Download B2B_Occupational__Environ_health M Afanasyeva

Back to Basics, 2016
POPULATION HEALTH
Environmental & Occupational Health
Marina Afanasyeva
MD, MPH, PhD, Public Health & Preventive Medicine PGY4
Based on the previous lectures by Drs. M. Maher, B. Pinard, G. Dunkley, R. Spasoff, and N. Birkett
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MCC Objectives: Population Health
78-6 Environment
Rationale:
• Environmental issues are important in medical practice because
exposures may be causally linked to a patient's clinical presentation and
the health of the exposed population. A physician is expected to work
with regulatory agencies and allied health professionals (e.g.,
occupational hygienists), where appropriate, to help implement the
necessary interventions to prevent future illness. Physician involvement
is important in the promotion of global environmental health.
© The Medical Council of Canada, 2016
Version Dec 2012
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MCC Objectives: Population Health
78-6 Environment
Key Objectives:
• Recognize the implications of environmental hazards at both the
individual and population level.
• Respond to the patients concerns through appropriate information
gathering and treatment.
• Work collaboratively with local, provincial and national
agencies/governments as appropriate to address the concerns at a
population level.
• Communicate with patients, communities, and employers, where
appropriate, concerning environmental risk assessment
© The Medical Council of Canada, 2016
Version Dec 2012
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MCC Objectives: Population Health
78-6 Environment
Enabling objectives
• Identify common environmental hazards and be able to classify them into the
appropriate category of chemical, biological, physical and radiation.
• Identify the common hazards that are found in air, water, soil and foods.
• Describe the steps in an environmental risk assessment and be able to critically
review a simple risk assessment for a community.
• Conduct a focussed clinical assessment of exposed persons in order to
determine the causal linkage between exposure and the clinical condition.
• Be aware of local, regional, provincial and national regulatory agencies that can
assist in the investigation of environmental concerns.
• Describe simple interventions that will be effective in reducing environmental
exposures and risk of disease (e.g. sunscreen for sunburns, bug spray for
prevention of West Nile Virus infection).
• Communicate simple environmental risk assessment information to both
patients and the community.
© The Medical Council of Canada, 2016
Version Dec 2012
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Environmental Hazards
• Environmental exposure:
– Natural and human-made environment
– Reservoirs: air, water, soil, food
– Route: inhalation, ingestion, absorption
– Exposure setting:
• Workplace: occupational health (high level exposure,
acute or chronic)
• Outside workplace: environmental health (low level
exposure, chronic)
March 2016
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Hazards in Air
Physical contaminants
• Radiation: Radon (lung cancer), UV (skin cancer)
• Sound waves (hearing loss)
Chemical contaminants
• Ozone at ground level (worsens asthma)
• Sulphur dioxide (SO2); nitrogen dioxide (NO2)
(respiratory irritants)
• Carbon monoxide (CO) (asphyxiation, headache)
• Organic compounds: benzene (carcinogen – leukemia)
• Second-hand tobacco smoke (lung cancer)
• Heavy metals; industrial emissions
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Hazards in Air
Biological contaminants:
• Bacteria: Legionella pneumophila (Legionnaires’
pneumonia, Pontiac fever)
• Dust mites (allergies)
• Moulds (allergies)
• Particulates (pollen, spores) (allergies, asthma)
Global warming-related:
• Extreme weather (heat waves), change in distribution
of vectors of disease, crop failures, etc.
