eLichens

Despite progress, air quality in urban areas remains a health and economic concern, leading Europe to adopt a Zero Pollution Action Plan as part of the Green Deal. Fine-scale air quality information is a key element but requires relevant and affordable technical solutions. eLichens has developed a new innovative hybrid approach that combines a network of connected fixed or mobile sensors and a neural network model to obtain robust high-resolution data.

The eLichens API allows the retrieval of this air quality data all around the world. More than 300 cities are currently covered. This API is freely available for researchers, municipalities, and citizens. Based on this API, two applications make the high-resolution air quality data visible and understandable:

- A website, that displays near-real time maps and 3-day forecasts of air quality and pollens indexes, accessible at: https://map.elichens.com.

- A smartphone application, eLichens Air, provides relevant information about the quality of the air you breathe. Thanks to the AQI (Air Quality Index), this app lets you know if the air quality is healthy or not and gives advice on impacts of air quality on your health and activities.

CAMS data is a fundamental part of the eLichens technology. Global forecasts, enhanced with near-real time measurements from reference stations, are used as reliable and accurate estimations of the worldwide background pollution. This background pollution is an input of our neural network model and is also used in the calibration process of our low-cost sensors when deployed in areas without any reference stations.

The added-value of the deployment of the eLichens outdoor solution has been demonstrated in different cities. Some examples:

- at San Francisco the eLichens stations’ network, combined with the street-level air quality neural model, was able to follow the evolution of the air quality during different fire events in California. We also studied the positive impact of the local Covid lockdowns on air quality.

- At Grenoble, France, the hybrid solution was validated during a long-term deployment. Also, among other studies, the impact of a public policy on mobility (during Covid lockdowns, some traffic lanes were transformed to bike lanes) has been highlighted.

- The easy-to-use API allows us to develop different use cases around air quality, most wanted by municipalities and local stakeholders. Some of these uses cases (less-polluted path, pollution exposure, impact of traffic…) are demonstrated at the website http://usecases.elichens.com/.