment in Winnipeg?
Storm sewers can overflow from summer rain so sometimes waste water is directly diverted into the Red River
What happens when organic compounds are put through a water treatment plant?
They are chlorinated, therefore becoming carcinogens (ex. trihalomethanes)
What is the guideline for trihalomethanes in Canada? How does it compare to WHO?
- WHO says 30 is too high.
What agencies deal with drinking water quality guidelines and which are the most stringent
WHO (most stringent), EPA (often more intense than Canada but not always), Canadian Task Force on Water Quality Guidelines, and Manitoba Water Quality Objectives (Manitoba Drinking Water Safety Act)
Why is it so hard to set up scientifically sound water quality guidelines?
IT is really hard to do research on the heath effects of many contaminants (latency periods are very long) , there are lots of complicating variables such as age and lifestyle
The _______ period is the time between first exposure and the time that you see symptoms of an ilness
Latency
Why is it that animal studies of water contaminants not useful?
Studies run for no more than 2 years - not enough time to identify effects of toxins - ex, cancer is very long term
What is toxicity?
The ability of a chemical to damage an organ system, disrupt a biochemical process or disturb an enzyme system in such a way that is causes clinical illness
Toxicity testing is based on what principle related to exposure to a toxin? Why is this not true for allergic reactions?
Based on the principle that intensity increases as dose increases. This is not true for allergic reactions because the first exposure (lowest amount) actually produces a less extreme reaction
Toxicity is expressed as LD50. What is this?
Expressed as amount per unity body weight that is lethal to 50% of organisms tested in a given time limit
Why is the LD50 sometimes not helpful when studying water contaminants?
Does not give a measure of chronic exposure
Why is animal toxicity testing often not accurate for humans?
Different animals are being used - the closest animal to us is monkeys but even monkeys have different immune systems and differences in toxicity
What is the NOEL level of a substance?
The “No observable effect level” - the level of a substance at which a change is viewed in the organism.
Why is NOEL often not a good guideline for toxicity?
Many effects are not easily assessed (ex. behavioural), or are too subtle to identify (ex. presence/absence of headache). There is huge variation in response to the same dose (even across males vs females, adults vs children). NOEL does not include carcinogens
When we as humans are exposed to chemicals in the environment, it is always is a cocktail of multiple contaminants. What does that mean in terms of response?
Sometimes they are antagonistic toward each other, sometimes they have additive toxicity, but the majority of the time they have synergistic toxicity (make each other worse)
Is synergistic toxicity often studied?
Nope. Toxicity data do not take that into account
TRUE OR FALSE: Canada manufactures DDT
True
_____ is the second leading cause of death in north america
Cancer
How does the Canadian government operate on an “innocent until proven guilty” basis for pharmaceuticals and food additives?
The Canadian food inspection agency allows
What are the primary parameters that determine what chemicals are on lists such as the Canadian Water Quality Guidelines?
- Known to be toxic (through the fundamentally flawed NOEL)
- Easily measurable (cheap)
- Likely to be present in some samples
Canada has a tendency to do what with water quality guidelines over time?
Reduce the threshold values
What are the different water quality guideline “types” found in Canada?
- Drinking
- Recreation
- Irrigation
- Livestock watering
- Protection of aquatic life (basically just fish)
In Manitoba, the ____ Act regulated public and private water supplies and distribution
Manitoba Public Health Act
The Manitoba Public Health Act regulations apply to what kind of systems?
Drinking water systems that have more than 15 service connections.
What group does water quality monitoring under the Manitoba Public Health Act?
Manitoba Conservation
How are municipal water supplies in Manitoba usually disinfected?
Usually chlorination, sometimes ozonation
What are the steps required to build a water treatment plant in Manitoba?
- Construction plan reviewed by MB conservation and Department of Health
- Facility built and water tested
- Disinfection (chlorination) and bacteriological limits set
- All monitoring will be by MB conservation
What is added to Winnipeg drinking water before it reaches citizens?
