Jersey Tubes 2005

Jersey; Diffusion Tube Surveys, 2005

Jersey; Diffusion Tube Surveys, 2005

Title   Air Quality Monitoring in Jersey; Diffusion Tube Surveys, 2005   Customer  Public Health Services, States of Jersey

Customer  reference  

Confidentiality,  Restricted - Commercial

copyright and

reproduction  This document has been prepared by AEA Technology plc in

connection with a contract to supply goods and/or services and is submitted only on the basis of strict confidentiality. The contents must not be disclosed to third parties other than in accordance with the terms of the contract.

File reference   ED 44958001   Report number   AEAT/ENV/R/2165   Report status  Issue 1

Netcen

551 Harwell Business Centre DIDCOT

Oxfordshire

OX11 0QJ

Telephone 0870 190 6518 Facsimile 0870 190 6377

netcen is an operating division of AEA Technology plc AEA Technology is certificated to BS EN ISO9001:(1994)

Name  Signature  Date

Author  A Loader  B Stacey  

Reviewed by   B Stacey   Approved by  P Willis  

Executive Summary

Netcen (an operating division of AEA Technology Environment) is undertaking an ongoing programme of air quality monitoring on Jersey, on behalf of the Public Health Services and Planning and Environment Department of the States of Jersey. This report presents the results of the ninth consecutive year of monitoring, calendar year 2005 – covered by the monitoring period 4th January 2005 to 3rd January 2006.

Diffusion tube samplers were used to monitor nitrogen dioxide (NO2) at 23 sites, and hydrocarbons at six sites. Monitoring sites were selected to include areas likely to be affected by specific emission sources (such as petrol stations or the waste incinerator), as well as general background locations.

NO2 and hydrocarbon diffusion tubes were exposed for periods of typically 4 to 5 weeks. The exposure periods were based upon those used in the UK NO2 Network. The tubes were supplied and analysed by Harwell Scientifics Ltd, and changed by Technical Officers of Jersey's Environmental Health Section.

Annual mean NO2 concentrations at two of the 11 kerbside and roadside sites in built- up areas were greater than the Limit Value of 40µg m-3, set by Directive 1999/30/EEC (to be achieved by 2010), and as an Objective by the UK Air Quality Strategy, to be achieved by 31st December 2005. However, application of an adjustment factor for known diffusion tube bias reduced the annual means at all sites to below 40µg m-3. The highest annual mean of 33 µg m-3 (after bias adjustment) was measured at the Weighbridge site.

Annual mean concentrations at urban and residential background sites were all well below 40µg m-3 in 2005.

Ambient NO2 concentrations at most of the sites in Jersey were on average slightly lower than those measured in the previous year (2004).

Ambient concentrations of NO2 still show no clear trends, although there have been year-to-year fluctuations. There is no statistically significant downward trend in Jersey's NO2 concentrations. The implication of this is that some kerbside sites that are currently close to the AQS Objective may remain so, unless action is taken.

The highest annual mean benzene concentration of 3.3µg m-3 was measured at Springfield Garage, where the tube is located at a petrol station. At all other sites the annual mean benzene concentration was below 2.0µg m-3. All sites therefore met the UK Air Quality Strategy Objective of 16.25 µg m-3 for the running annual mean. All sites also met the EC 2nd Daughter Directive annual mean Limit Value of 5 µg m-3 (which is to be achieved by 2010).

Contents

1 Introduction  1

1. BACKGROUND  1
2. OBJECTIVES  1

2 Details of Monitoring Programme  1

1. POLLUTANTS MONITORED  1

1. NO2 1
2. Hydrocarbons  2

2. AIR QUALITY LIMIT VALUES AND OBJECTIVES  3

1. World Health Organisation  3
2. European Community  3
3. UK Air Quality Strategy  3

3. METHODOLOGIES  3
4. MONITORING SITES  4

3 Results and Discussion  8

1. NITROGEN DIOXIDE  8

1. Summary of NO2Results  8
2. Comparison with NO2 Guidelines, Limit Values, and Objectives  8
3. Comparison with UK NO2data  15
4. Comparison with Previous Years' Nitrogen Dioxide Results  15

2. HYDROCARBONS  18

1. Summary of Hydrocarbon Results  18
2. Comparison with Hydrocarbon Guidelines, Limit Values and Objectives  26
3. Comparison with UK Data  26
4. Comparison with Previous Years' Hydrocarbon Results  27

4 Conclusions  33 5 Recommendations  34 6 Acknowledgements  34 7 References  35

Appendices

APPENDIX 1  AIR QUALITY STANDARDS

APPENDIX 2  HYDROCARBON RESULTS

1 Introduction

1. BACKGROUND

Netcen, (an operating division of AEA Technology Environment), on behalf of the States of Jersey Public Health Services, has undertaken a further programme of air quality monitoring on the island of Jersey in 2005. This is the ninth in a series of extensive annual monitoring programmes that began in 1997.

