Lecture 7 Biological Hazards

Question 1

Types of biological hazard agents

Answer 1

bacteria, fungi, parasites, arboviruses (west nile), other viruses, rickettsia, prions

Question 2

4 primary exposure routes

Answer 2

Percutaneous (needle-stick), Non-percutaneous (blood spatter), inhalation (saliva / mucous), Ingestion (drinking water)

exposures can be unintentional or intentional

Question 3

criteria for biohazard symbol

Answer 3

easily stenciled, symmetrical, acceptable to various ethnicities

Question 4

Percutaneous exposure examples

Answer 4

sharp injuries, animal bites, bug bites

Question 5

non-percutaneous exposures

Answer 5

mucous membranes, non-intact skin

Question 6

what metric is used to compare biological hazards?

Answer 6

R0, basic reproduction number

number of cases one case generates on average over the infectious period

based on duration, infectiveness, vulnerable population

Question 7

What are the elements of OSHA’s plan about bloodborne pathogens?

Answer 7

1991-2001: exposure control plan, methods of compliance, HIV/HBV research labs and production facilities, Hep B vaccination, Post-exposure evaluation and follow-up, Hazard communication, record keeping

2001 - exposure control plan, technology review, sharps injury log, solicit employee input

Question 8

Examples with needle upgrades

Answer 8

self re-sheathing needles, retractable needle, blunt-tipped blood drawing needles, winged steel needles, re-sheathing disposable scalpels, add on safety features (hinged or sliding shields)

Question 9

characteristics of Bioaerosols

Answer 9

either living (microorganisms) or from living organisms (dead microorganims, fragments, toxins, particulate wase, vapors)

Question 10

What was wrong with the AIPH cluster?

Answer 10

incorrect calculations, information bias (sampling was not blinded), aggressive non-standard technique

Question 11

Factors controlling indoor fungal growth

Answer 11

nutrient source (wood studs, cellulose ceiling tiles)
moisture (biggest challenge)
temperature

Question 12

fungal sampling strategies

Answer 12

source sampling: tape lift (you can’t see everything), swab sample

air sampling: spore trap, viable impactor (partitioning into different areas of the “lungs”)

Question 13

Elements of a fungal sampling plan

Answer 13

what agent? sources and reservoirs? concentration and variability? what sampling methods? operational parameters? location and time of sampling? analytical methods?

Question 14

Dealing with unacceptable fungal growth

Answer 14

remediation (remove and discard scaffolds for growth, clean non-porous materials)

prevention (avoid initiation conditions, use resistant materials, apply surface anti-growth compounds)

Question 15

Aflatoxins

Answer 15

acutely toxic, most carcinogenic natural compound, in corn (exposure stratified by activity showed big differences)

Question 16

Approaches for disinfecting water systems

Answer 16

1) chlorine: common, leaves residuals which react to form carcinogenic by-products, microbial cysts (cryptosporidium) are resistant
2) ozone and UV light : effect against microbial cysts, no biproducts, no residual disinfectant

best approach is some combination