Transport of traffic-related aerosols in urban areas

Health benefits to vulnerable populations by meeting particle-level guidelines inside schools with different ventilation conditions

We conducted simultaneous real-time measurements for particles on the premises of four schools, two of which were naturally ventilated (NV) and two mechanically ventilated (MV) in Kanpur, India. Health to school children from reduced particle levels inside classrooms simulated to the lowest acceptable levels (ISHRAE Class C: PM10 ≤ 100 µg/m3 & PM2.5 ≤ 25 µg/m3) using air filters were examined. Lung deposition of particles was used as a proxy for health impacts and calculated using the MPPD model. The particle levels in all classrooms were above the baseline, with NV classrooms having higher particle masses than MV classrooms: 72.16% for PM1, 74.66% for PM2.5, and 85.17% for PM10. Our calculation reveals a whooping reduction in particles deposited in the lungs (1512% for PM10 and 1485% for PM2.5) in the case of the NV classrooms. Results highlight unhealthy air inside classrooms and suggest urgent interventions, such as simple filtration techniques, to achieve acceptable levels of particles inside schools.

The concentration of particulate matter in the barn air and its influence on the content of heavy metals in milk

Heavy metals are one of the components of smog, which is mainly the product of burning fossil fuels in residential buildings. These elements, introduced into the body of cattle by inhalation, may enter the milk. The goal of this study was to assess the impact of particulate pollution in the atmospheric air on the concentration of particulate matter in the air of a dairy cattle barn and on the content of selected heavy metals in milk from cows present in the building. Measurements were taken between November and April (148 measurement days). The calculations carried out showed a high correlation (RS = + 0.95) between the concentrations of particulates measured outside and inside the barn, which is indicative of a significant impact of the atmospheric air on the particulate pollution level of the livestock building. The number of days in excess of the daily standard for PM10 inside was 51. The conducted analysis of the chemical composition of the milk collected under high particulate pollution (February) showed that the permitted lead level had been exceeded-21.93 µg/kg (norm 20.00 µg/kg).

Applying principal component, health risk assessment, source identification for metallic elements of ambient air total suspended particulates at Taiwan Scientific Park

This study collected ambient air total suspended particle (TSP) concentrations and dry depositions at Taichung Science Park sampling site. The metallic elements concentrations and dry depositions were analyzed. The possible pollutant sources are discussed in this study. In addition, this study used the principal component analysis method to find metallic element sources and their transportation pathway and distributions at Taichung Science Park (T.S.P). The results indicated that the average highest TSP concentrations and dry deposition fluxes occurred in the autumn and winter seasons. The highest average metallic element concentration and dry deposition was Fe, while the lowest average metallic element concentration and dry deposition was Hg(p). The study results further indicated that the lowest metallic element concentrations and dry depositions all occurred in the summer season. The pollutant parcels originated from the northern Taiwan counties and sea surface in the autumn, winter and spring seasons. Factor 1 was responsible for the local industrial emission results and traffic road dust. The metallic elements Hg(p) yield a value greater than 0.7 in Factor 2 which revealed that ambient air particulate pollutants were generated from Taichung Thermal Power Plant (T.T.P.P.) emissions and were transported from the coastal area of mainland China cities. The mean seasonal concentration differences existed for ambient air particulates, and there were no mean seasonal concentrations differences for all metallic elements. In addition, there were no significant mean concentrations differences for all metallic elements and meteorological factors such as temperature, humidity and wind speed. Therefore, the ambient air metallic element emissions were stable and considered primary emissions sources. The health risk value for metallic element Cr was higher than that for the acceptable health risk value suggested by the EPA. Metallic element Cr revealed that it was no mean seasonal concentrations differences. Thus, metallic element Cr was considered came from local emission source at this T.S.P. sampling site.

