Air quality

According to the WHO, air pollution is now the most important environmental factor affecting health, affecting everyone, rich and poor alike. It is estimated that air pollution kills nearly 7 million people a year worldwide, and this figure is constantly rising, unlike other sources of pollution (water, soil, etc.) where the situation is improving. Not to mention the major impact on the climate (global warming, melting glaciers, acid rain) directly linked to air pollution. It is therefore crucial to take energetic measures to reduce emissions, and to have continuous monitoring to verify the impact of abatement plans. As an Air Reference Laboratory, ISSeP manages these measurement networks, which are used to inform the public (peak ozone, smog alerts) and serve as a working base for scientific experts and the relevant authorities.

Click here for ambient air quality data for the Walloon Region.

Air quality correspondent: Benjamin Bergmans – 04 229 82 19

Our missions

Operation of the air quality monitoring network in Wallonia

In order to be able to judge the effectiveness of all the measures taken to protect the quality of the air we breathe, and to verify the limit values imposed by Directives 2004/107/EC and 2008/50/EC, it is important to have high-performance tools for analyzing this air. Wallonia has had monitoring networks for air quality for many years. ISSeP is responsible for operating these networks on behalf of SPW Agriculture, Natural Resources and Environment.
Click here for ambient air quality data for the Walloon Region.

A unit is also in charge of monitoring emissions from industrial stacks, and verifying compliance with environmental permits. Given the high concentration of industries close to highly urbanized sites, these measurements, in addition to European reporting obligations (EMEP/CORINAIR), are also important when drawing up abatement plans.
Activities are monitored and programmed by a technical committee made up of ISSeP scientists, SPW managers and external experts. A monitoring committee coordinates the various environmental quality monitoring networks.

Ambient air quality monitoring networks can be divided into three categories: telemetric networks, non-telemetric networks and mobile networks.

  • The telemetry network
    It continuously measures various pollutants using automatic analyzers located at twenty-six stations throughout Wallonia. The pollutants measured are: sulfur dioxide, nitrogen monoxide and dioxide, ammonia, carbon monoxide, ozone, gaseous mercury, black carbon and suspended particulates (PM10 and PM2.5). This network also records meteorological parameters (wind speed and direction, temperature, pressure, relative humidity and precipitation).
  • Non-telemetric networks
    Based on on-site sampling and laboratory analysis, these networks study various pollutants such as volatile organic compounds, polycyclic aromatic hydrocarbons, sedimentable dusts, heavy metals in suspended particles, fluorides (particulate and gaseous), mercury and wet deposition.
  • The mobile network
    This network is designed to measure pollution in little-studied areas, or areas with pollution that we wish to better characterize, both in terms of the pollutants emitted and their spatial distribution. It covers sampling and analysis techniques for telemetric and non-telemetric networks.

Emission measurement networks involve 2 major activities: the monitoring of discharges from industrial facilities and the continuous monitoring of dioxin emissions.

  • The network for monitoring discharges from industrial facilities
    The aim of this network is to carry out a complete characterization of emissions of major pollutants from industrial facilities at the request of the Administration. The pollutants measured include both mineral elements (heavy metals: Hg, Cd, Cr, etc., halogenated compounds, ….) and organic elements (dioxins, PCBs, VOCs, etc.), as well as dust and gaseous pollutants (SO2, CO, NOx). The correlation with self-monitoring measures imposed on manufacturers is also verified.
  • Continuous monitoring network for dioxin emissions
    Since January 2001, Wallonia has had a unique tool for continuous monitoring of dioxin emissions. To ensure compliance with European Directive 2000/76/EC on waste incineration, dioxin emissions from all household waste incineration furnaces are monitored by continuous flue gas sampling. The network has also been extended to other types of plant (cement works, etc.) which are potential major emitters of this pollutant.

All the measurements taken by these networks are particularly important for monitoring air quality, both in real time (alerting and informing the public) and over the long term (compliance with legal limit values).

