Environmental Health Flashcards
List 3 triggers of a food safety investigation
food borne illness outbreak food test result food inspection result consumer complaint company initiated international recall
What is radon?
A colourless odourless gas that is naturally occurring and a product of uranium decay from soil and rocks
List 3 ways radon gets into the home
cracks in basement/foundation dirt floors well water basement windows sumps and drains
Answer the following regarding fluoride:
a) Maximum Allowable Concentration (MAC)
b) What is the MAC based on?
c) What is the optimal level in water?
d) Approximately what proportion of Canadians have access to fluoridated tap water?
a) MAC = 1.5ppm
b) dental fluorosis (cosmetic)
c) optimal level = 0.7ppm
d) ~50%
Does 1mg/L = 1ppm or 1ppb?
1mg/L = 1ppm 1mcg/L = 1ppb
What is the MAC for lead in drinking water as per the Guidelines for Canadian Drinking Water Quality?
5ppb (note: 10ppb in ON)
List 5 potential sources of lead exposure in Canadian population
- drinking water (lead pipes, lead solder)
- lead paint (chips consumed by children)
- contaminated soil and/or food
- shooting ranges
- lead smelters
- some imported products (some medicines)
List the International Agency for Research on Cancer (IARC) categories and a description for each.
1 - carcinogenic 2a - probably carcinogenic 2b - possibly carcinogenic 3 - not classifiable 4 - probably not carcinogenic
List and briefly describe the four steps in a cancer cluster investigation.
Initial contact and response: Is there evidence that the situation presented fits the definition of a cluster and is it biologically plausible that the cancers share a common etiology? Use risk communication tools to communicate the response to the community member, who may be distressed
Assessment: Determine whether the suspected cancer cluster is a statistically significant excess; calculating the standardized incidence ratio is recommended (observed/expected); develop a communications plan
Determine the feasibility of conducting an epidemiologic study: Identify hypotheses; involve partners; consider whether an expert advisory panel is required; if a study is feasible, propose a study design; continue the communications plan
Conduct an epidemiologic study to assess the association between cancers and environmental causes: Correlation does not imply causation; determination of causation should also rely on clinical and laboratory studies
What are 3 defining criteria of a cancer cluster?
- greater number than expected
- all cases must involve same cancer type, or types proven to have the same cause
- carefully defined population by age, gender, etc.
- carefully defined geographical boundary
- over a period of time (<5 years of data = useless for baseline)
List the 5 parts of the ‘multi-barrier approach’ to safe drinking water
- source protection
- treatment
- securing distribution system
- monitoring
- responses to adverse conditions
Alternative
an integrated system of procedures, processes
and tools that collectively prevent or
reduce the contamination of drinking water from source to tap in order to reduce risks to public health.
Legislative and Policy frameworks
- who is responsible for each aspect of the drinking water system and their specific
responsibilities.
Research Science and Technology
- Research, disease surveillance, and associated science and technology development serve core functions in the multi-barrier approach.
Public Involvement and Awareness
- public be aware that they can report concerns to the appropriate authority.
Guidelines Standards and Objectives
- provide utility managers and system
owners with drinking water quality targets to strive to achieve within. These targets are closely linked to monitoring results
Monitoring
- qualified personnel to run the various aspects of the
system and plans in place to manage incidents and adverse events
Management
- Water quality monitoring takes place throughout the system for a number of reasons.
Source Water Protection
Drinking Water Treatment
Drinking Water Distribution System
List three concerns related to cyanobacterial blooms
- microcystins -> drinking water, potential liver toxicity
- direct irritation
- eutrophication and oxygen starvation of waterbody
- animal illness (livestock, pets)
- aesthetic
What are three different types of disinfection methods for drinking water? List one limitation for each.
- chlorination - limited effectiveness against protozoa
- UV - no secondary residual
- ozone - no secondary residual
What are four interventions to reduce lead exposure from an indoor firing range
Elimination
- encourage use of lead free ammunition
Engineering
- ensure ventilation is adequate
Administrative
- eating and drinking should not occur at the range
- Ensure proper cleaning of range (i.e. range should be cleaned using wet moping technqiues rather than dry techniques that may aerosolize lead containing dust)
PPE
- clothing and shoes should be changed after shooting and not brought back to the house of volunteers or participants before should be
List 3 groups at increased risk of head related illness
Elderly Very young children People with chronic conditions (eg. cvd, resp) People who work outdoors Homeless
List 4 components of a Heat Response Plan
- Suveillance and alert system
- Communication plan - public and stakeholders
- Response activities - cooling centres, access to water
- Evaluation
What is the air quality health index?
