Week 4: Industrial Hygiene, Environmental Management, and Environmental Ethics Flashcards
What are the 2 types of doses?
Internal dose and biologically-effective dose
Define internal and biologically-effective dose.
Internal Dose: the amount of a substance crossing one of the route barriers into the body
Biologically-effective dose: the amount of a substance reaching a target organ
What is the mathematical formula for dose?
Dose: concentration x exposure duration x rate at which material reaches body boundary
Define exposure science. What is the difference between industrial hygiene evolved in workplaces and exposure science?
Exposure science: modern field focused on exposure assessment in both workplace and environment
IH (occupational hygiene) evolved from measuring to controlling exposures and workplace risks
Exposure scientists measure/quantify exposures in general population (often in
research setting); results used for risk assessment, public health policymaking
What do industrial hygiene and exposure both try to do? What are 4 reasons why it is important?
Both try to quantify exposures
Important for:
Assessing potential problems
Directing preventive efforts, monitoring success
Checking compliance with regulations
In research, quantifying association between exposures and health outcomes
What are 4 details about anticipation and recognition?
IH paradigm: anticipation, recognition, evaluation
control; anticipation, 1st step
Hygienist gathers info. on site history, process, job
titles, materials safety data sheets on chemicals used
Develops preliminary list of potential hazards: safety hazards (e.g., inappropriate chemical storage), health hazards: physical (e.g., repetitive motion), chemical (acute, chronic hazards), biological (e.g., blood-borne pathogens), environmental (threats to public safety [e.g., chlorine tank rupture], health [e.g., solvents leaking to groundwater], or welfare, ecological damage)
Recognition phase: site visit/walk-through (visual
inspection), review health and safety programs, identify
workers at risk; write-up, incl. hazard eval. plan
What are 3 details about evaluation?
Quantify exposure through sampling/measurement: area sampling: in a room, in vicinity of some workers, personal sampling: in breathing zone of individuals, biological sampling/biomarkers: body fluids, breath, hair
Population sampling: identify/enumerate all who
could be sampled, choose sampling strategy (census of
all, stratified, convenience [biased], worst-case)
Instruments:
Direct reading: near real-time; available for many physical hazards (e.g., temp., noise, humidity, UV, radiation) and
pollutants (gases, vapors, airborne particles)
Sample collection: collects sample (e.g., volume of air) for
laboratory analysis; increasing volume increases contaminant mass collected, sensitivity for low levels
Why are sample collection instruments used?
Used instead of direct reading if multiple pollutants or additional laboratory analyses needed
Define active sample collection. Give the formulas and pros/cons.
Active: pump draws air through absorbing medium
Total volume air sampled = flow rate x sampling duration
Contaminant concentration = mass collected / volume of air
sampled (e.g., ug/m3)
Versatile, sensitive, specific for contaminants analyzed in
laboratory, but can be bulky, noisy, need batteries
Define passive sample collection. Give the formulas.
Passive: uses diffusion (concentration gradient) instead
of pump to collect air in absorbing medium that
removes compound by reaction or absorption
Flow rate of air to surface computed using Fick’s law;
Volume sampled = flow rate x sampling time;
Concentration = mass / volume (e.g., ug/m3)
Out of active and passive sample collection, which is used for biomonitoring?
Passive sample collection
What is control? What are 6 control strategies?
Control of workplace hazards = primary prevention
Substitution: replace hazardous materials/processes
w/less hazardous (e.g., replace benzene w/toluene)
Isolation: engineering controls to limit access to
hazardous materials (e.g., enclosed solvent washer)
Ventilation: introduce fresh air, use exhaust hoods
Administrative controls: policies/procedures to reduce
risk (e.g., lockout tag-out, worker rotation)
Protective devices (e.g., two-handed “On”)
Personal protective equipment (PPE) (e.g., respirators,
gloves, safety glasses, hardhats, etc.) – least preferable
of all control strategies
Frequency, intensity, and duration of exposure
What are the 3 principal routes of exposure? Give 4 details.
Inhalation, ingestion, and dermal
These routes of exposure are different from the exposure pathway, or the path by
which the contaminant moves from a source to a human receptor.
For example, pesticide exposures in children may come from several pathways.
Children may ingest pesticides from residues present on food (a dietary pathway);
they may get pesticides on their skin from their parents’ contaminated clothing if
the parents work on a farm (a take-home pathway); if spraying takes place close to
their home, they may inhale pesticide particles or vapors (a drift pathway)
These pathways differ substantially and each requires entirely different assessment
and control strategies to reduce exposure.
Contrast the 2 exposure assessment methods.
Imputing/modeling: indirect, used when direct measurements lacking or only partial data
Time-location studies, dietary exposure estimation
Exposure scenarios: typical individuals, activities, locations,
available data; inexpensive, used in risk assessment
Job-exposure matrix
Direct measurements (expensive, more accurate)
Environmental: fixed locations/area sampling
Personal exposures: portable devices; reflects time, location,
behavior; video exposure monitoring;
Biomarkers (gold standard): parent compounds or metabolites in body fluids, tissues; proves absorption, reflects bioavailability; genetic differences