The Institute is also involved in promoting environmental information. Its daily concern is to :

  • manage air quality monitoring networks;
  • ensure the formatting and transmission of results;
  • ensure the reliability of sampling and analysis methods;
  • develop new methods for sampling and analyzing atmospheric pollutants;
  • participate in research and development programs at regional, federal and European levels;
  • promote knowledge of air quality and atmospheric emissions monitoring tools;
  • provide technical and scientific assistance to public authorities, businesses and private individuals.

Air quality measurements at the request of other administrations, industries or consultancies

The ISSeP has measuring equipment for assessing air quality in response to specific pollution problems, characterizing sites with local features (nature of pollution, topographical situation, etc.), providing data or advice on pollution types and levels based on its field experience, validating models or carrying out preliminary studies prior to the installation of road or industrial infrastructure. At industrial level, emissions characterization helps optimize processes, and recommendations on standards and best practices are also given.

Air quality can be assessed using several complementary types of measurement:

  • continuous, real-time measurements using specific automatic analyzers.
    The parameters that can be analyzed are: sulfur dioxide, hydrogen sulfide, nitrogen oxides, ammonia, methane and total hydrocarbons, ozone, carbon monoxide, monocyclic aromatic hydrocarbons, black carbon, suspended particulates (PM10, PM2.5 and PM0.1) and sedimentable dust. Certain meteorological parameters can also be measured: wind speed and direction, temperature, humidity and atmospheric pressure.
  • continuous sampling for deferred laboratory analysis.
    Continuous sampling on suitable media can be carried out. Samples are collected at regular intervals, for subsequent analysis by the ISSeP air quality laboratories. The most frequently measured parameters are: volatile organic compounds, polycyclic aromatic hydrocarbons, heavy metals and sedimentable dusts.

For measurements in industrial stacks :

  • characterization of industrial plant emissions and optimization of production and purification processes;
  • help industries choose their abatement technique and calibrate their self-monitoring system;
  • advice on best practices when building a new facility or extending an existing one.

Expertise and advice

As a reference laboratory, ISSeP makes its technical expertise available to the French government and air laboratories. In addition to providing technical support to the Administration, this function includes the development and validation of analytical methods. The methods are then published in the form of a best practice guide, and approved laboratories are audited. The Institute also audits laboratories as part of the accreditation procedure, see the “Reference laboratory” section of this document.
As a sector operator, ISSeP assists the NBN at a technical level in all matters concerning “Air quality” standardization, both at CEN/TC264 and ISO/TC146 level. This includes appointing experts, managing mirror groups, monitoring the drafting and revision of domain standards, making documents available and managing votes for Belgium. In addition, several employees are experts and active in the various working groups.

Atmospheric emissions


Air quality is a major concern at the start of the 21st century. Controlling the sources of polluting emissions is a key part of pollution control, mainly in terms of compliance with emission standards and the development or monitoring of pollution control facilities.
Industrial companies are subject to regulations requiring them to carry out continuous monitoring (self-monitoring) and occasional analyses (by accredited laboratories) of their pollutant emissions.CCB_56
ISSeP carries out measurements of stationary sources for both the public and private sectors.
The parameters studied are a function of both industrial conduct and the operating permits in force. Less common parameters for which there is no sampling standard are studied on a case-by-case basis.
As a Reference Laboratory for the Walloon Region, the Institute participates in the accreditation procedure (technical part) as well as in the definition and development of reference methods for both sampling and analysis.

1. General

Emissions represent the discharges emitted by a source. Atmospheric emissions are related to air quality (monitored by networks), which represents the concentration of a pollutant in the ambient air in a given area. The latter concentration represents local emissions plus background pollution.
The most important aspect of emission measurements is the care taken with on-site sampling. A representative sample of the gas composition must be taken from the industrial pipe. It is not possible to intercept the entire gas flow. Standards have been drawn up to ensure representative sampling.CCB_25
Standards specify the position and distribution of sampling points in the duct, as well as the sampling flow rate. Others describe techniques for determining the concentration of a large number of analytes. Where no standard exists, the sampling technique is defined in collaboration with the analysis laboratory.

