Noise pollution and Fair Sharing

Much of the concern expressed by the opponents of Toronto City Centre Airport focuses on the noise it produces. This leads to the question: how much noise does Toronto City Centre Airport really produce, and how much less (or more) noise would the proposed alternatives subject the city to?

In Summary

To skip directly to a discussion of these talking points, click on the appropriate links.

• Dispatching a passenger from City Centre Airport by turboprop generates less noise than dispatching the same passenger from Pearson by jet.
• The communities around Pearson already experience substantially greater noise levels than the communities on the Toronto waterfront.
• According to the demographic data, the people who live around Pearson have an equal if not greater vulnerability to noise than their noise levels than their counterparts downtown.

Alternatives (and Associated Noise Levels)

The opponents of the revitalisation of Toronto City Centre Airport have one concrete proposal: move all commercial air traffic to Pearson International Airport, a project that Councillor (and now a candidate for Mayor) David Miller described in a June 12 2003 speech as "working to consolidate air travel at Pearson Airport". They want to use high speed trains to whisk travellers from the downtown to Pearson, where they will board aircraft for their ultimate destinations. That may reduce the number of takeoffs and landings at Toronto City Centre airport, or at least prevent them from increasing. It may or may not have a discernible effect on noise and pollution in the downtown core. To see what effect it will have on the people of north-west Toronto and Mississauga, use the maps below.

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Click on a square in the map to the right to listen to sound recordings taken from different parts of the city, and to see exactly where the recordings were taken.

You have just heard a jet departing from Pearson International airport on the flight paths which run directly North of Rexdale. Click the map to the left to hear it again. As the map shows, this sound was recorded at a school just south of Dixon Road. The school sits in the middle of a neighbourhood, about a kilometre south-east of the flight paths of jets leaving the southern runways (6L and 6R) of Pearson. To compare these sounds with the sound of a Dash-8 turboprop taking off from Toronto City Centre Airport, as recorded from the waterfront park by the Harbourfront fire station, please click on the square on the map above that covers the waterfront. All of these sounds were recorded using the same equipment, and published on the web with exactly the same settings, and in exactly the same way. All of the sounds from each location were each recorded in a single session. The recordings used were chosen based on their location, not on the noise levels. While different conditions may produce different perceived sound levels, these recordings reflect the average noise level measurements taken at the waterfront and around Pearson (see below for a complete explanation). As you can tell by comparing the noise impacts of operations at Pearson with the effects of operations on the waterfront, a serious question exists about whether diverting air traffic from the waterfront to Rexdale is just, or even wise. If you do not like this conclusion, by all means go out to Rexdale, Malton, and Mississauga. Find out where the jets are taking off and landing (operations vary, depending on the wind direction). Hear the planes for yourself.

You have just heard a Dash-8 turboprop taking off from Toronto City Centre Airport over the waterfront. Click the map to the left to hear it again. Compare this sound level with the noise made by jets from Pearson over Rexdale. As the map shows, this Dash-8 takeoff was recorded at the waterfront park by the Harbourfront fire station. To compare these sounds with the sound of a jet as recorded from the residential neighbourhoods of Rexdale, click on the upper square on the map above. All of these sounds were recorded using the same equipment, and published on the web with exactly the same settings, and in exactly the same way. Only one aircraft was recorded at each location. While different conditions may produce different perceived sound levels, these recordings reflect the average noise level measurements taken at the waterfront and around Pearson (see below for a complete explanation). However, please note that in many cases the smaller aircraft using Toronto City Centre Airport make more noise than the Dash-8 turboprops. The noise made by a propellor plane varies according to many factors, including the setting of the controls. However, while small aircraft may produce noise spikes, an increase in the traffic by the quiet Dash-8 aircraft will not mean a significant increase in the noise on the waterfront.

What Exactly is Noise Pollution

Noise pollution means any noise people can hear and don't like. If you don't like your neighbour's music, then you will probably class it as noise pollution. If airplanes frighten you, then you will probably consider any aircraft sounds, however faint, polluting and intolerable. The same goes for the sounds of cars, streetcars, and music.

But every neighbourhood has a mix of people-- some like the sound of aircraft, some hate it, most tolerate it. In a big city with two and a half million people rubbing shoulders, everyone will have to listen to some sounds they don't want to hear. We have the ability, and the obligation, to make sure our policies with regard to noise, as well as other pollution, reflect a basic level of fairness.

The physiological effects of noise depend on two factors: the loudness, or sound pressure, and the pitch, or frequency. Louder sounds obviously have more of an effect than softer ones, and high pitched sounds generally have somewhat more effects than lower pitched ones. Other factors, such as the time of the sound, come into play as well; people obviously mind aircraft noise more at night, when they are trying to sleep. To some extend, vulnerability to noise exposure varies by age; see below.

To regulate aircraft noise, Canada uses a measuring formula called the "Noise Exposure Forecast", or NEF. This formula converts the raw loudness measurements according to time of day and other factors, and comes up with a single index, representing the expected results of exposure to the given noise levels. The effect of noise around an airport is generally measured in a series of contour measurements and plotted using a geographic information system. At particular noise exposure factors, certain types of development are generally not recommended: for example, residential development inside the NEF-30 contour is not generally considered wise.

The map below shows the noise exposure contours for Pearson International Airport. The pink areas represent residential areas. Notice that the NEF-30 contour for Pearson International Airport overlaps the boundaries of the residential areas on both sides of the flight paths, despite recommendations against residential development inside an NEF-30 contour. This map comes from GIS work done by Shawn Morgan; used by permission.



By contrast, the NEF-25 contour of Toronto City Centre Airport only touches populated land at one point, where it includes one building with about 200 residents. The NEF-30 contour on the waterfront does not come near the shore. Clearly, Pearson International Airport has a considerably greater effect on the residential communities near it (and in fact on the whole of Toronto) than Toronto City Centre Airport does.

Vulnerabilities of the Communities Near Pearson

Demographic data obtained from the Census (Statistics Canada, 1996 and 2001 Census of Canada) indicate that the population of the census tracts in Malton include a higher proportion of young people than the population of the waterfront; proportionally, Malton has over twice as many children under fifteen as the census tracts right along the waterfront. Malton has many schools close to Pearson, and one school, "Our Lady of the Airways" sits less than a kilometre from the centre of an approach path, and barely more than 500 meters from the airport fence.

The age of the people exposed to noise matters, because of studies showing that noisy environments have a particular effect on the health and education of young children.

Opponents of the revitalisation of Toronto City Centre Airport sometimes claim that research into new technologies, or the development of high-speed rail, will make air travel obsolete. Possibly so, although the technology, as well as many of the more exotic claims about air travel and pollution, remain unproven. However, we do know this: that if we "consolidate" air travel at Pearson, then no technology, no breakthrough we make will reach back into the past and undo the effects our actions will have had on the children of Rexdale and Malton. A high-speed rail link in five years, or a miraculous non-polluting fast dirigible in twenty, will never undo the effects the jets have today, and that more jets from the "consolidated" air traffic may have tomorrow.



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