Аннотация:The catalogs of weak seismic events in Turkey and Iran (M≤4) were analyzed to identify signsof their contamination by blasts. A well-pronounced predominance of the number of seismic eventsand a decrease in their average magnitude in the period from 10 am to 5 pm local time is revealed.The epicenters of seismic events that occurred in this time interval at depths of less than 3 km arelocated much more compactly compared to other seismic events. Such factors can be considered asevidence of contamination of earthquake catalogs by road construction and quarry blasts. Thepresence of such an anthropogenic effect in the earthquake catalogs is also confirmed by the presenceof a well-defined weekly periodicity of seismic events. It manifests itself in the form of a significantdecreasing of the discussed daily extremum on Saturday and Sunday in Turkey and Friday in Iran.On the example of Turkey, where the observation service attempted to separate blasts and earthquakesin the seismic events catalog, it was shown that in the thus cleared catalog of seismic events, theprevalence of seismic events in the daytime over their number at night is still observed. However, itcannot be ruled out that this excess is only partly due to the presence of unidentified blasts caused byimperfect algorithms for identifying blasts. The results obtained show that when working even withthe earthquake catalogs that are designated by their compilers as cleared from blasts, it is necessaryto conduct preliminary studies of catalogs to assess their contamination by blasts. However, theproblem is compounded by the possibility that some of these events are weak earthquakes initiatedby relatively strong blasts. The opposite effect was also revealed: the presence of earthquakes in theblast catalog, i.e. there is a mutual contamination of the catalogs of earthquakes and blasts.