2. Sampling objectives

Emission measurements can be carried out not only for regulatory purposes, but also for the development of industrial techniques. These include :

  • Emissions checks, at the request of the relevant authorities (DPE, Walloon Region, etc.). The parameters to be measured and the frequency of measurements are determined by the operating permit.
  • Impact studies. When the operating permit has to be renewed, or when an important parameter of the operating conditions is modified, leading to a change in the pollutant content of the discharges, it is necessary to carry out a study of these.
  • Process studies, at the request of manufacturers. The development of industrial plants sometimes requires the measurement of specific parameters, and not necessarily at the stack.
  • Verification of purification systems (filters, afterburners, scrubbers, etc.), at the request of manufacturers. A simultaneous upstream and downstream measurement on a plant or prototype can be used to define the purification efficiency.CBR Lixhe 3792

3. Parameters studied

The parameters to be monitored depend above all on the type of industrial plant being studied:

  • gas flow in the pipe is the first parameter that can be determined, along with the concentration of dust suspended in the gas.
  • major compounds: H2O, O2 and CO2 (range: %). These values are also used to calculate flow rates and therefore determine withdrawal rates.
  • minor compounds: CO, SO2, NO, NOx, N2O, CxHy (range: mg/m3).

Alongside these parameters, which could be defined as classic, there are a great many inorganic and organic compounds which are measured depending on the type of plant encountered:

  • Inorganic compounds: chlorides, fluorides, cyanides, heavy and volatile metals (Hg, Cd, Tl, As, Co, Pb, Cr, etc.).
  • Organic compounds: dioxins and furans, PCBs, PAHs, etc.

P1000305 P1000415

4. Types of installation

Emission measurements can be carried out on all types of industrial pipe, provided they are fitted with sampling flanges that meet the relevant standards.
By sector, for example:

  • refuse and waste incinerators
  • cement and lime kilns
  • steel industry (mainly agglomeration)
  • the glass industry
  • the non-ferrous metals industry
  • CET (flares and engines)
  • agriculture (dryers)
  • the chemical industry

Regulatory basis and objectives

  • Order of the Walloon Government of May 27, 1999 on the mission of the Institut Scientifique de Service Public as a reference laboratory for water, air and waste, supplemented by AGW of July 15, 2010 on air-approved laboratories.
  • Walloon Government Order of March 27, 2003 organizing the management of environmental quality monitoring networks entrusted to the ISSeP, supplemented by annual subsidy Orders.
  • Wallonia Air-Climate Plan (March 15, 2007)
  • Directive 1999/13/EC on the limitation of emissions of volatile organic compounds in certain activities and installations (VOC Directive) and Directive 2004/42/EC on the limitation of VOCs from solvents and paints.
  • Directive 2000/76/EC on the incineration of waste (Directive WI)
  • Directive 2001/80/EC on the limitation of emissions of certain pollutants into the air from large combustion plants (LCP Directive)
  • European Pollutant Emission Register (EPER) and European Pollutant Release and Transfer Register (E-PRTR) to replace it
  • Directive 2008/1/EC concerning integrated pollution prevention and control (IPPC Directive) and Directive 2010/75/EU revising it (IED Directive)
  • Annual grant decree


List of accredited parameters

Telemetry network (TM)


The Telemetric Network is a monitoring and warning network covering the whole of Wallonia, equipped with specific analyzers that continuously measure certain pollutants in the ambient air in real time. Data is transmitted hourly via an Internet connection, and is centralized on a central server for analysis and processing. A file upload procedure then automatically sends the data to air quality information sites: and

The pollutants analyzed are sulfur dioxide (SO2), nitrogen oxides (NO/NO2/NOX), ammonia (NH3), ozone (O3), carbon monoxide (CO), gaseous mercury (Hg), suspended particulates (PM10/PM2.5/PM1 and ultrafine) and black carbon.

At some stations, meteorological parameters such as temperature, relative humidity, atmospheric pressure, precipitation, wind speed and direction are also measured.

