Air Quality Report 6
Volatile Organic Compound Monitoring
Monitoring of Volatile Organic Compounds (VOC) in air using diffusion tubes has been undertaken between 8 March 2024 and 13 August 2024. The diffusion tubes used for this monitoring are called TENAX tubes and were provided by the same laboratory providing the Hydrogen Sulphide tube analysis.
During the latest exposure period, tubes were positioned alongside the Hydrogen Sulphide tubes at the community locations, with the exception of positions D3, D5, D9, D11 and D12. Tubes were also positioned at D13 (Pembroke Dock), D14 (St David’s), Saron (D15) and Llandarcy (D16).
On site, they were positioned at locations WL2, WL4 and WL5 alongside the Hydrogen Sulphide tubes.
VOC diffusion tubes work in the same way as Hydrogen Sulphide diffusion tubes, i.e. during the exposure period air is free to circulate into the tube and at the end of the period the tube is sealed and returned to the laboratory for analysis.
3.2.1 Review of VOC results
Volatile organic compounds (VOCs) are a complex variety of chemical substances. Like Hydrogen Sulphide, they may be generated and released by a variety of natural processes and human activities. This large group of compounds is defined on the basis of their ability to exist as a vapour. Common examples include the recognisable odour associated with paint and petrol, the smell detectable from air fresheners and the smell of freshly cut grass – all these smells are due to the presence of a range of different VOCs, some of which produce a detectable odour.
The VOC laboratory certificate for the latest exposure period is presented in Appendix 2. Each of the tubes were analysed for the top 20 VOCs found to be present. Readers will note that the certificate spans several pages and includes tables of data from each of the different monitoring positions. To aid understanding, visualisation and assessment of these data, the concentration data expressed in units of µg/m3 (micro grammes per cubic meter of air) has been extracted from the last column of the certificate and repeated in Table 3-6 which spans several pages. This same data is also graphically presented as a series of charts following the table.
To the right-hand side of the monitoring data in Table 3-6 are criteria used to assess air quality. These come from a range of sources and are intended to provide a yardstick against which the reader can better appreciate the levels reported from the diffusion tubes. As noted in all previous monitoring reviews, it is evident from this comparison that the concentration levels estimated from the tubes are many times lower than these criteria, where values have currently been found to be available.
Coupled with review of the charts it is evident that:
- The VOCs reported continue to be found at very low levels just above the level of detection in many cases.
- Some compounds are detected at higher concentration off-site compared to the tubes located on-site, and vice versa.
- The off-site positions in South Wales (D13-D16) have higher recorded levels of certain VOCs compared to the community positions (D1-D12) around the landfill site. The levels still fall below the evaluation criteria
Table 3‑6 Results from VOC Diffusion Tubes (µg/m3)
Volatile organic compounds (VOC) |
Community position: D1 |
Community position: D2 |
Community position: D4 |
Community position: D6 |
Community position: D7 |
Community position: D8 |
Community position: D10 |
Community position: D13 |
Community position: D14 |
Community position: D16 |
Community position: D15 |
on-site position: WL2 |
on-site position: WL4 |
on-site position: WL5 |
Evaluation criteria: EAL and
|
|
1,2-Benzenedicarboxylic acid, |
no data |
no data |
no data |
no data |
no data |
