Expolis/Methods

The text on this page is taken from the EXPOLIS-project homepage under "The Field Phase".

EXPOLIS is a monitoring study that measured the population exposures to key air pollutants in six European cities. Concentrations were measured in home indoor, home outdoor and work indoor environments and in addition personal exposure were measured for 48hr with carry-on samplers. Measurements took place in 1996-1997.

The original EXPOLIS-project

EXPOLIS is a study about population exposures to air pollution. Epidemiological studies have connected air pollution to adverse health effects, like sickness and pre-mature death. These are caused when population comes to contact with pollution.

Originally the EXPOLIS Study was launched as European Comission (EC) project in the Program for Research and Technology Development (RTD), Framework IV. This Framework was for years 1994-98, and EXPOLIS started in 1996.

This chapter givers information on the orignal EXPOLIS project: among other things the scientific background, study design, measurements, selected pollutants and quality assurance. As a large international study, EXPOLIS related work is continuing and producing new related research plans, studies and results. The current and future activities are discussed in the next chapter.

History of the EXPOLIS project. The field work in the original six centers was carried out in 1996-97. The scientific analysis of the collected samples and the created database continues at least for 2000-2005.

Scientific background

EXPOLIS study is based on the scientific literature review and research plan, the publication on the EXPOLIS design and the EXPOLIS Final Report.

One-page summary if the key issues is presented below:

Background: What do we know?

Epidemiological air pollution studies in the last decade have shown that

• increased daily pollution levels increase daily mortality, and
• increased long term levels reduce the average length of life of large urban populations.

Mortality increases are clearly associated with small aerosol particles, but also other pollutants, especially sulfates and ozone seem significant.

Practical and Scientific Problem

The studies have related mortality statistics to air pollution levels at urban monitoring sites. The affected people, however, spend very little time breathing this monitored outdoor air, but instead breathe air inside homes, workplaces and transportation vehicles. They are exposed to the contaminants in the air that surrounds them through the day - indoors and outdoors.

Solution: The EXPOLIS study and it's goals

Expolis study collects air pollution exposure data from adult urban populations in Europe to assess

• air pollution exposure levels and distributions, and relations to ambient air quality,
• personal, environmental, and communal determinants of these exposures,
• and to develop a probabilistic simulation technique for modeling exposures of subpopulations and impacts of urban development alternatives on exposures.

Funding

The EXPOLIS study was launched in March, 1996 as part of the European Comission Research and Technological Development (EC RTD) Program IV, 1994-1998. In this program was part of Environment and Climate, Activity 1/III6.

In each of the participating centres, national funding has been granted. Some of these are listed below:

• EXPOLIS has been supported by EU contracts ENV4-CT96-0202 and ERB IC20-CT96-0061 (Prague),
• Academy of Finland contract N:o 36586 (Helsinki),
• Swiss Ministry for Education and Science contract BBW N:o 95.0894 (Basel),
• French National Environment Agency (ADEME), Union Routière de France and Grenoble Communauté de Communes (Grenoble),

Other national research funds, and intramural funding from the participating institutes.

• EAS (Elemental Analysis Study in EXPOLIS) has been supported by Swiss National Science Foundation contract No: 32-52990.97/1, Academy of Finland Contract No: 42610, and intramural funding from University of Basel and KTL.
• EXPOLIS IndEx has been supported by Cefic LRI Contract NMALRI-A3.3UBAS0207.

Expanding EXPOLIS

After the original start-up of EXPOLIS study back in 1996, launched by the European Commission, several new research groups have selected to use the tested and well designed procedures of EXPOLIS study in population exposure measurements.

Substantial amount of work, including literature reviews, thorough evaluations of measurement techniques and equipment and planning the study design has been done in planning and preparing for the original EXPOLIS study. This work can be utilized by other workgroups.

