Noise: The Invisible Pollutant

The Big Picture

By 2050, an estimated one million new individuals are expected to make their home in the Metro Vancouver area. [i] This projected influx of new residents is in line with the UN’s prediction that 68% of the world population will live in urban centres by 2050. This phenomenon will inevitably result in more noise pollution creating harmful urban environments that will need to be constantly monitored.

The Significance of Noise

Noise can simply be defined as any undesirable sound that provokes discomfort. Beyond being an inconvenience, extended exposure to noise can have lasting effects on our health and can lead to elevated blood pressure, high heart rate, sleep disruption and hearing impairment. [ii] Noise also impacts urban wildlife, especially songbirds who are extremely sensitive to changes in their environment. Noise makes it more difficult for them to communicate with each other eventually leading to lower songbird populations which has an impact on the balance of urban ecosystems. [iii] Ongoing monitoring of noise is crucial as the decisions made by our policy makers and urban planners will affect the daily life and health of anyone living in a city.

Data Acquisition

The data was collected in South Burnaby, covering an area of approximately 11 km2 with a population of over 66,000 people and an average density exceeding 6,000 inhabitants per km2.

In order to collect our data, we repurposed smartphones running on Android 6 and 7 on which we deployed a customized TensorFlow Lite Model capable of recognizing a wide range of sounds. We take advantage of the smartphones’ computing power to conduct unmanned surveys lasting up to 12 hours while the devices run on battery alone. Our data offers all stakeholders some actionable insight to build urban spaces that prioritize both human well-being and environmental sustainability.

The Map

The primary goal of our map is to show the main sources of noise around South Burnaby. By hovering your mouse on the interactive map which you will find here, one can hear actual sounds recorded during our surveys. Those recordings include for the most part vehicles (cars, buses, trucks), rail transit, songbirds and ambient noise.

The map provides data down to the local level in order to allow policymakers and urban planners to make informed decisions. The scale of colours indicate the nature and intensity of the noises. Areas in dark green represent areas with negligible urban noises and mostly songbird sounds while areas in red correspond to Dissemination Areas where traffic and rail transit are the most common source of noise. The boundaries used on the map represent what Statistics Canada refers to as Dissemination Areas (DA). They are made up of adjacent blocks and usually include between 400 to 700 residents.

Insights and Takeaways

The surveyed area is not representative of the City of Burnaby. Therefore, we acknowledge that the conclusions drawn below are specific to our region of interest and should not be extrapolated to the rest of the city. The divide is quite clear.

Zoning and Parks

88.9% of the area we cover is zoned for residential use, 4.8% is dedicated to parks and open spaces and approximately 4.7% for commercial purposes while the remainder 1.5% is zoned for institutional use.

The quieter areas are located in the southern part and tend to be closer to conservation areas and ravines (dark green) but also to neighbourhoods located in proximity of those areas (light green) which are mostly zoned for Single Family Homes.

On the contrary, the noisiest neighbourhoods (orange and red on the map) were located in the proximity of major roads as well as rail transit which constitute the 2 main sources of noise in the area we surveyed.

Roads

Roads are the main source of noise. The map below shows the different categories of roads that span across the area. Intermittent noise level recordings confirm that the average decibel level varies based on the classification of each road. Residential roads (in blue) are quieter than major roads (in red and white) where most of the traffic happens due to use of cars, buses or trucks.

Inequalities

Denis Agar from Movement and Jens von Bergmann from MountainMath have created the map below to show the distribution of renters across Metro Vancouver. [iv]

When zooming in on South Burnaby, we quickly notice the positive correlation between noise and renter density. In other words, the quietest neighbourhoods have the lowest tenant density while the majority of the noisiest neighbourhoods have a high tenant density.

While keeping in mind that correlation does not imply causation, we can state that people who rent are more likely to be exposed to urban noises and suffer from the long-term health implications. On the other hand, people who own their home are more likely to live in areas with minimum exposure to noise and as a result are less likely to suffer from it. These conclusions are in concordance with the World Health Organization’s who states that “the less affluent who cannot afford to live in quiet residential areas or have adequately insulated homes, are likely to suffer disproportionately.”

Songbirds

Songbirds play a central role in urban ecosystems. They contribute to pest control and their active participation in seed dispersal is equally important in order to ensure floral diversity in our cities. [v]

The data we collect also allows us to model the distribution of the songbird population and eventually track how neighbourhoods compare over time in maintaining healthy ecosystems.

The Next Phase

Our goal is to set up autonomous noise stations in strategic locations in order to collect live data and make it available to all. To achieve that goal, we aim at creating partnerships with community members and for profit organizations to help monitor noise levels in different parts of the city. Noise is a powerful indicator. It allows us to measure the well-being of our neighbourhoods and cities while tracking the state of urban wildlife population as well as pointing out social inequalities. We believe the data we gathered is valuable as it provides actionable data for community members, stakeholders and policy makers to build neighbourhoods as envisioned in the 2050 Burnaby plan. [vii]

This link will take you the interactive map.

i. https://metrovancouver.org/media-room/media-release/783
ii. https://www.who.int/tools/compendium-on-health-and-environment/environmental-noise
iii. https://news.ncsu.edu/2020/11/noise-and-light-pollution-impact-songbird-reproduction/
iv. https://mountainmath.ca/planned_displacement_map.html/
v. https://www.nature.com/articles/s41598-020-78736-x
vi. https://www.nature.com/articles/s41598-022-20207-6?itid=lk_inline_enhanced-template
vii. https://www.burnaby.ca/our-city/projects/burnabys-official-community-plan-project