The pollutants measured were nitrogen dioxide (NO2), and a range of hydrocarbon species (benzene, toluene, ethyl benzene and three xylene compounds), collectively termed BTEX. Average ambient concentrations were measured using passive diffusion tube samplers. NO2 was measured at 23 sites on the island, and BTEX at six sites.

This report presents the results obtained in the 2005 survey, and compares the data from Jersey with relevant air quality Limit Values, Objectives and guidelines, data from selected UK monitoring stations and previous years' monitoring programmes.

2. OBJECTIVES

This survey follows on from those in the years 1997 to 20041-8. The objective, as in previous surveys, was to monitor at sites where pollutant concentrations were expected to be high, and compare these with background locations. The monitoring sites used during 2005 consisted of a mixture of urban and rural background sites, together with some locations where higher pollutant concentrations might be expected, such as roadside and kerbside sites, and some close to specific emission sources.

2 Details of Monitoring Programme

1. POLLUTANTS MONITORED

1. NO2

A mixture of nitrogen dioxide (NO2) and nitric oxide (NO) is emitted by combustion processes. This mixture of oxides of nitrogen is termed NO . NO is subsequently oxidised to

NO2 in the atmosphere. NO2 is an irritant to the respiratoryX system, and can affect human health. Ambient concentrations of NO2 are likely to be highest in the most built-up areas,

especially where traffic is congested, or buildings either side of the street create a "canyon" effect, impeding the dispersion of vehicle emissions. The units used for NO2 concentration in this report are microgrammes per cubic metre (µg m-3). Some earlier reports in this series have used parts per billion (ppb): to convert to ppb to if required, the following relationship should be used:

1 µg m-3 = 0.523 ppb for nitrogen dioxide at 293K (20C) and 1013mb.

2. Hydrocarbons

There are many sources of hydrocarbon emissions. Methane, for example, is a naturally occurring gas, while xylene compounds are synthetic and used in many applications, for example as a solvent in paint. A range of hydrocarbons is found in vehicle fuel, and occur in vehicle emissions. In most urban areas, vehicle emissions would constitute the major source of hydrocarbons, in particular benzene. Also, there is the potential that they may be released to the air from facilities where fuels are stored or handled (such as petrol stations).

A wide range of hydrocarbons is emitted from both fuel storage and handling, and from fuel combustion in vehicles. It is not easy to measure all of these hydrocarbon species (particularly the most volatile) without expensive continuous monitoring systems. However, there are four moderately volatile species, all of which may be associated with fuels and vehicle emissions, which are easy to monitor using passive samplers. These are benzene, toluene, ethyl benzene and xylene. They are not the largest constituents of petrol emissions, but due to their moderate volatility they can be monitored by diffusion tubes. Diffusion tubes are available for monitoring this group of organic compounds, and are known as "BTEX" tubes.

1. Benzene

Of the organic compounds measured in this study, benzene is the one of most concern, as it is a known human carcinogen; long-term exposure can cause leukaemia. It is found in petrol and other liquid fuels, in small concentrations. In urban areas, the major source is vehicle emissions. Benzene concentrations in ambient air are generally between 1 and 15 µg m-3. In this report, concentrations of benzene are expressed in microgrammes per cubic metre (µg m-3). Previous reports in the series used parts per billion (ppb): to convert to ppb to if necessary, the following relationship should be used:

1 µg m-3 = 0.307 ppb for benzene at 293K (20C) and 1013mb. (only applicable to benzene).

2. Toluene

Toluene is also found in petrol in small concentrations. Its primary use is as a solvent in paints and inks; it is also a constituent of tobacco smoke. It has been found to adversely affect human health. Typical ambient concentrations range from trace to 3.8 µg m-3 in rural areas, up to 204 µg m-3 in urban areas, and higher near industrial sources. There are no recommended limits for ambient toluene concentrations, although there are occupational limits for workplace exposure9. The best estimate for the odour threshold of toluene has been reported10 as 0.16ppm (613µg m-3). In this report, concentrations are expressed in microgrammes per cubic metre (µg m-3). Previous reports in the series used parts per billion (ppb): to convert to ppb to if necessary, the following relationship should be used:

1 µg m-3 = 0.261 ppb for toluene at 293K (20C) and 1013mb. (only applicable to toluene).