Sulphur, chlorine, phosphorous
What chlorine residual must be in water that is distributed to houses? How is this measured?
0.5mg/L. Measured daily and sent to MB conservation and the public health inspector
What are the coliform bacteria requirements for tap water
At least 90% of samples must have no total coliforms, and no one sample may have over 10. No fecal coliforms can be found.
If coliform bacterial requirements are exceeded, what is the procedure?
- Add more disinfectant
- Resample
- Issue warning
- More disinfectant - resample
- Boil water advisory issued
The _____ Act governs American drinking water quality. Are theses standards or guidelines?
Safe Drinking Water Act. They are legally enforceable standards
Is the American Safe Drinking Water Act more strict than Canadian guidelines?
Generally, yes
What are some different sources of drinking water and which areas use them most often?
Desalinated seawater (usually desert countries, reduced from 3.5% salt to 0.5% salt)
Groundwater
Surface freshwater
Define surface water
Any water exposed to the surface (the atmosphere)
Why is the presence of oxygen important for drinking water?
O2 kills anaerobes, oxidizes many harmful chemicals into harmless forms, precipitates dissolved iron, prevents some toxic materials (ex. hydrogen sulfide) from forming
At what time of year might some surface waters become anaerobic
winter - when organisms eat up all the oxygen in a lake
Why is exposure to UV light a positive thing for drinking water
Kills some microorganisms and degrades some toxic organics (ex. cyanide or anatoxin-a)
Why is the presence of aquatic macrophytes important for drinking water?
They control algal growth by releasing compounds that inhibit them and by sequestering nutrients
What are some downsides of relying on surface waters for drinking purposes?
Potential for algal blooms and subject to atmospheric fallout/environmental hazards, subject to pollution
What are different sources of pollution in Shoal Lake?
Agriculture, the winter road that takes supplies to Shoal Lake 40, cottages, boat traffic, runoff from roads
Aquifers extend from soil surface to up to ______km deep
0.8 km
Is there more surface water or groundwater on the planet?
Groundwater
About _____% of canadians drink groundwater
26%
Why is it that groundwater (as drinking water) usage has gone up over the past 20 years?
Most surface water is too contaminated
Why is it that we have no idea how many wells there are in Canada?
We do not require private citizens to report well drilling
There are two kinds of aquifers: _____ and _____
unconfined and confined
The impermeable layer on top of which an unconfined aquifer sits is called an _____. Unconfined aquifers have a _____ volume
Aquitard. Indeterminate
Describe confined aquifers
Squeezed between two aquitards, finite volume which is under pressure, and can emerge as an artesian spring/well
How can drilling wells spoil good aquifers?
Allows bad water to enter another level (otherwise known as intrusion), damaged well casings and heat pumps may affect water, or deep injection of hazardous waste can really fuck them up
Where has the water table level lowered in MB?
Lowe Farm, Winkler, that general area. Also, Charleswood, where buildings as young as 50 years old are having foundations crack, subsidence or sinking of homes
What are some disadvantages of using groundwater for drinking?
Main one is that there is no oxygen. Harmful anaerobes can grow, toxins like H2S can be produced, NH3 is not oxidized, Radon gas can be present, can contain radioactive substances in areas such as the Precambrian Shield, no UV breakdown of toxic substances, pathogens are preserved because water is cold
Why are gas stations a major source of groundwater pollution?
Underground gas tanks can be leaking for years without anyone noticing.
Very toxic substances are often injected deep underground in the town of _____, MB
Gimli, MB
How is groundwater contamination something that is not easy to detect?
Usually it cannot be tasted or smelled, and when it is reported MB conservation usually doesn’t do anything
What are some different ways in which toxic substance can enter the body?
Ingestion (via cooking, drinking, accidents)
Absorption (via skin, mucous membranes)
Inhalation (via aerosols, dusts)
injection (medical procedures, accidental penetration)
How does the acid environment of the stomach influence ingestion of contaminants
Promotes solubility of compounds that are weak acids. Ex. metals easily absorbed
What is enterohepatic recycling and how does it influence the absorption of toxic materials by the body?
