The city of Ostrava, the capital of the Moravian-Silesian Region, is a significant industrial centre of the Czech Republic, where air pollution was a serious issue in the second half of the 20th century. Due to a major restructuring of the industry and a package of air quality related measures initiated by the City of Ostrava, the situation has significantly improved over time resulting in a nearly 90% pollution decrease in the city. The wide range of measures in place, targeting improved air quality, include among others:
- emission control measures implemented in the industrial sector,
- a household boiler replacement programme,
- the development of the public transport system (construction and reconstruction of tram and trolleybus tracks),
- intensive road cleaning that reduces secondary air pollution caused by vehicle traffic,
- construction of cycling infrastructure,
- the operation of a bike share system,
- expansion of pedestrian zones in the city,
- the conversion of municipal fleet to low-emission or electric vehicles,
- rehabilitation of parks and the planting of tolerant greenery on roads.
Despite the restructuring and the above measures, air quality still remains one of the city’s biggest environmental issues. The main sources of air pollution in Ostrava include metallurgical production, power generation, domestic heating, and transport. As the city is part of the Upper Silesian metropolitan area, an international industrial agglomeration, pollution arriving from the nearby industrial conurbation of Katowice in Poland increases the concentration levels of air pollutants in Ostrava. The situation is further aggravated in the city occasionally by local meteorological conditions in winter, which are characterised by frequent inversions that result in poor dispersion of pollutants.
One of the major pollutants in the city is particulate matter. The legal limit value for the annual mean for particulates was often exceeded in case of PM2.5 and PM10 over the period between 2004 and 2014. Exposure to particulates can lead among other to heart disease, stroke, lung cancer, aggravated asthma, chronic bronchitis, and kidney disease. Particles with a diameter less than 10 micrometres (PM10) are small enough to pass through the throat and nose and enter the lungs. Particles less than 2.5 micrometres in diameter (PM2.5) can penetrate deeply into the lung and can even get into the bloodstream reaching almost all organs.
Monitoring data in Ostrava have shown that exposure to benzo(a)pyrene is high, as for many years the legal limit has been exceeded at all locations where concentrations of this pollutant has been measured. Benzo(a)pyrene is a polycyclic aromatic hydrocarbon (PAH) that is formed during the incomplete combustion of organic matter. Sources of benzo(a)pyrene include residential wood burning, vehicle exhaust and industrial processes. It is a carcinogenic substance that can adversely affect the immune system, the reproductive system and the brain function.