The air quality KPI provides metrics on the concentration of atmospheric pollutants in the study area, based on the variable selected by the user. The indicator enables monitoring of exposure to primary and secondary pollutants, comparison with international regulatory standards (WHO Air Quality Guidelines, 2021; EEA Air Quality in Europe, 2023) and analysis of daily trends and average values for the selected period.
Air pollution is recognised as one of the primary risk factors for human health and biodiversity: the WHO estimates that 99% of the world's population lives in areas with air quality below recommended limits. Ecologically, high levels of NOx, O3 and SO2 cause soil acidification, eutrophication, and direct damage to vegetation.
| Indicator | Unit | Description |
|---|---|---|
carbon_monoxide | mol/m² | Carbon monoxide: produced by incomplete combustion |
formaldehyde | mol/m² | Formaldehyde: secondary pollutant from VOC photodegradation |
methane | ppb | Methane: greenhouse gas and tropospheric ozone precursor |
nitrogen_dioxide | mol/m² | Nitrogen dioxide: from traffic and industry; NOx indicator |
ozone | mol/m² | Tropospheric ozone: secondary pollutant with oxidising action |
sulfur_dioxide | mol/m² | Sulphur dioxide: from fossil fuel combustion and volcanoes |
uv_aerosol_index | - | UV aerosol index: estimate of UV absorption by aerosols |
Also includes European AQI and US AQI for comparison with European and US regulatory standards.
Data come from the Open-Meteo Air Quality API (source: WRD_OPNAQ_99), which integrates data from European (CAMS — Copernicus Atmosphere Monitoring Service) and American atmospheric models, with a spatial resolution of ~11 km and temporal coverage from 2013 to present with hourly updates.
For each selected variable, the system calculates:
| Indicator | Unit | Range | Inverted |
|---|---|---|---|
carbon_monoxide | mol/m² | [0, 0.02, 0.03, 0.04, 0.05, 1] | Yes |
formaldehyde | mol/m² | [0, 0.00005, 0.0001, 0.00015, 0.0002, 1] | Yes |
methane | ppb | [0, 1800, 1850, 1900, 1950, 2500] | Yes |
nitrogen_dioxide | mol/m² | [0, 0.00003, 0.00006, 0.0001, 0.00015, 1] | Yes |
ozone | mol/m² | [0, 0.12, 0.13, 0.14, 0.15, 1] | No |
sulfur_dioxide | mol/m² | [0, 0.00005, 0.0001, 0.0002, 0.0004, 1] | Yes |
uv_aerosol_index | - | [0, 0.5, 1, 2, 3, 10] | Yes |
Inverted = Yes (all except ozone): lower concentrations indicate cleaner air → level A (Excellent). Higher concentrations indicate greater pollution → level E (Critical).
Exception — ozone (Inverted = No): stratospheric ozone is essential; the indicator measures the total ozone column (mol/m²), so higher values indicate greater presence of the protective layer.
| Level | General Interpretation |
|---|---|
| A (Excellent) | Optimal quality: concentration below WHO 2021 limits |
| B (Good) | Good quality: slight exceedance of WHO annual limits |
| C (Moderate) | Moderate quality: values within European caution ranges |
| D (Poor) | Poor quality: values above EU legal limits |
| E (Critical) | Critical quality: significant risk for health and ecosystems |
Responsible: Claudio Barbieri
carbon_monoxide
(mol/m²)nitrogen_dioxide
(mol/m²)ozone
(mol/m²)sulfur_dioxide
(mol/m²)uv_aerosol_index
Concentration of atmospheric pollutants: PM10, PM2.5, NO2, O3, SO2, CO, formaldehyde, methane, UV aerosol index. Source: Open-Meteo Air Quality API (WRD_OPNAQ_99). Integrates data from CAMS (Copernicus Atmosphere Monitoring Service) models at ~11 km resolution covering 2013–present. Includes European AQI and US AQI for comparison with regulatory standards. Shows daily trends and mean values for the selected period. Hourly updates. KPI upgraded from v0 to v1 (current version).