There are two approaches to ventilating road tunnels. Obviously the longer the tunnel the bigger the problem, both logistically and in terms of the volume and concentration of the released toxic air.
The best method by far is “in tunnel filtration”.
This begins with the design of the tunnel. Special areas adjacent to and at staggered points along the length of the tunnel are constructed to house the filtration equipment.
This gear is designed to remove both particulate matter and the oxides of nitrogen. Overseas tests in Japan and other countries have proven this approach to be almost 100% effective.
The sub-standard, absurdly expensive and totally ineffective NSW approach is to import the exhaust emissions and push them along the entire length of the tunnel, then attempt to dilute it by sucking in “fresh” air from outside, and finally pumping the polluted mass out through the exhaust stacks, without any form of filtration!
Thus the closer a vehicle gets to the exit portal, the greater the volume of air and exhaust pollution. With four exhaust stacks in close proximity, Rozelle is indeed Sydney’s exhaust pipe!
This lethal approach is of special significance to residents who live in the fallout zones and also to the occupants sitting in the slow-moving/stalled tunnel traffic approaching the exits, as the level of cancer-causing ingested polluted air adjacent to the portals is way off the scale!
This is the approach that is adopted here in Australia.
It comes down to either filtering or diluting and releasing the unfiltered tunnel air.
The powers that be continue to lie about “world’s best practice”.
“In tunnel filtration” is the world standard and importing and then pumping high concentrations of cancer-causing pollution from the exhaust stacks isn’t a solution at all. It’s a problem. A fu*king big problem.
Although particulate matter and oxides of nitrogen have extremely serious health consequences that can be almost entirely eliminated through tunnel filtration, carbon dioxide (CO2) – the primary component of car exhaust – has no viable filtration technology.
Fixing the problem
CO2’s contribution to the global climate emergency is of course well known. The obvious way to address that problem is through upgrading public and active transport infrastructure, which was so shamefully ignored when WestConnex was first conceived.
To be totally honest, retrofitting of the tunnels to filter the air is certainly possible, but highly improbable, because of the extensive work needed within the tunnel complex; and with WestConnex’s 33 kilometres of tunnels, it is now almost certainly cost-prohibitive.
Apart from the question of who would bear the cost, there is the fact that the Government and the RMS would be forced to admit that they totally stuffed up the whole project right from the design phase.
If they were coerced into such an admission; that they’d lied and continue to lie about “world’s best practice” and that the diesel exhaust plumes do cause at least eight different forms of cancers, they would then be faced with the huge problem of retrofitting every road tunnel in the State, which could then lead to other States adopting this approach throughout the entire country.
Obviously, they would also leave themselves open to massive compensation claims of wrongful death – if they aren’t liable already – just like the cigarette companies.
But just like the cigarette companies and the structural damage caused by the WCX tunnelling, proving causality is the stumbling block.
The fact remains that both major parties support the current tunnel methodology, so retrofitting of the stacks almost certainly won’t happen.
However, this shouldn’t stop us from demanding that the tunnels be filtered. It will be years before fossil fuel burning vehicles are outnumbered by vehicles powered by green technology.
In the interim, hundreds of thousands of locals will die prematurely because of the unfiltered exhaust plumes, dumping hundreds of tonnes of carcinogenic material annually into the air that you, I and every other local person and tunnel user is forced to breathe.
The cancer-related deaths associated with the unfiltered M5 East plume, generated by just 2.2 kilometres of tunnel, clearly demonstrate that.
After alarm bells rang, tests were undertaken to determine the cause of the cancer cluster in Turrella residents who lived downwind of the exhaust stack plume.
This group showed a 44 per cent increase in lung cancers while over the same period, the State average fell by 9 per cent!
A succession of both Labor and Liberal State Governments still refuse to recognise a causal relationship, meanwhile those who live in the plumes emitted from these road tunnel stacks, and those under construction, will continue to die premature and painful deaths.
Surely this is worth remembering when casting a vote at the next Local, State and Federal elections?