Objectives

This project is directed towards an increased understanding of the adverse biomedical effects of ambient and motor engine particles. Furthermore aspects the particles chemical composition as well as size, numbers and other physical characteristics are investigated in relationship to what effects they are causing in the experimental models, as well as European.

More in detail the overall objectives of this research project are:
· To assess the inflammatory and toxicological potential of ambient suspended particles (collected at places across Europe with contrasts in traffic intensity) in comparison with diesel and gasoline engine particles.
· To relate this to the previously demonstrated effects of exhaust on human airways.
· To relate this to the population based epidemiological findings of adverse health effects of ambient particles.
· To overall assess toxicity in-vitro and in-vivo in animals and humans, as well as health effects in epidemiological studies in relation to the physico-chemical characteristics of PM.

Results and milestones

Work package 1 (WP1) was directed at collection and characterization of ambient and engine particulate matter (PM). The first milestones were met in motivating sampling sites primarily identified in association to the ISAAC-II-study together with additional sites in Rome, Northern Sweden together with motor engine particle collection. Sampling sites were chosen in locations representative to the pollution levels in the ISAAC-II school yards, as generation of noice and vibrations from the high volume samplers prevented use in these school yards. The second milestone was performance of the sampling campaign. The high volume sampler (HVS) was a highly innovative and cutting edge equipment allowing for large amounts of particles to be collected into different size cuts. This equipment was a cornerstone for the project and an innovative action not previously used in research projects outside the labs of the American manufacturer. The project suffered a major time delay when a number of adjustments had to be performed in order to get the equipment working in European milieu, outdoors and with European wirings. This complementary work was only solved when multidisciplinary resources were organized to solve the problems. Additionally the slits allowing for the particle separations had to be remanufactured. Lastly the equipments were validated against reference low flow pumps, as well confirmation that there was no variability between the tree sampler to be used in the project. Equipments were eventually found to be working properly, even though some aspects as regards sampling efficiency and filter overload, allowed for some changes in durations of the actual particle collections.

Work package II concernes toxicological in-vitro screening of PM. The in-vitro models at King's College London, Napier University, Edinburgh and ISS, Rome were fine-tuned and reference particles introduced. A study of aging of particles was added to the project plan. It was demonstrated that no additional aging took place from the time when the particles arrived to the labs following the collection period and particle extraction work. The stability of data was at three, five and seven months suggests oxidations and other aging actions to occur early. This allows for recovery of some of the time delay as PM do not have to be stored until the annual sampling campaign has been completed.

In Work package III oxidative and inflammatory mechanisms of PM responses in cells and lung fluids is evaluated. The work has been initiated to work in parallel rather than following the in-vitro screening, allowing for an earlier arrival at the milestones.

Work package IV concerns the overall toxicity and PM composition evaluation, which is to be completed following the ongoing screening work.

Work packages V and VI include diesel engine exhaust exposures in human subjects. Asthmatics experienced a significant increase in bronchial hyperresponsiveness 24 hours after the exposure, as compared with filtered air. A complementary study investigated the peak responses to diesel exhaust that were expected at 18 hours after exposure to 100 mg PM10/m3 for two hours vs filtered air. The study based was expanded to comprise healthy subjects, individuals with allergic rhino conjunctivitis and two groups of asthmatics, with and without inhaled corticosteroid treatments. The experience from bronchoalveolar lavage data suggest some airway inflammatory differences between healthy and the other groups. The full set of data from the analyses of the bronchial mucosal tissue biopsies sampled, are therefore expected to be particularly interesting to review.
Local bronchial instillations of PM will be performed following the in-vitro and animal screenings of PM. The planned comparisons between diesel and gasoline PMs is still depending upon ability to secure the substantial findings which are demand for this part of the project.

Work package VII. The final work package is based upon the collection of data from the preceeding WP:s to allow for an increased understanding of what physical and chemical characteristics of ambient and motor engine PM that are related to different effects seen in the experimental and epidemiological studies.

Benefits and Beneficiaries

Novel research equipments have now been established for field use to collect European ambient particles, which in combination with experimental laboratory models is expected to increase the knowledge of how particulate pollution may cause adverse health effects. Additional knowledge has been obtained in how asthmatic respond to diesel exhaust pollution. Beneficiaries may be the general population in Europe, and in particular subjects with pre-existing medical conditions such as asthma, allergy and chronic obstructive pulmonary disease (COPD).

Future actions
The continued sampling campaign, in-vitro animal and human experimental exposure models generates large quantities of data, which will be combined with epidemiological data for an extensive scientific evaluation.