Alejandro Martín Sánchez
University of Extremadura, Spain
Alejandro Martín Sánchez works at the University of Extremadura (Spain). He completed his studies at the Autonomous University of Madrid (Spain). He was the Head of the Physics Department for 12 years. He has published more than 100 papers in the most reputed journals about Environmental Radioactivity and Nuclear Physics.
Remedial actions are necessary in environments with high radon concentrations. A first survey about measurements of indoor radon concentration in working places was performed in Extremadura (Spain). Sites studied included resorts, spas, caves, tunnels, mines, facilities storing or dealing with water, and other underground and surface suspected work places (warehouses, parking lots, hotels, museums, educational centres, etc.). Results showed that about 85% of more than 300 working places measured, were below an annual average concentration of 200 Bq/m3, 9% were between 200 and 400 Bq/m3, and 6% were above 400 Bq/m3. A second study was undertaken, performing surveillance and applying mitigation methods when necessary. Four surveys were performed to fulfil one year study. Remedial or mitigation actions (ventilation, changing the working place inside the same building, limiting the time of residence of people, or architectonics actuations) were applied. A total of 240 measurements were performed in 35 sites. At this time, following the actual Spanish legislation, the working places were classified as 191 results (in 26 sites) with average indoor radon concentration lower than 600 Bq/m3, 38 results (in 6 sites) between 600 and 1000 Bq/m3, and 11 results (in 3 sites) with concentrations above 1000 Bq/m3. In some special cases, a continuous monitoring device was used to study the hourly variation of the indoor radon concentration. Results showed then a very great variability. Concentration variations in the working day and journey should be considered in this case because otherwise the dose received by workers could be erroneously estimated.