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Hazards in Water
Biological agents:
• Viral: Novovirus, hepatitis A virus
• Bacteria: E. coli, Salmonella, Pseudomonas
• Protozoa (cysts): Giardia, Cryptosporidium (GI
symptoms mainly)
• Blue green algae (skin irritation, GI symptoms)
• Higher risk: Aboriginal Canadians, rural population
Chemical agents:
• Volatile organic compounds (VOC), pesticides, heavy
metals, other waste from industries (effects depend on
contaminant)
• Chlorination by-products - trihalomethanes (THM)
(cancer)
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Hazards in Soil
Chemical agents:
• Pesticides, petroleum hydrocarbons, solvents, motor
oil, lead (effects depend on contaminant)
• Higher risk: infants/toddlers
Biological agents:
• Bacteria (tetanus)
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Hazards in Food
 Biological Contaminants
• Viruses: Norovirus (gastroenteritis; #1 cause), hep A virus
• Bacteria:
• Campylobacter - raw poultry (diarrhea, maybe bloody)
• Salmonella - raw eggs, poultry, meat (diarrhea, maybe bloody)
• E. coli - hamburger meat (diarrhea, HUS)
• Listeria monocytogenes (listeriosis)
• Toxins: Clostridium botulinum (botulism); B. cereus; aflatoxin
• Parasites: Cyclospora cayetanesis (fresh fruits and vegetables)
• Prions: BSE
 Chemical Contaminants
• PCBs, dioxins/furans, pesticide residues (DDT), mercury
• Food additives: nitrites, sulfites (allergy)
• Drugs given to livestock: antibiotics, hormones
 Physical: foreign objects, such as stones, bone fragments, glass, staples
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Environmental Risk Assessment
Process of evaluating the likelihood of occurrence
and probable severity of health effects due to a
hazard
Done by: occupational health agencies,
environmental protection agencies, public health
authorities, clinicians
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Health Risk is the result of the interaction of
Hazard, Exposure, and Susceptibility
(each component is necessary)
Exposure
Hazard
Risk
Susceptibility
Individual
characteristics
Steps in Risk Assessment
1. Hazard identification: Is an environmental hazard involved? What is it?
What health problem does it cause?
2. Hazard (risk) characterization: How does it cause these symptoms in
this type of patient?
– dose-response
– toxicology
3. Exposure assessment: Is the patient’s exposure enough to cause these
symptoms? Magnitude, frequency, duration, route, etc.
4. Risk estimation:
Individual level: How much has the hazard contributed to the patient’s
condition?
Population level: How much extra risk of the condition in the
population is attributable to the exposure?
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Hazard Identification:
Workplace Hazardous Material Information System (WHMIS)
Canada's national hazard communication standard; the key
elements of the system are
• Hazard classification
• Labelling of containers
• Provision of (material) safety data sheets ((M)SDSs)
•
•
•
•
•
Identification: for the product and supplier
Hazards: physical (fire and reactivity) and health
Prevention: steps to reduce or prevent exposure, or in an emergency
Response: appropriate responses in various situations (e.g., first-aid)
http://www.ccohs.ca/oshanswers/chemicals/whmis_ghs/sds.html
• Provision of worker education and training programs
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WHMIS 2015 Uses 9 of These 10 Symbols
Except for this
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Hazard Identification:
International Agency for Research on Cancer (IARC)
Classification of Carcinogens
• Group 1
Carcinogenic to humans (117 agents)
– Arsenic, asbestos, benzene, diesel engine exhaust, radon
• Group 2A Probably carcinogenic to humans (74 agents)
• Group 2B Possibly carcinogenic to humans (287 agents)
• Group 3
Not classifiable (503 agents)
• Group 4
Probably not carcinogenic to humans (1 agent)
Final Step in Risk Assessment:
Risk Estimation
Probability of harm and the estimate of the
magnitude of harm given
•this particular exposure
•to this particular hazard
•in this particular individual
(or a group of individuals)
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Dosis facit venenum
• What is there that is
not poison? All things
are poison and
nothing without
poison. Solely, the
dose determines that
a thing is not a poison.
– Paracelsus (1493-1541)
Adopted from the lecture by Michael A. Trush.
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Toxicokinetics
• What happens to the toxicant!
• Time course of toxicants in the body during the
processes of absorption, distribution, metabolism
(biotransformation), and excretion (clearance) or
storage (ADME)
• The end result of these toxicokinetic processes is a
biologically effective dose of the toxicant
• It is a part of the exposure assessment
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Toxicodynamics
• What happens to the human body!
• The molecular, biochemical, and physiological
effects of toxicants or their metabolites in
biological systems
• It is a part of the hazard characterization
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Environmental History
A part of hazard identification and exposure
assessment
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Clues to Environmental Causes
• Clues that illness is caused by environmental factors:
– Patient suspects it
– Illness pattern is atypical (absent usual risk factors, unusual age
group or course, no response to treatment)
– Temporal pattern of illness (weekends/weekdays,
holidays/home)
– No obvious other cause
– Signs/symptoms suggest specific agent
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Environmental history - CH20PD2
•
Community: neighborhood sources of hazard; industry, waste storage
•
Home: year of construction, renovations; materials used in construction and
decoration; moulds; garden and house plants; use of cleaning products, pesticides,
herbicides
•
Hobbies and leisure: exposure to chemicals, dusts, or micro-organisms
•
Occupation: current and previous occupations; longest occupation; work with
known hazards; air quality; use of PPE
•
Personal habits: hygiene products; smoking; recreational drugs
•
Diet: sources of food and water; cooking methods; food fads
•
Drugs: prescription, non-prescription, and alternative (naturopathic, Ayuverdic);
health practices
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Focused Environmental History
• If a scanning question reveals a possible hazard, ask detailed
questions about the nature and level of the hazard and then
check:
• Time: When did symptoms begin? When did exposure begin?