The network currently comprises 26 stations, with the parameters measured at each station depending on its type of environment.

Regulatory basis and objectives

Directive 2008/50/EC of the European Parliament and of the Council of May 21, 2008 on ambient air quality and cleaner air for Europe, transposed into Walloon Government decree of July 15, 2010.


Lists of accredited parameters.

Sedimentable dust network (PS)


Depending on their size and density, airborne dust can remain in suspension or fall to the ground more or less quickly. Coarse, heavy particles settle quickly, causing damage to the immediate environment of the springs. This dust, known as sedimentable, is defined as any particle found in a deposit gauge.

Sedimentable dusts represent a low direct toxic risk for humans. Above all, they are a nuisance because of the damage they cause to buildings, plants, the landscape and the general living environment. This deterioration in living conditions is strongly felt by local residents and is the subject of numerous complaints, especially as it is often linked to other damage caused by the operation (noise, vibrations, cartage, etc.). Sedimentable dusts also have an indirect toxicological impact, as the pollutants they may contain can accumulate in soils and ecosystems.

Wallonia is heavily confronted with this problem, due to the high proportion of high-emission industries (iron and steel, quarries, cement works, etc.), which are often embedded in the urban fabric.

Sampling is carried out by deposit into “OWEN” type gauges. The analysis method is inductively coupled plasma mass spectrometry (ICP/MS).

There are currently 150 measurement points.

Regulatory basis and objectives

There is no regulatory basis, but this network is an excellent indicator of the nuisance felt by local residents of activities generating larger dust particles.

Heavy Metals Network (XM)


Metal compounds are emitted into the atmosphere either by natural sources or by human activities such as fossil fuel combustion, metallurgy, waste incineration, etc.

These compounds fall into two main categories: firstly, trace elements (Ca, Si, Fe, Mg, etc.), which are of little or no toxicity, but whose proportions make it possible to determine the origin of the dust and the responsibility of a given sector of activity; and secondly, toxic elements, including heavy metals. Unlike the first category, these elements are found in trace amounts and must be monitored for obvious public health reasons.

Sampling is carried out on daily cellulose nitrate or quartz filters. The analysis method is energy-dispersive X-ray fluorescence spectrometry (EDXRF).

There are currently 2 permanent measurement points, and this network also supports the mobile network for one-off campaigns.

This network has been retained for its ability to analyze a very large number of filters, since the analysis method requires no prior preparation. This is particularly useful for one-off campaigns to characterize an area and identify sources.


ISSeP is accredited for X-ray fluorescence analysis of Pb and Ni using an in-house method.

Fluorine network (RF)


The fluorine network monitors air quality in relation to the fluorine compounds present, whether in the form of hydrofluoric acid, gaseous or particulate fluorides, or soluble fluorides.

Sampling is carried out on pre-treated cellulose nitrate daily filters. The analysis method is potentiometry with a specific electrode.

There are 8 sampling points.

Regulatory basis and objectives

There is no regulatory basis, but this network is justified in certain areas where there are specific transmitters, such as Engis and Battice.

Wet deposition network (PA)


This network is commonly referred to as the “acid rain” network, as it was originally concerned with atmospheric acidification, but more recently heavy metals and mercury have also been measured in this wet deposition.

Some pollutants emitted into the atmosphere, such as sulfur dioxide, nitrogen oxides and ammonia, can break down into acidic compounds in the atmosphere, resulting in acidification of the environment. This phenomenon, commonly known as “acid rain”, results in damage to buildings, altered plant health, disruption of ecosystems and degradation of water and soil quality. In the 1970s and 1980s, acid rain caused forests and lakes in northern Europe and America to die back.

This acidification of the environment takes place in two ways: dry fallout, in the form of gas and dust, and wet fallout, in the form of snow, rain or fog.

The acid rain network is designed to quantify the wet fraction of acidifying pollutant deposition.

Sampling is carried out in weekly bottles. The analysis method is ion chromatography.