Manufacturing agglomeration, urban form, and haze pollution

Manufacturing agglomeration promotes rapid economic development while also causing severe environmental pollution. This paper investigates the impact and mechanism of manufacturing agglomeration on haze pollution from the Chinese city level. Furthermore, we discuss the moderating effect and threshold effect of the three urban forms of urban external shape complexity, urban compactness, and urban fragmentation on the relationship between the two. The result shows the following: (1) The aggregation of the manufacturing industry presents an inverted U-shaped characteristic of promoting first and then inhibiting haze pollution in China's overall, eastern and central regions. (2) The complexity of the city's external shape and the city's fragmentation has a positive moderating effect on the relationship between manufacturing agglomeration and haze pollution. And urban fragmentation shows a negative moderating effect on the relationship between the two when the level of manufacturing agglomeration is on the right side of the inverted U-shaped curve. (3) The urban form shows a significant double threshold characteristic for haze pollution, increasing the complexity of the city's external shape and the city's fragmentation. The agglomeration of manufacturing shows the characteristics of first inhibiting and then promoting haze pollution. As urban compactness increases, the inhibitory effect of manufacturing agglomeration on haze pollution increases.

High Resolution On-Road Air Pollution Using a Large Taxi-Based Mobile Sensor Network

Traffic-related air pollution (TRAP) was monitored using a mobile sensor network on 125 urban taxis in Shanghai (November 2019/December 2020), which provide real-time patterns of air pollution at high spatial resolution. Each device determined concentrations of carbon monoxide (CO), nitrogen dioxide (NO2), and PM2.5, which characterised spatial and temporal patterns of on-road pollutants. A total of 80% road coverage (motorways, trunk, primary, and secondary roads) required 80-100 taxis, but only 25 on trunk roads. Higher CO concentrations were observed in the urban centre, NO2 higher in motorway concentrations, and PM2.5 lower in the west away from the city centre. During the COVID-19 lockdown, concentrations of CO, NO2, and PM2.5 in Shanghai decreased by 32, 31 and 41%, compared with the previous period. Local contribution related to traffic emissions changed slightly before and after COVID-19 restrictions, while changing background contributions relate to seasonal variation. Mobile networks are a real-time tool for air quality monitoring, with high spatial resolution (~200 m) and robust against the loss of individual devices.

Will improvements in transportation infrastructure help reduce urban carbon emissions?--motor vehicles as transmission channels

Achieving the "dual carbon" goal requires focusing on the issue of urban transportation carbon emissions. This study derives the mechanism of transportation infrastructure on urban carbon emissions and uses panel data from 284 cities in China from 2004 to 2017 as a basis for empirical analysis through the two-stage least squares method (2SLS). The results of the study show that the improvement of transportation infrastructure has a significant negative effect on the level of urban carbon emissions, and it is greater than the positive spillover of the increase in the number of motor vehicles on urban carbon emissions. Further, research has shown that improvement of transportation infrastructure has no significant impact on the purchase of motor vehicles; therefore, the transportation infrastructure will not affect the "induced traffic" through the purchase of motor vehicles, thereby further affecting the level of urban carbon emissions. The enlightenment of this article include the following: In urban planning and construction, attention should be paid to reducing urban carbon emissions by improving the construction of transportation infrastructure to help China achieve its carbon peak and carbon neutral goals at an early date.

How air pollution lowers the domestic value-added ratio in exports: an empirical study of China

This paper analyzes the theoretical mechanism and transmission channel for the impact of air pollution on firms' domestic value-added ratio (DVAR) in exports. Based on the matched Chinese Industrial Enterprises Database and China Customs Enterprise Database, the DVAR in exports is measured, and this mechanism is empirically tested with standard measurement methods. The study concludes that air pollution is not conducive to raising the DVAR during the sample period. This conclusion remains robust to many issues, such as endogeneity, measurement error, extension of the sample interval, substitution of the air pollution index, and policy changes. The impact of air pollution on the DVAR varies by the type of firm ownership, size, and age, as well as the size and location of the city. In addition, the negative impact of air pollution on the DVAR grows with increases in the PM2.5 concentration. The growing factor prices of domestic intermediate goods and the falling productivity due to air pollution are important transmission channels for the negative impact of air pollution on the DVAR. In order for firms to open up on all fronts through quality trade development, we recommend the prevention and control of air pollution, fueling internal driving forces for firms' independent innovation, and encouraging firms to target the medium- and high-end markets.