When do symptoms get worse? When do they improve?
• Place: Where is the patient when symptoms get worse?
Where is the likely hazard? What is the channel through
which the hazard reaches the patient?
• Person: Does anyone else have similar symptoms? Who?
When? Where?
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Environmental Health Jurisdiction
– Local (or Regional) Public Health
• Enforcement of water and food safety regulations, sanitation, local hazard
assessment, reportable diseases
– Municipal
• Garbage disposal, recycling
– Province/territory
• Toxic waste disposal, air/water standards
• Ontario Ministry of the Environment (monitors air quality across ON)
– Federal
• Health Canada - food regulations, designation and regulation of toxic substances
• CFIA (Canadian Food Inspection Agency) – enforcement of regulations
• Environment Canada - The Asbestos Mines and Mills Release Regulations
– International
• Multilateral agreement (Kyoto Protocol)
•
Whom to ask
• Local public health - Ottawa Public Health (613) 580-6744 – environmental exposures
• Ontario Ministry of Labour – occupational hazards
• Poison Control Centre - specific toxicants
• Motherisk – effects on fetus
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Risk management
• Interventions to reduce environmental exposures:
– Carbon monoxide: CO home detector
– Salmonella: well-cooked poultry and eggs, safe food handling
– Listeria: avoidance of unpasteurized cheese for pregnant
women
– West Nile Virus: bug spray
– UV light: sunscreen, sunglasses, shade, hat, long sleeves
– Radon: ventilation, air exchanger, radon test kits
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Risk Communication
• Important to allow people to understand the
risk and take action to reduce risk
• Elements of communication:
o Message
o Messenger (meaning)
o Encoding
o Channel
o Decoding
o Recipient (understanding)
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Risk Perception:
Risk = Hazard + Outrage
• Factors increasing perception of danger:
– Characteristics of exposure:
• Involuntary; not under personal control
• Unnatural; unfamiliar
• No trust in institution involved; media attention
– Characteristics of outcome:
• Catastrophic (not chronic); immediate; irreversible
• Unknown, uncertain outcome, dreaded outcome
• Affect children or identifiable people
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UV Index
WHO, 2002, Global Solar UV Index
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UV Index Specifics
•
The UV Index that is reported as part of the weather forecast is the highest
expected value for the day
•
UV rays can cause sunburns, eye cataracts, skin aging, and skin cancer (SCC; BCC;
melanoma)
•
Highest in the early afternoon (about 1:30 PM Eastern Daylight Saving Time in
Southern Ontario) and during the months of June and July
•
Avoid the mid-day sun (between 11 AM and 4 PM)
•
If you must be outside, seek shade, wear sunglasses, use sunscreen, if possible
cover up with lightweight clothing and wear a hat
•
Sunscreen products with SPF 15 are recommended for daily use
•
Broad spectrum products (protective against UVA (320-400 nm) and UVB (290-320
nm)) with SPF30 or higher are recommended for individuals performing outdoor
work, sports, or recreational activities
What is the diagnosis?
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Air Quality Health Index
• Public health information tool developed by
Health Canada and Environment Canada
• Support decision-making about activity levels
during increased levels of air pollution
• Calculated based on:
• Ozone (O3) at ground level
• Particulate Matter (PM2.5/PM10)
• Nitrogen Dioxide (NO2)
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Health Risk
Low Risk
Moderate
Risk
High Risk
Air Quality
Health Index
General Population
Enjoy your usual
outdoor activities.
Ideal air quality for outdoor
activities.
4-6
Consider reducing or
rescheduling strenuous
activities outdoors if you
are experiencing
symptoms.
No need to modify your
usual outdoor activities
unless you experience
symptoms such as coughing
and throat irritation.
