Community Services
Environmental Health
POLLUTION - AIR QUALITY
Under Part IV of the Environment Act 1995, local authorities
are required to review and assess air quality in their areas. The primary
objective of this process is to identify areas where air quality is unlikely
to meet the objectives prescribed in the Air Quality Regulations 1997,
within the relevant period (i.e. by the end of 2005).
POLLUTANTS MEASURED
The pollutants for which national objectives have been prescribed
for under the 1997 Regulations are shown below:
| Pollutant |
Standard
Concentration |
Standard
Measured as |
Objective to be achieved by the
end of 2005
|
| Benzene |
5ppb |
running annual mean |
5ppb |
| 1,3-butadiene |
1ppb |
running annual mean |
1ppb |
| Carbon monoxide |
10ppm |
running 8-hour mean |
10ppm |
| Lead |
0.5ug/m3 |
annual mean |
0.5ug/m3 |
| Nitrogen
dioxide |
150ppb |
1-hour mean |
150ppb hourly mean
|
| 21ppb |
annual mean |
21ppb annual mean
|
| Particles (PM10) |
50ug/m3 |
daily max.
Running 24hr means
|
50ug/m3 measured
as the 99percentile
|
| Sulphur dioxide 100ppb |
100ppb |
15minute mean |
100ppb measured
as
The 99.9th %il
|
WHAT DOES MONITORING INVOLVE?
Air quality monitoring involves measuring the ambient concentrations
of pollutants in air at a given place and point in time. The measurements
produced are always average values over a defined period of time, which
may range from a month to a few seconds. A variety of techniques, of varying
sophistication, exist for measuring concentrations of pollutants in air.
In order to ensure a cost-effective monitoring strategy, appropriate techniques
should be utilised.
The methods fall into four main groups:
- Passive sampling (e.g. diffusion tubes)
- Active sampling (bubblers, filters etc)
- Automatic point monitoring
- Long-path/remote monitoring
GOVERNMENT RECOMMENDATIONS
The Government recommended a phased approach to making reviews
and assessments of local air quality where people are regularly present
and might be exposed to air pollution.
Local authorities were required to undertake an initial screening process
reviewing sources of pollution in the area followed, if necessary, by
a more detailed survey using simple monitoring techniques. If these surveys
indicated that the prescribed objectives are likely to be exceeded by
the end of 2005, then a detailed assessment using accurate monitoring,
modelling and other techniques should be undertaken.
EAST AYRSHIRE'S MONITORING ACTIVITIES
Prior to recent legislation, East Ayrshire Council have been monitoring
the ambient air quality over a number of years using diffusion tubes to
sample NO2 concentrations and 8-port bubblers to sample SO2 and smoke
(particulate) concentrations at a various of locations throughout the
district.
East Ayrshire Councils Environmental Health Service has embarked
on addressing their obligation under the relevant section(s) on the Environment
Act 1995 by:
Whilst the Air Quality Review has been submitted to The Scottish Office,
the diffusion tube survey is still on going.
The tubes are affixed to pre-identified lamp posts in strategic areas,
throughout the district, which have been considered to meet the requirements
of the DETR guidelines. These tubes are in their locations for one month
per every three months and are analysed by Clyde Analytical Laboratories
at Greenock.
MOBILE AIR QUALITY MONITORING STATION
East Ayrshire Council has recently taken delivery of a mobile Air Quality
Monitoring Station from Enviro Technology Services plc. This unit monitors
for:
- Sulphur dioxide (SO2)
- Nitrogen (NO)
- Nitrogen dioxide (NO2)
- Oxides of Nitrogen (NOX)
- Carbon monoxide (CO)
- Particulate (PM10)
- Weather
All monitoring is logged by real time, electronic analysers and downloaded
automatically to an office based P.C. on a daily basis. The equipment
can be programmed for various modes (e.g. 15 min. averages) from the P.C.
and analysed accordingly, either statistically and/or graphically, daily,
weekly or monthly.
It is anticipated that this station will play a major role in assisting
East Ayrshire Council with the monitoring of the prescribed pollutants
identified above.
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