1.Air pollution
the presence of contaminants, of biological or chemical nature, at [ ] and duration levels that are large enough to interfere with the enjoyment of life and propert, and become evident as damage to buildings animal and plant life
Negative Effects of Air Pollution (5)
- Reduced visibility
- Low growth rates in veges
- Lower photosynthetic rates
- Respiratory, ear, nose, throat, illness
- corrosion of structures
Categories of Air samples55 4
- ambient air
- source (emission)
- indoor air
- atmospheric (soil air)
General considerations in Air sampling 5
- Meteorological (thời tiết) conditions
- Air pollutant properties
- sample collection time & volume
- Pollutant concentration
- Time of day - divinal (đoán) dispersion
Why air sampling depends on time of the day
bc in the evening, decrease downwind dispersion, higher downwind [ ] than in the daytime
site activities may be detected
the sampling duration may need to be lengthened
Equipment 1- Whole air
- Canister, gas bottles, syringes, gas (tedlar) bag
- Used when [ ] is constant in short period
Equipment 2 - Active sampling
- Pump, sorbent tubes (break thru)
- Used for hazardous compounds CH3O, Nox, O3
- Works on the principles of adsorption and absorption
Equipment 3 - Diffusion/ passive
- no pump, use passive badges (long sampling time but lightweight)
- Dependant on what you impregnate the badge with
Equipment 4 - Direct sampling
- single and multi-gas monitoring systems - Eagle Hydrocarbon sniffer
- used where immediate data is needed. there are direct sensors which are costly and require calibration
Equipment 5 - directly measure pollutant
- Analytical tubes
- inexpensive, no/ little training
- used for as varied as the presence of adsorbent
