EPH - definitions, CDWG Flashcards
define environmental health (1)
1- Branch of public health that is concerned with all
aspects of natural factors (physical, chemical, and
biological) and the built environment that may affect
human health
define toxicology (1)
1- study of the adverse effects of chemicals on living organisms
define toxicity (1)
1- intrinsic ability of a substance to harm
living organism
define xenobiotic (1)
1- any substance foreign to the body
define toxico-dynamics (1)
1- dose-response effects of
xenobiotics on an individual (i.e. what a drug does
to your body)
define toxico-kinetics (1)
1- what the body does to the drug
what are 4 subtypes of toxico-kinetics (4)
1- absorption
2- distribution
3- metabolism
4- excretion
re: toxico-kinetics, what is absorption (1)
1- ability to pass into the body
re: toxico-kinetics, what is distribution (1)
1- transport throughout the body
re: toxico-kinetics, what is metabolism (1)
1- activation vs. detoxication
re: toxico-kinetics, what is excretion (1)
1- elimination from body
re: dose-response, what is dose (1)
1- amount of agent deposited within the body following an exposure, dependent on concentration and duration of exposure
re: dose-response, what is response (1)
1- biological reaction to an agent
what is no-observed effect level (NOEL) (1)
1- highest dose at which there is no effect
what are the layers/barriers of the multi-barrier approach to safe drinking water - LPR/SSGT/DM/A (10)
1- Legislative & policy frameworks
2- Public involvement & awareness
3- Research, science & technology
4- Source water protection
5- (Water) system management
6- Guidelines, standards & objectives
7- Treatment
8- Distribution systems
9- Monitor/respond to parameters
10- (Drinking water) advisories
what is the rationale for the multi-barrier approach to safe drinking water (1)
1- Ensures clean, safe, reliable drinking water by
understanding and protecting the water supply from
source all the way to the consumer’s tap
re: safe drinking water, what is the role of Environment Canada (1)
1- dictates federal water policy
re: safe drinking water, what are the relevant federal legislation - CEPA, FA, CWA (3)
1- Canada Water Act
2- Fisheries Act
3- Canadian Environmental Protection Act
re: safe drinking water, what is the role of P/T (3)
1- oversight of drinking water quality
2- oversight of compliance
3- performance monitoring
re: safe drinking water, what is the role of municipalities (2)
1- delivery of water
2- infrastructure funding
re: safe drinking water, what kinds of things should the public be made aware of/involved in - SRP (3)
1- safety guidance - Educate public on health risks, water disinfection,
guidelines, conservation
2- reports - Make monitoring reports available
3- private systems - Educate owners of private small drinking water
systems on their responsibilities
how should research/science/tech be involved with safe drinking water -SDC (3)
1- disease surveillance
2- science/tech development
3- collaboration done with all levels of government
what are types of source water - SAG (3)
1- surface water (river, lakes)
2- aquifers (sand/gravel bedrock saturated with water)
3- ground water (fresh water beneath Earth’s surface)
what are threats to source water - NEL (3)
1- natural
2- eutrophication
3- land use
re: threats to source water, what does ‘natural’ mean - RSSW (4)
1- rainfall
2- slopes
3- soil drainage
4- wildlife
re: threats to source water, what does ‘eutrophication’ mean (1 with example)
1- eutrophication: influx of nutrients causes increase in algae (e.g. cyanobacteria)
re: threats to source water, what does ‘land use’ mean - AMRUD (5)
1- agricultural runoff (pesticides, fertilizers, livestock)
2- mining
3- recreation
4- urban development
5- discharge of waste water
what are ways to protect source water, categories - GAFE (4)
1- General
2- Agriculture
3- Forestry
4- Engineering
re: protecting source water, what does ‘general’ mean LTIRR (5)
1- land acquisition
2- trespass control
3- inspection programs
4- reservoir use restrictions
5- restricting development (density, location)
re: protecting source water, what does ‘agriculture’ mean - CGW (3)
1- soil and water conservation
2- grazing restrictions
3- waste management
re: protecting source water, what does ‘forestry’ mean - ERB (3)
1- erosion control
2- road and trail
construction
3- buffer zones
re: protecting source water, what does ‘engineering’ mean - RISSD (5)
1- retention basins (permanent ponds to deal with storm runoff)