There are 10 measuring points for acid rain, 1 measuring point for heavy metals and 1 measuring point for mercury.

Regulatory basis and objectives

There are no regulations directly requiring the measurement of wet deposition, but this network is very important for the calculation of critical loads under the Convention on Long-range Transboundary Air Pollution (LRTAP Convention).


  • pH measurement based on a derivative of ASTM D 5015
  • Conductivity measurement based on a derivative of ISO 7888
  • Ion chromatographic analysis of cations: Na, Ca, NH4, K, Mg according to a derivative of ISO 14911
  • Ion chromatographic analysis of anions: F, Cl, PO4, NO3, SO4 according to a derivative of ISO 10304-1
  • Mercury analysis by atomic fluorescence direct measurement and after amalgam enrichment according to NBN EN ISO 17852

Volatile Organic Compounds (VO) Network


There is a huge variety of organic compounds. They can come from natural sources, such as forests, or from human activities.

Some are volatile under ambient conditions, others are not; they may or may not be persistent.

Involved in the ozone formation cycle, they are of particular importance.

These compounds fall into 4 main categories: saturated hydrocarbons, unsaturated hydrocarbons, chlorinated compounds and BTEX.

Sampling is carried out in tubes with specific adsorption phases. The analysis method is gas chromatography/mass spectrometry (GC/MS).

There are currently 16 measuring points.

Regulatory basis and objectives

Directive 2008/50/EC of the European Parliament and of the Council of May 21, 2008 on ambient air quality and cleaner air for Europe, transposed into Walloon Government decree of 07/15/2010.

This directive requires the measurement of benzene and some thirty ozone precursors.

The analysis of these pollutants is also of interest from a public health point of view, for example chlorinated compounds, which are highly toxic.

Polycyclic Aromatic Hydrocarbons (PAH) network


Polycyclic aromatic hydrocarbons (PAHs) are emitted by various types of sources: industrial sources (coking plants, primary aluminum production, etc.), natural sources (fires, volcanoes, etc.), domestic sources (heating, etc.) and traffic.

They have been classified by the International Agency for Research on Cancer (IARC) as probable or possible carcinogens.

Sampling is carried out in tubes with specific adsorption phases. The analysis method is gas chromatography/mass spectrometry (GC/MS).

There are currently 12 measuring points.

Regulatory basis and objectives

Directive 2004/107/EC of December 15, 2004 relating to arsenic, cadmium, mercury, nickel and polycyclic aromatic hydrocarbons in ambient air, transposed into Walloon Government Decree of May 16, 2007 and Walloon Government Decree of July 15, 2010.

This directive requires the measurement of benzo(a)pyrene and the monitoring of other polycyclic aromatic hydrocarbons, including at least benzo(a)anthracene, benzo(b)fluoranthene, benzo(j)fluoranthene, benzo(k)fluoranthene, indeno(1,2,3-cd)pyrene and dibenz(a,h)anthracene.

Heavy Metals Network (EM)


Metal compounds are emitted into the atmosphere either by natural sources or by human activities such as fossil fuel combustion, metallurgy, waste incineration, etc.

These compounds fall into two main categories: firstly, trace elements (Ca, Si, Fe, Mg, etc.), which are of little or no toxicity, but whose proportions make it possible to determine the origin of the dust and the responsibility of a given sector of activity; and secondly, toxic elements, including heavy metals. Unlike the first category, these elements are found in trace amounts and must be monitored for obvious public health reasons.

In Wallonia, heavy metals present in fine particles are measured in the ML heavy metals (TSP – X-ray fluorescence) and EM heavy metals (PM10 – ICP/MS) networks. This document describes the EM network.

There are currently 17 measuring points.

Regulatory basis and objectives

Directive 2008/50/EC of the European Parliament and of the Council of May 21, 2008 on ambient air quality and cleaner air for Europe, transposed in the Walloon Government decree of 07/15/2010.

