Airly sensors are small devices that measure the level of outdoor air pollution. In real time, the sensors read a series of air parameters (PM1, PM2.5, PM10, temperature, pressure and humidity) in a particular location. Research confirms the quality and reliability of the data collected by Airly’s sensors, as well as the fact that weather conditions (e.g. humidity) do not affect the measurements.
State Environmental Monitoring stations
As well as the Airly sensors, the platform also includes visualized data coming from the State Environmental Monitoring stations. This information is automatically updated every hour. The stations gather data on air pollution and send it to the Environmental Protection Inspectorates. These then deal with the processing and sharing of the information online. Use of different measurement methods, along with the time needed for data processing on the EPI servers, can mean data from this source gets delayed for up to 1.5 hours.
Heatmap and platform color scheme
A dense network of sensors within an increasing number of cities means we can interpolate the results from those sensors. With the help of algorithms and artificial intelligence techniques, we can estimate the air quality between sensors with very high accuracy. This we call ‘interpolated measurement’ and it results in a colored ‘heatmap’. The color intensity of the heatmap (that is, the area around each sensor) indicates the certainty with which we estimate the measurements in a given place.
The points on our map represent the location of the sensors, and their color mirrors the quality of air: from the best (green), above the permissible standard (orange) to health-threatening standards repeatedly exceeded (red).
Air pollution forecast
Our air quality forecast is the first in Poland featuring neural network powered predictions!
To help forecast pollution, we use weather data drawn from the DarkSky portal.
The air quality sensors read in real time a series of parameters: PM1, PM2.5, PM10, temperature, pressure and humidity on the subject of the current state of air in the location where they are located.
Our sensors are placed in such locations to best reflect air quality in a given area. As a result, some of them are focused on solar radiation, which affects temperature readings from the sensor. Thanks to special algorithms, we are able to level the Sun's influence and show the real temperature.
The value given is the pressure above the sea level, calculated from the values given by the sensor, taking into account the height at which it was mounted.
The CAQI scale - what do the colors on the platform show?
In European cities, a simpler presentation of air quality data is accomplished using various different indices, each converting their measurements into one easily understood number. In our monitoring system, we use the hourly index, which describes the current air quality based on the average of all measurements from the last hour. The platform updates its data on average every 3 minutes, so the measurements shown are the rolling average of the last full hour.
The air quality index used in Europe, CAQI, has five ranges, with the values presented on a scale from 0 (very low) to >100 (very high). It is a relative measure of the amount of air pollution.
In Airly, when providing the CAQI index, we consider PM10 and PM2.5 dust.
To show the differences in air pollution, a colored 7-level scale operates on our platform. This starts with green, which indicates very good quality air. The scale graduates all the way through to maroon, which shows the air pollution standards are being repeatedly exceeded and it would be wise to stay indoors!
Standards for fine dust
In Poland, PM10 fine dust standards are set at three levels:
- acceptable level 50 μg/m3 (daily)
- information level 200 μg/m3 (daily)
- alarm level 300 μg/m3 (daily)
On the other hand, for fine particulates such as PM10 and PM2.5, the European Union has only established an acceptable level. These are: for PM10 - 50 μg/m3 (daily) and 40 μg/m3 (annual average), and for PM2.5 - 25 μg/m3 (annual average only as there a daily measure is not available for this pollutant).
The norms of acceptable daily concentrations established by the World Health Organization are 50 μg/m3 for PM10. and 25 μg/m3 for PM2.5.