Directorate for Nuclear Safety and Security
REM database details
The Radioactivity Environmental Monitoring (REM) data bank was set-up in 1988 to bring together and store in a harmonized way environmental radioactivity data produced in the aftermath of the Chernobyl accident. In this way the data bank has mainly two objectives:
  • to keep a historical record of the Chernobyl accident, for further scientific study
  • to store the radioactivity monitoring data of the EU Member States in order to prepare environmental radioactivity monitoring reports. By means of these reports, Member States are informed of the radioactivity levels in the environment in the European Union, as stated in art. 35 - 36 of the Euratom Treaty.

The information held by the bank covers data from the twenty-eight EU Member States, as well as other European countries for both environmental samples and foodstuffs from 1984 onwards. The current total number of data records stored in REM exceeds 4.5 million. The data are sent by the national contact points to the JRC by means of the "REM data submission tool", which was designed and developed for that specific purpose. Published data are on-line available to external users. Whilst querying the bank, the user can download the selected dataset on his/her PC in most popular data formats.

The REM database (REMdb)
The REM database (REMdb) was set up by the European Commission Joint Research Centre (JRC) at Ispra, to help integrate and preserve some of the vast quantities of data concerning artificial environmental radioactivity produced in the aftermath of the Chernobyl accident and with the overall aim of making them widely available in a coherent form for scientific study and for obtaining a European picture of the contamination situation.

Included in the database are the results of radionuclide measurements of both environmental samples and foodstuffs; best represented are air, deposition, water, milk, meat and vegetables. Alongside each measurement, information is stored about the location, sampling (when and how), analysis and source of the data.

Part of the work of the REM project is to generate subsets of specially qualified data. These can, for example, be used in environmental research, modelling exercises and monitoring reports.

How data are used

All environmental radioactivity results received from the Member States Authorities are introduced into the REM database. Compilations of the information received are published by the Commission as monitoring reports.

The aim of these reports is to provide information on low levels of radioactivity in the European environment by making use of standardized reporting levels. These reporting levels are supported by presenting more detailed values of radioactivity levels from a limited number of stations that provide high-sensitivity measurements, the so called “sparse network data”.

Reporting levels are meant to be a tool for facilitating the presentation of the results: if the results for a certain sample type radionuclide combination are above their corresponding reporting level (RL), then the measured values are stated in the report. Otherwise they are reported “<RL”.

Sampling media reported

Sampling medium Icon How samples are taken
Air Sampling is carried out by pumping air through filters at a flow rate of several thousand cubic metres per day.
Surface water Samples are either taken continuously or bulked for monthly or quarterly analysis, or alternatively, spot samples are taken periodically several times a year and analyzed individually.
Drinking water Samples may be taken from ground or surface water supplies, from water distribution networks, mineral waters, etc.
Milk Samples are generally taken on a monthly basis; but sometimes only during the pasture season.
Mixed diet Samples are taken as ingredients or as complete meals, mostly at places where many meals are consumed (i.e., factory restaurants, schools).

Dense vs. Sparse network data representation

Dense network data

The sampling locations which are distributed all over the Member States'territories, are referred to as the “dense network”.

The dense network results are presented on a map (with the exception of surface water as this sample type does not allow for geographical presentation) and in tabular form. The graphical representation illustrates the annual average radioactivity concentrations for each geographical region. Four shades are used to indicate the concentrations on a scale ranging from less than the reporting level to ten times the reporting level. In addition, each sampling location is illustrated.

An example of the results in airborne particulates sample type presented graphically:

and the corresponding results presented in tabular form:

These results are averaged over geographical regions and over a particular time period (quarter, semester or whole year, depending on the availability of data). The total number of sampling locations (column L) and the number of measurements (column N) used to calculate the annual averages are given for each geographical region. In addition, the monthly maximum (column Monthly max) and the month (column M) in which this occurred are given for those values above the appropriate reporting level.

Sparse network data

Actual concentrations are presented for a number of representative locations that were selected to this purpose. This is referred to as the “sparse network”. High-sensitivity measurements are performed at these locations and the individual results are presented graphically. The results for the sparse network are preceded by a map illustrating the sampling locations. The data are presented as time versus activity concentration graphs from 1984 onwards (where the data are available).

The following figure shows an example of a map with sampling locations for airborne particulates in the sparse network:

The following graph shows an example of activity trends for Be-7 in airborne particulates for the sparse network:

The choice of 1984 as a start date enables the pulse of radioactivity which entered the environment of the EU from the 1986 Chernobyl accident in the Ukraine to be seen clearly.


Treaty Establishing the European Atomic Energy Community (E.A.E.C. -EURATOM), Title Two - Provisions for the Encouragement of the Progress in the Field of Nuclear Energy, Chapter III: Health and Safety, ARTICLE 36


Authorities of all European Member States provide data to the REM group on an annual basis for checking and storing in REMdb.

For more information please visit the REMdb public or restricted area.