Role of diesel exhaust particles in the induction of allergic asthma to low doses of soybean

INTRODUCTION

Exposure to environmental pollutants such as diesel exhaust particles (DEP) increases the risk of asthma and asthma exacerbation. However, the exact mechanisms inducing asthma to low doses of allergens remain poorly understood. The present study aimed to analyse the immunomodulatory effect of the inhalation of DEP in a mouse model exposed to non-asthmagenic doses of soybean hull extract (SHE).

MATERIAL AND METHODS

BALB/c ByJ mice were randomly divided into four experimental groups. Two groups received nasal instillations of saline and the other two groups received 3 mg ml-1 SHE during 5 days per week for 3 weeks. One group in each pair also received 150 μg of DEP in the same instillations 3 days per week. SHE-specific IgE levels, oxidative stress, leukocyte pattern and optical projection tomography (OPT) imaging studies were assessed.

RESULTS

Inhalation of SHE and/or DEP increased levels of H2O2 in BAL, while coexposure to SHE and DEP increased SHE-specific IgE levels in serum. Inhalation of SHE alone increased eosinophils, B cells, total and resident monocytes and decreased levels of NK cells, while inhalation of DEP increased neutrophils and decreased total monocytes. Regarding dendritic cells (DC), the inhalation of SHE and/or DEP increased the total population, while the inhalation of SHE alone increased Th2-related DCs (CD11b + Ly6C-) and decreased tolerogenic DCs (CD11b-Ly6C-). However, coexposure to SHE and DEP increased oxidative stress-sensitive DCs (CD11b-Ly6C+) and decreased Th1-related DCs (CD11b + Ly6C+). As regards macrophages, inhalation of SHE and DEP decreased total and alveolar populations. DEP deposition in lung tissue did not differ between groups.

CONCLUSION

Coexposure to DEP activates the asthmatic response to low doses of soy by triggering the immune response and oxidative stress.

Review of the Newly Developed, Mobile Optical Sensors for Real-Time Measurement of the Atmospheric Particulate Matter Concentration

Due to the adverse effects on human health and the environment, air quality monitoring, specifically particulate matter (PM), has received increased attention over the last decades. Most of the research and policy actions have been focused on decreasing PM pollution and the development of air monitoring technologies, resulting in a decline of total ambient PM concentrations. For these reasons, there is a continually increasing interest in mobile, low-cost, and real-time PM detection instruments in both indoor and outdoor environments. However, to the best of the authors’ knowledge, there is no recent literature review on the development of newly designed mobile and compact optical PM sensors. With this aim, this paper gives an overview of the most recent advances in mobile optical particle counters (OPCs) and camera-based optical devices to detect particulate matter concentration. Firstly, the paper summarizes the particulate matter effects on human health and the environment and introduces the major particulate matter classes, sources, and characteristics. Then, it illustrates the different theories, detection methods, and operating principles of the newly developed portable optical sensors based on light scattering (OPCs) and image processing (camera-based sensors), including their advantages and disadvantages. A discussion concludes the review by comparing different novel optical devices in terms of structures, parameters, and detection sensitivity.

The Impact of Urban Transportation Infrastructure on Air Quality

While previous study has confirmed significant correlation between infrastructure construction and air quality, little is known about the nature of the relationship. In this paper, we intend to fill this gap by using the Panel Smooth Transition Regression (PSTR) model to discuss the nonlinear relationship between transportation infrastructure construction and air quality. The panel data includes 280 cities in China for the period 2000-2017. We find that the transportation infrastructure investment is positively correlated to the air quality when the GDP per capita is below RMB 7151 or the number of motor vehicle population per capita is below 37 (vehicles per 10,000 persons) where the model is in the lower regime, and that the transportation infrastructure investment is negatively correlated to the air quality when the GDP per capita is greater than RMB 7151 or the number of motor vehicle population per capita is larger than 37 (vehicles per 10,000 persons) where the model is in the upper regime. The empirical results of the three sub-samples, including eastern, western and central regions, are similar to that of the national level. Furthermore, increasing transportation infrastructure investment is conducive to improving air quality. Urban bus services, green area, population density, wind speed and rainfall are also conducive to reducing air pollution, but the role of environmental regulation is not significant. After adding the instrumental variable (urban built-up area), the conclusions are further supported. Finally, relevant policy recommendations for reducing air pollution are proposed based on the empirical results.

