EPH

Question 1

List 3 categories of food hazards and given an example of each

Answer 1

List 3 categories of food hazards and given an example of each
Chemical:
Lead
Arsenic
Mercury
Aflatoxin
Dioxin
Cyanide (cassava)
Allergens (peanut)
Acid (kombucha)
Pesticides
Sanitizer residue

Biological (95%):
Bacteria - C. jejuni, E. coli O157:H7, S. flexneri, S. sonnei, L. monocytogenes
Biotoxins - Paralytic shellfish poisoning toxin, botulinum toxin,
Viruses - norovirus, hepatitis A
Fungi - aspergillus
Parasites - giardia

Physical:
Glass
Metal
Plastic
Wood
Animal bones, feathers, shells

Question 2

List and describe 3 federal acts related to food safety

Answer 2

Food and Drugs Act - establishes standards for food labeling for foods that are imported or transported between provinces,packaging, composition, advertising, additives, and pesticides
Safe Food for Canadians Act - streamlines existing food legislation (Fish Inspection Act, Meat Inspection Act, Canadian Agricultural Products Act) to safeguard against food tampering, strengthens regulations for imported foods, improves food traceability, prohibits the sale of recalled food,
Canadian Food Inspection Agency Act - established the CFIA, and provides powers to recall food

Question 3

List and describe 3 surveillance systems for monitoring food borne illness in Canada.

Answer 3

List and describe 3 surveillance systems for monitoring food borne illness in Canada.

FoodNet - monitors foodborne illness and pathogens from 4 sentinel sites, collecting data from human, retail food, farm, and water sources

PulseNet - monitors and connects genetic data on organisms that cause foodborne illness across Canada, via NML

NESP - National Enteric Surveillance Program. Weekly reporting for detection of emerging and priority enteric disease trends. Integrates national and international data on lab-confirmed foodborne illness

Question 4

List 5 principles that should be included in a food safety plan

Answer 4

List 5 principles that should be included in a food safety plan

HACCP:
Hazard analysis
Identifying critical control points
Establishing critical limits for each critical control point
Establishing monitoring procedures for critical control points
Establishing corrective actions
Record keeping
Establishing verification procedures

Question 5

List and describe the roles of 4 stakeholders involved in an inter-provincial food-borne illness outbreak investigation

Answer 5

List and describe the roles of 4 stakeholders involved in an inter-provincial food-borne illness outbreak investigation
CFIA – inspection of food, livestock, feed, plants, seeds; food safety investigations (tracing), recalls
Health Canada – health risk assessments to the CFIA and P/T, public communication
PHAC – coordinates the outbreak response
NML – reference services for strain identification and characterization, surveillance, disseminate information via PulseNet Canada and the National Enteric Surveillance Program (NSEP)
CNPHI – facilitate communication, early notification for potential outbreaks
P/T governments and associated agencies – food safety investigations, foodborne illness investigations
FNIHB – food safety investigations, foodborne illness investigations on reserve

Question 6

Define “cluster”

Answer 6

higher than expected incidence of a disease for a defined group of people, in an area for a given time period

Question 7

Steps in a cluster investigation (4)

Answer 7

Initial contact
Assessment - significantly more cancer than expected? Standardized incidence ratio (observed/expected)
Feasibility study - hypothesis, likelihood,
Etiologic investigation - draw epidemiologic association between the hazard and cancer incidence

Question 8

List 5 limitations and challenges of cancer cluster investigations

Answer 8

Small samples
Forced case definitions
Unclear geographic boundary
Migration
Long latency period
Poor exposure data- Poorly characterized, heterogeneous, low in concentration
Recall bias

Question 9

List 3 functions of the Canadian Environmental Protection Act

Question 10

Describe the difference between bioaccumulation, biomagnification, and biotransformation

Answer 10

Bioaccumulation: the progressive increase in amount of a chemical in an organ or organism as the rate of uptake exceeds the rate of excretion

Biomagnification: the sequence of processes in an ecosystem by which higher concentrations of a chemical are attained in organisms at higher levels of the food chain

Biotransformation: intermediary metabolism; biochemical changes that occur when a chemical reaches human cells to decrease (detox) or increase (activation) toxicity

Question 11

What is the difference between the reference dose and tolerable daily intake (TDI) for a substance?

