Industrial hygiene & control ms eva karpinski

Trinidad and Tobago National Safety Week April 28 – May 4, 2013

Recognition and Prevention of Occupational Diseases

Industrial Hygiene Perspective

Eva Karpinski, M.Sc., P.Eng.Industrial Hygiene Engineer

Occupational Health and Safety DivisionWorkplace Directorate

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Definition of Occupational Disease

Occupational disease – a disease associated with exposure to a chemical, physical, biological, ergonomic, or psychosocial hazard in a workplace.

Canadian Standard Association (CSA):

CSA Z795-03 Coding of Work Injury or Disease Information (not referenced in the COHSR)

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Workplace hazards which may cause occupational disease

Chemical hazards – dusts, fumes, smoke, aerosols, mists, gases and vapours

Physical hazards – noise, vibration, ionizing and non-ionizing radiation, thermal stresses

Biological hazards – bacteria, viruses, fungi, moulds, insects Ergonomic hazards – improperly designed tools/work areas, improper

lifting/reaching, repeated motions, mechanical vibrations Nanomaterials – materials with any external dimention in the nanoscale or

having internal structure or surface structure in the nanoscale (1 nm to 100 nm)

Psychosocial hazards – violence, bullying, harassment, other chronic stressors identified by workers

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Effects of exposure to hazardous substances

Acute effects – the ill-health effects caused by sudden one-time exposure to relatively high concentrations of hazardous substances. Most acute effects are over in a few minutes, hours, days or at most, in a few weeks. Recovery is complete (e.g. pulmonary edema) or there is a permanent disability or death (e.g. exposure to IDLH condition).

Chronic effects – the ill-health effects caused by repeated exposure to relatively low concentrations of hazardous substances or as long term effect of a short but severe exposure to a hazardous substance. Recovery is complete (e.g. tendonitis) or there is a permanent disability or death (e.g. pleural thickening, mesothelioma).

Latent period – the time from the first exposure to the disease development

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Routes of entry

Inhalation Skin absorption Ingestion Eyes

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Examples of occupational diseases

Asthma, e.g., caused or triggered by exposure to isocyanates Silicosis, caused by exposure to silica Hearing impairment caused by noise Tuberculosis, caused by mycobacterium tuberculosis Carpal tunnel syndrome, caused by repetitive motions combined

with extreme postures of the wrist and forceful exertions Mesothelioma, caused by exposure to asbestos

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Occupational diseases in Canada

Injuries Musculoskeletal system disorders continue to rank the highest but are

showing a sharp decline over the 11 year period.  (It may be related to

increased knowledge of the importance of ergonomics.)

Note: Musculoskeletal system disorders have made up at least half of

occupational injuries every year in the 11 year period.

Infectious diseases peculiar to the intestines over the 11 year period

(15% increase from 2001 to 2011, peaking in 2010). 

Other diseases seem to be trending downward. 

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Fatalities

• Malignant neoplasms and tumors continue to rank the highest and are showing an upward trend. Note1: This disturbing trend is likely due to: – work practices in the past

– long latency periods – increased association of adverse health outcomes with work history– advances in occupational medicine

Note2: This trend is expected to peak within the next few years and then trend downwards

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Prevention of occupational disease

Primary prevention – preventing development of disease by taking necessary measures to eliminate or control worker exposure

Secondary prevention – early detection of disease, intervention and treatment to prevent from further development, e.g. medical surveillance

Tertiary prevention – medical management of established disease

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Primary prevention of occupational disease

Industrial hygiene elements include:

anticipation recognition evaluation control

of hazards which may cause illness, impaired health, or significant discomfort among workers.

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Recognition

In order to recognize a hazard it is necessary to:

study the process identify all the ingredients used and their quantities obtain their safety data sheets understand the chemistry involved identify and quantify all the products and by-products of the

process identify sources of contaminant generation

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• establish the toxicity of the hazardous substances and their limits of exposure

• study their physical properties

• determine the effectiveness of control measures already in place

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Evaluation

If a potential hazard to the health of a worker is identified, the next step is to evaluate the hazard.

At the evaluation stage, the following factors must be determined: the number of employees exposed and the duration of exposure the number of samples the type of samples and period of activity to be sampled

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• the concentration or level of the hazardous substance to which a worker is exposed

• whether this concentration or level of the hazardous substance is in excess of the occupational exposure limit for that hazardous substance, e.g., TLV

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Types of control measures

Source Elimination Substitution Source or process modification Automation Isolation/containment/enclosure Local exhaust ventilation

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Path• General ventilation

• Increased distance

Worker• Good work practices

• Operating procedures

• Job rotation/work scheduling

• Personal protective equipment

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Secondary prevention of occupational diseases

Employers may establish a medical surveillance program for the benefit of workers that includes:

medical examination (pre-employment, pre-placement, periodic)– history, e.g., previous exposure, smoking, signs and symptoms– physical examination

clinical tests, e.g., pulmonary function tests, chest x-ray, blood and urine tests action levels health education, e.g., personal cleanliness, hazards, discussion of examination

results record keeping

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Tertiary prevention of occupational diseases

Medical management of established disease

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Questions?

Thank you!