Respiratory Impact of Lifestyle

Question 1

particulates

Answer 1

term relates to exposure to a dry aerosol composed of separate particles which are themselves scientifically defined as very small pieces of solid matter

Question 2

risk equation

Answer 2

risk = hazard x exposure

Question 3

importance of size

Answer 3

nanoparticles cause more inflammation than the same mass of fine respirable particles composed of the same material

Question 4

what is based upon aerodynamic diameter

Answer 4

penetration of the lungs (and deposition)

Question 5

inhalable fraction

Answer 5

the mass fraction of total airborne particles which is inhaled through the nose and mouth

Question 6

extrathoracic fraction

Answer 6

the mass fraction of inhaled particles failing to penetrate beyond the larynx

Question 7

thoracic fraction

Answer 7

the mass fraction of inhaled particles penetrating beyond the larynx

Question 8

respirable fraction

Answer 8

the mass fraction of inhaled particles penetrating to the unciliated airways

Question 9

the aerodynamic diameter

Answer 9

defined as the diameter of a unit density sphere with the same settling speed as the particle of interest

Question 10

fibres

Answer 10

defined as having a length greater than 5um, diameter less than 3um and a length to width ratio of greater than 3:1

Question 11

naturally occurring fibres

Answer 11

asbestos
pele’s hair
plant fibres (e.g. cotton)

Question 12

man-made fibres

Answer 12

insulation wools
refraction ceramic fibres
silicon carbide
carbon nanotubes

Question 13

normal clearance - what does failure of normal movement result in

Answer 13

an inability to clear long fibres out of the lungs

Question 14

what happens after fibre exposure

Answer 14

deposition of short or long fibres

Question 15

what happens after deposition of short fibres

Answer 15

effective phagocytosis and macrophage clearance

Question 16

what are the classifications of long fibres

Answer 16

non-biopersistent
biopersistent

Question 17

what happens to non-biopersistent long fibres

Answer 17

dissolution

Question 18

what happens to biopersistent long fibres

Answer 18

incomplete phagocytosis, cell activation and failed clearance

Question 19

what does incomplete phagocytosis, cell activation and failed clearance lead to

Answer 19

inflammation, fibrosis, cancer

Question 20

what happens after dissolution of non-biopersisitent long fibres

Answer 20

breakage which leads to short fibres and subsequent effective phagocytosis and macrophage clearance
OR
they dissolve

Question 21

fibre biopersistence - physiological processes

Answer 21

clearance (mucociliary, macrophage mediated)
translocation

Question 22

fibre biopersistence - physicochemical processes

Answer 22

biodurability - dissolution, leaching, breaking with extracellular or intracellular environment

Question 23

what does fibre biopersistence lead to

Answer 23

retention - either short or long

Question 24

short retention

Answer 24

non-pathogenic - limited inflammatory response

Question 25

long retention

Answer 25

pathogenic - chronic inflammation, fibrosis, cancer