Answer 11

Tolerable Daily Intake (TDI): the estimate of total daily exposure that is unlikely to result in adverse health effect in a lifetime to a human population, usually expressed as mg/kg/day

Reference dose (RfD): estimate of total daily exposure that is likely to be without appreciable risk over a defined period of time, usually a lifetime. This term has replaced TDI and ADI (acceptable daily intake)

Question 12

Define the precautionary principle

Question 13

A small rural community has raised concerns that a nearby smelter is releasing large amounts of heavy metals into the air.
List and describe 4 steps of a risk assessment.

Answer 13

1. Hazard identification: identify the agent, health effects, population impacted, and identify possible data sources
2. Dose response - determine the LOEL and risk threshold (zero, de minimis, de manifestos, ALARA etc.)
3. Exposure assessment - estimate exposures along the source to human pathway (soil/water/air, location, population, route of exposure (dermal, ingestion, inhalation), magnitude, duration)
4. Risk characterisation - summary of the risk (quantitative or qualitative), make sure to acknowledge assumptions

Question 15

Provide 6 examples of mitigation measures against an environmental hazard using the agent-path-receptor framework

Answer 15

1. Remove the hazard
2. Remediation
3. Containment
4. Block transmission
5. Relocate people
6. Change the land use

Question 16

List 5 IARC group 1 heavy metals and the cancers they cause

Answer 16

1. Arsenic - lung, skin
2. Cadmium - lung
3. Aluminum - bladder
4. Iodine - thyroid
5. Nickle - nasal cavity

Question 17

List 5 outrage factors and 5 safe factors to consider when communicating risk

Answer 17

General principles: be first, be credible, be right.
Outrage factors: MUSIC
- morally relevant, memorable
- unfair
- scary or dreaded
- industrial hazard (vs. natural)
- catastrophic (vs. chronic)

Safe factors: VICTOR
- voluntary
- control
- trusted source
- old threat vs new
- responsive

Question 18

Where do heavy metals come from and why are they an issue of public health importance?

Answer 18

Typically released from natural sources (the Earth’s crust) or industrial sources (mining, smelting0
Issue of public health importance because they can be toxic at low doses and tend to persist for long periods without degrading

Question 19

What is the MAC and blood limit for for lead?

Answer 19

MAC 0.005mg/L
BLL 10 micrograms/dL

Question 20

What is the MAC and blood limit for mercury?

Answer 20

MAC 1 microgram/L
Blood mercury limit 5.8 microgram/L

Question 21

What is the recommended limit for fish consumption to avoid mercury toxicity?

Answer 21

150g/week for the general population
150g/ month for pregnant people
125g/month for children 5-11
<75g/month for children 1-4

Question 22

List 2 acute and 2 chronic health effects from lead

Answer 22

Acute: nausea/vomiting, abdominal pain, drowsiness, encephalopathy, death

Chronic: developmental delay, motor deficits, anemia, hypertension, miscarriage

Question 23

List 2 acute and 2 chronic health effects from mercury

Answer 23

Acute: parenthesis, dysarthria, weakness, minimata disease, AKI
Chronic: acrodynia, Mad Hatter disease, developmental delay

Question 24

List 2 acute and 2 chronic health effects from arsenic

Answer 24

Acute: cardiotixicity, encephalopathy, cramping, nausea/vomiting/diarrhea

Chronic: neurotoxicity, peripheral neuropathy, bone marrow suppression, diabetes mellitus, bladder cancer, lung cancer, SCC

Question 25

List 2 acute and 2 chronic health effects of cadmium

Answer 25

Acute: headache, weakness, pneumonitis, Itai-Itai disease Chronic: COPD, nephrotoxicity, lung cancer

Question 26

What are endocrine disruptors and why are they of public health importance?

Answer 26

Endocrine disruptors are a group of synthetic chemicals that impact the synthesis, transportation, binding, or metabolism of endogenous human hormones. They are of public health importance because they can lead to growth failure/short stature, developmental disabilities, impaired sexual development, infertility, increase susceptibility to cancer, and disruptions in the immune and nervous systems

Question 27

List 2 routes through which people could be exposed to BPA and 2 risk mitigation measures.