(iii)ethyl benzene

Again, there are no limits for ambient concentration of ethyl benzene, and although there are occupational limits relating to workplace exposure9, as discussed in previous reports in this series, they are several orders of magnitude higher than typical outdoor ambient concentrations.

(iv)xylene

Xylene exists in ortho (o), para (p) and meta (m) isomers. Occupational limits relating to workplace exposure, are 100 ppm over 8 hours, and 150 ppm over 10 minutes. Xylene, like toluene, can cause odour nuisance near processes (such as vehicle paint spraying), which emit it. Its odour threshold varies according to the isomer, but the best estimate for the odour threshold of mixed xylenes is 0.016ppm (16 ppb or 70 µg m-3)10.

In this report, concentrations of ethylbenzene and xylenes are expressed in microgrammes per cubic metre (µg m-3). To convert to ppb to if necessary for comparison with previous reports, the following relationship should be used:

1 µg m-3 = 0.226 ppb for ethyl benzene or xylenes at 293K (20C) and 1013mb. (applicable to ethylbenzene, m-, p- and o-xylene).

2. AIR QUALITY LIMIT VALUES ANDOBJECTIVES

1. World Health Organisation

In 2000, the World Health Organisation published revised air quality guidelines11 for pollutants including NO2. These were set using currently available scientific evidence on the effects of air pollutants on health and vegetation. The WHO guidelines are advisory only, and do not carry any mandatory status. They are summarised in Appendix 1. There are WHO guidelines for ambient NO2 (hourly and annual means) but not benzene.

2. European Community

Throughout Europe, ambient air quality is regulated by EC Directives. These set Limit Values, which are mandatory, and other requirements for the protection of human health and ecosystems. EC Daughter Directives covering pollutants including NO2 and benzene 12,13 have been published in recent years. The Limit Values are summarised in Appendix 1.

3. UK Air Quality Strategy

The UK Air Quality Strategy (AQS) contains standards and objectives for a range of pollutants including NO2 and benzene14. These are also summarised in Appendix 1. Only those Objectives relating to the whole UK (as opposed to England, Wales, etc.) are applicable to Jersey, and the AQS does not at present have mandatory status in the States of Jersey.

3. METHODOLOGIES

The survey was carried out using diffusion tubes for NO2 and BTEX. These are "passive" samplers, i.e. they work by absorbing the pollutants direct from the surrounding air and need no power supply.

Diffusion tubes for NO2 consist of a small plastic tube, approximately 7 cm long. During sampling, one end is open and the other closed. The closed end contains an absorbent for the gaseous species to be monitored, in this case NO2. The tube is mounted vertically with the open end at the bottom. Ambient NO2 diffuses up the tube during exposure, and is absorbed as nitrite. The average ambient pollutant concentration for the exposure period is calculated from the amount of pollutant absorbed.

BTEX diffusion tubes are different in appearance to NO2 tubes. They are longer, thinner, and made of metal rather than plastic. These tubes are fitted at both ends with brass Swagelok fittings. A separate "diffusion cap" is supplied. Immediately before exposure, the Swagelok end fitting is replaced with the diffusion cap. The cap is removed after exposure, and is replaced with the Swagelok fitting. BTEX diffusion tubes are very sensitive to interference by solvents.

Diffusion tubes were prepared by Harwell Scientifics Ltd for AEA Technology, and supplied to local Technical Officers of Jersey's Public Health Services, who carried out the tube changing. The tubes were supplied in sealed condition prior to exposure. The tubes were exposed at the sites for a period of time. After exposure, the tubes were again sealed and returned to Harwell Scientifics for analysis. It was intended that where possible, the exposure periods should correspond (within +2 days) to those used in the UK NO2 Network, as has been the case in previous years.

The diffusion tube methodologies provide data that are accurate to + 25% for NO2 and + 20% for BTEX. The limits of detection are 0.4 µg m-3 for NO and 0.2 µg m-3 for BTEX. It

2

should be noted that tube results that are less than 10 x the limit of detection will have a higher level of uncertainty associated with them.