The impact of smog on the concentration of particulate matter in the antelope house in the Silesian zoological garden

Persistent negligence in the field of environmental protection in Poland as well as strong dependance of the energy sector on the fossil fuels have led to serious pollution of the air with particulate matter, which at high concentrations is capable of penetrating into the buildings. The aim of this study is to assess the impact of particulate airborne pollution on the concentration of particulate matter inside the antelope house in the Silesian Zoological Garden located within the Upper Silesia in Poland. The research was conducted from February to May in 2018. The records taken in the research period show that the concentration of PM10 exceeded the level of 50 µg/m³ outside the building during 26 days and 11 days when it comes to the concentration of particulate matter inside the antelope house. The quantity of particulate matter in the antelope house is strongly correlated with the concentration of the particles in the air. Despite fitting existing ventilation system with a filter that reduces the dust level by 60% during the highest level of smog, particulate matter concentration in the antelope house exceeded acceptable limit for PM10 more than twofold. Particle size-fraction analysis revealed that as much as 85% of the particles detected in the studied compartment constitute PM2.5.

Impacts of PM2.5 on respiratory system among traffic policemen

BACKGROUND

Malaysian traffic policemen are constantly exposed to unhealthy air in the outdoor environment, which results in various health problems. This study investigates the relationship of the personal exposure level to PM2.5 and lung functions in traffic policemen in Kuala Lumpur and Johor Bahru.

METHODS

A pulmonary function test using a spirometer was carried out to measure the lung function of the traffic policemen. The personal exposure level to PM2.5 was measured using a pump with a PVC filter and 5.0μm pore size. A questionnaire requesting the background data, such as age, height, and weight, was also used for testing lung function abnormalities.

RESULTS

The PM2.5 personal exposure level was found to be significantly related to lung function (predicted FEV1 and predicted FVC) at p-value < 0.05.

CONCLUSIONS

Traffic policemen are mainly exposed to physical hazards from traffic pollutants emitted by vehicles, such as fine particles and particulate matter. The findings of this study indicate that there is a trend of lung function deterioration among traffic policemen. These baseline data can serve as a reference for the top management of traffic police to aid in the development of occupational safety and health guidelines for police officers, as the traffic police are not covered by the Occupational Safety and Health Act (OSHA, Act 514 1994).

Vehicular Emission: Estimate of Air Pollutants to Guide Local Political Choices. A Case Study

The aim of this case study was to show how, with the use of software, is it possible to carry out a preventive screening of vehicular emissions. Moreover, thanks to this preliminary analysis, some areas that are potentially polluted can be identified in advance and suitable samplings on small-scale on them would help to verify the effectiveness of policies that can be adopted for the reduction of pollution. To this end, this paper reports a case study on vehicle traffic pollution in Calabria, a region in the south of Italy. We used the methodology called Corinair (Coordination Information AIR), developed by the EEA (European Environment Agency) and uses the software Copert4 (Computer Program to calculate Emission from Road Traffic). The total emissions per area were analyzed and the emissions for particular pollutants per unit area (km²) and per citizen were considered. The obsolete vehicles determined a substantial impact on the local atmospheric pollution. It was demonstrated how it is possible to substantially reduce the pollution of an area by adopting policies that encourage, for example, through tax concessions, the replacement of old cars of private citizens.

Health risk assessment of metal(loid)s in soil and particulate matter from industrialized regions: A multidisciplinary approach

In this study, samples of soil and particulate matter obtained from the highly industrialized region of Ostrava, Czech Republic, are used for the toxicity evaluation of the selected metal(loid)s (Cd, Cr, Cu, Ni, Pb, Zn, As). We investigated the samples from sites supposedly affected the most by the local pollution sources using mineralogical techniques (XRD, SEM/EDS) to understand the solid speciation of the contaminants as the crucial factor affecting their release. Although the bulk composition was defined by common silicates and oxides that are rather resistant to leaching, the presence of tiny Ni, Pb, and/or Zn sulfate-like droplets indicated a potential increase of the solubility of these metals. In vitro tests simulating gastric and lung fluids were used to assess the exposure risk for humans, as well as metal(loid) bioaccessibility. Based on the results, the potential risk for the observed age group (3-year-old children) could be recognized, particularly in the cases of As, Pb and Cd for both oral and inhalation exposure. Arsenic exhibits high bioaccessibility (7.13-79.7%, with the median values of 10.6 and 15.6 for SGL and SLF, respectively), high daily intake (1.4- to 8.5-fold higher than the tolerable daily intake) and high concentrations in atmospheric PM₁₀ (2.5 times the tolerable concentration in air). In contrast, Ni exceeded tolerable concentrations in the atmosphere up to 20-fold, but its bioaccessibility remained relatively low (0.1-22%), and Ni did not pose a major threat to human health. Cadmium, Pb and As originating from industrial activities and domestic heating have been suggested to be the most important pollutants (tolerable daily intake was exceeded by up to 74-, 34- and 8-fold for Cd, Pb and As, respectively).