Answer 27

Routes: ingestion, inhalation (usually from polycarbonate plastics in food containers) Mitigation measures: ban products with BPA, check the components in food containers, microwave food in glass only Additional info: BPA is categorised as an endocrine disruptor and can lead to fertility with a possible role in obesity and metabolic disease

Question 28

List 2 routes through which people could be exposed to phthalates and 2 risk mitigation measures

Answer 28

Routes: Ingestion (water), inhalation Mitigation measures: choose phthalate-free personal care products, wear a mask if working with construction materials that could contain phthalates Additional info: Phthalates are a group of endocrine disruptors that are found in plastics such as PVC and construction materials as well as personal care products like perfume, hair gel, and lotion. Most phthalates have no known health effects but DEHP is IARC 2B for HCC and adenomas. There is a possible link between phthalates and disruptions in the reproductive system

Question 29

What are volatile organic compounds and why are they a threat to health?

Answer 29

VOC's are chemicals that easily evaporate (volatile); precursors to ground level ozone, from natural and anthropogenic sources such as forest fires, animals, cigarettes, crude oil, coal, industrial solvents, and dry cleaning products. Health effects include drowsiness/ altered level of consciousness, anemia, neurotoxicity, hepatotoxicity, skin irritation, leukemia, and renal cancer

Question 30

List 2 sources of benzene, the usual route of exposure, and 2 examples of risk mitigation measures.

Answer 30

Sources: crude oil seepage, incomplete combustion of organic materials, coal, industrial solvents, gasoline evaporation, industrial intermediates (plastics, acetone, rubber, detergents, dyes) Route of exposure: inhalation Mitigation: Avoid indoor gas heating, don't store benzene-containing products inside the home, no smoking inside Note: IARC Group 1 for AML

Question 31

List 2 sources of trichloroethylene, the usual route of exposure, and 2 examples of risk mitigation measures.

Answer 31

Sources: Pain remover, grease remover, dry cleaning products Exposure: inhalation, ingestion in water or food Mitigation: Regulation of the use and disposal of trichloroethylene-containing products, stop manufacturing trichloroethylene-containing products in Canada Note: IARC Group 1 for renal cancer

Question 32

What are Persistent Organic Pollutants (POP's) and what are their health impacts?

Answer 32

POP's are synthetic substances from industrial production that last int he same environment for a long time. They can biomagnify in the food chain. Health effects include disruptions in the immune system, nervous system, and endocrine system.

Question 33

List 2 health effects of polychlorinated biphenyls, 2 common sources, and 2 mitigation measures

Answer 33

Health effects: skin discolouration, hepatotoxicity, disruption in immune system, endocrine, and nervous systems Sources: electrical capacitors/transformers, flame retardant, adhesives, lubricants, plasticisers. Mitigation: Regulation to restrict the use in Canada (the Stockholm Convention global treaty to decrease or eliminate use), avoid burning treated/painted wood Note: route of exposure is usually ingestion through contaminated water or food. Accumulates in fatty tissues in animals e.g. fish

Question 34

List 2 sources of dioxins or furans, and 2 mitigation measures

Answer 34

Sources: iron and steel production, wood burning, burning solid and liquid fuels, smoking Mitigation: Avoid burning garbage, avoid burning treated wood or plastic, trim the fat before eating meat or fish Note: route of exposure is usually ingestion from milk, meat, or fish living in contaminated environments, inhalation from cigarettes are another route/source. TCDD is IARC Group1 for all sites combined

Question 35

Define radiation and ionising radiation

Answer 35

Radiation: Energy that travels at the speed of light Ionising radiation: energy that can remove an electron from an atom. For example, gamma rays, X-rays, and high energy UV rays

Question 36

Define "noise". What is the Canadian and WHO recommendation for sound limit at night? List 3 mitigation strategies for noise

Answer 36

AKA acoustical radiation; unwanted sound produced from vibrating air/water/solids Canadian and WHO recommendation is 40dB night noise limit Mitigation: bylaws for quiet hours, setback distances between highways and homes, sound barriers, traffic management, ear plugs

Question 37

What are sources of radio-frequency electromagnetic fields (RF-EMF)? Why is RF-EMF an issue of public health importance? List 2 mitigation measures against RF-EMF

Answer 37

Sources: radio, TV, microwaves, cell phones, traffic radar Health effects: mild localised heating of body tissue, EMF hypersensitivity Mitigation: decrease cell phone use, exposure limits for controlled and uncontrolled exposures in Health Canada Safety Code 6