The Local Air Quality Management Technical Guidance LAQM.TG(03)15 states that when using diffusion tubes for indicative NO2 monitoring, correction should be made where applicable for any systematic bias (i.e. over-read or under-read compared to the automatic chemiluminescent technique, which is the reference method for NO2). Harwell Scientifics state that their diffusion tubes typically exhibit a positive bias, and have provided a "bias adjustment factor" for 2005 of 0.70. (This applies only to NO2 diffusion tubes, not BTEX tubes, as the latter are not affected by the same sources of interference). The NO2 diffusion tube results in this report are uncorrected except where clearly specified.

4. MONITORING SITES

Monitoring of NO2 was started in 1999 with just three sites. During 2000, this was expanded to 19 sites, all of which remain in operation; two further sites were added in 2003, taking the total to 21.

Two NO2 monitoring sites changed during the course of the year. At the beginning of April 2005, the two roadside sites at the Taxi Rank and Camera Shop, both in La Columberie, St Helier, were replaced by two new roadside sites in the same town: Union Street and New Street. The total remains at 21.

Table 1. NO2 Monitoring Sites

*The Parade site was moved to its current roadside location at the end of 2000.

Kerbside: less than 1m from kerb of a busy road. Roadside: 1-5m from kerb of a busy road. Background: > 50m from the kerb of any major road.

Note: all grid references are from OS 1:25000 Leisure Map of Jersey and are given to the nearest 100m.

Figure 1a. Site Locations Outside St Helier

Key:

1. LeBasCentre
2. MontFelard
3. LesQuennevais
4. RueDesRaisies
5. FirstTower
6. Weighbridge
7. LangleyPark
8. Georgetown
9. ClosStAndre
10. L'AvenueetDolmen
11. RobinPlace
12. Beaumont
13. TheParade
14. Maufant
15. JaneSandeman
16. SavilleStreet
17. BroadStreet
18. BeresfordStreet
19. LaPouquelaye
20. NewStreet
21. SpringfieldGarage
22. UnionStreet
23. Airport
24. HandsfordLane

Figure 2a. Sites in St Helier town

BTEX hydrocarbons were monitored at six sites during 2005. These are shown in Table 2. The aim was to investigate sites likely to be affected by different emission sources, and compare these with background sites. The sites at Beresford Street and Le Bas Centre are intended to monitor hydrocarbon concentrations at an urban roadside and urban background location respectively.

The Handsford Lane site was close to a paint spraying process – a potential source of hydrocarbon emissions, especially toluene and xylenes. This site replaced a similar site in Elizabeth Lane, which ceased operation when the process closed down in October 2003.

The Springfield Garage site is located by a fuel filling station, a potential sources of hydrocarbon emissions including benzene. In December 2003, the fuel supplier began using vapour recovery when filling the tanks; it was anticipated that subsequent results for this site would show a reduction in ambient concentrations of hydrocarbons.

The Clos St Andre site is located near the Bellozanne Valley waste incinerator, and the Airport site is located at Jersey Airport, overlooking the airfield.

Table 2. BTEX Monitoring sites

3 Results and Discussion

1. NITROGEN DIOXIDE

1. Summary of NO2 Results

NO2 diffusion tube results are presented in Table 3, and Figures 2 (kerbside and roadside sites) and 3 (background sites). Individual monthly mean NO2 results ranged from 3.9

µg m-3 (in July at the rural Rue des Raisies site), to 51.4 µg m-3 (in September at the kerbside Beaumont site).

There were nine occasions when no valid value was obtained. Five of these were tubes that went missing from their sites during the exposure period (in one case the tube was found on the ground).

The other four were cases where the coloured end-cap of the tube had developed a split during the exposure period. If this happens, moisture and contamination can enter, and the tube result is not valid. The number of occurrences of split end caps was high in 2005 compared to previous years. The situation should be monitored and the laboratory informed if the problem continues.

One unusually high value was recorded: at Jane Sandeman Road, the monthly mean for September was 31.5 µg m-3. While this would not be unusual at an urban kerbside site, it was unusually high for the rural Jane Sandeman site. However, in the absence of any evidence to suggest that it is spurious, the value has not been rejected.

Annual mean NO concentrations ranged from 6.8 µg m-3 (at Rue des Raisies) to 43.9 µg m-

2

3 at the Weighbridge site. The latter is a location in the centre of St Helier which is used as a central stopping point for buses.

