Public Lab Research note

Putting Odor Issues on the Map: Using citizen science to curb odors in the EU

by joyofsoy | June 25, 2019 16:30 25 Jun 16:30 | #19858 | #19858

A version of this story from D-NOSES is published in Public Lab's Community Science Forum, Issue 16. Photos courtesy of D-NOSES.

The human nose is capable of recognising up to a trillion different smells and is by far the best instrument, even scientifically, that we have to detect odours. Not all odours are pleasant however, as many who have spent time near waste management facilities, chemical plants, or even food industries can agree. Our noses are delicate instruments that can detect harmful molecules such as hydrogen sulphur in concentrations as low as 10 parts per billion, protecting us from lethal exposure. When persistently exposed to bad odours, the wonder of the sense of smell can soon turn into a nightmare.

In terms of regulation, odour pollution is relatively ignored. In Europe and globally, it is the second largest cause of environmental complaints after noise, and yet there is little effort to harmonise or create regulation at a local or national level. Part of the reason is that detecting and measuring odours can be tricky, and pin-pointing sources or estimating effects even more so. European standards (EN13725:2003) establish how to measure odour concentration, but cannot measure the real impact on people. This is the other part of the problem: odours are assumed to be annoying, but harmless. However, there is growing evidence that persistent exposure to bad odours can have significant effects beyond mere inconvenience. People in affected communities can suffer from headaches, throat and eye irritation, nausea, sleeplessness, anxiety, stress, or even respiratory problems.

The problem is that short term economic interests, inconsistent regulation, and lack of reliable data to demonstrate the severity of the problems usually prevent significant action from taking place. This is why Rosa Arias and the D-NOSES team received funding from the EU to create an alternative, bottom-up approach to odour pollution involving citizens as key actors for change. Volunteers can register smells in their communities with the new OdourCollect smartphone and web-app, turning the noses of the residents into a sensor array that can report odours in real time. The app uses geolocation to pinpoint where the odour was detected, and the user describes the smell, rating its type, intensity (how strong the smell is) and hedonic tone (how pleasant or unpleasant the smell is). This simplicity hides the complexity of the validation and back tracing process in the background. Reports are fed into a sophisticated retro-trajectory dispersion model, including complete geographical and weather data, to calculate an odour’s path to its source. Considering similar reports, this can validate and confirm the source of the odour. Odour experts and citizen scientists can then match observations with industrial processes at the source and co-design ways to minimize the problem.

While that sounds relatively simple, the truth is that scientific data is not enough. For change to happen, communities must mobilise, stakeholders have to agree, and local authorities need to take action. D-NOSES proposes a method, following the quadruple helix model for stakeholder engagement, to bring together communities, local authorities, private enterprises, and research institutions into a constructive dialogue. This will become a platform where effective and balanced solutions can be found, with improved communication and transparency. It uses a highly inclusive approach, where people are encouraged to participate regardless of their literacy and socio-economic levels, cultural background, or gender.

The project will run 10 carefully selected pilots to demonstrate the power of citizen science and the ability to get results in different settings. In some cases, the pilots focus on different types or odour sources. In Barcelona, the affected area has a long history of odour issues from several waste management facilities and wastewater treatment stations concentrated nearby. This has been a growing concern since the municipality tried to revitalise the previously depressed area with new high-rise developments and housing. In Thessaloniki, residents are repeatedly exposed to fumes from a nearby refinery, but it was the population that grew around the refinery over the last 50 years. These cases show how an accommodation needs to take place as communities and industries develop over time. The balance between industry, economic and social development, city planning, and environmental management is one that D-NOSES hopes to achieve.

In São João da Madeira, the pilot will tackle a persistent odour problem from an animal by-product processing plant. There have been previous odour mapping projects that unfortunately did not result in any practical improvement. This case aims to show that beyond data, the positive engagement of all stakeholders is required to find practical solutions.

The Forum area in Barcelona is surrounded by four large waste management facilities, which continue to expose the long time local residents to persistent bad environmental odours. The Forum area in Barcelona is surrounded by four large waste management facilities, which continue to expose the long time local residents to persistent bad environmental odours.

The D-NOSES method can be used in other contexts. In Sofia, it will help diagnose and explore cost-effective performance improvements for an existing municipal program to eliminate odours from food waste around the city. In Porto, volunteers will help to track odours that may reveal and help stop sources of pollution in the Rio Tinto river, hopefully reversing the environmental damage. These pilots demonstrate the flexibility of the approach to deal with a wider range of issues relating to the impact of odour pollution.

The project findings will go toward creating the International Odour Observatory—a place for anyone who finds themselves a stakeholder in an odour management issue. For residents it will give access to the odour mapping applications and instructions on how to use them effectively. For industry it will describe how they can use the same process to have cheaper and more effective control on their emissions, as well as better relationships with their surrounding communities. For local authorities it will provide a blueprint for an engagement platform that can defuse conflict situations and promote win-win scenarios for all stakeholders. For scientists it will compile state-of-the-art advancements in odour science.

The wind might already be shifting for odour regulation. Recently, Chile approved a legislative proposal that classifies odours as contaminating agents. Portugal and Italy, are working on similar regulations to control odours. New regulations should set a consistent framework that enforces more careful planning of both locations and operations of odorous facilities, both for the safety of the people as well as the investments of the operators.

Odor tracking and tracing could help identify and stop sources of pollution in the Rio Tinto River, preventing further environmental damage Odor tracking and tracing could help identify and stop sources of pollution in the Rio Tinto River, preventing further environmental damage.

To find out more about D-NOSES, visit and follow them on Twitter at @dNOSES_EU and Facebook at @dNOSES.EU.

Rosa Arias is the D-NOSES project coordinator. She has over 14 years experience as a consultant within environment and innovation projects (with an expertise in odour pollution) and has participated in and coordinated several other European projects. She is passionate about Responsible Research and Innovation (RRI), citizen science, and the role of women in science.

Nora Salas Seoane is an experienced psychologist in social intervention and community-based projects within disadvantaged neighbourhoods. She has also worked as a social scientist and coordinated social and international cooperation projects within Gender Studies, Migratory Movements and Interculturalism and Social Anthropology, working with different communities across Europe and Africa.*

Jose Uribe-Echevarria is the D-NOSES project communications manager. In his regular job he is responsible for strategic projects at the International Solid Waste Association. He has extensive experience as an innovation manager both in the commercial and non-profit sectors.


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