Variation in the Concentration of Metals in Road Dust Size Fractions Between 2 µm and 2 mm: Results from Three Metallurgical Centres in Poland

The composition of road dust is influenced by emissions from local industry as well as by traffic emissions. Thus, the composition of urban road dust can be used as an indicator for environmental pollution. Pollutants contained in road dust also are transferred into the atmosphere by resuspension and into the aquatic system by wash-off. In this transfer, the particle size of the road dust particles is of extreme importance. Therefore, information about the composition of road dust in dependence of the particle size is crucial. In this study, road dust samples were separated by air classification into size fractions down to 2 µm. The chemical analysis of the size fractions also revealed a significant size dependence of the metal concentrations in the finest size fractions. The least polluted size fraction was generally the fraction 200-500 µm, whereas the highest concentrations were measured in the finest size fraction < 2 µm. These results are important for the assessment of the mass fraction of the various pollutants in the mobile size fractions in re-entrainment as well as in run-off during rainfall.

Assessment of crustal element and trace metal concentrations in atmospheric particulate matter over a coastal city in the Eastern Arabian Sea

Major/crustal elements (Al, Ca, Mg, K, and Fe) and trace metals (Mn, Cr, Cu, Pb, Zn, and Ni) in atmospheric particulate matter at three sites in Goa (a coastal city in the Eastern Arabian Sea) were assessed during winter (December) and summer (March-May) months of 2015. A significant spatial and temporal variability was observed in PM10 mass concentration, crustal element, and trace metal composition at the sampling area (pristine, urban, and industrial locations). Using a diagnostic crustal element ratio (Fe/Al, Ca/Al, and Mg/Al), mineral dust components were characterized and found to show large spatial and temporal variability. The concentration levels of trace metals were further assessed for enrichment factor (EF) analysis, wherein reported elements were classified into two major groups. The first group consists of Cr, Cu, and Pb with 10< EF < 100 compared to continental crustal values (w.r.t. Al), suggesting a dominant contribution from anthropogenic sources with minor contribution from natural sources; the second group consists of Zn and Ni showing very high EF (>100)-these are solely derived from anthropogenic sources. Source identification for trace metals was further assessed based on principle component analysis (PCA). PCA highlights that the major contribution of trace metals is from anthropogenic emissions at all three locations. However, contributions from mineral dust were observed at pristine and urban locations during winter months. The reported data of trace metal concentrations in aerosols give baseline information on the atmospheric supply of micronutrients to the Arabian Sea, which has implications for the various surface ocean biogeochemical processes.Implications: This paper reports on crustal and trace metal composition and concentration level in atmospheric aerosols over a coastal city located on the Eastern Arabian Sea. This study highlights the role of various factors (meteorology and emission sources) controlling the abundance of metals over a coastal site. The contribution from various sources (anthropogenic vis-à-vis natural) has also been identified using enrichment factor analysis as well as principle component analysis. This study has implications for the supply of micronutrients to the coastal Arabian Sea, which can significantly impact various surface ocean biogeochemical processes.

