aerosol
Let an agent reason about aerosols by particle size, composition and source, which decide their health effects, climate effects and behaviour.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify
Researched by: Claude
Purpose and description
Let an agent reason about aerosols by particle size, composition and source, which decide their health effects, climate effects and behaviour.
A suspension of fine solid particles or liquid droplets in a gas, such as mist, smoke, dust, haze or a spray.
What it is for: Explaining air quality, disease transmission, clouds, climate effects and spray products.
It can be measure it, by particle counters and filters as PM10 and PM2.5; generate it, with spray cans, nebulisers and industrial processes; filter it, with masks, filters and ventilation; model it, in air quality and climate models.
Distinguishing features
A two-phase system: particles in a gas
Behaviour depends strongly on particle size
Includes both natural and human-made sources
Aerosol spray cans are one product use of the term
What it looks like
Haze, smoke, mist or a visible spray; fine aerosols can be invisible.
Physical character
particle diameter: 0.001-100 micrometres - PM2.5 is below 2.5 micrometres
residence time in air: seconds to weeks time - fine particles stay aloft longest
How it is recognised
Reduced visibility and haze
Visible plumes of smoke or spray
Many harmful aerosols are too fine to see
Related models
includes - fog is a liquid aerosol, smoke a combustion aerosol
affects - fine particles are major pollutants
affects - aerosols scatter light and seed clouds
is filtered by - protective equipment
In practice
Families and kinds
by phase: liquid droplets, solid particles
by source: natural (sea salt, dust, volcanic), anthropogenic (combustion, industry)
primary and secondary aerosols
bioaerosols and respiratory aerosols
Standards and regulation
WHO air quality guidelines for PM2.5 and PM10
EU Ambient Air Quality Directive
Occupational exposure limits for airborne particles
EU Aerosol Dispensers Directive for spray cans
Failure modes and hazards
Respiratory and cardiovascular harm from fine particles
Airborne disease transmission
Flammable propellants in aerosol cans
Reduced visibility for transport
Also called
Where this came from
wikidata · CC0 1.0
Also registered as vr.tr.aerosol
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.
Composition and size What the particles are and how big.
Size and composition decide behaviour and harm.
Size distribution
Particle diameters.
Size data
The size distribution measured.
- What is the particle size distribution? measurement
- What fraction is below 2.5 micrometres? measurement
Composition
Chemical and biological content.
Composition data
The chemical make-up.
- What are the particles made of? measurement
- Which components are toxic? boundary
Source and transport Where it comes from and where it goes.
Sources and transport explain exposure.
Source
Natural or human-made.
Source attribution
The sources contributing.
- What are the main sources of this aerosol? provenance
- How was the attribution made? provenance
Transport and removal
Dispersion and deposition.
Transport behaviour
How long it stays and how far it travels.
- How far and how long does it travel? measurement
- How is it removed from the air? definition
Health and exposure Effects on people.
Fine aerosols are among the largest environmental health risks.
Exposure
Concentrations people breathe.
Exposure level
Measured concentrations against limits.
- What concentration are people exposed to, against which limit? measurement
- Which groups are most vulnerable? boundary
Protection
Masks, filters, ventilation.
Protective measures
Measures that reduce exposure.
- Which protective measures work for this aerosol? action
- When should people be advised to stay indoors? action
Products and safety Spray products.
Aerosol cans are pressurised products with their own hazards.
Aerosol dispensers
Spray cans.
Dispenser rules
Rules for pressurised dispensers.
- Which rules apply to this aerosol dispenser? provenance
- Is the propellant flammable? boundary
Disposal
Empty and partly full cans.
Disposal rules
How cans are disposed of.
- How should used cans be disposed of here? action
- What hazards arise in waste handling? boundary
What the second pass must settle
- Should aerosol spray products be a separate entry from the physical aerosol?
- How should particle size distributions be represented?
- Which air quality standards should be linked by jurisdiction?