2. Comparison with NO2 Guidelines, Limit Values, and Objectives

Limit Values, AQS Objectives and WHO guidelines for NO2 are shown in Appendix 1. These are based on the hourly and annual means. Because of the long sampling period of diffusion tubes, it is only possible to compare the results from this study against limits relating to the annual mean.

µg m-3. The EC 1st Daughter Directi1v1e12  cont2ains Limit Values for NO as follows:

The WHO non-mandatory guideline for NO is that the annual mean should not exceed 40

2

200 µg m-3 as an hourly mean, not to be exceeded more than 18 times per calendar

year. To be achieved by 1 January 2010.

40 µg m-3 as an annual mean, for protection of human health. To be achieved by 1

January 2010.

There is also a limit for annual mean total oxides of nitrogen (NOX), of 30 µg m-3, for

protection of vegetation (relevant in rural areas).

The UK Air Quality Strategy contains Objectives for NO2, which are very similar to the EC Daughter Directive limits above: the only differences being the more stringent dates by which they must be attained (31 December 2005).

2005 was thus a significant year for NO2, as the AQS Objective was to be achieved by the end of this period.

Annual mean NO2 at two sites exceeded 40µg m-3; these were Weighbridge and Beaumont, both urban kerbside sites that have recorded relatively high annual mean NO2 concentrations in previous years of this survey.

However, as explained in Section 2.3, it is necessary to take into account any systematic bias when comparing annual mean NO2 concentrations based on diffusion tube results with the AQS Objective15. Harwell Scientifics' NO2 diffusion tubes typically overestimate NO

2 concentration. Harwell Scientifics have quantified this overestimation, by participation in

ongoing co-location studies, and provided a bias adjustment factor (for 2005) of 0.70, to be applied to the annual mean NO2 concentration.

Applying this factor reduces the annual means at all sites to below the AQS Objective of 40µg m-3. The highest annual mean (at Weighbridge) is reduced from 43.9 µg m-3 (unadjusted) to 30.8µg m-3 (adjusted). Application of the bias adjustment factor reduced the annual mean NO2 concentrations at the 12 background sites to well below 40 µg m-3. All Jersey sites met the AQS Objective for annual mean NO2 by the due date.

The 30µg m-3 limit for protection of vegetation is only applicable at the one rural background site, Rue des Raisies; the annual mean NO2 concentration at this site was well within the limit.

Table 3. NO2 Diffusion Tube Results 2005, Jersey. Concentrations in µg m-3 .

K = Kerbside, R = Roadside, UB = Urban Background, Res B = Residential Background, Rur B = Rural Background. TM = tube missing, SC = split end cap.

60

50

First Tower

40

Weighbridge

Georgetown

Beaumont

30 The Parade

Broad Street

La Pouquelaye

Camera Shop, Coulomberie 20

Taxi Rank, Coulomberie

10

0

Exposure period

Figure 2. Monthly Mean Nitrogen Dioxide Concentrations at Roadside and Kerbside Sites, 2005

50

45

40

35

Le Bas Centre

30

L'Avenue et Dolmen Robin Place

25

Jane Sandeman Saville Street

20

Beresford Street

15 Mont Felard

Les Quennevais

10 Langley Park

Clos St.Andre

5 Maufant

Rue Des Raisies

0

Exposure period

Figure 3. Monthly Nitrogen Dioxide Concentrations at Background Sites, 2005

Figure 3 clearly shows the unusually high monthly mean of 31µg m-3 measured at Jane Sandeman Road in September. It may be that this result is due to a contaminated or damaged tube: however, no such anomaly was recorded. In the absence of any evidence that the result is spurious, it has been accepted.

3. Comparison with UK NO2data

The UK Nitrogen Dioxide Survey monitored this pollutant at around 1200 sites across the UK during 2005, using diffusion tubes. This survey, which ceased at the end of 2005, concentrated mainly on urban, not rural, areas. Sites are categorised as;

Roadside, 1-5m from the kerb of a busy road

Urban background, more than 50m from any busy road and typically in a residential

area.

The UK Network annual means for 2005 (which are provisional at present, pending full data ratification) were 38 µg m-3 for roadside sites and 21 µg m-3 for urban background sites (unadjusted for bias). The unadjusted 2005 annual means for the Jersey survey were comparable: 36 µg m-3 for kerbside and roadside sites combined, and 21µg m-3 for urban and residential background sites combined.

