22 occupational health II Flashcards
what is this lecture about?
review of hazard assessment-ask, observe, measuring (hazard assessment)
-personal monitoring
-area monitoring
-biological monitoring
what is hazard evaluation?
-in industrial hygiene, evaluation is the decision-making process that assesses the level of exposure of a hazard to workers (usually using equipment but also important to use senses)
-must be done in the context of an overall evaluation of work processes including interview, observation (walk through), literature review and exposure assessment
what are the aspects of ask?
ask:
-workers
-employer
-colleagues
-the literature
find out
-inventory of hazards
-description of process or operation
-transport and disposal issues (unusual exposures?)
what do we need to do in observe?
general site visits
-cover most or all of a work site
-provide an overall idea of working processes, conditions, hazards
specific site visits
-focus on a specific area, task, worker or group of workers, or hazard
what are we looking for in site visits?
-recognize hazards
-recognize controls that are present
-recognize when controls are absent
make use of your senses (listen, smell observe)
how do we measure? how do we choose equipment?
choosing equipment depends on:
-what you wish to sample (e.g. dust, organic vapour, noise, radiation, etc)
-how you wish to sample it (personal, area)
-personal monitoring
-area monitoring
-biological monitoring
what is used to measure dusts, particulates and fumes?
-can usually be collected on a filter and weighed
-type of filter depends on the substance
how do we measure chemicals, solvents and vapours?
-often have to be collected in liquid or granular sorbent media
-granular sorbent media is usually charcoal or silica gel
how do we measure noise?
noise dosimeters
when do we use personal monitoring?
-measure’s a particular employees personal exposure
-employee usually wears the sampling device for an entire work shirt (8 hours)
-should reflect the employees actual exposure
what needs to be noted about personal monitoring?
note that the capturing device (e.g. filter) is placed as close as possible to the contaminants route of entry to the body (usually inhalation)
-usually clipped to a lapel close to the worker’s breathing zone
still mat not reflect actual exposure:
-other routes of absorption not accounted for
-worker fiddles with or turn off the pump
-pump failure not recognized
what is area monitoring?
-monitoring a given area or location at a workplace, not a particular employee
-sampling device usually mounted or placed in a relevant location, doesn’t have to be portable (though portable devices often used)
-sampling device “stays put”, doesn’t move around with employee
-provides exposure information for an area (e.g. noise)
how do we decide to use area vs personal monitoring?
-which is better?
-which should you use?
depends on the question being asked
-is worker X exposed over the 8-hr workplace contamination limit? (personal)
-what are the dust levels in room X? (area)
what are two examples of choosing between area vs personal monitoring?
- two sawmill workers out of a group of 6 come to you concerned about being overexposed to noise over the course of their work shift
- a poultry barn worker is wondering about the dust level in the poultry barn, particularly when the birds are very agitated and active
what are the general principles of area vs personal monitoring?
-if you’re interested in knowing how dusty a location is (area monitoring)
-if you’re interested in knowing how much dust a worker is exposed to (personal monitoring)
legal occupational exposure limits are based on personal monitoring
what is biological monitoring?
-refers to the sampling of exhaled air, blood, urine or tissue (e.g. hair) for contaminants or metabolites of contaminants
-sometimes routine medical tests that detect occupational exposures (e.g. chest x-ray to detect asbestos changes in the lung) are included as ‘biological monitoring’ but the term is typically reserved for hazard-specific tests
-advantage: can assess a worker’s total exposure by all routes (air can miss dermal and ingestion exposure)