Concentration, contamination level, source identification of selective trace elements in Shiraz atmospheric dust sediments (Fars Province, SW Iran)

Geogenic dust is one of the most important environmental hazards in Iran. This study investigated the concentration, contamination level, potential sources, and ecological risk and human health assessment of Shiraz atmospheric dust, the largest city in southern Iran. Contents of atmospheric dust sediments geochemistry were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES). The mean concentrations of the elements in atmospheric dust are Zn (106.6 mg/kg), Cr (98.4 mg/kg), Ni (68.1 mg/kg), Cu (40.5 mg/kg), Pb (30.6 mg/kg), As (4.5 mg/kg), and Cd (0.28 mg/kg). Except As and Cd, levels of all other elements in dust sediments samples were higher than corresponding background world soils. In comparison with the concentrations of studied heavy metals in Shiraz urban street dust, the concentrations of heavy metals in Shiraz atmospheric dust were substantially at low levels. Based on Enrichment Factor (EF) and Geo-accumulation index (Igeo), Shiraz atmospheric dust is moderately to minimally polluted by selected heavy metals. The values of risk index (RI) for seven heavy metals in all dust samples were 146.2 and 130.8, which were lower than 150, indicating that ecological risks posed by studied elements in atmospheric dust were moderate. Human health risk assessment (non-carcinogenic) suggested that of the three exposure pathways, ingestion of atmospheric dust was the major pathway exposure to heavy metals in dust, followed by skin contact. The hazard index (HI) values for all studied heavy metals decreased in the following order: Cr > Pb > Ni > Cu > Zn > Cd for both children and adults. Cr and Ni contribute most to health risk posed by atmospheric dust exposure for both children and adults, and Cd, Zn, and Cu have smaller contributions. The result of cancer risk assessment suggested that Cr, Ni, and Cd were all below the safe level. Principal component analysis (PCA) indicated that grouped Cd, Ni, and Zn and grouped Cr, Cu, and Pb could be controlled by two different types of anthropogenic source. Whereas, As and Zn were controlled by both human and geogenic sources.

Heavy metals in the finest size fractions of road-deposited sediments

The concentration of heavy metals in urban road-deposited sediments (RDS) can be used as an indicator for environmental pollution. Thus, their occurrence has been studied in whole road dust samples as well as in size fractions obtained by sieving. Because of the limitations of size separation by sieving little information is available about heavy metal concentrations in the road dust size fractions <20 μm. In this study air classification was applied for separation of dust size fractions smaller than 20 μm from RDS collected at different times during the year. The results showed only small seasonal variations in the heavy metals concentrations and size distribution. According to the Geoaccumulation Index the pollution of the road dust samples deceased in the following order: Sb » As > Cu ≈ Zn > Cr > Cd ≈ Pb ≈ Mn > Ni > Co ≈ V. For all heavy metals the concentration was higher in the fine size fractions compared to the coarse size fractions, while the concentration of Sr was size-independent. The enrichment of the heavy metals in the finest size fraction compared to the whole RDS <200 μm was up to 4.5-fold. The size dependence of the concentration decreased in the following order: Co ≈ Cd > Sb > (Cu) ≈ Zn ≈ Pb > As ≈ V » Mn. The approximation of the size dependence of the concentration as a function of the particle size by power functions worked very well. The correlation between particle size and concentration was high for all heavy metals. The increased heavy metals concentrations in the finest size fractions should be considered in the evaluation of the contribution of road dust re-suspension to the heavy metal contamination of atmospheric dust. Thereby, power functions can be used to describe the size dependence of the concentration.

Trace element contents in fine particulate matter (PM2.5) in urban school microenvironments near a contaminated beach with mine tailings, Chañaral, Chile

Air quality in schools is an important public health issue because children spend a considerable part of their daily life in classrooms. Particulate size and chemical composition has been associated with negative health effects. We studied levels of trace element concentrations in fine particulate matter (PM_2.5) in indoor versus outdoor school settings from six schools in Chañaral, a coastal city with a beach severely polluted with mine tailings. Concentrations of trace elements were measured on two consecutive days during the summer and winter of 2012 and 2013 and determined using X-ray fluorescence. Source apportionment and element enrichment were measured using principal components analysis and enrichment factors. Trace elements were higher in indoor school spaces, especially in classrooms compared with outdoor environments. The most abundant elements were Na, Cl, S, Ca, Fe, K, Mn, Ti, and Si, associated with earth's crust. Conversely, an extremely high enrichment factor was determined for Cu, Zn, Ni and Cr; heavy metals associated with systemic and carcinogenic risk effects, whose probably origin sources are industrial and mining activities. These results suggest that the main source of trace elements in PM_2.5 from these school microenvironments is a mixture of dust contaminated with mine tailings and marine aerosols. Policymakers should prioritize environmental management changes to minimize further environmental damage and its direct impact on the health of children exposed.