Table 4 shows annual mean NO2 concentrations measured at a selection of UK air quality monitoring stations using automatic (chemiluminescent) NO2 analysers. The automatic data have been fully ratified. The sites used for comparison are as follows:

Exeter Roadside – a roadside site in the centre of Exeter, Devon.

Plymouth Centre - an urban non-roadside site, in the centre of a coastal city.

Lullington Heath - a rural site on the South Coast of England near the town of

Eastbourne.

Harwell - a rural site in the south of England, within 10km of a power station.

Table 4 - Comparison of NO2 in Jersey with UK Automatic Sites

The bias adjusted annual mean NO2 concentrations measured at the kerbside and roadside sites in Jersey ranged from 18 to 31µg m-3. The annual mean at Exeter Roadside was therefore considerably higher than these. The Jersey urban background sites had (bias adjusted) annual mean NO concentrations ranging from 11 µg m-3 to 25 µg m-3; mostly

2

somewhat lower than sites such as Plymouth Centre. Residential background sites well outside Jersey's larger towns (e.g. Les Quennevais, Clos St Andre, Maufant) had bias- adjusted annual mean NO2 ranging from 6 µg m-3 to 18 µg m-3, and thus were more comparable with rural sites such as Lullington Heath and Harwell. The bias-adjusted annual mean of 4.8 µg m-3 at the Jersey rural background site, Rue des Raisies, was considerably lower than that measured at either Harwell or Lullington Heath.

4. Comparison with Previous Years' Nitrogen Dioxide Results

It is generally considered that at least five years' data are required to assess long-term trends in air quality. The majority of the sites in this survey have been in operation since 2000, thereby meeting this requirement. However, the survey includes three long-running sites, which have been in operation since 1993, as part of the UK Nitrogen Dioxide Network.

Annual mean concentrations for the three long-running sites are shown in Table 5 and Figure 4. Also included are overall means for the other sites in the kerbside and roadside, urban background and residential background categories. These data are not adjusted for diffusion tube bias; prior to 2002 there was no reliable information on which to carry out bias adjustment, so for consistency, uncorrected data are used in this section.

NO2 concentrations in the UK as a whole, as measured by the NO2 diffusion tube network, have shown a small but statistically significant downward trend between the mid 1990s and 2005, despite an increase (attributed to meteorological factors) in 2003. None of the three long-running Jersey sites show any significant downward trend (based on Theil's non-parametric analysis), although in the case of the Maufant and Jane Sandeman sites it does appear that NO2 concentrations are lower than they were in the early 1990s.

The average NO2 concentration for all roadside and kerbside sites appears to have no statistically significant downward trend in the long-term for any of the three categories shown (roadside and kerbside, urban background and urban residential). However, there appears to be a short-term decrease at many sites since 2003.

The fact that there is no clear downward trend long-term suggests that sites currently at risk of exceeding AQS objectives or EC limit are likely to remain so.  

Maufant (Rural Bkgd.)

Jane Sandeman (Res. Bkgd.) All Residential Background All Urban Background

50 All Kerbside & Roadside

Beaumont (Kerbside)

45

40

35

30

25

20

15

10

5

0

1993 1994 1995 1996 1997 1998 1999 2000

Year 2001 2002 2003 2004 2005

Figure 4. Trends in Annual Mean NO2 Concentrations

(not corrected for diffusion tube bias).

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Table 5 Annual mean NO2 concentrations, µg m-3 (not bias adjusted)

Site  1993  1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005 Beaumont  44  25  24  -  38  40  44  46  42  48  39  42

(Kerbside)

Jane Sandeman (Res. Bkgd.)

Maufant (Rural Bkgd.)

All Kerbside & Roadside

All Urban Background

All Residential Background

21  19 17  15

- -

- -

- -

21  21  - 13  11  -

- -  -

- -  -

- -  -

17  17  15 10  11  10

- -  43

- -  27

- -  16

17  17  19  16  15 8  10  11  9  9 43  43  44  38  37 27  27  30  25  25 16  17  19  15  16

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2. HYDROCARBONS

1. Summary of Hydrocarbon Results

Results of the hydrocarbon survey for the six sites are shown in Appendix 2, Tables A2.1 to A2.6 respectively. Graphical representations are shown in Figures 5 to 10.

A summary of annual average hydrocarbon concentrations is shown in Table 6. Some measurements, particularly at the airport site, were below the detection limit. By convention, when calculating annual averages and plotting graphs, such results are assumed to be half the detection limit.