2.6 |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
|
1,4-Benzenedicarboxylic acid, |
20 |
47 |
27 |
no data |
no data |
124 |
38 |
63 |
no data |
33 |
50 |
69 |
45 |
55 |
no data |
|
1-Butanol |
no data |
0.7 |
no data |
no data |
<0.2 |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
|
1-Hexanol, 2-ethyl- |
0.8 |
2.6 |
0.8 |
0.6 |
0.5 |
1.1 |
1.2 |
0.7 |
1.6 |
0.7 |
1.1 |
1.0 |
1.0 |
1.3 |
570 |
|
1-Propanone, |
no data |
no data |
no data |
<0.5 |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
|
Acetic acid |
0.4 |
0.4 |
0.4 |
0.2 |
0.2 |
no data |
0.2 |
0.4 |
0.5 |
0.5 |
0.5 |
no data |
1.2 |
no data |
3700 |
|
Acetophenone** |
0.9 |
1.3 |
1.7 |
1.8 |
<0.3 |
2.3 |
1.7 |
1.8 |
1.9 |
2.2 |
1.8 |
1.6 |
1.8 |
2.0 |
no data |
|
Behenyl benzoate |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
27 |
no data |
|
Benzaldehyde** |
1.2 |
1.4 |
1.8 |
1.4 |
0.6 |
2.1 |
1.8 |
2.0 |
1.9 |
2.2 |
2.2 |
1.6 |
2.0 |
1.8 |
350 |
|
Benzene |
1.1 |
0.4 |
0.5 |
0.3 |
0.4 |
no data |
0.4 |
0.4 |
0.4 |
no data
|
0.4 |
no data |
0.4 |
no data |
5/30 |
|
Benzeneacetaldehyde** |
no data |
no data |
no data |
<0.3 |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
|
Benzenecarbothioic acid |
no data |
no data |
0.6 |
no data |
no data |
no data |
0.6 |
no data |
0.6 |
0.9 |
0.6 |
no data |
0.7 |
no data |
no data |
|
Benzenesulfonamide, |
no data |
no data |
no data |
no data |
no data |
3.8 |
no data |
1.5 |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
|
Benzoic acid |
2.3 |
1.8 |
3.4 |
2.0 |
<0.3 |
5.9 |
4.4 |
3.5 |
2.5 |
7.3 |
4.6 |
4.1 |
4.6 |
5.2 |
no data |
|
Benzoic acid, |
no data |
no data |
no data |
no data |
no data no data |
no data |
no data |
no data |
no data |
no data |
no data |
10 |
no data |
no data |
no data |
|
Benzothiazole |
no data |
no data |
no data |
no data |
no data no data |
no data |
1.0 |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
|
Benzoylformic acid |
no data |
no data |
no data |
no data |
no data no data |
no data |
no data |
no data |
no data |
0.7 |
no data |
no data |
no data |
no data |
no data |
|
Butane |
0.7 |
0.5 |
no data |
no data |
no data no data |
no data |
no data |
0.5 |
0.4 |
no data |
0.5 |
no data |
no data |
no data |
no data |
|
Cyclohexane, |
no data |
no data |
no data |
no data |
<0.4 |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
|
Cyclopentasiloxane, |
no data |
1.5 |
no data |
1.3 |
<0.9 |
no data |
no data |
no data |
no data |
1.9 |
2.0 |
no data |
no data |
no data |
no data |
|
Cyclotetrasiloxane, |
1.6 |
2.8 |
1.7 |
2.1 |
1.3 |
no data |
1.7 |
no data |
1.8 |
2.2 |
1.8 |
2.3 |
2.0 |
2.4 |
no data |
|
Cyclotrisiloxane, |
2.9 |
no data |
3.7 |
4.8 |
3.3 |
5.5 |
3.5 |
2.7 |
5.0 |
5.2 |
4.7 |
5.5 |
5.2 |
4.9 |
no data |
|
Decanal** |
0.6 |
no data |
0.8 |
0.6 |
0.4 |
no data |
no data |
no data |
0.9 |
no data |
no data
|
no data |
no data |
no data |
no data |
|
Dibutyl adipate |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
1.7 |
no data |
2.7 |
no data |
|
Dibutyl phthalate |
no data |
no data |
no data |
no data |
no data |
9.6 |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
|
Diethyl Phthalate |
no data |
no data |
no data |
3.9 |
no data |
46 |
3.6 |
11 |
no data |
no data |
no data |
no data |
no data |
6.1 |
no data |
|
Diphenyl sulfide |
no data |
no data |
no data |
no data |
no data |
1.8 |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
|
Docosane |
no data |
20 |
no data |
no data |
no data |
25 |
no data |
14 |
no data |
no data |
29 |
8.8 |
no data |
17 |
no data |
|
Eicosane |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
32 |
no data |
44 |
no data |
no data |
no data |
13 |
no data |
|
Heptadecane, 9-octyl- |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
61 |
no data |