Directive 2004/107/EC of December 15, 2004 relating to arsenic, cadmium, mercury, nickel and polycyclic aromatic hydrocarbons in ambient air, transposed into Walloon Government Decree of May 16, 2007 and Walloon Government Decree of July 15, 2010.

These Directives require the measurement of lead, arsenic, cadmium and nickel in ambient air.

Mobile Network (RM)


Measuring ambient air quality in areas where there are no measuring stations is no simple matter. Modern, reliable techniques are needed to set up high-performance analytical equipment compatible with the requirements for validating results.

The mobile network combines the techniques of the various other networks, as well as other non-regulated parameters such as ammonia, hydrogen sulfide, sedimentable dust, ultrafine particles and BTEX on a continuous basis.

The mobile network comprises 16 trailers, 3 compact stations and numerous samplers, analyzers and other analytical equipment that can be installed independently.

Some mobile network analyses are subcontracted internally to the air quality unit’s various networks.

Regulatory basis and objectives

The Mobile Network provides a rapid response to demand.

It enables

  • Responding to specific pollution problems;
  • Explain any exceedances of standards observed in the permanent network;
  • A better understanding of sites with local characteristics;
  • Provide data for little-studied areas;
  • Validating models ;
  • Carry out preliminary studies before installing a permanent station or commissioning a road infrastructure or industry.

EMEP station


The European Monitoring and Evaluation Programme (EMEP) is a program of the Convention on Long-range Transboundary Air Pollution, which focuses on air quality and deposition monitoring in areas remote from pollution sources, as well as pollutant emission inventories and atmospheric transport and deposition modeling.

The aim is to have the Vielsalm station recognized as an EMEP station. To this end, the parameters measured at this station must gradually be adapted to meet EMEP criteria.

Regulatory basis and objectives


Some parameters in the measurement program are already accredited by other networks.

Passive tubes


The importance of mapping at higher spatial resolution to detect variations in concentrations over short distances is becoming apparent, in order to better assess individual exposure and better understand pollution phenomena, especially in urban environments or those with high concentrations of industry.

Various measurement methods provide the basic data needed to model air quality in urban and industrial environments. The passive tube sampling method enables campaigns to be carried out with a very large number of measurement points, giving very good spatial resolution of pollutants. and also to analyze its evolution over time. The system has been developed to measure BTEX, NO2 and NH3. The sampling system has already been developed for BTEX. In 2012, ISSeP acquired the analytical and human resources to develop this technique for NO2.

The ISSeP is currently carrying out measurement campaigns for nitrogen oxides in various Walloon cities (Namur, Charleroi, Liège, etc.). Depending on the objectives requested, measurements at certain strategic locations provide an indication of the concentration ranges encountered in areas not directly influenced by road traffic.

Regulatory basis and objectives

Mapping at higher spatial resolution

Ultrafine particles (UFP)


An ultra-fine particle is defined as a nano-object whose three dimensions are on the nanometric scale, i.e. a particle with a nominal diameter of less than 100 nm. Another, broader definition calls a “nanoparticle” an assembly of atoms with at least one dimension on the nanometric scale.

Some nanoparticles (natural or artificial), released into the environment, particularly through the air, are strongly suspected of having negative effects on the environment, and on health when they are inhaled or penetrate the body via the skin, water or food; “Toxicological studies clearly demonstrate that the very small size of nanoparticles is a key element in toxicity, especially in the case of particles with low or no solubility (…) surface properties, the ability to induce free radicals or release certain ions can also have a substantial influence on toxicity…. surface properties, the ability to induce free radicals or to release certain ions can also have a substantial influence on toxicity. Several pulmonary effects have been documented, including the ability of certain nanoparticles to induce pulmonary granulomas.

Thanks to the PM-Lab project funded by INTERREG, ISSeP has been able to invest in ultrafine analyzers.

The Vielsalm site is part of the German Ultrafine Aerosol Network (GUAN): http: //

Regulatory basis and objectives

Ultrafine particles are among the emerging parameters that could become mandatory in a few years’ time

Data management and enhancement / Scientific report


Air quality measurement networks generate a wealth of information that needs to be managed and stored reliably in databases.