Enterohepatic recycling is the process of blood being cycled from the small intestine to the liver to the bile and back to the small intestine. This results in many toxic substances cycling through the body, prolonging the amount of time they spend in the body
How does eating plants influence absorption of toxic substances?
Cellulose fiber binds to many toxic chemicals.
Why is that eating burnt toast can help in the event of a poisoning emergency?
Because activated charcoal adsorbs poison
The _____ is the primary site for bodily detoxification and the _____ is the secondary one
Liver, kidney
The ____ has another pathway where the residence time of poisons in the body can be prolonged
Bladder
What are some skin/hair products through which we may absorb toxic materials
jewelry, clothing, cosmetics, hygiene, grooming products, medical and dental devices
When can water droplets be inhaled?
When bathing, showering, swimming, using humidifiers, garden hose mist, steam from washing dishes
How does asbestos cause disease?
Asbestos lodges in the alveoli permanently and eventually leads to cancers
____,MB has the highest amount of chloroform in the water of any place in CANADA
Whitemouth
How does smoking affect the absorption of toxic substances?
Amplifies the effects of airborne pathogens
Many chemicals never leave the body. What is this referred to?
The “body burden” - the idea that many chemicals are not removed from the body and gradually increase in concentration as we age
Why is it that alcohol is smelled on the breath when drunk?
Because alcohol is removed from the body by exhalation
What are a few different ways in which chemicals can exit the body?
Sweat, urine, tears, exhalation, poop, breastmilk, saliva, bleeding, amniotic fluid, hair and nails
What kind of toxic substances are deposited in hair and nails?
Arsenic, many heavy metals
List the physical water quality parameters
Odour, colour, oil/grease, turbidity
Why are chemical water quality parameters considered more useful than physical?
They deal with specific chemicals, whereas physical parameters may be perfectly healthy
_____ is the most frequent type of complaint by consumers to water suppliers
Taste/odour
What are some sources of bad tastes/smells in drinking water?
Microorganisms (ex. actinomyces), produced during water treatment (ex. from chlorination), compounds from algal blooms, decaying plant/animal matter, oil, H2S gas, iron bacteria, tannins, metals, pesticides, industrial pollution, landfill leaching
If surface water becomes stratified in summer, sometime anaerobic bacteria grow in the low layers - what compound can be produced from that?
Hydrogen sulfide gas
How does low pH affect metals in water?
Low pH causes metals to become more soluble and affect the taste of water
The most common cause for colour change in surface waters is what? What colour does the water turn? IS this deadly?
Fulvic acids that come from decomposition of plant material, leaf litter, etc. Turns water brown but is perfectly safe to drink
In groundwater, what is the most common cause of brown water? Is it toxic?
Manganese/iron. Both are.
What is the water quality guideline for colour in Manitoba?
“There shall be no objectionable colour”
How is colour measured?
TCU = total colour units
Petroleum products are referred to as ______ under Canadian water quality guidelines
“Gasoline and its organic constituents”
______ molecular weight petroleum compounds can be tasted in water
Small
TRUE OR FALSE: All petroleum products are toxic
TRUE
Where would petroleum products that contaminate surface water come from?
Spills, leaking fuel tanks, lubricants, dumping of aircraft fuel, train derailments
How do petroleum products and other volatile organics react with the water?
Some sink below the surface, some float above
How is turbidity measured?
Nephelometer
Why is turbidity considered an issue?
May harbor microorganisms, some small particles like algae, asbestos, clay (absorbs heavy metals and pesticides), or calcium carbonate/lime (beneficial to health) appear.
How can turbidity be a problem in UV light disinfection systems?
Shields pathogens from being killed by UV light
What is total dissolved solids? What is it measured in?
