Radiation risk cannot be limited by territorial boundaries. This fact and the long exposure time of radioactive elements (most of which have a decay period of tens to hundred thousand of years), require measures of timely assessment of the level of risk, with the aim of prevention and control, called radiation monitoring. The study is based on monitoring of the gamma radiation background and studying of its relation with the surface contamination over three monitoring points and the surface contamination, detected on the air filters of PM2.5 and PM10. The research is performed with personal portable dose rate meter Radiagem 2000 and Alpha/Beta/Gamma external CSP probe at two ecosystems—terrestrial and marine within the Black Sea coastal zone area. There is a positive correlation between the amount of the particles PM2.5, deposited on the filters and the surface contamination, which can be related with the presence of the black carbon, acting as an absorbent.