Introduction: We have previously reported that outdoor levels of fine particles (PM2.5, diameter <2.5 μm) are associated with urinary CC16, a marker for lung damage, in Helsinki, Finland, but not in the other two ULTRA cities (Amsterdam, The Netherlands, and Erfurt, Germany). We here evaluated whether PM2.5 from specific source categories would be more strongly associated with CC16 than (total) PM2.5. In addition, we compared two source apportionment methods.Methods: We collected biweekly spot urinary samples over 6 months from 121 subjects with coronary heart disease for the determination of CC16 (n = 1251). Principal component analysis (PCA) was used to apportion daily outdoor PM2.5 between different source categories. In addition, the multilinear engine (ME) was used for the source apportionment in Amsterdam and Helsinki. We analyzed associations of source category-specific PM2.5 and PM2.5 absorbance, an indicator for combustion originating particles, with logarithmized values of CC16 adjusting for urinary creatinine using multivariate mixed models in STATA.Results: In the pooled analyses, CC16 was increased by 0.6% (standard error 0.3%) per 1 × 10−5 m−1 increase in the same-day levels of PM2.5 absorbance. Source category-specific PM2.5 concentrations were not consistently associated with the levels of CC16 in the three cities. Correlations between source category-specific PM2.5 determined using either PCA or ME were in general high. Associations of source category-specific PM2.5 with CC16 in Amsterdam and Helsinki were statistically less significant when ME was used.Conclusions: The present results suggest that PM2.5 from combustion sources increases epithelial barrier permeability in lungs.
This paper describes the resuspension of road dust in an urban subarctic environment and focuses especially on the effect of wind speed on the formation of resuspended dust episodes.The study was conducted in Kuopio, Finland, in the spring of 1995. There were 36 daily measurements of mass concentrations of fine particulate matter (PM2.5), thoracic particulate matter (PM10), total suspended particulate matter, black carbon and carbon monoxide; size-segregated number concentrations of particles (diameter range 0.01-10 microm); and meteorological parameters. Total elemental compositions of PM2.5 and PM10 samples were analyzed with inductively coupled plasma mass spectrometry.The mass and number concentrations of particles in all the size ranges and the concentrations of soil-derived (iron) and combustion-derived (vanadium and lead) elements in the PM2.5 and PM10 increased during the dust episodes. The daily average wind speed dually affected the episodes. The pollutant concentrations increased at wind speeds of <4 m/s and >5 m/s. The former was related to inversion-type conditions characterized by low wind speeds, while the latter was likely to be due to wind-blown resuspended dust. Resuspended lead accounted for an average of 27% of the total lead, and resuspended vanadium for 46% of the total vanadium in PM2.5.Resuspended dust episodes were related to both low and high wind speeds, and the relationship suggests that factors other than wind speed, such as turbulence induced by traffic, affect the emergence of such episodes. The contribution of elevated levels of crustal material and toxic metals in resuspended PM2.5 to human adverse health effects should be investigated.
Evidence on the correlation between particle mass and (ultrafine) particle number concentrations is limited. Winter- and springtime measurements of urban background air pollution were performed in Amsterdam (The Netherlands), Erfurt (Germany) and Helsinki (Finland), within the framework of the EU funded ULTRA study. Daily average concentrations of ambient particulate matter with a 50% cut off of 2.5 μm (PM2.5), total particle number concentrations and particle number concentrations in different size classes were collected at fixed monitoring sites. The aim of this paper is to assess differences in particle concentrations in several size classes across cities, the correlation between different particle fractions and to assess the differential impact of meteorological factors on their concentrations. The medians of ultrafine particle number concentrations were similar across the three cities (range 15.1 × 103–18.3 × 103 counts cm−3). Within the ultrafine particle fraction, the sub fraction (10–30 nm) made a higher contribution to particle number concentrations in Erfurt than in Helsinki and Amsterdam. Larger differences across the cities were found for PM2.5 (range 11–17 μg m−3). PM2.5 and ultrafine particle concentrations were weakly (Amsterdam, Helsinki) to moderately (Erfurt) correlated. The inconsistent correlation for PM2.5 and ultrafine particle concentrations between the three cities was partly explained by the larger impact of more local sources from the city on ultrafine particle concentrations than on PM2.5, suggesting that the upwind or downwind location of the measuring site in regard to potential particle sources has to be considered. Also, relationship with wind direction and meteorological data differed, suggesting that particle number and particle mass are two separate indicators of airborne particulate matter. Both decreased with increasing wind speed, but ultrafine particle number counts consistently decreased with increasing relative humidity, whereas PM2.5 increased with increasing barometric pressure. Within the ultrafine particle mode, nucleation mode (10–30 nm) and Aitken mode (30–100 nm) had distinctly different relationships with accumulation mode particles and weather conditions. Since the composition of these particle fractions also differs, it is of interest to test in future epidemiological studies whether they have different health effects.