Question 38

Define "pest"

Answer 38

Plants, animals, or microorganisms that threaten human health

Question 39

List and describe 5 elements of integrated pest management

Answer 39

Steps of integrated pest management (IMPACtEd) 1. Identification of the pest, damage 2. Monitoring - pest numbers, damages, environmental conditions 3. Prevention - plan and manage any environmental contributing factors (i.e. eliminate standing water) 4. Action Threshold - the threshold can be based on cost, damage, beneficial organisms and the environment 5. Control - methods to reduce pests to acceptable levels 6. Evaluation - evaluate the effects and effectiveness of the control measures

Question 40

List 4 types of pesticides

Answer 40

Atrazine Carbamates Pyrethroid Neonicotinoid Organophosphates

Question 41

List 4 methods of pest control and give an example of each

Answer 41

Physical - barriers, screens Chemical - pesticides (crop dusting, soil injection) and insect repellants (DEET) Mechanical - infrared Biological - predatory or parasitic insects Crops - crop rotation, pruning, pest resistant variants

Question 42

List the components of the multibarrier approach to safe drinking water

Answer 42

Legislative and policy frameworks; public involvement and awareness; Research, science and technology; Guidelines, standards and objectives Monitoring and Management Source protection; Distribution system protection; Treatment Result: clean, safe and reliable water system

Question 43

List 3 federal acts related to water protection

Answer 43

1. Canada Water Act - 2. Fisheries Act - 3. Canadian Environmental Protection Act

Question 44

Describe the role of Federal, Provincial/Territorial, and Municipal partners in protecting drinking water quality

Answer 44

1. Federal - set national guidance (Canadian Drinking Water Quality Guidelines which list physical, chemical, biological, and radiological parameters for drinking water) 2. Provincial/Territorial - oversee drinking water quality, compliance monitoring, and performance monitoring for drinking water systems 3. Municipalities: deliver drinking water, sometimes via 3rd party contracted operators. Provide the infrastructure and funding.

Question 45

Monitoring drinking water quality is important to ensure ongoing compliance. List 6 steps that should occur if a quality parameter is not met.

Answer 45

1. verify the data is accurate 2. notify appropriate authorities (ministry of health, ministry of environment) 3. re-sample 4. gather more info - are other quality parameters met? Bacti, turbidity, chlorine residuals, chemical 5. take corrective action - flush lines, increase disinfection, identify a cause 6. notify the public

Question 46

List 3 aspects of management of drinking water systems that should be in place to ensure safe water

Answer 46

1. commitment and cooperation from relevant governmental ministries (health, environment, ag, municipal waste management) 2. ensure operators are certified and have SOPs 3. Plans to deal with potential sources of contamination

Question 47

List 3 threats to source water contamination and 3 mechanisms for protection

Answer 47

Threats 1. Natural - wildlife, rainfall, slope, soil drainage, local hydrogeology 2. Anthropogenic - livestock, pesticides, mining, urban development, wastewater discharge, recreation 3. Eutrophication - influx of nutrients causing increases in algae Mechanisms for protection 1. general- restrict development near source water 2. general- prohibit recreational use 3. agriculture - regulate waste management for nearby farms 4. forestry - control erosion 5. engineering - divert storm water

Question 48

List 3 potential vulnerabilities in a water distribution system and 3 mechanisms to prevent contamination

Answer 48

Vulnerabilities 1. Water main break 2. Pipe corrosion 3. Broken service connection 4. Maintenance or cleaning Mechanisms for preventing contamination 1. Design the layout of the system so that pressure can be maintained 2. Maintain the system to prevent pipe corrosion 3. Backflow prevention devices (valves?) 4. Physical separation of the drinking water system from sewage system

Question 49

List the 7 steps of drinking water treatment

Answer 49

1. Screen - remove debris 2. Pre-chlorination - arrest bacterial growth 3. Coagulation - rapidly mix chemicals to bind large particles together 4. Flocculation - gentle mixing to increase the particle size 5. Sedimentation - suspended particles settle out 6. Filtration - filter out solids, protozoa, cysts 7. Disinfection - inactivation of pathogens - primary disinfection kills/inactivates organisms - secondary disinfection provides longer lasting treatment as water moves throughout distribution system

Question 50

List 3 types of disinfection for drinking water and 1 benefit and 1 drawback for each

Answer 50

1. Chlorination - pro: cheap, no secondary disinfection required - con: harmful byproducts 2. Ozone - pro: high capacity, removes taste and odour - con: expensive, requires secondary disinfection 3. UV Radiation - pro: simple/easy to maintain, no chemicals - con: requires pre-treatment filtration and secondary disinfection

Question 51

List 3 common disinfection byproducts, their source and 1 health effect for each.