Table 6. Summary of Average Hydrocarbon Concentrations, Jersey, 2005

All sites achieved full data capture, except Handsford Lane, where no April or May result was obtained.

Springfield Garage measured the highest annual mean concentrations of all five BTEX compounds in 2005, as it typically has in previous years. However, ethylbenzene concentrations appear to have returned to their pre-2004 levels, following the increase measured in 2004.

Handsford Lane (near the paint spraying process) measured slightly higher levels of ethylbenzene and m+p xylene compared with the other sites. However, ambient concentrations of toluene at this site have fallen from 16.1µgm-3 in 2004 to just 3.7µgm-3 in 2005.

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18.0

16.0

14.0

12.0

benzene

10.0 toluene

ethyl benzene

8.0 m,p -xylene o-xylene

6.0

4.0

2.0

0.0

Start Date of Exposure period

Figure 5. Monthly mean hydrocarbon concentrations at Beresford Street, 2005

9.0

8.0

7.0

6.0

benzene

5.0 toluene

ethyl benzene

4.0 m,p -xylene o-xylene

3.0

2.0

1.0

0.0

Start Date of Exposure period

Figure 6. Monthly mean hydrocarbon concentrations at Le Bas Centre, 2005

12.0

10.0

8.0

benzene toluene

6.0 ethyl benzene m,p -xylene o-xylene

4.0

2.0

0.0

Start Date of Exposure period

Figure 7. Monthly mean hydrocarbon concentrations at Handsford Lane, 2005

30.0

25.0

20.0

benzene toluene

ethyl benzene 15.0

m,p -xylene o-xylene

10.0

5.0

0.0

Start Date of Exposure period

Figure 8. Monthly mean hydrocarbon concentrations at Springfield Garage, 2005

7.0

6.0

5.0

4.0 benzene toluene

ethyl benzene m,p -xylene

3.0 o-xylene 2.0

1.0

0.0

Start Date of Exposure period

Figure 9. Monthly mean hydrocarbon concentrations at Clos St Andre, 2005

7.0

6.0

5.0

4.0 benzene toluene

ethyl benzene m,p -xylene

3.0 o-xylene 2.0

1.0

0.0

Start Date of Exposure Period

Figure 10. Monthly mean hydrocarbon concentrations at the Airport, 2005

2. Comparison with Hydrocarbon Guidelines, Limit Values and Objectives

Of the hydrocarbon species monitored, only benzene is the subject of any applicable air quality standards. The UK Air Quality Strategy sets the following objectives for benzene:

16.25µg m-3 (for the running annual mean), to be achieved by 31 December 2003 3.25 µg m-3 (for the calendar year mean), to be achieved by 31 December 2010.

These are applicable to the whole UK (though not mandatory in Jersey). The annual mean benzene concentration (which can be considered a good indicator of the running annual mean) did not exceed 16.25µg m-3 at any of the Jersey sites. The calendar year mean was less than the 2010 objective of 3.25 µg m-3, at all sites except Springfield Garage.

The EC 2nd Daughter Directive13 sets a limit of 5µg m-3 for annual mean benzene, to be achieved by 2010. All sites met this limit.

3. Comparison with UK Data

Table 7 compares hydrocarbon data from the 2005 Jersey survey with a selection of automatic UK air quality monitoring stations, which measure hydrocarbons using pumped tube samplers. The sites used for comparison are:

London Marylebone Road - an urban kerbside site, located on a major route into Central London. Heavy traffic, and surrounded by tall buildings.

London Eltham – an urban background site in south east London, in parkland over 25m from the nearest road.

Glasgow Kerbside – a city centre kerbside site.

Harwell - a rural site in the south of England, within 10km of a power station.

Benzene was also measured using pumped-tube samplers at a larger network of 30 UK sites in 2005. Annual mean concentrations ranged from 0.86 µg m-3 (at Coventry's Memorial Park) to 4.47 µg m-3 (at Gawber, Barnsley), but were typically in the range of 1-3 µg m-3 at most urban sites.

Table 7. Comparison with Hydrocarbon Concentrations at Other UK Sites, Calendar Year 2005 (With data capture in brackets).

n/a = not available.

