Air pollution, mainly by fine particles and ground-level ozone, may cause health problems, lead to premature death (several studies have demonstrated a strong correlation between air pollution and respiratory and cardiovascular diseases), reduced agricultural crop yields, changes in ecosystem function and species composition, and damage to buildings and materials.

The air quality in Hungary generally corresponds to the EU average, though there are Hungarian settlements where air quality is still not on the 'good' level, with significant differences between rural parts and larger cities.

Concentrations of SO₂, CO, benzene and lead are below set limits throughout the country. Decreased emissions of sulphur dioxide over the past one to two decades resulted in a lower ambient air concentration of that pollutant (Figure).

Levels of nitrogen oxides and ground-level ozone are (relatively) high, with the latter showing an increasing trend similar to other parts of Europe. Nitrous oxides play a significant role in acidification and eutrophication of ecosystems, while ground-level ozone poses a serious threat to agricultural production. Levels of particulate matter and NO_x in ambient air occasionally exceed the health limit values near main traffic routes in larger cities.

As a result of better understanding its health effects and of the availability of advanced measurement technology, fine particle pollution represents the highest risk to public health (in terms of air quality). An assessment of the health effects of PM₁₀ in Budapest and other cities, based on data from 2004, suggests that 170 premature deaths per 100 000 inhabitants per year can be attributed to long-term exposure to high PM concentrations.

According to data from the National Children’s Respiratory Survey performed by the National Institute of Environmental Health in the autumn of 2005, the prevalence of chronic bronchitis symptoms among 9-10-year old Hungarian children was 17.3 % which showed statistically significant associations with the yearly mean levels of PM₁₀ in the towns of the Central Transdanubian and the Central Hungarian Regions. At national level, the yearly mean PM₁₀ levels were significantly associated with the prevalence of clinically diagnosed asthma (7.3 %) and allergy cases (20.6 %), the latter showing significant correlation with high levels of different pollen concentrations.

The improvement in ambient air quality has resulted in a decreasing trend in morbidity and mortality associated with respiratory diseases, which is especially evident since 2000. However, further investigation is needed to identify the most recent trends and to isolate the health effects of outdoor air quality from the effects of cigarette smoke.

Air quality is measured by a sophisticated national air quality monitoring network which has been extended through the contribution of EU funds, doubling the number of on-line sampling points, and upgrading the vast majority of measuring stations. The National Institute of Environmental Health provides daily health-related information on the ambient air pollution level in Budapest and five other towns in order to protect the health of the potentially affected population and operates the Aerobiological Network.

In recent years, a significant reduction in industrial pollutant emissions has been achieved in Hungary. Emissions of SO₂ have declined during the last decades as a result of implementing emission control legislation and of structural changes in the energy sector. However, the levels of some air pollutants still exceed short‑term limit values several times annually, mainly due to the increasing volume of road transport.

Emissions of NO_x and VOCs have fluctuated slightly around the same level since 2001 and have just recently decreased, making it a challenge to meet the respective emission ceilings. Consequently the annual average limit NO₂ value has been exceeded in some areas and in major cities of the country. Particulate matter and ground-level ozone are of particular concern. PM₁₀ daily and annual average limit values have also been exceeded in several parts of the country.

As emissions of air pollutants and greenhouse gases from the household and transport sectors have become key issues, further efforts are needed to improve energy efficiency in these sectors. The growing motor vehicle fleet, as well as the boom in road freight transport which followed EU accession threatens to offset progress achieved through improvements in vehicle technology and fuel quality.

Implementation of the measures included in recent air quality action plans will reduce national emissions and decrease the levels of air pollutants in ambient air, so air quality should improve significantly, resulting in the reduction of the impacts on human health and ecosystems. To reduce PM₁₀ concentration in ambient air, regional inspectorates prepared updated air quality plans in 2008. Implementation of the measures prescribed within these should result in compliance with limit values by 2011.

Depending on how – both at national and European level – economic, energy and transport policies develop and to what extent they integrate environmental aspects, the outlook on the future of air quality can vary significantly. Progress in terms of sustainability and energy efficiency can improve it greatly, while the lack of considerable developments can lead to stagnation or can even cause deterioration (in terms of human health, ambient air quality, built environment etc.).

Due to the timescale involved and the pace of change in drivers, pressures and technology, it is difficult to estimate the changes that can be achieved in terms of air pollutant emissions and ambient air quality. Furthermore, not enough is known about synergies and trade-offs in terms of the measures foreseen, especially with regard to those aimed at tackling climate change. How the higher average temperatures foreseen for the future can modify the processes through which air pollutants affect ambient air quality is just one example for a single factor that can determine future effects on human health.

 Nitrogen oxides emission trend in Hungary [kt/year]