Air quality measurements should be representative of all
exposed persons.
Pollutants
The concentrations of the
following pollutants should be determined, nitric oxide (NO), nitrogen
dioxide (NO2), carbon monoxide (CO). In addition concentrations
of benzene, toluene, xylene and suspended particulate matter (SPM)
should also be determined whenever possible.
There are
two general approaches to air quality sampling that can be adopted.
Static site monitoring, typically involving continuous monitoring
techniques and personal sampling which employs both passive and active
methods. Static site monitoring usually includes the more accurate
and sensitive techniques, but as the sampling site is fixed the measurements
are not entirely representative of exposure. Personal samplers are
worn by a representative sub-set of exposed individuals throughout
the sampling period. Personal sampling techniques are not usually
as sensitive or accurate. Ideally, personal sampling methods should
be validated using more sophisticated techniques at regular intervals.
The following methods are recommended.
|
Static site monitoring
|
| Pollutant
|
Sampling
and analysis method
|
| Nitrogen
dioxide
|
Chemiluminescence, reagent tube, grab sampling/laboratory analysis
|
| Nitric
oxide
|
Chemiluminescence reagent tube, grab sampling/laboratory analysis
|
| Carbon
monoxide
|
Non-dispersive infra red absorption, reagent tube, grab sampling/laboratory
analysis
|
| Benzene
|
Real time
gas chromatography
|
| Toluene
|
Real time
gas chromatography
|
| Xylene
|
Real time
gas chromatography
|
| Suspended
particulates*
|
Dual beam
radiation absorption, Tapered Element Oscillating Microbalance,
gravimetric
|
|
*Suspended particulate matter can be sampled as total suspended
particulate matter, PM10, respirable dust (≤5μm).
|
|
Personal monitoring
|
| Pollutant
|
Sampling
and analysis method
|
| Nitrogen
dioxide
|
Passive
(badge) sampler-ion chromatography
|
| Nitric
oxide
|
Electrochemical*
|
| Carbon
monoxide
|
Electrochemical*
|
| Benzene
|
Passive
badge sampler-gas chromatography/FID (Flame Ionisation Detection)
|
| Toluene
|
Passive
badge sampler-gas chromatography/ FID
|
| Xylene
|
Passive
badge sampler-gas chromatography/ FID
|
| Suspended
particulates**
|
Personal
sampler, gravimetric
|
|
* Electrochemical methods are susceptible to interference, therefore it
is recommended that these methods are regularly validated by
intercomparison with other techniques in the test environment.
|
|
** Suspended particulate matter can be sampled as total suspended
particulate matter or respirable dust (≤5μm).
|
Supplementary measurements of local air velocity, temperature
and relative humidity should also be undertaken.