7-10
Reduce or reschedule
strenuous activities
outdoors. Children and
the elderly should also
take it easy.
Consider reducing or
rescheduling strenuous
activities outdoors if you
experience symptoms such
as coughing and throat
irritation.
Avoid strenuous
activities outdoors.
Children and the elderly
should also avoid
outdoor physical
exertion.March 2013
Reduce or reschedule
strenuous activities
outdoors, especially if you
experience symptoms such
as coughing and throat
irritation.
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1-3
> 10
Very High
Risk
At Risk Population
The Lancet 2014 383, 1581-1592 (Copyright @ 2014 Elsevier Ltd)
Occupational Medicine
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MCC Objectives:
78-8 Work-Related Health Issues
• Key Objective:
• Given a patient with a health problem, the candidate
will evaluate the possible workplace etiological
factors, to assess the contribution of occupational
exposures for the most common pathologies, to
assess the impact of the condition on the ability to
work, and develop an appropriate management plan.
Particular attention should be paid to the
identification of occupational risks for the patient
and his/her co-workers.
© The Medical Council of Canada, 2016
Version Feb 2014
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MCC Objectives
Causal Conditions (list not exhaustive)
• Ergonomic hazards (mechanical)
– e.g. awkward postures and movements, poor lighting; repetitive strain
• Chemical hazards
– e.g. organic solvents, metals, asbestos, toxic gases
• Physical hazards
– e.g. noise, vibration, radiation
• Biological hazards
– e.g. blood or other body fluids, animal and bird droppings
• Psychological and work organization hazards
– e.g. workplace stressors, workplace bullying; high demand/low control
© The Medical Council of Canada, 2016;
version Feb 2014
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MCC Enabling Objectives
Version Feb 2014
Given a worker with a health problem, the candidate will list and interpret critical clinical findings, including:
•
•
•
•
•
•
•
•
•
•
•
•
•
perform a history and focused physical examination to identify the illness and determine the possible
relationship of symptoms to work;
identify hazards in the workplace that could have had an impact on the health problem (work and
exposure history);
identify protective equipment being used and environmental controls that are in place;
identify non occupational factors that could influence the condition.
list and interpret critical investigations, including:
appropriate laboratory or radiologic investigations depending on the presenting health problem (e.g. chest
radiography, ultrasound);
physiologic and/or functional assessments (e.g. PFTs , audiograms, occupational therapy assessment).
construct an effective initial management plan, including:
initiate specific therapy as required for the health problem;
determine whether the patient should be assigned to a different work, or stop work and advise the patient
on this topic;
determine follow up care and whether further consultation, counselling and/or a multi-disciplinary
approach to care is needed;
advise the patient on workers compensation;
advise the relevant authorities if necessary (notifiable disease, reporting a dangerous situation).
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Occupational Medicine (OM) in MCCQE Part 1
• As a primary question
• Integrated into options for other questions
• Think about classic occupational skin and lung issues
• Also think about other domains in which OM can play a role,
such as psychiatry, and also specific conditions which have
occupational causality such as abnormal liver
enzymes/function tests, fatigue, hypertension etc.