Answer 51

1. Choramine - Source: monochloramine secondary disinfection (reaction between chlorine and ammonia) - Health effects: N/A 2. Trihalomethanes - Source: chlorination - Health effects: Liver toxicity 3. Haloacetic acids - Source: Chlorination - Health effects: Liver cancer 4. Bromate - Source: Ozone - Health effects: testicular mesothelial cancer 5. Chlorate: - Source: Chlorine dioxide - Health effects: thyroid colloid depletion

Question 52

List 4 things that should be on a drinking water advisory

Answer 52

1. What: contaminant, cause 2. When: start/anticipated end 3. Where: areas impacted 4. How: boil water vs. do not consume/use

Question 53

List 2 reasons why a boil water advisory might be issued

Answer 53

1. Positive test result 2. Precaution if there was an issue with the distribution system or maintenance

Question 54

List 3 criteria for rescinding a boil water advisory

Answer 54

1. Two consecutive negative bacteriological samples taken 24h apart 2. Operational failures are corrected 3. Cluster/outbreak has ended with incidence of cases returning to background levels

Question 55

List 2 differences between Do Not Consume and Do Not Use water advisories and give an example of a hazard that would trigger each.

Answer 55

1. Reason for advisory: Do not consume advisories are indicated when the contaminant will not be removed by boiling. Do not use advisories are indicated when dermal or inhalation exposures are of concern 2. Action: with Do Not Consume advisories, water can be used to shower and flush toilets but not for preparing food or brushing teeth. With Do Not Use advisories, water cannot be used for any domestic purposes 3. Do Not Consume example: water lead levels above the MAC Do Not Use example: gasoline spill into the source water

Question 56

Health Canada authors the Canadian Drinking Water Quality Guidelines to ensure safe, clean, and reliable water. Describe the 4-3-2-1-0 process guideline for water treatment

Answer 56

4 log reduction in viruses 3 log reduction in protozoa such as Giardia or cryptosporidium 2 treatment processes such as disinfection and filtration < 1 NTU turbidity with the target of 0.1NTU 0 fecal coliforms, total coliforms, and e.coli

Question 57

List 3 criteria for classification as a drinking water contaminant, according to the Canadian Drinking Water Quality Guidelines

Answer 57

1. Exposure could lead to adverse health effects 2. Contaminant frequently detected in drinking water in Canada 3. Could expect to detect at a level of possible health significance

Question 58

1. What is cyanobacteria and why is it an important public health issue? 2. List 4 possible control measures against cyanobacteria

Answer 58

1. Naturally occurring microorganisms that pose threat to health in recreational and drinking water due to the production of cyanotoxins. People can be exposed to cyanotoxins by dermal contact (e.g. swimming) which can lead to rashes and irritation. Exposure by ingestion can also occur (water, shellfish with PSP toxin) which can lead to acute GI illness and acute neurologic symptoms (headache, paralysis) 2. E's Engineering - decrease nutrient load in the water by diverting storm water, setback distances from farms Engineering - treat contaminated water with ultrafiltration, oxidation, or activated charcoal) Education - No swimming signs Environmental - Do not consume advisories Enforcement - Close beaches

Question 59

Biofilms can provide an environment for microbial growth on water pipes leading to corrosion, bad taste and odour, and contamination with Legionella pneumophilia and pseudomonas. List 3 measures to mitigate the risk of bacteriological contamination in drinking water from biofilms in the distribution system.

Answer 59

1. Nutrient control in the source water 2. Prevent back flow 3. Increase disinfectant residuals 4. Corrosion control

Question 60

Community Water Fluoridation is a contentious issue. The main community-level benefits come from protecting children from dental caries, especially children living in poverty who might not have access to private-pay preventative dental care. List 4 considerations for an ethical analysis of CWF.

