Health effects of particles

Question 1

Health effects on lungs and respiratory tract

Answer 1

• Asthma
• Decreased lung function
• Chronic obstructive pulmonary disease (COPD)
• Cancer

Question 2

Systemic health effects

Answer 2

• Premature death in people with heart or lung disease
• Heart attacks
• Irregular heartbeat

Question 3

Reproductive health effects

Answer 3

• Deaths of new born in infection of the respiratory passage
• Reduced birth weight
• Effects on development of children’s lungs

Question 4

Types of studies

Answer 4

In vivo - studies taking place on whole living organisms
In vitro - Studies on cells, or microorganisms
ex-vivo - studies done on dead organisms

Experimental studies

• Human exposure
• Animal exposure
• Cell studies (in-vitro)
• …

Epidemiological studies
- Time series of a populations
- Cross section studies
- Long term studies of selected sub
population

Question 5

Chamber exposure studies

Answer 5

Humans in chamber exposed to doses around 300 µg/m^3. samples before, during and after

Question 6

cell exposure studies

Answer 6

Traditional liquid cell exposure

The NACIVT Air-Liquid Interface (ALI) chamber - charged particles

Question 7

Lung structure

Answer 7

5 lobes: 3 left, 2 right
Head airway
Brochiolar region
Alveolar region

Question 8

Deposition mechanisms in lung

Answer 8

Primary:
• Impaction
• Sedimentation
• Diffusion
Secondary:
• Interception (Fibre)
• Electrostatic forces
• Convective transport
No particle “bounce” in the lungs

Question 9

Impaction is important in

Answer 9

upper airways due to high air flow. Particles > 1 µm

Question 10

Sedimentation is important in…

Answer 10

the smaller airways and alveoli, and horizontal airways (short distances, long residence time). Particles >0.2 µm

Question 11

Diffusion is important in…

Answer 11

the lower airways (short distances, long residence time). Particles < 0.5 µm

Question 12

Interception important for…

Answer 12

fibres

Question 13

Deposition in head airways

Answer 13

• High air velocity, large airways: The very most large particles deposit by impaction
• The VERY smallest particles deposit in head airway by diffusion despite the large airway dimensions since the diffusion rate is very high.

Question 14

Deposition in Trachebroncial region:

Answer 14

• Large partilcles deposit by sedimentation due to long residence times and small enough airway dimensions. Small particles by diffusion due to the same reasons.

Upper size restriction for deposition of large particles: particles have already been deposited in the head airways airways. Lower restriction: sedmentation distance gets smaller and particles to not reach airway surface. Upper restriction for deposited size is due to decreased diffusion rate.

Question 15

Deposition in Alveolar region:

Answer 15

Large partilcles deposit by sedimentation due to long residence times and small airway dimensions. Small particles by diffusion by the same reasons.
The deposition for large particles peaks at lower sizes than for the trachebronchial deposition peak due to smaller airways and longer resicence times in the alveoli. Upper size restriction for deposition of large particles is due to the largest particles have already being deposited in the head airways airways or in the trachebronchial region. Lower size restriction is that the
sedmentation distances gets to small for particles to hit airway surface (too large airways realtive to sedimentation distance).
For small particles the upper size restriction is due smaller diffusion rate as size goes up. Lower size restriction: all particles have already been deposited in head airways of int eh trachebronchial region.