Fine and ultrafine particles in ambient air are more consistently associated with severe adverse health effects than coarse particles. We assessed whether the effects of PM(2.5) on peak expiratory flow (PEF) and respiratory symptoms in asthma patients differ by the source or the chemical properties of particles. A panel of 57 adult asthmatics was followed for 181 days from November 1996 to April 1997 with 3 daily PEF measurements and diaries. Air quality, including elemental analyses of PM(2.5) filters every 2 days (n= 83), was monitored at a central site. Daily concentrations of PM(2.5) from different sources were estimated using principal component analysis and multiple linear regression. Associations of PM(2.5) from different sources with respiratory endpoints were examined using a generalized least squares autoregressive model after adjustment for covariates. PM(2.5) attributable to local combustion was consistently negatively associated with all measurements of PEF. One interquartile increase (1.3 microg/m(3)) in 5-day average concentrations of PM(2.5) attributable to local combustion was associated with an average 1.14 L/min decline in evening PEF (95% CI: -1.95 to -0.33 L/min). We also observed that PM(2.5) attributable to long-range transport was positively, and soil-derived PM(2.5) negatively, associated with PEF. No consistent associations were observed between source-specific PM(2.5) and respiratory symptoms or between individual chemical elements and any respiratory endpoints. Our results suggest that the negative effects of PM(2.5) on PEF in adult asthmatics are mainly mediated by particles related to local combustion sources.
Abstract The associations between residential outdoor and ambient particle mass, fine particle absorbance, particle number (PN) concentrations, and residential and traffic determinants were investigated in four European urban areas (Helsinki, Athens, Amsterdam, and Birmingham). A total of 152 nonsmoking participants with respiratory diseases, not exposed to occupational pollution, were included in the study, which comprised a 7-day intensive exposure monitoring period of both indoor and home outdoor particle mass and number concentrations. The same pollutants were also continuously measured at ambient fixed sites centrally located to the studied areas (fixed ambient sites). Relationships between concentrations measured directly outside the homes (residential outdoor) and at the fixed ambient sites were pollutant-specific, with substantial variations among the urban areas. Differences were more pronounced for coarse particles due to resuspension of road dust and PN, which is strongly related to traffic emissions. Less significant outdoor-to-fixed variation for particle mass was observed for Amsterdam and Birmingham, predominantly due to regional secondary aerosol. On the contrary, a strong spatial variation was observed for Athens and to a lesser extent for Helsinki. This was attributed to the overwhelming and time-varied inputs from traffic and other local sources. The location of the residence and traffic volume and distance to street and traffic light were important determinants of residential outdoor particle concentrations. On average, particle mass levels in suburban areas were less than 30% of those measured for residences located in the city center. Residences located less than 10 m from a street experienced 133% higher PN concentrations than residences located further away. Overall, the findings of this multi-city study, indicated that (1) spatial variation was larger for PN than for fine particulate matter (PM) mass and varied between the cities, (2) vehicular emissions in the residential street and location in the center of the city were significant predictors of spatial variation, and (3) the impact of traffic and location in the city was much larger for PN than for fine particle mass.
P-048 Introduction: We have earlier reported heterogeneous results between three countries in the association between daily PM2.5 and urinary Clara Cell protein CC16. CC16 is a 16-17-kDa protein secreted by Clara cells in the bronchial lining. Concentration of CC16 in urine evaluates integrity of lung epithelial barrier. In the present analysis we aim to test, if using source-specific PM2.5 will resolve some of the heterogeneity between the centres. Methods: 121 subjects with coronary heart disease in three European cities were followed for 6 months with biweekly spot urinary samples for determination of CC16 (n = 1251). Daily levels of source-specific PM2.5 have earlier been determined using principal component analysis and multiple linear regression based on measured elemental composition and absorbance of PM2.5 filters, selected gases and ultrafine number counts. Log(CC16/urinary creatinine) was analyzed using mixed model in SAS. Centre-specific basic models were first built considering following variables: dummy for each subject, long term time trend, temperature (lags 0–3), relative humidity (lags 0–3), barometric pressure (lags 0–3), and the weekday of the visit. Results: The only significant pooled association with source-specific PM2.5 was with soil source, lag 0 (pooled estimate 2.3% (SE 1.0%) increase for 1 μg/m3). The association was not heterogeneous between centres. There was no association with other lags. There was a consistent association with absorbance of PM2.5 filters, which reached statistical significance at lag 0 (5.9% (SE 2.6%) pooled estimate for 1/m2*105 increase in absorbance at lag 0, 4.4% (SE 2.7%) at lag 1). Neither of the estimates was heterogeneous between centres. The association was similar among subjects with and without chronic lung disease. There was also a suggestion for an association with ultrafine number counts, calcium, and nickel. Conclusions: The present results suggest that especially PM2.5 from combustion and possibly from soil source might lead to increased epithelial barrier permeability in lungs in subjects with coronary artery disease.
