By David Amaya
Emission controls, tree planting and cycling networks are among the reasons to breathe deeply in the CBD.
The Index Air Quality taken by the state’s Environmental Protection Authority (EPA) shows that pollution levels in the central city is relatively low, considering this area is one of the busiest places in Australia.
The authority evaluates the level of up to seven pollutants through air monitoring stations. A station located in Carlton Gardens measures the air quality in the CBD and other nearby suburbs.
Each pollutant has a different unit of measurement and therefore its level of toxicity has a different range.
For example, coarse particles PM2.5, and PM10, are reported in micrograms per cubic metre (µg/m3). To be considered harmless, they must remain between 0-8.9 µg/m3, and 0-16.4 µg/m3, respectively.
Carbon monoxide is measured in parts per million (ppm) and must be between 0–8.9 ppm, whereas sulfur dioxide is measured in parts per billion (ppb) and must remain between 0-65 ppb.
Rarely do these pollutants rise to levels of toxicity in the CBD.
John Rees, EPA spokesman, said overall, Melbourne’s air quality had improved in the last two decades largely due to the introduction of emission controls on cars.
“As old cars are retired and replaced by new cars meeting tighter standards, pollution from motor vehicles has decreased despite an increase in the number of vehicles on the road,” Mr Rees said.
He also added that the removal of lead from petrol had also been an important strategy.
There are other measures too that have played an important role in keeping a low level of pollution in this area of Melbourne.
It is important to point out that measures, including restrictions of vehicles in some streets, the cost of parking, the cycling network and tree planting strategies, haven’t been implemented only to maintain the good air quality but for other environmental purposes and for controlling traffic.
The City of Melbourne has restricted the flow of vehicles in some of the CBD streets.
Swanston St is permanently closed to private cars, and Little Collins St has the same restriction between 12pm and 2pm.
This significantly reduces the production of pollutants in this area of Melbourne, mostly in rush hours when the amount of motor vehicles increases the most.
Additionally, the high price of the approximately 2400 on-street metred parking spaces in this area of Melbourne could be seen as detrimental to drivers’ budgets, and has discouraged vehicles.
The fewer vehicles on the streets, the lower the likelihood to increase pollution levels.
In contrast, clean transport methods such as walking or cycling are promoted. According to data provided by the City of Melbourne, almost 90 per cent of daily trips in the CBD are made on foot.
On the other hand, the city’s cycling network, with over 135km of on and off-road routes, has encouraged bike riding.
A survey conducted by the council in March 2017 measured the number of bicycles and vehicles travelling in approximately 19 routes towards the central city during the morning peak (from 7am to 10am).
“Up to 17 per cent of all route users recorded were cyclists,” a council spokesperson said.
This helps to reduce the traffic volume that, according to Mr Rees, “causes other aspects of motor vehicle emissions such as particles from road dust, brake wear and tyre wear”.
Besides the control on pollution emissions, the City of Melbourne released in 2013 its Urban Forest Strategy to increase canopy cover by 2040.
Currently, there are 2500 trees within the Central City Precinct planted in parks and along the streets. The city aims to double its canopy cover by 2040 and is currently planting 3000 trees per year to achieve this target.
“This directly improves air quality by removing pollution and particulate matter from the air,” the council spokesperson said.
All these conditions together make the CBD not only a business centre and entertainment spot, but also a place where it is possible to breathe deeply.