Nature has taken a break from human activity

Measures to prevent the spread of the novel coronavirus have resulted in a reduction in the intensity of human activity, including those which have long-term environmental impacts and negatively affect the lives of humans and other lifeforms. Will this development help nature?

08. 06. 2020 10.41 hod.
By: CU Public Relations Office

The pandemic caused by the SARS-CoV-2 virus and the measures taken by each country to contain it have caused a significant decline in human activity in almost all areas of the economy. This decrease has also triggered a specific effect in the form of a significant reduction in pollutants in the environment.

Passenger and freight transport are among the largest producers of nitrogen oxides, which are harmful to both humans and the environment. Long-term exposure, even with low concentrations, can cause people to develop chronic respiratory diseases, such as asthma, and it also increases the risk of inflammatory respiratory diseases. In natural environments, nitrogen oxides get into the air, and alongside water, oxygen, and other particles they produce acids and contribute to the formation of acid rain. From the air, nitrogen oxides get into water systems, where eutrophication then disrupts the functioning of ecosystems. This then affects the food chain, which humans are at the end of.

After reacting with nitrogen oxides, the particles that form in the air are visible and produce smog. ESA and NASA satellite imagery has recorded a massive reduction in nitrogen dioxide over approximately a month, with this phenomenon being observed not only over China but also over northern Italy. In these regions, radical measures were taken to limit people's movement, and therefore it can be stated almost with certainty that this reduction directly correlates with the positive impact of the reduction in car transport on air purity in particular.

A similar effect has been recorded in Slovakia. The Slovak Hydrometeorological Institute analysed the concentration data of several pollutants in the first month (13 March to 13 April) of the implementation of measures taken against the spread of COVID-19. Compared to the ten-year average, the nitrogen oxide concentrations decreased in nineteen measurements by an average of 28.5 per cent. This significant decrease in concentrations was primarily recorded at transport hubs, where, in the case of Trnavské mýto in Bratislava, decreases of up to 64 per cent were recorded at peak times.

The short-term reduction of the amount of pollutants in the air can mean a temporary improvement in the health of people who have developed chronic respiratory diseases. However, in the case of environmental and ecosystem services, which have a direct impact on the quality of life, comprehensive systematic development and the implementation of scientific innovation is needed. Only then will it be possible to minimize the release of pollutants by human activity into the environment.

Peter Hanajík, Faculty of Natural Sciences, Comenius University

Sources: Slovak Hydrometeorological Institute and