2- infiltration devices (direct rainwater into ground)
3- storm water diversion
4- maintain septic systems
5- divert runoff from landfills
What kind of person does water safety management (1)
1- Qualified personnel follow standard operating
procedures
what do qualified personnel do for water safety management, what are they ensuring is done? - TC (2)
Ensure:
1- treatment and distribution systems are operating at optimum levels
2- contingency procedures in place (e.g. water main break, treatment plant failure)
what are the guidelines used to ensure safe drinking water (2)
1- Canadian Drinking Water Quality Guidelines for
select physical, chemical, microbiological, and
radiological parameters
2- Health Canada provides guidance for issuing things like boiled water advisories
see MISC/GRAB BAG deck for drinking water treatment cards
n/a
After drinking water leaves the BLANK1, its
quality must be maintained through the BLANK2 (2)
1- treatment plant
2- water distribution system
what can cause a water main break - CLIT (4)
1- corrosion or collapse
2- Loss of pressure can allow backflow of contaminated water (e.g. chemical sprayer
attached to hose) or leakage from soil
3- Indicator: water main pressure below 5 psi
4- Temperature change
what are other vulnerabilities that could exist in a drinking water distribution system - ROM(4)
1- Many service connections
2- Routine cleaning and maintenance
3- Older systems
how do you prevent contamination of a drinking water distribution system - PM/SCH (5)
1- pressure - Design layout to maintain sufficient pressure
2- maintenance- Watermain maintenance and replacement
3- Secondary disinfection
4- Cross-connection controls such as backflow prevention devices
5- Horizontal separation between a water main and
storm sewer to avoid contamination
what are the steps to Monitor/response for parameter exceedance - VNRGCNabc
1- Verify information is accurate: system operator,
testing laboratory
2- Notify relevant authorities: Ministry of Health,
Ministry of Environment
3- Re-sample: if appropriate
4- Gather other data: turbidity, chlorine residuals
5- Corrective action: increase disinfection, flush
lines, equipment repair, identify cause
6- drinking water notices
6a- Issue notice to public: DWA
6b- Immediate DWA: E. coli or fecal coliforms
6c- Urgent DWA: low chlorine residuals
why are drinking water advisories issued (1)
1- issued to inform consumers about
actions they should take to protect themselves from
threat to drinking water supply
what are the elements of a drinking water advisory (DWA) - DAPA-OS (6)
1- Describe situation
2- adverse effects - Potential adverse health effects from water
3- population and area at risk, including susceptible populations
4- Actions consumers should take, including specific guidance on how to boil water and whether
alternate water supplies should be used
5- operator actions being taken to correct the situation
and when they expect to resolve the situation
6- share - Encourage recipients to share notice
re: DWA, what do you describe as part of the ‘describe the situation’ step (2)
1- contaminants of
concern and levels
2- when it occurred
when is a boil water advisory (BWA) issued (1)
1- when microbiological quality of drinking
water is suspected or confirmed to be compromised, and contaminant(s) can be removed/reduced through boiling
what is the timeline of a BWA - in general, not actual days/weeks (1)
1- Intended to be short-term, incident-specific interventions while corrective actions are taken
what percentage of BWAs are issued due to an actual problem vs. as a precaution (1)
1- ~80% BWA issued as precaution and 20% issued on emergency basis due to microbiological detection
what are reasons for issuing a BWA, i.e. reasons why microbiological quality of drinking water may be compromised - MEC-PB (5)
1- maintenance - Local maintenance on distribution system
2- equipment - Minor equipment malfunction
3- change - Unexpected change to source water quality
4- Change in routine monitoring parameter
5- Breach in system (e.g. broken water main)
when is a ‘do not consume’ advisory issued (1)
1- Issued when exposure to the contaminant of
concern could be through ingestion
when do you use ‘do not consume’ advisory vs. a boil water advisory (1)
1- Use if water is unsuitable for consumption
purposes even if boiled, as boiling does not remove
or reduce contaminant concentration
what are examples of contaminants that cannot be removed/reduced through boiling - MNCR (4)
1- metals
2- nitrates
3- cyanobacterial toxins
4- radionuclides
etc.