• For a sampling of “hot topics” in OM, go to the Scientific
American website and type Occupational Medicine in the
search box
Types of clinical scenarios that may involve
occupational exposure
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Cough
Hand and wrist injuries; overuse tendinopathies (DeQuervain’s tenosynovitis)
Numbness / tingling / altered sensation
Fatigue (shiftwork; CO exposure)
Allergic reactions and atopy (occupational asthma)
Altered hemoglobin levels (anemia in lead poisoning)
Syncope and pre-syncopy (heat)
Dysmenorrhea
Proteinuria
Sleep disorders
Bone or joint injury
Back pain
Neck pain
Poisoning
Prenatal care
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Occupational Health as a Public Health Concern
• Most of the world’s population (58%) spend 1/3 of their adult
life at work (WHO 1994)
• Canada
• 920 work place deaths in 2001; 919 in 2014
• 1 of 68 employed workers in 2010 was injured/harmed on the job and
received workers compensation as a result
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Occupational Health Outcomes
• The most significant chemical exposures tend to be solvents
and heavy metals:
– Most solvents cause CNS depression, irritation and
dermatitis
– Some solvents causes PNS, hepatic and/or renal toxicity
– Heavy metals primarily cause CNS, PNS, haem, and renal
toxicity
This material is courtesy of Aaron Thompson, MD, MPH, FRCPC
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Occupational Health Outcomes
•Many chemical and biological exposures can cause allergy
resulting in:
o Asthma (occupational or work-exacerbated)
18% of asthma is work related
If true allergy – sensitizer-induced asthma (vs. irritantinduced asthma)
Skin prick testing (immediate hypersensitivity type I)
o Allergic contact dermatitis (vs irritant contact dermatitis)
Patch testing (delayed hypersensitivity type IV)
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Occupational Health Outcomes
• Approximately 10% of all cancers are occupational
– Common occupational cancers are lung, bladder,
and mesothelioma
– Common occupational carcinogens are asbestos,
polyaromatic hydrocarbons (PAHs), and aromatic
amines
This material is courtesy of Aaron Thompson, MD, MPH, FRCPC
44
Table 10.5: Some examples of occupational disease
Condition
Agent
Berylliosis
Byssinosis
Beryllium
Cotton dust (numerous
agents)
Mould in hay
Asbestos
Farmer’s lung
Asbestosis,
Mesothelioma
Hepatitis A
Silicosis
Hepatitis A virus
Silica dust
Example of at risk
occupation
Aerospace industry
Cotton industry
Farming
Demolition work; ship-building
Sewer workers
Stone workers
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Asbestos
• Pulmonary fibrosis (asbestosis) – exertional dyspnea and bibasilar
end-inspiratory rales
• Localized and diffuse pleural thickening, rounded atelectasis,
mesothelioma, and lung cancer; may be associated with cancer at
extra-thoracic sites
• Most important route of exposure is inhalation
• Miners, shipbuilding facility workers, demolition worker
• Asbestos in the air adheres to work clothing, even if the clothes are
brushed
• Cleaning of clothes at home liberates asbestos fibers and has been
shown to cause cancer in family members (para-occupational
disease)
46
Noise-induced hearing loss
• High-frequency sensorineural loss
• Usually is similar in both ears
• Hearing is relatively normal between 250 -1,000 Hz (the loss
at the low frequencies rarely exceeds 40 dB)
• “Noise notch” between 3000-6000 Hz, typically centered at
4,000 Hz (which rarely exceeds 75 dB)
• Recovery at the higher frequencies of 6,000-8,000 Hz
• Word recognition is fairly good ( > 75%)
47
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Work-related health issues: prevention
• Primary prevention
– Preventing the onset of disease by altering behaviours or
exposures that can lead to disease, or by protecting
against the effect of exposure to a disease agent
– Achieved using hierarchy of controls
• Elimination
• Substitution
• Engineering
• Administrative
• Personal Protective Equipment (PPE)
This material is courtesy of Aaron Thompson, MD, MPH, FRCPC
49
Controlling Occupational Risks
Source
Path
Receiver
Potential approaches to risk control
Eliminate
Modify
Redesign
Substitute
Relocate
Enclose
Engineering controls:
Absorb, block, dilute,
ventilate
Administrative controls:
Regulate exposure
duration
Enclose
Protect
Relocate
PPE
50
Work-related health issues: prevention
• Secondary prevention
– Preventing the establishment or progression of a disease
– Examples
• Screening to detect disease at an early stage when
intervention may be more cost-effective
• Medical surveillance
This material is courtesy of Aaron Thompson, MD, MPH, FRCPC
51
Work-related health issues: prevention
• Tertiary prevention
– Preventing the return of a disease that has been
treated in its acute phase. It seeks to limit or
delay the impact caused by the disease on the
patient’s function, longevity, and quality of life.
