4.

The following requirements should be met: (a) Monitoring networks (i) Each Member State should define representative geographical regions for its own territory. (ii) Each Member State should define for each type of medium a sparse monitoring network and a dense monitoring network. (iii) The sites comprising a network should be representative of the regional situation taking into account, where appropriate, the population distribution within the region. (b) Sampling media, types of measurements, and periodicity (i) The sampling media and types of measurements are listed in Annex I. Except where otherwise specified in this Recommendation, measurements should preferably be carried out for the sparse network on a monthly basis and for the dense network quarterly. (ii) For the sparse monitoring network, the detection limits and sensitivities of the measurement instruments should allow the actual levels to be quantified. (iii) For the dense monitoring network, the detection limits of the measurement devices should be lower than the reporting levels defined in Annex III. (iv) The Member States should inform the Commission of the detection limits and of the uncertainties taken into account. (v) The Member States should retain measurement techniques that have proven reliable and ensure quality control of the results. (vi) Member State laboratories supplying data under the terms of this Recommendation should periodically participate in intercomparison exercises, in particular those organised by the Commission, so as to ensure the intercomparability of the data reported. (c) Sampling strategies and measurements in relation to each of the required sampling media (i) Airborne particulates Measurements of gamma emitting radionuclides should be performed on a routine basis to detect and measure man-made radioisotopes as well as naturally occurring radionuclides. Beryllium-7 should be reported as a qualitative check of the methods used. Where gross beta activity ( 4 ) measurements are recorded these should also be reported. Sampling locations should be in the vicinity of densely populated areas; adequate geographical coverage should be ensured by the choice of at least one sampling location per geographical region. Sampling should be performed by systems operating continuously. (ii) External ambient gamma dose rates should be measured continuously. No reporting level is defined. (iii) Surface water Samples should be taken from major inland waters of the Member States' territory and, if relevant, from coastal waters. In the case of river water, sampling should be carried out, where practicable, at locations for which flow rate measurements are available. In such cases, the average flow rate during the sampling period should be reported to improve the representativeness of the mean values calculated by the Commission. Gamma emitting radionuclides should be monitored. Where residual beta activity ( 5 ) measurements are recorded these should also be reported. (iv) Water intended for human consumption Monitoring of levels of radioactivity in drinking water should be such as to ensure compliance with the requirements of Directive 98/83/EC. For the purposes of compliance with Article 36 of the Euratom Treaty, values should be reported for major ground or surface water supplies and for water distribution networks such as to ensure a representative coverage of the Member State. The corresponding volumes of water distributed or produced in a year should be reported to improve the representativeness of the mean values calculated by the Commission. (v) Milk Milk samples should be taken from dairies. The necessary statistical information on production rates should be reported to improve the representativeness of the mean values calculated by the Commission. The spread of dairies should be sufficient to ensure representative coverage of the Member State. Gamma emitters and strontium-90 should be monitored; potassium-40 should be reported as a qualitative check of the methods used. (vi) Mixed diet Due to the trade in foodstuffs, the mixed diet is not necessarily representative of the regional or national environmental contamination but is an indicator of public exposure. Where appropriate, foodstuffs are measured as separate ingredients; in this case the Member State should report to the Commission the results of measurements of the individual ingredients and the composition of the diet. The sampling programme should take into consideration regional variations in dietary patterns. Individual ingredients should be from market places or local distribution centres providing food products to large population groups. Appropriate account should be taken of products from natural or semi-natural ecosystems, to the extent that the fallout from the Chernobyl accident may still affect such systems. In addition, Member States should sample complete meals to give a representative figure for the average level of radioactivity in mixed diet. Actual meal samples should be taken from large consumption centres such as canteens or restaurants. Gamma emitters and strontium-90 should be monitored; the measurements should be not less frequent than quarterly. Where carbo-14 measurements are performed, these should also be reported.