A tool for summarizing local air quality conditions for the purpose of health messaging.
Which air pollutants are included in the AQHI?
PM 2.5, O3, NO2
What are 4 limitations of the AQHI?
Doesn’t account for other pollutants (only PM2.5, O3, NO2)
Assumes additive effect
Unknown relationship with chronic exposure
Doesn’t account for importance of spatial location in exposure
Based on urban locations only
Limited evidence on benefits from messaging
What are the 3 pollutants associated with Traffic related air pollution?
PM2.5
NO
NO2
What are some mitigation strategies to reduce exposure to TRAP?
Buffer zone between major arteries and LTCH, schools, daycares
decrease commute times/ distances
physical activity away from busy roads
restrict diesel fuelled vehicles
decrease vehicle usage, and decrease barriers for active transport
List 4 surveillance methods for West Nile Virus.
- Mosquitoes
- Horses
- Birds
- Human
List 5 ways to reduce your risk of WNV
- Use insect repellents containing chemical DEET or icaridin on your skin and clothing when outside
- Cover exposed skin when outside including long pants, long-sleeve loose-fitting shirts, socks, hats +/- mosquito net on hat
- Avoid outdoor activities when mosquitoes most active (at dawn (first light) and dusk (just before dark)).
- Get ride of standing water around your home
- Install screen on your windows and doors to keep mosquitoes out of your home.
List 5 ways to reduce your risk for Lyme Disease
- Don’t venture into wooded or forested areas within risk areas for Lyme disease;
- Walk on cleared paths or walkways;
- Wear light coloured long-sleeved shirts and pants to spot ticks more easily and tuck your shirt into your pants, and pull your socks over your pant legs;
- Use insect repellent containing DEET or Icaridin on your skin and clothing (always follow the directions on the label)
- Shower or bathe within two hours of being outdoors to facilitate a prompt tick check and to remove ticks that have not attached yet
- Do a daily full-body check for ticks on yourself and your children, especially in the hair, in and around the ears, under the arms, inside the belly button, behind the knees, between the legs and around the waist
- Do a tick check on your outdoor gear and your pets as they could carry ticks inside your home
- Put dry outdoor clothes in a dryer on high heat for 10 minutes to kill any remaining ticks. If your clothes are damp, additional drying time is needed. If you need to wash your clothes first, hot water is recommended. If the clothes cannot be washed in hot water, tumble dry on low heat for 90 minutes or high heat for 60 minutes.
What is Lyme Disease prophylaxis? When do you consider giving a patient Lyme Disease prophylaxis?
Prophylaxis is a single dose of 200 mg of doxycycline for adults and children >=8yo
4 criteria usually have to be met for prophylaxis:
- The tick can be reliably identified as a blacklegged tick and is estimated to have been attached for > 36 hours * Note >24 for Ontario guideline. (i.e. degree of engorgement or by certainty of when the individual was bitten)
- Prophylaxis can be started within 72 hours after the feeding tick has been removed.
- Doxycycline not contraindicated (e.g. not recommended for pregnant women and children < 8yo)
- The local rate of Borrelia burgdorferi infection in ticks is >20% (check with local public health).
What are the stages of Lyme Disease ?
There are three stages to Lyme Disease:
- Early localized lyme disease
- Early disseminated lyme disease
- Late disseminated lyme disease
What is erythema migrans? What is the treatment?
- EM is a typical rash > 5 cm caused by blacklegged tick bites that is infected with the bacteria Borrelia burgdorferi within prior 30 days. Aka Early localized lyme disease
- Doxycycline PO BID x 14-21 days
What are three chemical in pressure treated wood?
List a health complication for each chemical
Chromium - IARC 1 - lung Cancer, also causes skin ulcers
Arsenic - IARC 1 Bladder Cancer
Coper - liver damage (intentional ingestions)
