4 Types of air quality decisions
- Determination of effects: perceive a problem exists and is caused by constituents in the atm
- Identification of pollutants causing effects: atm constituent must have the Chem and physical properties and be present in sufficient quantities to be harmful
- Source attribution: can only reduce exposure to air pollutants by going to their sources
- Emission control: many alternatives exist for reducing emissions
Air quality sample types 4
- Ambient air sample
- Indoor air sample
- Emissions sampling (autos, incinerator stacks)
- Soil atm (landfills,contaminated soils from spills)
% of air pollutants that are organic?
90
Definition of an aerosol
Finely divided particles of solids or liquids suspended in the atmosphere or gas
Considerations when selecting a sapling site
- source of contamination
- air flow direction and velocity
- density of contaminants
- intensity of light
- tune of day
- presence of obstructions
- traffic and site access
Meteorological considerations when sampling
Wind direction and speed
Temp
Atm stability and pressure
Precipitation
4 collection methods air sampling
Absorption/adsorption- analyses in a sample of air is adhered to a physical material
Flirtation- a high volume air sampler draws air through quartz or glass fibre filters -filter pore sizes dictate the amount and type of particulates
Whole air sampling- air pumped into pre evacuated container, usually stainless
Cryogenics- preferred when dealing with volatile organics, under vacuum and extreme cold, samples condense and are analyzed