Answer 60

1. Equity - CWF will close the gap in dental health between children living in lower income and higher income households 2. Autonomy - Individuals are unable to choose to have fluoride in their tap water, however can choose to filter out. 3. Least restrictive means - consider other policy/program alternatives to accomplish the same outcome such as topical fluoride varnish programs for high-risk children. 4. Harm principle - The health benefits (prevention of dental caries) are expected to outweigh harms (possible dental fluorosis) when water fluoride levels are kept below the MAC of 1.5 micrograms/L as systemic harms such as skeletal fluorosis are only seen at much higher concentrations.

Question 61

What are the top 4 causes of death from occupational exposures?

Answer 61

1. Cancers 2. CV disease 3. Respiratory disease 4. Unintentional injury

Question 62

List 3 rights of workers denied in the Occupational Health and Safety Act

Answer 62

1. Right to know the risks 2. Right to participate 3. Right to refuse unsafe work

Question 63

List the 4 top occupational cancers by incidence

Answer 63

1. Lung - diesel exhaust, PM2.5, asbestose, crystalline silica, arsenic, radon 2. Bladder - Arsenic, aromatic amines 3. Mesothelioma - asbestos 4. Skin - UV radiation, ionising radiation, arsenic (5. Leukemia - benzene, formaldehyde, radiation) (6. Liver - vinyl chloride, arsenic)

Question 64

List 5 categories of occupational hazards and one example of each

Answer 64

1. Physical - noise, falls 2. Chemical - inhalation of formaldehyde 3. Biological - exposure to microorganisms such as Hep B 4. Radiation - UV radiation and burns from working outside 5. Ergonomic - repetitive stress injury 6. Psychological - workplace harassment

Question 65

List the 5 Meredith Principles for WCB

Answer 65

SINCE acronym 1. Security off benefits - employees continue to be paid 2. Independent administration (non-governmental) 3. No fault compensation - benefits are paid regardless of who is at fault 4. Collective liability - all employers contribute to one system 5. Exclusive jurisdiction - only workers compensation organisations can provide insurance (no competitors allowed)

Question 66

1. What is the AQHI? 2. What are the AQHI recommendations at each risk level? 3. What is the threshold for issuing an air quality advisory?

Answer 66

1. Air Quality Health Index (AQHI) is a scale used to communicate health risk (excess mortality) from acute pollution exposure. It is calculated using a weighted sum of PM 2.5/10, NO2, and ground level ozone. - Each increase in unit corresponds to a 1% increase in daily mortality. - Recommendations are categorized for the general population and "at risk" population. - The at risk population includes people with DM, CVD, Resp disease, children, and seniors 2. Recommendations AQHI 1-3 Low risk: General pop - ideal for outdoor activities. At risk - enjoy usual activities AQHI 4-6 Moderate risk: general pop - no need to modify usual activities unless Sx. At risk - consider rescheduling or reducing outdoor activities if Sx AQHI 7-10 High risk: General pop - consider reducing outdoor activity if symptoms occur. At risk - reduce or reschedule outdoor strenuous activity. AQHI >10 Very high risk: General pop - reduce or reschedule outdoor activity, esp if Sx. At risk - avoid strenuous outdoor activity 3. Advisory if 7+ for 3h Special air quality statement of 7+ for 1-2h

Question 67

List 3 limitations of the AQHI

Answer 67

1. Assumes additive effect of of three pollutants, opposed to synergistic 2. Assumes all people are exposed to the same level of pollution within a geographic area 3. Only accounts for acute exposure and mortality; doesn't assess chronic risk 4. Does not take into account morbidity 5. Unclear validity in rural settings

Question 68

List 6 examples of control measures to decrease fuel emissions.

