View from space on the air we breathe in Moldova

UNDP partners with the European Space Agency to complement the existing air monitoring data

February 10, 2021

Level of carbon monoxide, May 2018 vs. July 2020

What do you know about the air you breathe? Is the air in your city/region more polluted than the accepted standards or is it exceeding the norms? Are the data we have available enough?

In Moldova, the national air monitoring system is updated daily, using information from 17 monitoring stations (based on manual sampling). Only the cities of Chisinau, Balti, Bender, Tiraspol and Ribnita are covered by the respective monitoring system. Additionally, 2 automatic monitoring stations are located in Rezina and Leova. So, the country is not fully covered.

For the first time in Moldova, in partnership with the European Space Agency (ESA), a study was conducted to map the air pollution in Chisinau, the capital city, and the rest of Moldova, using earth observation data. The study was conducted during the COVID-19 lockdown, but it also covers rich historical datasets (2017 onwards). So, it is possible to assess the impact of COVID-19 on air pollution and whether the lockdown implies or not consistently lower levels of air pollution, particularly in dense urban and industrial areas.

Air quality is influenced by human activities, transport, industrial production and natural sources of pollutants and the historical trend is that air pollution was increasing with time, particularly in densely populated and industrial areas.

The same trend was valid for Moldova’s case - higher concentration of pollutants is observable only in the capital city and near large power plants. However, the overall situation of air pollution in Moldova revealed itself as a favourable one, specifically when compared to other European countries (and particularly in COVID-19 context), including Ukraine, Romania and others.

Visual: European State Agency

The research team used satellite data provided by Sentinel 5P – a cutting edge satellite technology equipped with latest technologies for atmospheric measurements, to analyse the main air pollutants: Ozone (O3), Nitrogen dioxide (NO2), Sulphur dioxide (SO2), Particulate Matter (PM10 and PM2.5), thus revealing some interesting insights:

Level of Nitrogen Dioxide during May 2018 - July 2020

  • Overall, the level of air pollution in Moldova, as seen from space, is relatively low compared to other European countries and our neighbours, largely being within the limits of Air Quality Guidelines provided by the World Health Organization.
  • Concentrations of nitrogen dioxide in Moldova are generally low. This air pollutant comes mostly from cars and other motor vehicles, also oil and metal refining, electricity generation, manufacturing industries and food processing. It affects the respiratory system resistance towards bacterial and viral infections. Elevated values were observed in and around Chisinau, around the border with Ukraine, especially where the Cuciurgan power plant is located, and around the cities of Tiraspol and Ribnita. Chisinau, Bender, and Balti regions have the highest average pollution levels of nitrogen dioxide.
  • Values of sulphur dioxide are generally low throughout the country, with only modest increase around the capital city. This pollutant is mostly connected to coal-fired power stations, industrial processes or other fossil fuel burning activities. According to the research, the amount of sulphur dioxide in the air peaks during the winter period, is usually increasing five to ten times compared to summer, due to the heating season. In terms of impact on health, short exposure to high concentration of sulphur dioxide may cause severe breathing difficulties (most affected are asthma ill persons, children, older people and people with chronic respiratory diseases), while long exposure to low concentration may result in respiratory tract infections.
  • The distribution of carbon monoxide is relatively similar across Moldova, with Bender, Cahul, Glodeni and Chisinau regions having the highest average concentrations. The pollutant is a product of incomplete combustion in vehicles, heating, coal power plants, waste disposal, and biomass burning. The pollution in the Cahul area is explained by the presence in its proximity of the largest Romanian steel mill (Galati steel works). Carbon monoxide is a toxic gas, lethal in high concentrations by affecting respiratory and cardiovascular systems. At relatively low concentrations, it causes breathing difficulties, reduced physical capacity, migraines, nausea, among other symptoms.

While further research and correlation between air pollution and health is required for Moldova’s case, the most recent World Bank analysis reveals a worrisome situation. According to the World Bank, at a global level, the cost associated with health damage from ambient air pollution is estimated to be $5.7 trillion, equivalent to 4.8% of global GDP. In individual countries, the economic burden of pollution associated with premature mortality and morbidity is also significant, equivalent to 5 to 14% of countries' GDPs.

As one of the main focuses of the study was the impact of COVID-19 lockdown on the pollution indexes, it revealed that while the lockdown started in the spring of 2020 caused a serious economic downturn leading to cleaner air in some regions, the overall change in air pollution data was not a considerable one.

To complement the research project, two easy-to-read dashboards were developed, showcasing the results of the analysis. The interactive maps allow for switching between various pollutants and checking their concentrations of across Moldova during the last 2 to 3 years from the Sentinel 5P satellite and the Copernicus Atmosphere Monitoring Service.

GIF: UNDP Ukraine. The animation shows how far can the dust be taken by wind from the source of origin.

While the study concludes that air pollution in Moldova is generally low in comparison to most European countries, it also highlights the fact that there are multiple pollutants that are not currently observed by Sentinel 5P satellite, that can be however spotted by in-site ground measurements, provided by the national air monitoring system.

To diminish the overall pollution levels and their impact in human health and quality of daily lives, it is recommended the reduction of coal plants and subsidizing fossil fuels, while focusing on green economy targets and programs aimed at achieving them. While pollution is not always visible to the eye, it is however incorporated on a “drop by drop” basis by human bodies, until the point of no return.

"COVID-19 Impact on Air Quality in Ukraine and the Republic of Moldova" study was developed by World from Space for the United Nations Development Programme (UNDP) within the European Space Agency EO clinic framework in 2020.

The main data source was Sentinel-5P mission (S5P), currently the most precise satellite in orbit devoted to atmosphere monitoring. It was launched in October 2017 as part of the EU Copernicus Programme. It carries the TROPOMI spectrometer measuring concentrations of nitrogen dioxide, ozone, formaldehyde, sulphur dioxide, methane, carbon monoxide and atmospheric aerosols with daily global coverage and a resolution of about 5.5 km x 3.5 km.

The study contains modified Copernicus Atmosphere Monitoring Service data [2017-2020] and modified Copernicus Sentinel data [2018-2020]. Maps contain data from © OpenStreetMap contributors (

The cooperation between UNDP and ESA is only starting to unfold. The project aims to continue and expand cooperation to setting up operational monitoring of air pollution available to any public, setting up an operational early warning system for air quality monitoring, extension of the use of web application and the analysis to other countries and areas world-wide.