odour : Smells like team spirit

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Let's be honest. Odours are not the centerpieces of the planning in environmental permitting processes. In the best of cases, the potential impact is modelled and included - an ounce of prevention that can avoid serious conflict and expense. However, there are many cases where odour impact on neighbours is not considered, or dismissed as mere nuisance. This despite growing evidence of significant health, social and economic consequences associated with long term exposure to odour pollution.

Consistent and coherent odour regulation has so far been lacking, with a patchwork of policies at different levels. One of the reasons for this is that odours are difficult to measure and have some subjective characteristics. Another reason is the intricate web of intersecting interests of stakeholders including industries, citizens and policy makers. D-NOSES was born from the lack of a proper, balanced response to odour issues, and the need to fill this perceived regulatory gap. After all, odours are the second most common complaint after noise, at least in Europe.

The big idea

The D-NOSEs method consists of two parts. The first one uses citizen science to measure and track odours based on their real-time impact by using a geo-localised app for local residents to report odours as they perceive them in their daily lives. This allows the reports to be easily combined with weather data and information from processes at nearby odour sources that can help diagnose problems as well as test the effects of possible solutions. The second part is a stakeholder engagement model that brings together industry, citizens, policy makers and odour experts in a so-called quadruple helix to discuss and co-create possible mitigation scenarios.

Measuring odour impact - the app

Odour Collect is the preferred D-NOSES tool for collecting data on odours. After all, people are already equipped with the best possible and most flexible odour sensor there is - their noses. The free application is simple and only requires users to rate detected odours on their hedonic tone (is it a pleasant or unpleasant smell), and their intensity. The data collected is automatically registered in time and location, which allows data reliability analysis to be done on the frequency and impact of odours. Because of the real-time component, it is also possible to build-in extra validations by trusted experts to ensure the validity and transparency of the data.

The apparent simplicity of the odour collection app hides some of the complexity of the validation and back tracing process in the background. Odour reports can be used in dispersion models that include geographical and weather data, indicating the odour path to their probable source. This tool has proven invaluable in differentiating odours and impacts from different sources, as it is often difficult to differentiate types of smells coming from industry, waste or agrarian sources.

The Odour Collect app is available for free and can be used anywhere in the world to register odours as people go about their daily life. These records, built up over time, will give odour experts a rich database of background odour information that can help to distinguish significant odour events and their impacts.

Pilots - where the concept meets the real world

The innovative methods developed in the project are based on the experience of odour and Citizen Science experts. As with anything new, testing in real world situations is essential. This was done in pilot case studies conducted across Europe and the world, testing the methods and tools in varying contexts. For example in Barcelona, where the Forum Area is surrounded by 64 possible odour sources. The data collected over a full year of citizen observations has been useful in better separating the main sources of irritation for residents. This allows for more targeted solutions and discussions to alleviate the problem. Likewise, while analysing a complex and long-standing odour source issue in Lombardy, the data collected suggested there was a previously unidentified and unexpected source of odour impact at play in the area. This helped to explain the lack of significant effect from the mitigations that had been previously implemented.

In Sofia, Bulgaria, the municipality introduced a food waste and bio-bin collection program to help alleviate odour issues across the city, mostly centred around food and catering sites. As with all new processes, it needs monitoring and improvement. Large scale data collection was done across the city and around sources of food waste to regularly measure the levels of odours and impact. This data has led to improved collection frequency and schedules that lower the nuisance on neighbours and passing tourists.

At the other extreme, a pilot was conducted in Kampala, Uganda. Like any city there are odours of all sorts, and some of them unpleasant - particularly from open burning of household waste which is commonplace. There is however ineffective policy and legislation to regulate odour pollution. Recently, the proposed methodology was officially recognised by the local government as a valid approach that could help create an evidence base to direct scarce resources - even though it has not yet been put to use.

Legacy - odour management in the future?

If nothing else, D-NOSES offers an alternative and complementary approach to traditional methods for odour measurement and issues management. Like all other methods it has certain qualities that make it more, or less suitable for any particular setting. Transparent real time impact data shows the reality now rather than relying on studies that might show previous snapshots of the situation. Particularly when this can be linked to operations at the source, this can lead to smarter and more cost-effective strategies to mitigate impacts. Investigating multiple odour sources using the track and trace possibilities of retro-trajectory modelling helps in separating the level of impact and can show which source is causing the most problems. The final legacy of the project is the International Odour Observatory. It is a website that collects the information, guidelines and practical help needed to better understand the issues around odour management and how to get started when you find yourself as a stakeholder in such an issue. You can visit the odourobservatory.org to find out more.

Register here for the free D-NOSES Conference on Odour Management & Citizen science, with 3 separate sessions aimed at general, technical and policy interested audiences on October 14, 18 and 20 respectively.