Answer 68

Engineering - stack standards for industrial facilities, wet scrubbers and filters, fuel modification, public transportation infrastructure, active transport infrastructure Education - public awareness of the health (and environmental) impacts of emissions, public awareness on ways to decrease personal pollution Economic - carbon tax, affordable/accessible public transit Enforcement and legislation - Create idle-free zones, develop standards for vehicle emissions, reduce speed limits, cap and trade legislation for industrial emitters Empowerment - encourage carpooling, generate public support

Question 69

List 3 important methods of improving indoor air quality

Answer 69

1. Source contro 2. Ventillate 3. Filter

Question 70

List 3 common sources of indoor air contamination

Answer 70

1. indoor combustion 2. product residue e.g. furniture off-gassing 3. outdoor air

Question 71

List 3 common contaminants of indoor air and a source for each

Answer 71

1. Particulate matter - wood-burning furnace 2. Carbon monoxide - gas cookers/stoves 3. VOCs - photocopiers, paints Ozone - photocopiers, electrostatic air purifiers Formaldehyde - furniture, carpet Dust mites - carpet, foam furniture cushions Mould - leaky water pipes

Question 72

List 5 potential interventions to mitigate mould growth indoors

Answer 72

1. Economic - financial incentives for landlords to maintain homes 2. Engineering - increase ventilation with fans and open windows 3. Environmental - dehumidifier 4. Environmental - remove mould as soon as it is detected 5. Enforcement - inspection for proper construction and maintenance

Question 73

What is radon and why is it an issue of public health importance?

Answer 73

Radon is a colourless, odourless radioactive gas emitted from rocks. It is a breakdown product of naturally occurring uranium. It is important because it is a known carcinogen for lung cancer, with about 16% of lung cancer deaths attributed to radon in Canada.

Question 74

What is the threshold and target for radon remediation?

Answer 74

200 Bq/m^3 average annual concentration in normal occupancy areas. Note: 7% of Canadian homes exceed this limit Remediation target: ALARA

Question 75

What is the Air Quality Management System (AQMS)?

Answer 75

Comprehensive and collaborative approach by F/P/T governments to reduce emissions and ambient concentrations of various pollutants of concern. Framework for collaboration action across Canada to protect human health and the environment from harmful air pollutants through continuous air quality improvements.

Question 76

Describe the purpose of the Canadian Ambient Air Quality Standards (CAAQS).

Answer 76

Standards to drive improvement in outdoor air quality in Canada. These standards are established as objectives in the Canadian Environmental Protection Act. Standards have been developed for the following pollutants: fine PM (PM2.5), ozone, nitrogen dioxide, and sulphur dioxide for a variety for averaging time periods (annual, 24h, 8h, 1h). https://ccme.ca/en/air-quality-report#slide-7

Question 77

List 4 mechanisms for improving outdoor air quality, outlined in the AQMS.

Answer 77

1. Air zone management: a place-based approach to air quality mgmt 2. Air shed coordination: coordination in the 6 regional air shed areas in Canada allowing for joint action on pollutants that move between provinces and territories. 3. Mobile sources: Addressing emissions from the transportation sector 4. Industrial emissions: BLIERs (base-level industrial emission requirements) established by industry and equipment type for PM, NOx, SO2, VOCs

Question 78

List 2 examples of regulatory legislation to decrease emissions at the federal, provincial, and municipal level each.

Answer 78

1. Fed - Canadian Environmental Protection Act regulates vehicle emissions, allowable fuels for vehicles, railways, and marine vessels 2. P/T- Air quality standards and guidelines, Air Shed management plans 3. Municipal - bylaws to create idle-free zones, transportation infrastructure planning

Question 79

The US EPA has established Airborne Exposure Guideline Levels (AEGLs) which state toxicity thresholds for acute exposures to airborne hazards. Describe the difference between the 3 AEGL levels

Answer 79

AEGL-1: symptoms are transient and not disabling AEGL-2: symptoms are irreversible or serious AEGL-3 symptoms are lifethreatening

Question 80

List the top 4 food-borne illnesses by incidence

Answer 80

1. Norovirus 2. C. perfringens 3. Campylobacter 4. Salmonella

Question 81

List the top 4 causes of food-borne illness hospitalisation

Answer 81

1. Norovirus 2. Salmonella 3. Campylobacter 4. E. coli

Question 82

List the 4 top causes of food borne illness deaths

Answer 82

1. Listeria 2. Norovirus 3. Salmonella 4. E. coli

Question 83

List the 3 top pathogens detected from food samples

Answer 83

1. Campylobacter 2. Salmonella 3. Listeria

Question 84

List the top 3 pathogens detected in water

Answer 84

1. E. coli (STEC) 2. Campylobacter 3. Salmonella

Question 85

List the top 2 pathogens detected on farms

Answer 85

1. Campylobacter 2. Salmonella