From my original Facebook note.
Berkeley Group founder and chair Tony Pidgley promised to share their onsite air quality monitoring data with us almost two months ago. We’re still waiting.
Today,I finally received a response to my email of 29 September, in which I asked Tony to confirmm what his trusty sidekick Karl Whiteman told us when we met with the both, that benzene levels were ‘averaging 3.25 parts per million (ppm) [sic], and never exceeding 5ppm.’
‘Dear David,
I trust you are well.
I appreciate that you have been awaiting the release of data for some time and I do apologise for the continuing delay. I am afraid there is a great deal of data and the insurers are still going through the detail.
In the meantime, as I think it is unreasonable to keep you waiting any longer, I have asked our advisers to produce resumes of the information which I am enclosing and which I hope you will find helpful.
If you would like to set up another meeting with me, please liaise with my PA, Jo Potton.
With kindest regards,
Tony’
Update for residents on monitoring.
FAQs - Air Quality Monitoring.
In these ‘resumes’, Atkins restate what they said at Ealing Council’s Air Quality Scrutiny Panel meeting in September - that during the period July to September, average levels of benzene did not exceed 5 micrograms per cubic meter (mg/m3), and that this is ‘well within the UK legal limit for benzene’ [sic].
The UK Health and Safety Executive states that the legal limit for benzene is 1 part per million (ppm).
Converting ppm to mg/m3:
Conversion Calculator
$\text {“mg/m3}$ to ppm” or “ppm to $\mathrm {mg}/\mathrm {m}^{3}$
The conversion equation is based on 25 °C and 1 atmosphere:
$Xppm=(Y$ mg/m3)(24.45)/(molecular weight)
or
$\mathrm {Y}\mathrm {mg}/\mathrm {m}^{3}=(\mathrm {X}$ ppm)(molecular weight)/24.45
Fill in either the $‘ppm”$ value (X) or the $\text {"}\mathrm {mg}/\mathrm {m}^{3}$ value (Y) AND the molecular weight of the compound. Then press the “Calculate” button.
ppm:1 $\mathrm {mg}/\mathrm {m}^{3}$ molecular weight:78.11184
Calculate Reset
| ppm value | $\mathrm {mg}/\mathrm {m}^{3}\mathrm {valu}$ | based | on the molecular weight of |
|---|---|---|---|
| 1 | 3.19 | 78.11184 |
Remember to consider significant digits in your use of the answer.
$$1\text {ppmbenzene}=3.19\mathrm {mg}/\mathrm {m}_{3}$$
Molecular weight of benzene = 78.11184
So, Berkeley Group, via their sub-contracted ‘independent’ air quality monitoring partner corporation Arkins are stating that the average level of benzene during the summer months was less than 5 mg/m3, or less than 1.57 ppm:
Conversion Calculator
" $\mathrm {mg}/\mathrm {m}^{3}$ to ppm" or “ppm to mg/m³”
The conversion equation is based on 25 °℃ and 1 atmosphere:
$Xppm=(Y$ g/m3)(24.45)/(molecular weight)or
$\mathrm {Y}\mathrm {mg}/\mathrm {m}^{3}=(\mathrm {X}$ ppm)(molecular weight)/24.45
Fill in either the $“ppm”$ value (X) or the $“mg/m3”$ value (Y) AND the molecular weight of the compound. Then press the “Calculate” button.
ppm: mg/m³:5 molecular weight: 78.11184
Calculate Reset
| ppm value | $\mathrm {mg}/\mathrm {m}^{3}\mathrm {valu}$e | based on the molecular weight of |
|---|---|---|
| 1.57 | 5 | 78.11184 |
Remember to consider significant digits in your use of the answer.
$$5\mathrm {mg}/\mathrm {m}_{3}\text {benzene}=1.57\mathrm {ppm}$$
1.57 ppm is $57%$ higher than the UK legal limit of 1 ppm.
The reason Atkins and Berkeley presented data for benzene over the summer period is because they believe this was the period with the highest levels (due to the heat), and that they say it can reasonably be deduced from this that the average over the year, therefore, must be even less.
I would like to see the monthly, weekly, daily and real-time data.
I believe it could reasonably be deduced that the average for July was over 5 ppm, and that the levels of benzene could be significantly higher on many occasions over shorter periods. But we will never know, unless we are given access to the data.
And none of the above tells us what is causing the smell of petrol.
My gran used to mothball all her clothes, and I think I would recognise that smell. So, while I’m sure naphthalene may well be part of what we smell, it’s not the whole story. And naphthalene is just fine isn’t it?
And then there are all the other polycyclic aromatic hydrocarbons like xylene and toluene that they haven’t mentioned. Because, we all know that sniffing an unknown, uncontrolled chemical cocktail every day for eighteen months is bound to be safe, too. It just stands to reason!