what activities should you avoid using water for in a ‘do not consume’ advisory - PPWWD (5)
Avoid using the water for:
1- preparing food/drinks
2- personal hygiene
3- washing food
4- washing dishes
5- drinking
when is a ‘do not use’ advisory issued (1)
1- Issued when dermal or inhalation exposure to the
contaminant could affect skin, eyes, and/or nose
(e.g. gasoline spill into water)
what activities should you avoid using water for in a ‘do not use’ advisory (1)
1- Avoid water for all domestic purposes including
showering and flushing toilet
what are conditions for rescinding a boil water advisory - QFO (3)
1- quality - Bacteriological water quality normal
2- failure - Operational failure corrected
3- Outbreak ended
re: conditions for rescinding a boil water advisory, what does ‘bacteriological water quality normal’ mean - i.e. what needs to happen for water quality to be considered normal (1)
1- Bacteriological water quality normal: at least 2 consecutive sets of bacteriological samples, collected 24 hours apart, both negative results
re: conditions for rescinding a boil water advisory, what does ‘operational failure corrected’ mean (1)
1- Operational failure corrected: when all
corrective actions have been completed and water
quality has been confirmed through bacteriological
testing (see ‘bacteriological water quality normal’)
re: conditions for rescinding a boil water advisory, what does ‘outbreak ended’ mean (1)
1- Outbreak ended: after the above conditions have been met and when surveillance indicates that the incidence of the illness in the community has returned to background/baseline levels
home water treatment: how to appropriately boil water (4)
1- fill a pot with water
2- rolling boil x 1 minute - KEY POINT HERE
3- turn off heat source and let water cool
4- pour into clear container and cover for storage
home water treatment: what do you use boiled water for - DPF (3)
1- drinking - Use boiled water for drinking
2- personal hygiene - brushing teeth
3- food - washing/preparing food, formula
home water treatment: how do you disinfect water (2)
1- add 1/8 teaspoon unscented bleach (8 drops) to 1 gallon (16 cups) clear water, mix well
2- wait 30 minutes before drinking
re: Canadian Drinking Water Guidelines (CDWG), which government bodies established them (2)
1- Health Canada in collaboration with
2- the Federal-Provincial-Territorial Committee on Drinking Water (CDW) and other federal government departments
why were the CDWG established by Health Canada (1)
1- Health Canada sets parameters that all water
systems should strive for in order to deliver the
cleanest, safest, and most reliable drinking water
what are examples of guidance set for each parameter as part of the CDWG - MAT (3)
1- treatment goals
2- maximum acceptable
concentration (MAC)
3- as low as reasonably
achievable (ALARA) - a kind of MAC
CDWG are established specifically for contaminants that meet which criteria (3)
1- Exposure to the contaminant could lead to
adverse health effects
2- Contaminant frequently detected in drinking water
throughout Canada
3- Contaminant could be expected to be detected at
a level that is of possible health significance
what are the 3 contaminant parameters that are part of the CDWG - MRC (3)
1- microbiological
2- chemical/physical (primary and secondary disinfectants are part of this)
3- radiological
re: CDWG, what are the microbiological parameters - PC TEV (5)
1- (enteric) protozoa (giardia, cryptosporidium)
2- (total) coliform
3- turbidity
4- E. Coli
5- (enteric) viruses
re: CDWG, microbiological parameters, enteric protozoa, what is the guideline (1a) and what is the source (1b)
1a- Treatment goal: Minimum 3 log removal and/or inactivation of cysts and oocysts
1b- human and animal feces
re: CDWG, microbiological parameters, total coliforms, what is the guideline (1a) and what is the source (1b)
1a- MAC of none detectable/100 mL in water leaving a treatment plant and in nondisinfected groundwater leaving the well
1b- Human and animal
feces; naturally occurring in water, soil and vegetation
re: CDWG, microbiological parameters, turbidity, what is the guideline (1a) and what is the source (1bc)
1a- Treatment limits for individual filters:
* Membrane filtration: ≤ 0.1 NTU
* Conventional and direct filtration: ≤ 0.3 NTU
* Slow sand diatomaceous earth filtration: ≤ 1.0 NTU
1b- Inorganic: clays, silts, metals
1c- Organic: decomposed plant, animal debris, micro-organisms
re: CDWG, microbiological parameters, E Coli, what is the guideline (1a) and what is the source (1b)
1a- MAC: none detectable/100 mL
