In addition to on-line monitoring, more than 1300 environmental samples are taken annually, to assess the overall impact of CERN’s activities on the environment. 

Distribution of laboratory analyses

Air monitoring

A fraction of the aerosols emitted by stacks are collected on filters by ventilation aerosol samplers for later analysis in the laboratory. In parallel, analysis of filters from environmental aerosol samplers located on and near CERN sites are used to prove that emissions remain negligible. Air flow rates of exhaust stacks are monitored and the flow rates in the sampling lines are regulated so as to guarantee stable values.

Effluent Water

Once a year, river water, sediments and bryophytes (moss) are sampled in all watercourses receiving CERN’s effluents and analysed in the laboratory to assess the impact of CERN's effluents on the receiving watercourses. Up to twenty five parameters are tested to fulfil the quality objective set by both France and Switzerland. In addition, more detailed analyses are carried out on the main CERN’s effluents that are discharged into watercourses, on a monthly (11 parameters), quarterly (18 parameters) and annual (18 parameters) basis.


The meteorological data collected by CERN for calculation purposes concerns wind speed, azimuth and precipitation.

Laboratory equipment

Both radiological and physicochemical analyses are carried out in the CERN environmental laboratory.

The radiological analyses performed in the laboratory concern gamma spectroscopy, alpha/beta counting and tritium liquid scintillation counting. The laboratory is equipped with:

  • 6 gamma spectrometers;
  • 2 alpha/beta counters;
  • 2 liquid scintillation counters used for tritium.

Gamma spectrometers in the environment laboratory

The physicochemical analyses include all relevant standard water quality parameters such as suspended matter, heavy metals, nitrogenous and organic compounds, including hydrocarbons. The laboratory is equipped with:

  • Portable devices with thermometers, pH-meters and probes for conductivity and dissolved oxygen;
  • Turbidimeter;
  • 1 Photometer U.V.;
  • 1 Ionic Chromatography
  • 1 Voltametry method analyser;
  • 1 Total Organic Carbon Analyser;
  • 1 Adsorbable Organic Halogen (AOX) analyser;
  • 1 FT – IR spectrometer;
  • 1 ICP-MS measurements of minor and major water elements.

ICP-MS measurements of minor and major water elements


For releasing water please fill in a request at the following address: SNOW.

For any questions please address them to