no data |
no data |
|
Heptanal |
no data |
no data |
no data |
no data |
<0.3 |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
|
Hexanal** |
no data |
no data |
no data |
no data |
0.4 |
no data |
no data |
no data |
0.5 |
no data
|
no data
|
no data |
no data |
no data |
no data |
|
Hexane, 2,4-dimethyl- |
no data |
no data |
1.0 |
0.3 |
no data
|
no data |
no data |
no data |
no data |
no data |
no data |
no data |
1.0 |
no data |
no data |
|
Isopropyl palmitate |
no data |
no data |
no data |
no data |
no data
|
no data |
no data |
no data |
no data |
no data |
no data |
7.1 |
no data |
8.7 |
no data |
|
Methane, iodo- |
1.5 |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
|
Nonanal** |
9.4 |
6.3 |
9.3 |
3.1 |
2.1 |
11 |
12 |
2.1 |
4.2 |
7.9 |
4.2 |
4.9 |
13 |
8.4 |
no data |
|
Nonanoic acid |
no data |
no data |
no data |
no data |
no data |
no data |
0.9 |
no data |
no data |
no data |
no data |
no data |
1.0 |
no data |
no data |
|
Octacosane |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
28 |
no data |
no data |
no data |
no data |
19 |
no data |
no data |
|
Octadecane |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data
|
no data |
no data |
12 |
no data |
no data |
no data |
no data |
|
Octanal** |
0.7 |
0.6 |
0.9 |
0.4 |
0.4 |
1.1 |
1.2 |
no data |
0.8 |
0.7 |
no data
|
0.6 |
1.2 |
no data |
no data |
|
Octane |
0.8 |
0.5 |
no data |
no data |
no data |
no data |
1.1 |
no data |
no data |
0.7 |
no data |
no data |
no data |
no data |
no data |
|
Pentacosane |
4.0 |
2.5 |
7.4 |
no data |
no data |
7.2 |
no data |
3.0 |
11 |
3.2 |
no data
|
3.4 |
5.8 |
6.8 |
no data |
|
Phenol |
0.5 |
0.6 |
0.6 |
0.3 |
0.3 |
0.9 |
0.7 |
0.6 |
0.7 |
0.7 |
0.7 |
0.7 |
0.6 |
0.6 |
200/3900 |
|
Phenylmaleic anhydride |
0.9 |
0.7 |
1.6 |
0.5 |
no data
|
2.6 |
1.6 |
2.0 |
1.7 |
2.8 |
1.9 |
1.8 |
1.7 |
2.2 |
no data |
|
Several compounds. |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
|
Silanediol, dimethyl- |
0.7 |
0.5 |
1.0 |
no data |
<0.2 |
0.8 |
0.7 |
no data |
0.5 |
0.4 |
0.5 |
0.6 |
0.7 |
0.6 |
no data |
|
Tetracosane |
9.4 |
35 |
9.1 |
no data |
no data
|
22 |
13 |
no data |
3.8 |
no data
|
48 |
12 |
no data |
29 |
no data |
|
Tetrahydrofuran |
no data |
no data |
no data |
no data |
0.2 |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
|
Toluene |
no data |
no data |
no data |
<0.2 |
<0.2 |
no data |
no data |
0.7 |
no data |
no data |
no data |
no data |
no data |
no data |
no data |
Notes
** Compounds may be an artefact due to reaction of ozone with Tenax sorbent.
Compounds with a quality match below 85% are noted as a tentative identity and shown in italics. These compounds are outside of the scope of laboratory UKAS accreditation.
Wooden posts at D9 Rudbaxton Bridge appear to have been recently stained. It is not precisely known when this work was done but it was not before 21 March 2024 based on review of photographs.
Evaluation Criteria:
EAL / EA 2010 – Environmental Assessment Level. EALs represent a pollutant concentration (µgm3) in ambient air at which no appreciable risks or minimal risks to human health are expected.
EAL values taken from Air emissions risk assessment for your environmental permit available on gov.uk and EA 2010 values from Environment Agency Report: P1-396/R Table 5.2.
The following charts contain the information from Table 3-6;
Chart 3‑1 VOC’s detected at D1 New Spittal Cross Farm
Chart 3‑2 VOC’s detected at D2 Spittal School
Chart 3‑3 VOC’s detected at D4
Chart 3‑4 VOC’s detected at D6
Chart 3‑5 VOC’s detected at D7
Chart 3‑6 VOC’s detected at D8
Chart 3‑7 VOC’s detected at D10
Chart 3‑8 VOC’s detected at D13
Chart 3‑9 VOC’s detected at D14
Chart 3‑10 VOC’s detected at D15
Chart 3‑11 VOC’s detected at D16
Chart 3‑12 VOC’s detected on site