All dissolved organic and inorganic matter in the water. Measured in ppm (mg/L)
Ideally, we want water to be between _____ and _____ TDS
100 and 150
How does high TDS affect water distribution?
Can coat pipes
How is TDS measured?
Electrode
TRUE OR FALSE: Hardness is the same as alkalinity
FALSE
What is meant by “hardness” of water? Where are the hardest waters in Canada?
Hardness is the total cations present in water, consisting of mostly Ca and Mg. Hardest waters are in Manitoba, Southern Ontario, and Saskatchewan
What is meant by “alkalinity” of water?
The ability of a water to neutralize acid
Metals are more soluble in ____ (more/less) alkaline water. How is this related to shoal lake?
less. This less alkaline water leaches things such as lead from pipes
What substances contribute to alkalinity of water
carbonate, phosphate, silicate, sulphide, ammonia, iron, magnesium, manganese, gasses (CO2), particulates
TRUE OR FALSE: Waters in Manitoba are generally very alkaline
TRUE
High alkalinity waters share what traits?
Great ability to sustain acid rain, acid pollution, less heavy metal toxicity,
Hard water is beneficial to health in what ways?
Lower risk of stroke, cardiovascular diseases, cerebral hemmorhage. Maybe due to less heavy metal absorption
___ to ____ mg/L of CaCO3 for hardness is considered “acceptable”
80-100mg/L
1ppm = __mg/L
1mg/L
TRUE OR FALSE: pH must be measured in situ. Why or why not?
TRUE, as pH changes over time
The _____ the pH is, the more corrosive it is
Lower
Heavy metals are more soluble in ___ metals
Heavy
What is higher pH associated with?
High hardness. Can also reflect problems such as eutrophication
As you approach a pH of ____, all fish will die
4
Generally the minerals absorbed at ___ (low/high) pH are more dangerous than minerals absorbed at _____ (low/high) pH
low, high
What are some problems caused by high chloride in water?
Water tastes salty, corrodes pipes/fixtures
High chloride water is found particularly in _____ of MB
Southwestern parts
The Canadian guideline for chloride in water is ____
250 mg/L
Water softener salt is made of _____. How does this affect rural (farm) houses?
NaCl. This can backlog into the septic field and create a very salty environment, which can leach into the groundwater over time
How does manure affect chloride concentrations in groundwater?
Manure in lagoons is very salty and can cause NaCl to leach into groundwater
What are some different sources of nitrogen in MB?
Livestock waste, fertilizers, sewage, cottages
How does mining affect nitrogen levels in Manitoba?
Gold mining is done using cyanide, which enters water systems and increases nitrogen levels
How soluble is ammonia?
Very very soluble
What are some sources of ammonia?
Runoff, leachings, sewage, industry, natural decomposition of organic matter, cleaners (ex. windex), anhydrous ammonia, mixed with irrigation water, excretion by aquatic organisms
What are some problems caused by the presence of ammonia in a water system?
Corrode distribution system, toxic to all animals, promotes bacterial growth
Is there a canadian drinking water guideline for ammonia?
No
What is one way to prevent ammonia from building up too much
Aerate the water, converting ammonia to nitrite (NO2)
The number one cause of mortality in Lake Winnipeg fish is _____ from Winnipeg sewage
ammonia
Levels of nitrite above ______mg/L indicate pollution
01.mg/L
Nitrite is about ____ as toxic as nitrate
10x more
Is there a Canadian drinking water guideline for nitrite?
Nope.
What is the primary concern with nitrite in groundwater?
There is almost no O2 in groundwater so nitrite cannot be converted to nitrate. This may lead to Methemoglobinemia: Blood vessels dilate, oxygen supply to brain/extremities reduced. Hemoglobin is converted to methemoglobin and blue skin, lips, nails (cyanosis) can occur. May lead to “blue baby disease”.
Often methemoglobinemia is misdiagnosed as ______
Sudden infant death syndrome
_____ is a dental product used to treat dry mouth that can induce methemoglobinemia
Biotene