Evaluating the suitability of different environmental samples for tracing atmospheric pollution in industrial areas

Samples of lichens, snow and particulate matter (PM₁₀, 24 h) are used for the source identification of air pollution in the heavily industrialized region of Ostrava, Upper Silesia, Czech Republic. An integrated approach that uses different environmental samples for metal concentration and Pb isotope analyses was applied. The broad range of isotope ratios in the samples indicates a combination of different pollution sources, the strongest among them being the metallurgical industry, bituminous coal combustion and traffic. Snow samples are proven as the most relevant indicator for tracing metal(loid)s and recent local contamination in the atmosphere. Lichens can be successfully used as tracers of the long-term activity of local and remote sources of contamination. The combination of PM₁₀ with snow can provide very useful information for evaluation of current pollution sources.

Intraurban and longitudinal variability of classical pollutants in Kraków, Poland, 2000-2010

In spite of a dramatic decrease in anthropogenic emissions, ambient concentrations of major pollutants have not changed within many urban locations. To clarify the relationship between ambient air quality trend and the population exposures, we compared the intraurban versus temporal variability of the collocated measurements of five major air pollutants including particulate matter (PM) with an aerodynamic diameter <10 µm (PM₁₀), < 2.5 µm (PM₂.₅), tropospheric ozone (O₃), sulfur dioxide (SO₂), and nitrogen dioxide (NO₂), in Kraków, Poland, during the 2000-2010 period. Strong seasonal trends and overall absence of spatial heterogeneity in PM₁₀ and PM₂.₅, except in the traffic monitoring site, were observed across the monitoring network. The range of median PM₂.₅ concentrations during winter (54-64 µg/m³) was 3- to 4-times higher than the summer medians (15-26 µg/m³) across the sites during 2009-2010. Furthermore, large proportion of PM₁₀ appears to be comprised of PM₂.₅ (PM₂.₅/PM₁₀ concentration ratios range, 0.5-0.7). At each monitoring site, the Pearson's correlation coefficients between PM₂.₅ and PM₁₀ ranged between 0.944 and 0.963, suggesting a health-relevance of PM10 monitoring. One ln-unit increase in PM₁₀ was associated with 92%-100% increase in PM₂.₅ concentrations in the same location. While PM₁₀ did not demonstrate a clear temporal trend, SO₂ concentrations steadily declined by 40% during the 2000-2010 period. Summertime median NO₂ concentration was acutely elevated ‎(70 mg/m³ vs. 22 mg/m³) at the traffic oriented site compared to the city's central monitoring site. The traffic and the industrial sites were associated with highest number of days during which 24-hour mean PM₁₀ and PM₂.₅ concentrations exceeded the European Union standard. Steadily growing contributions by vehicular emissions appear to be associated with the absence of clear trend in PM₁₀. Current practices of air quality control within Kraków may not be adequate for the protection of the public's health.

A detailed investigation of ambient aerosol composition and size distribution in an urban atmosphere

This research was executed between March 2009 and March 2010 to monitor particulate matter size distribution and its composition in Istanbul. Particulate matter composition was determined using ion chromatography and inductively coupled plasma optical emission spectrometry. The sampling point is adjacent to a crowded road and the Bosporus Strait. Two prevailing particulate modes are found throughout PM10 by sampling with a nine-stage low-volume cascade impactor. First mode in the fine mode is found to be between 0.43 and 0.65 μm, whereas the other peak was observed between 3.3 and 4.7 μm, referring to the coarse mode. The mean PM10 concentration was determined as 41.2 μg/m(3), with a standard deviation of 16.92 μg/m(3). PM0.43 had the highest mean concentration value of 10.67 μg/m(3), making up nearly one fourth of the total PM10 mass. For determining the effect of traffic on particulate matter (PM) composition and distribution, four different sampling cycles were applied: entire day, nighttime, rush hour, and rush hour at weekdays. SO4(-2) and organic carbon/elemental carbon proportions are found to be lower in night samples, representing a decrease in traffic. The long-range transports of dust storms were observed during the sampling periods. Their effects were determined analytically and their route models were run by the HYSPLIT model and validated through satellite photographs taken by the NASA Earth Observatory.