– Examples
• Disability management
• Return to work
This material is courtesy of Aaron Thompson, MD, MPH, FRCPC
52
Work-related health issues: prevention
• 1o prevention
– Minimize Exposure, prevent Outcome
– Approach using hierarchy of controls
• 2o prevention
– Early detection of Outcome
– Screening, surveillance
• 3o prevention
– Mitigate effects of Outcome
– RTW +/- accomodation once effectively treated and
controls have been put into place to prevent recurrence
This material is courtesy of Aaron Thompson, MD, MPH, FRCPC
53
1o, 2o, and 3o Prevention
Example: Lead Exposed Worker at a
Battery Recycling Plant
• 1o prevention
– Substitute tin for lead
– Enclose process, increase ventilation
– Optimize hygiene – no eating/drinking/smoking,
separate clothes, shower post shift, housekeeping
– Fit tested lead cartridge respirator
• 2o prevention
– Surveillance: annual Hx, physical, CBC, blood lead level (BLL)
• 3o prevention
– Chelation if indicated
– RTW when BLL acceptable and control measures in place
54
Lead: Exposure History
 Occupational: manufacturing or use of batteries, pigments, solder,
ammunitions, paint, car radiators, cable and wires, some cosmetics,
ceramic ware with lead glazes, tin cans
• Significant exposures in primary and secondary lead smelting and
refinement
 Hobbies: distillation of "moonshine" alcohol; home repairs; shooting at
gun ranges * (bullets have lead, particularly home-made)
 Lead-glazed tableware and cookware; ceramic dishes (pottery)
 Ayurvedic medicines *, herbal medications, recreational drugs
* Currently the most common causes of increased BLL
55
Lead: Health Effects
Blood levels are elevated if ≥ 10 μg/dL = 0.48 μmol/L
Main burden in adults is due to
• neuro effects (both CNS and PNS)
• high BP
Short-term (< 1 year)
Spontaneous abortion
Reduced birth weight
Postnatal developmental delay
Nonspecific symptoms
Neurocognitive deficits
Encephalopathy
Sperm abnormalities
Anemia (basophilic stippling)
Colic
Additional long-term (> 1 year)
Hypertension
Nephropathy
Peripheral neuropathy
Gout
56
Lead: Management
• Eliminate the exposure
• Education
• Chelation is considered if ≥ 50 μg/dL
57
Occupational Health Conditions:
Clinical Assessment and Management
• Confirm diagnosis, then address work relatedness
– Work description and occupational profile
– Prior and current exposure to hazards
– Review of relevant workplace (materials) safety data
sheets ((M)SDSs))
– Depending on the condition, there are various objective
means to determine work relatedness
• Prescribing return to work (with restrictions if necessary) is
part of the treatment plan
• If unsure, refer! (Occupational Medicine Specialist)
Based on the material from the lecture by Aaron Thompson, MD, MPH, FRCPC58
Medico-Legal Aspects
• 90% of workers are under provincial jurisdiction
• 10% of workers are under federal jurisdiction: 16 federallyregulated industries (e.g. banks, airports, highway transport)
– under Canada Labour Code
• Ontario: Occupational Health and Safety Act
–Enforced by Ministry of Labour (inspectors)
– Employers
• must protect health and safety
• report workplace illnesses and injuries
• accommodate injured/ill workers
• pay cost of injury, illness
• Compensation is tied to province of work, not province of
residence
59
Workplace Safety and Insurance
Act (Ontario)
– Establishes WSIB to oversee work-site
injuries/disease
– Funded by employers only
– Non-fault protection but no right to sue
– MD must submit medical report to WSIB (if WSIB
requests); no need for patient waiver
60
“Duties” of the treating physician
– Treat worker and assist in RTW process
– File Worker’s Compensation claims
– Report to Ministry of Labour if designated substance has
resulted in disability
– CMA Policy 2000
• Be knowledgeable of workplace
• Draft clear recommendations
• Make use of available occupational health resources
– Occupational Health Physician assumes lead in advising on
RTW/accommodation
This material is courtesy of Aaron Thompson, MD, MPH, FRCPC
61
This material is courtesy of Aaron Thompson, MD, MPH, FRCPC
62
Parts of the slide are courtesy of Aaron Thompson, MD, MPH, FRCPC and Richard Wells, Ph.D. CRE-MSD, IWH
63
Resources for your practice
•
MSDS are available on the web – should find one site and bookmark it (Health Canada): http://www.hc-sc.gc.ca/ewhsemt/occup-travail/whmis-simdut/index-eng.php
•
List of diseases reportable to the medical officer of health (and the reporting form)
http://app06.ottawa.ca/online_services/forms/health/support/professionals/communicable_disease/form_en.pdf?redirec=
no
•
Ottawa Public Health 613 580-6744
•
List of regulations by Environment Canada
http://ec.gc.ca/lcpe-cepa/eng/regulations/detailReg.cfm?intReg=56
•
Check your local AQI and refer your patients to this site
http://www.airqualityontario.com/reports/summary.php
•
Occupational Medicine Specialists of Canada
http://www.omsoc.org
•
Case studies in Environmental Medicine
http://www.atsdr.cdc.gov/csem/csem.html
•
Lange CURRENT Occupational & Environmental Medicine: Fourth Edition Joseph LaDou McGraw Hill Professional, Oct 23,
2006
•
•
•
Call Poison Control Centre for all questions regarding toxicants (you can always ask to speak to a physician – toxicologist)
Call and refer patients to Motherisk for all questions regarding exposures during pregnancy
64
Questions about chemical spills – call CANUTEC
Environmental
and Occupational Health
Multiple Choice Questions
for discussion
65
1) Which one of the following is not a typical
feature of asbestosis?