The annual mean benzene concentration at Springfield Garage (where fuels are stored) was higher than any of the other Jersey or UK Network sites, including London Marylebone Road (which is beside a very busy city road), or Glasgow Kerbside. Lower concentrations were measured at the urban background sites on Jersey; benzene levels at these sites appear comparable with those at the other two automatic sites in Eltham and Glasgow, and the UK pumped-tube sites. Benzene levels at Clos St Andre and the Airport remain lower than typical UK urban levels, and comparable with the mean from the rural Harwell. Benzene concentrations at Handsford Lane were no higher than those at Beresford Street or Le Bas; the nearby paint spraying process is not a significant source of benzene.

No annual mean toluene concentrations have been reported for the mainland UK sites, as insufficient data capture was achieved in 2005.  

4. Comparison with Previous Years' Hydrocarbon Results

Table 8 shows annual mean hydrocarbon concentrations for these sites, for years 1997 – 2005. Figures 12 to 16 illustrate how annual mean concentrations of these hydrocarbons have changed over the years of monitoring.

As well as the six sites currently in operation, Table 8 also shows previous years' results from a site at Elizabeth Lane. This site was located close to a paint spraying process: when the process closed down, monitoring was re-located to Handsford Lane, which is close to another similar process.

With a few exceptions, levels of all five hydrocarbon species were lower during 2005 than in the previous year. In particular, concentrations of ethylbenzene have reduced in 2005 after the increase reported (particularly at Springfield Garage) in 2004.

At Springfield Garage, the fuel supplier has used vapour recovery when filling the tanks since the end of 2003; it was thought that there might be a reduction in hydrocarbon concentrations at Springfield Garage as a result. Indeed, there has been some reduction in concentrations of BTEX compounds compared with the 2003 values, though it is not known whether this can be attributed to the use of vapour recovery.

Table 8. Comparison of Hydrocarbon Concentrations, Jersey, 1997 - 2005.

benzene,  toluene,  ethylbenzene m+p xylene,o-xylene,

µg m-3 µg m-3 µg m-3 µg m-3 µg m-3

Beresford Street

Le Bas Centre

Elizabeth Lane (ceased site)

Springfield Garage

 Clos St Andre

Airport

 Handsford Lane

2004  1.0  16.1  7.3  8.5  2.0

2005  1.0  3.7  2.1  7.1  2.2

Handsford Lane Airport

30.0 Clos St Andre Elizabeth Lane

Le Bas Centre

Beresford Street 25.0

Springfield Garage 20.0

15.0

10.0

5.0

0.0

1997 1998

1999 2000

2001

2002

2003

2004

2005

Figure 12. Trends in Benzene Concentration

50.0

 Handsford Lane Airport

45.0

 Clos St Andre

40.0 Elizabeth Lane

Le Bas Centre

35.0 Beresford Street Springfield Garage

30.0

25.0

20.0

15.0 10.0

5.0 0.0

1997

1998

1999

2000

Year 2001 2002

2003

2004

2005

Figure 13. Trends in Toluene Concentration

RESTRICTED - COMMERCIAL

14.0

12.0 10.0

8.0 6.0

4.0 2.0 0.0

1997

1998

1999

2000

2001

Year 2002 2003

2004

2005

AEAT/ENV/R/2165 Issue 1

 Handsford Lane Airport

 Clos St Andre Beresford Street Le Bas Centre Elizabeth Lane Springfield Garage

Figure 14. Trends in Ethylbenzene Concentration

 Handsford Lane Airport

 Clos St Andre 25.0

Beresford Street

Le Bas Centre

Elizabeth Lane

Springfield Garage 20.0

15.0

10.0

5.0

0.0

1997 1998 1999 2000 2001 2002

Year 2003 2004

2005

Figure 15. Trends in m+p- Xylene Concentration

 Handsford Lane

20.0 Airport

 Clos St Andre

18.0 Beresford Street Le Bas Centre

16.0 Elizabeth Lane Springfield Garage

14.0 12.0 10.0

8.0 6.0

4.0 2.0 0.0

1997 1998 1999 2000

2001 2002

Year 2003 2004 2005

Figure 16. Trends in o-Xylene Concentration

Most hydrocarbon species appear to have decreased over the six years of monitoring, being in most cases lower now than in the late 1990s.

Benzene showed a marked drop in 2000: this is due to the maximum permitted

benzene content of petrol sold in the UK being reduced from 2% in unleaded (5% in super unleaded), to 1% as of 1st January 2000. Concentrations have continued to fall slightly year on year.

Toluene concentrations show a small but steady downward trend over the

complete period of the survey (1997-2005).

Ethylbenzene concentrations do not show a clear trend. Concentrations appear to