Editorial.

This special issue of the CEJPH focuses on air pollution and its public health effects. Despite the fact that the body of knowledge of possible health effects of air pollutants is growing over the last two decades, mainly as a result of multiple epidemiological studies conducted all over the world, many questions still remain unanswered. As the air pollution in the Silesian part of the Czech Republic, and in the Ostrava Region in particular, is a significant environmental phenomenon in Europe, the data on pollution exposure, types, and health effects at various levels could be an important contribution to the body of evidence on this (sometimes) seemingly local issue. Although this is one of the most polluted areas of Europe, apart from the conclusions of the Silesia Project (with the participation of the US EPA) and Caesar Project (with the participation of the WHO) from the 1990s, only a few studies addressing some aspects of air pollution appeared. To collect all available and credible data on air quality in this region and related impacts on human health and to submit them to the reader in a single issue (this issue contains three review articles) was the first reason for publishing this special issue.