a) increased risk of cancer
b) pleural thickening and calcification
c) interstitial fibrosis
d) obstructive pattern on pulmonary function tests
e) none of the above
66
The following statements regarding noise are
true EXCEPT:
a) temporary threshold shift recovers following
cessation of noise exposure
b) permanent threshold shift is characterized by a
progressive pattern of hearing loss
c) most cases of permanent threshold shift are
surgically treatable
d) higher frequency noise is more damaging than
low frequency noise
e) none of the above
67
The frequencies most necessary for the
understanding of speech extend from about:
a) 20-20 000 Hz
b) 400-4 000 Hz
c) 250-8 000 Hz
d) 100-5 000 Hz
e) none of the above
68
Lead exposure typically results in:
a) chronic dermatitis
b) resting and intention tremor
c) extensor muscle weakness
d) arrhythmias
e) cerebellar ataxia
69
Which of the following statements concerning the
Worker’s Compensation Act is true?
a) the worker reserves the right to sue the
employer for negligence
b) funding is provided by the provincial government
c) the worker is guaranteed payment from the first
day of injury/illness if it is deemed to be workrelated
d) the Worker’s Compensation Board is an
independent, private agency
e) none of the above
70
Which of following statements regarding
radiation is false?
a) natural background radiation accounts for about
half of a typical person’s exposure
b) ionizing radiation causes intestinal villi to
become denuded
c) exposure to non-ionizing radiation may result in
cataracts
d) ionizing radiation results in an increased
incidence of neoplasia such as lung and thyroid
e) none of the above
71
All of the following statements concerning
occupational health are true EXCEPT:
a) disorders of reproduction are among the top
10 work-related diseases and injuries
b) most workers are covered by both federal and
provincial legislation with respect to workplace
health and safety
c) skin problems and hearing problems together
are responsible for half of WCB claims
d) a complete occupational medical history
includes investigation of the temporal
relationship between symptoms and exposure
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Which of the following statements concerning
exposure to solvents in the workplace is
true?
a) each solvent compound has a specific antidote
that can be used to treat exposure
b) a prominent symptom of solvent exposure is
memory loss
c) some solvents can cause skin dryness and loss
of subcutaneous adipose tissue
d) solvents do not affect the bone marrow
e) all of the above
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All of the following statements about environmental
health are true EXCEPT:
a) levels of toxic agents measured in the
environment may not reflect internal organ
levels
b) the federal government monitors the quality
and types of industrial emissions and toxic
waste disposal
c) sick building syndrome is associated with
Pontiac fever and Legionnaire’s disease
d) all humans have detectable levels of PCBs
e) none of the above is true
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More MCQs
• Here are some more questions that students
can use to test their own knowledge:
http://www.medicine.uottawa.ca/sim/data/Selftest_Qs_Environmental_e.htm
• (The questions contain comments on the
answers, to illustrate why a given response is
not correct)
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Self-test (1)
• Which one of the following gases is NOT
irritating to the respiratory tract?
a) ozone
b) sulfur dioxide
c) hydrogen chloride
d) carbon monoxide
e) chlorine
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Self-test (2)
• How much radiation is an "average Canadian adult
woman" typically exposed to each year from the
following sources: background dose; one screening
mammography, and one abdominal CT scan?
a) Background 0.1 Sv; mammography 0.5 Sv; CT 1.0 Sv.
b) Background 1.0 Sv; mammography 0.5 Sv; CT 0.1 Sv.
c) Background 1.0 mSv; mammography 50.0 mSv; CT 5.0 mSv.
d) Background 2.0 mSv; mammography 3.0 mSv; CT 10.0 mSv.
e) Background 1.0 mSv; mammography 0.1 mSv; CT 0.1 mSv.
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