Chemical Compositions Responsible for Inflammation and Tissue Damage in the Mouse Lung by Coarse and Fine Particulate Samples from Contrasting Air Pollution in Europe

Abstract

Inflammation is regarded as an important mechanism in mortality and morbidity associated with exposures of cardiorespiratory patients to urban air particulate matter. We investigated the association of the chemical composition and sources of urban air fine (PM_2.5−0.2) and coarse (PM_10−2.5) particulate samples with the inflammatory activity in the mouse lung. The particulate samples were collected during selected seasons in six European cities using a high-volume cascade impactor. Healthy C57BL/6J mice were intratracheally instilled with a single dose (10 mg/kg) of the particulate samples. At 4, 12, and 24 h after the exposure, the lungs were lavaged and the bronchoalveolar lavage fluid (BALF) was assayed for indicators of inflammation and tissue damage: cell number, total protein, and cytokines (tumor necrosis factor [TNF]-α, interleukin [IL]-6, and KC). Dicarboxylic acids and transition metals, especially Ni and V, in PM_2.5−0.2 correlated positively and some secondary inorganic ions (NO₃^-, NH₄⁺) negatively with the inflammatory activity. Total organic matter and SO₄^2- had no consistent correlations. In addition, the soil-derived constituents (Ca²⁺, Al, Fe, Si) showed positive correlations with the PM_2.5−0.2-induced inflammatory activity, but their role in PM_10−2.5 remained obscure, possibly due to largely undefined biogenic material. Markers of poor biomass and coal combustion, i.e., monosaccharide anhydrides and As, were associated with elevated PAH contents in PM_2.5−0.2 and a consistent immunosuppressive effect. Overall, our results support epidemiological findings that the local sources of incomplete combustion and resuspended road dust are important in urban air particulate pollution-related health effects.

This study was conducted within the framework of the project “Chemical and biological characterization of ambient air coarse, fine, and ultrafine particles for human health risk assessment in Europe” (PAMCHAR) coordinated by the National Public Health Institute of Finland (http://www.pamchar.org). The authors highly appreciate funding by the EC-FP5 Quality of Life and Management of Living Resources Programme (contract QLK4-CT-2001-00423), the Academy of Finland (FINE-contract 201701), and the Centre of Excellence Programme 2002–2007 of the Academy of Finland (contract 53307) and the Finnish Funding Agency for Technology and Innovation (Tekes, contract 40715/01). The authors are grateful to all the PAMCHAR teams conducting the field work and collaborating in the project: Dr. Thomas Kuhlbusch (Institut für Energie- und Umwelttechnik, Duisburg, Germany); Assoc. prof. Martin Branis (Charles University in Prague, Czech Republic); Prof. Bert Brunekreef (University of Utrecht, the Netherlands); Prof. Jordi Sunyer (Institut Municipal d'Investigació Mèdica, Barcelona, Spain); Prof. Klea Katsouyanni and Dr. Ilias Kavouras (National and Kapodistrian University of Athens and National Observatory of Athens, Greece); Dr. Flemming Cassee (National Institute of Public Health and the Environment [RIVM], Bilthoven, the Netherlands); Prof. Paul Borm (Institut für Umweltmedizinische Forschung [IUF], Düsseldorf, Germany); MSc Anna Frey, MSc Sanna Saarikoski and MSc Ulla Makkonen (Finnish Meteorological Institute); and MSc Erik Sandell and Ms Sirpa Himberg (Technical Research Centre of Finland, VTT Processes, Espoo, Finland). The laboratory assistance by Heli Martikainen, Arja Rönkkö, and Reetta Tiihonen, and the statistical assistance by MSc Pekka Tiittanen (National Public Health Institute, Kuopio, Finland) are highly appreciated. The PAMCHAR project belongs to the COST Action 633 on Particulate matter: properties related to health effects (http://cost633.dmu.dk).