Among new research groups accommodating the EXPOLIS procedures are:

• Columbia University, New York, USA
• Imperial College of Science, Technology & Medicine, London, UK
• Middlesex University, London, UK

Besides these studies that use EXPOLIS procedures for similar measurements in new cities and for new populations, EXPOLIS links to other concurrent studies:

• EXPAND Study, Finnish Meteorological Institute (FMI)
• DIANA/MOBILE2 Study, FMI
• EAS-EXPOLIS Study, KTL
• RELEX/MOBILE2 Study, KTL

The cities

The cities selected for population exposure measurements in the original EXPOLIS study were:

• Athens
• Basel
• Grenoble
• Helsinki
• Milan
• Prague

The Dutch National Institute for Public Health and the Environment, RIVM, is sited in Bilthoven. RIVM participates in the data analysis and simulation activities. No measurements were carried out in Bilthoven.

These cities represent variety of sizes, geographical locations and nationalities in the European scale.

Population samples

The target population in each of the original EXPOLIS cities are the 25-55 year old (i.e. working age) people. Several population samples were drawn from target population:

1. random sample for short mailed or interviewed questionnaire
2. random sample for time activity diary and in-depth questionnaires
3. sample for exposure and microenvironmental concentration measurements

In Helsinki, a larger exposure measurement sample was drawn for more detailed analysis of exposure determinants (n=201). In other centers the exposure sample size was 50. The target size for mailed questionnaire was 2000, the true sample sizes in each city varying up to 3000.

Response rates in different cities varied. Tuulia Rotko has studied the sub population characteristics compared to the whole target population in each city.The results are published in:

Tuulia Rotko, Lucy Oglesby, Nino Künzli and Matti J. Jantunen (2000): Population Sampling In European Multicity Expolis Study And Comparability Of Air Pollution Exposure Results. Submitted to Journal of Exposure Analysis and Environmental Epidemiology.

Pollutants

The exposures and microenvironmental concentrations in the most important personal environments were measured for several key pollutants:

1. Fine Particulate Matter, particle size < 2.5 µm (PM2.5) and elemental composition pf PM and BS index.
2. Volatile Organic Compounds (VOCs) of environmental health relevance
3. Carbon Monoxide (CO)
4. and optionally Nitrogen Dioxide (in some centers only)

The concentration of 30 VOC compounds were analyzed in every sample. Some 300 other compounds were identified in same samples.

The selection of measured pollutants is discussed in more detail in

Jantunen M, Hänninen O, Katsouyanni K, Knöppel H, Kuenzli N, Lebret E, Maroni M, Saarela K, Srám R and Zmirou D (1998): Air Pollution Exposure in European Cities: The Expolis Study. JEAEE 8: 495-518.

Sampling media. Particulate matter was sampled on Teflon filters (left) and VOCs on Tenax tubes (top) using a pump. NO2 was sampled on Palmes tubes (bottom) with passive diffusion.

List of elements: PM 2.5 elemental composition. Na, Mg, Al, S, Cl, K, Ca, Fe, Ni, Cu, Zn, Ga, As, Se, Br, Rb, Sr and Pb

Table 1. EXPOLIS VOC Target Compound List.

Alkanes	CAS Number
hexane	110-54-3
nonane	111-84-2
decane	124-18-5
cyclohexane	110-82-7
undecane	1120-21-4
Alcohols	CAS Number
2-methyl-1-propanol	78-83-1
1-butanol	71-36-3
2-ethyl-1-hexanol	104-76-7
phenol	108-95-2
2-butoxyethanol	111-76-2
1-octanol	111-87-5
Alkanals	CAS Number
hexanal	66-25-1
benzaldehyde	100-52-7
octanal	124-13-0
Halogenated	CAS Number
trichloroethene	79-01-6
tetrachloroethene	127-18-4
1,1,2-trichloroethane	79-00-4
Miscellaneous	CAS Number
dl-limonene	138-86-3
1-methyl-2-pyrrolidinone	872-50-4
3-caren	13466-78-9
alfa-pinene	80-56-8
Aromatics	CAS Number
benzene	71-43-2
toluene	108-88-3
ethylbenzene	100-41-4
m- & p-xylene	108-38-3
o-xylene	95-47-6
styrene	100-42-5
naphthalene	91-20-3
propylbenzene	103-65-1
trimethylbenzenes	95-63-6

See also

• Expolis
• Expolis/Study
• Expolis/Methods
• Expolis/Materials