open-seneca: air quality sensing powered by citizen science

open-seneca

Started in 2018, the open-seneca initiative has deployed pilot citizen science networks of low-cost air quality sensors in cities in the UK (Cambridge), Argentina (Buenos Aires and Mendoza), Kenya (Nairobi), and Brazil (Belo Horizonte). The team has in-depth experience in the design of open-source, mobile, low-cost air quality monitors and capacity building in partner cities, the education and engagement of citizens, and calibration, analysis, and visualisation of the data collected with the low-cost sensors to aid with decision making.

The open-seneca team 2020

In addition to providing sensors, we aim to educate. We host workshops prior to each deployment. In each workshop we cover the relevant topics related to air pollution and how it affects our health and our environment. We also cover how one can monitor air quality and how each sensing method works. This then follows an interactive session where we show how one can build a sensor, using one of our open-source designs.

Introductory lecture given by Matias Acosta in Buenos Aires.

Open-seneca monitoring devices use the Sensirion SPS30 Particulate Matter Sensor. This sensor has received the MCERTS² Performance Standards for Indicative Ambient Particulate Monitors for PM2.5 in the range of 0 - 75µg/m³. The uncertainty of this sensor is ±8.9%, complying with the data quality objective for indicative measurements.

According to this classification, the SPS30 sensor used in the open-seneca air quality sensor would be suitable for any of the applications of Tier I-V. The aim of the open-seneca initiative is to empower citizens with data about their personal exposure to particulate pollution (Tier IV), to raise awareness and drive behaviour change (Tier I), and to provide high spatial and temporal resolution pollution maps that highlight hotspots of particulate pollution (Tier II and III) to inform policy. However, in a citizen science setting where the sensors are mobile, the uncertainty required for Tier V might be compromised, and the initiative does not aim to ensure regulatory compliance of cities to current air quality regulations.

We currently use off-the-shelf components interfaced with a 'plug & play' style PCB. They aim to be simple to build and versatile enough to be applied to any setting, and to be modular and accesible to everyone. Our designs are open-source and available from our public GitHub.

Current open-seneca plug & play PCB.

The device requests data every second from each respective sensor, and stores it on the microSD card. The requested data is similarly transmitted via BLE or GSM. Additional sensors and other common IoT communication protocols (e.g. WiFi, LoRa, Sigfox, NBIoT) can be added upon request. We currently have a basic Android app to interface with our sensors via BLE, which can be found here.