1b- human and animal feces
re: CDWG, microbiological parameters, enteric viruses, what is the guideline (1a) and what is the source (1b)
1a- Treatment goal: minimum 4 log reduction (removal
and/or inactivation)
1b- human feces
re: CDWG, what are the chemical/physical parameters to focus on (subset of many) - “flamin’ air canada” FLMN ACC (7)
1- fluoride
2- lead
3- mercury
4- nitrate
5- arsenic
6- cadmium
7- cyanobacterial toxins
re: CDWG, chemical/physical parameters, **fluoride, what is the maximum acceptable concentration, MAC, in mg/L (1a) and what is the sources (1bc)
1a- 1.5
1b- Naturally occurring (rock and soil erosion)
1c- May be added to promote dental health
re: CDWG, chemical/physical parameters, **lead, what is the maximum acceptable concentration, MAC, in mg/L (1a) and what is the sources (1b)
1a- 0.005 ALARA
1b- Leaching from plumbing (pipes, solder, brass fittings and lead service lines)
re: CDWG, chemical/physical parameters, mercury, what is the maximum acceptable concentration, MAC, in mg/L (1a) and what is the sources (1b)
1a- 0.001
1b- Releases or spills from industrial effluents, waste disposal, irrigation or
drainage of areas where agricultural pesticides are used
re: CDWG, chemical/physical parameters, nitrate, what is the maximum acceptable concentration, MAC, in mg/L (1a) and what is the sources (1bcd)
1a- 45 as nitrate
1b- Naturally occurring
1c- Leaching or runoff from agricultural fertilizer use, manure, sewage
1d- Excess ammonia or nitrification in the distribution system
re: CDWG, chemical/physical parameters, arsenic, what is the maximum acceptable concentration, MAC, in mg/L (1a) and what is the sources (1bc)
1a- 0.01 ALARA
1b- Naturally occurs (erosion and weathering of soils, minerals, ores)
1c- Releases from mining; industrial effluent
re: CDWG, chemical/physical parameters, cadmium, what is the maximum acceptable concentration, MAC, in mg/L (1a) and what is the sources (1bc)
1a- 0.007
1b- Leaching from galvanized pipes, solders or black polyethylene pipes
1c- industrial and municipal waste
re: CDWG, chemical/physical parameters, cyanobacterial toxins, what is the maximum acceptable concentration, MAC, in mg/L (1a) and what is the sources (1b)
1a- 0.0015
1b- Naturally occurs (released from blooms of blue-green algae - planktonic blooms and benthic mats)
re: CDWG, what are the primary/secondary disinfectants from drinking water treatment (subset of chemical/physical parameters) - “BC chat” BC CHT (5)
1- bromate
2- chlorate
3- chloramine
4- haloacetic acids
5- trihalomethanes
re: CDWG, primary/secondary disinfectants, bromate, what is the maximum acceptable concentration, MAC, in mg/L (1a), what is the sources (1bc), and what is the health basis of the MAC (1d)
1a- 0.01
1b- by-product of drinking water disinfection with ozone
1c- Possible contaminant in hypochlorite solution
1d- Tumours of the
testicular mesothelium
re: CDWG, primary/secondary disinfectants, chlorate, what is the maximum acceptable concentration, MAC, in mg/L (1a), what is the sources (1bc), and what is the health basis of the MAC (1d)
1a- 1
1b- by-product of drinking water disinfection with chlorine dioxide
1c- Possible contaminant in hypochlorite solution
1d- Thyroid gland (colloid depletion)
re: CDWG, primary/secondary disinfectants, chloramine, what is the maximum acceptable concentration, MAC, in mg/L (1a), what is the sources (1bc), and what is the health basis of the MAC (1d)
1a - none required
1b- Monochloramine used as a secondary disinfectant
1c- Formed in presence of both chlorine and ammonia
1d- n/a
re: CDWG, primary/secondary disinfectants, haloacetic acid, what is the maximum acceptable concentration, MAC, in mg/L (1a), what is the sources (1b), and what is the health basis of the MAC (1c)
1a- 0.08 ALARA
1b- by-product of drinking water disinfection with chlorine
1c- liver cancer
re: CDWG, primary/secondary disinfectants, trihalomethanes, what is the maximum acceptable concentration, MAC, in mg/L (1a), what is the sources (1bc), and what is the health basis of the MAC (1de)
1a- 0.1
1b- By-product of water disinfection with chlorine
1c- Industrial effluents
1d- liver toxicity (fatty cysts)
1e- renal/colorectal cancers
re: CDWG, for microbiological parameters, what is the 4-3-2-1-0 mnemonic (5)
Mnemonic for microbiological parameter guidelines:
4- log 4 reduction in enteric viruses
3- log 3 reduction in enteric protozoa
2- relates to multi-barrier approach to safe drinking water
1-
0.1-1 NTU for turbidity though various filtration methods
0- no E.Coli or total coliform
4-3 = VP