These databases are used both as management tools and for data transmission and enhancement.

The purpose of the annual scientific report is twofold: to disseminate the results of the measurement networks in the form of a summary document, and to analyze the data not only to take stock of the past year, but also to assess changes in the Walloon situation over time.

Regulatory basis and objectives

The Directives impose data quality objectives that require pollution data to be processed. For example, it is necessary to assess the population potentially exposed to levels exceeding a limit value for the protection of human health.

Action plan

Adaptation and restructuring of databases to enhance their value, particularly in terms of cartography (Project proposal no. 1: enhancement of existing data).

Valorization of models developed in Wallonia and development of new models

Website development and consolidation

Ensure traceability of data to source The disparity of metadata from different tools and sources creates confusion about the “real” data.

Carry out a more in-depth scientific analysis of the data



Over the past ten years, epidemiological and experimental studies have highlighted the health risks associated with atmospheric particles. This undoubtedly explains why European regulations on exposure levels are becoming increasingly stringent. Under these conditions, the problem of discrimination between different emission sectors becomes crucial. In this respect, a feasibility study carried out in the context of air quality control highlighted some of the major potential of micro-analysis to complement the information provided by more traditional metrological approaches.

Based on point analysis by scanning electron microscopy (SEM) coupled with an energy dispersive spectrometer (EDX), on the one hand, and global analysis by X-ray diffraction (XRD), on the other, micro-analysis provides information on the nature of the particles making up PM10 and sedimentable dust. In order to respond to the concerns of the Administration, radiocrystallographic (Rietveld method) and microscopic (SEM/EDX counting in automated mode) quantifications have been developed.
Given the essential tools required for this approach, expert assessments are carried out in collaboration with the Université de Liège, in particular the Laboratoire de Chimie Inorganique Structurale (LCIS-GREEnMat), and the Laboratoire de Minéralogie et Cristallochimie.

Regulatory basis and objectives

Micro-analysis has three main objectives:

  • determine the contribution of different emission sources, including natural and anthropogenic sources;
  • distinguish between natural, primary and secondary particles;
  • quantify the different particle families.


Action plan

Microanalysis was successfully used in the Engis campaign, where the telemetry station was in breach of European Directive 2008/50/EC. Notwithstanding the complexity of the site, the main industrial activities responsible for exceeding particulate levels have been unambiguously identified.

MicroAnalysis. Anthropogenic snowball gypsum


Technological, legal and new technology watch


Technological and scientific watch consists of systematically keeping abreast of the latest techniques, and above all of their availability. Knowing this information enables the administration to better anticipate future air quality obligations, and to comply with these requirements in the most appropriate way.

ISSeP sits on a number of technical and scientific committees concerned with ambient air quality.

CEN/TC264/WG32 – “Air quality – Ambient air – Determination of the particle number concentration”.

AQUILA: Air Quality Reference laboratories

ISSeP also takes part in numerous seminars and workshops on the subject of air quality.

ISSeP is also involved in research projects that have positioned it at the forefront of certain fields, such as ultrafine particles and particle characterization by microscopy.

Regulatory basis and objectives

Order of the Walloon Government of May 27, 1999 concerning the public service scientific institute’s mission as a reference laboratory for water, air and waste.

In addition to the tasks listed in this decree, the ISSeP is also responsible for

  • participate in national and international working groups on sampling, in situ measurement and analysis methods and techniques
  • develop, improve and test sampling, in situ measurement and analysis methods
  • provide technical support to the administration.

Action plan

Participation in technical groups on the scientific and technical revision of the Directives.

Participation in research projects (Life, INTERREG, etc.)

Development of new methods in the fields of particle characterization (microanalysis, development of assay methods for PCBs, CrVI, EMEP parameters, etc.), nanoparticle metrology, measurement using remote sensing techniques (LIDAR, DOAS, etc.), etc. (Project proposal no. 9: development of the air reference laboratory and project proposal no. 10: microanalysis and isotope analysis).