Influence of source distribution and geochemical composition of aerosols on children exposure in the large polymetallic mining region of the Bolivian Altiplano

The Bolivian Altiplano (Highlands) region is subject to intense mining, tailing and smelting activities since centuries because of the presence of large and unique polymetallic ore deposits (Ag, Au, Cu, Pb, Sn, Sb, Zn). A large scale PM(10), PM(2.5) aerosol monitoring survey was conducted during the dry season in one of the largest mining cities of this region (Oruro, 200,000 inhabitants). Aerosol fractions, source distribution and transport were investigated for 23 elements at approximately 1 km(2) scale resolution, and compared to children exposure data obtained within the same geographical space. As, Cd, Pb, Sb, W and Zn in aerosols are present at relatively high concentrations when compared to studies from other mining regions. Arsenic exceeds the European council PM(10) guide value (6 ng/m(3)) for 90% of the samples, topping 200 ng/m(3). Ag, As, Cd, Cu, Pb and Sb are present at significantly higher levels in the district located in the vicinity of the smelter zone. At the city level, principal component analysis combined with the mapping of factor scores allowed the identification and deconvolution of four individual sources: i) a natural magmatic source (Co, Cs, Fe, K, Mn, Na, Rb and U) originating from soil dust, resuspended by the traffic activity; ii) a natural sedimentary source (Mg, Ca, Sr, Ba and Th) resulting from the suspension of evaporative salt deposits located South; iii) an anthropogenic source specifically enriched in mined elements (As, Cd, Cu, Pb, Sb and Zn) mainly in the smelting district of the city; and iv) a Ni-Cr source homogenously distributed between the different city districts. Enrichment factors for As, Cd and Sb clearly show the impact of smelting activities, particularly in the finest PM(2.5) fraction. Comparison to children's hair metal contents collected in five schools from different districts shows a direct exposure to smelting activity fingerprinted by a unique trace elements pattern (Ag, As, Cu, Pb, Sb).

Effects of urban particulate deposition on microbial communities living in bryophytes: an experimental study

Our previous in situ study showed that bryophyte-microorganism complexes were affected by particulate atmospheric pollution. Here, the effect of urban particulate wet deposits on microbial communities living in bryophytes was studied under controlled conditions. An urban particulate solution was prepared with particles extracted from analyzer' filters and nebulized on bryophytes in treatments differing in frequency and quantity. The bryophytes did not accumulate metallic trace elements, which were present in very weak concentrations. However, in treated microcosms the total microbial biomass and the biomasses of cyanobacteria, active testate amoebae and fungi significantly decreased in response to the deposition of particles. These results confirm that microbial communities living in terrestrial bryophytes could be more sensitive indicators of atmospheric pollution than bryophytes. Moreover, they suggest that unicellular predators--such as testate amoebae--could be especially useful microbial indicators, since they seem to be both directly and indirectly affected by pollution.

A case study of exposure to ultrafine particles from secondhand tobacco smoke in an automobile

Secondhand tobacco smoke (SHS) in enclosed spaces is a major source of potentially harmful airborne particles. To quantify exposure to ultrafine particles (UFP) because of SHS and to investigate the interaction between pollutants from SHS and vehicular emissions, number concentration and size distribution of UFP and other air pollutants (CO, CO(2) , and PM(2.5)) were measured inside a moving vehicle under five different ventilation conditions. A major interstate freeway with a speed limit of 60 mph and an urban roadway with a speed limit of 30 mph were selected to represent typical urban routes. In a typical 30-min commute on urban roadways, the SHS of one cigarette exposed passengers to approximately 10 times the UFP and 120 times the PM(2.5) of ambient air. The most effective solution to protect passengers from SHS exposure is to abstain from smoking in the vehicle. Opening a window is an effective method for decreasing pollutant exposures on most urban roadways. However, under road conditions with high UFP concentrations, such as tunnels or busy freeways with high proportion of heavy-duty diesel trucks (such as the 710 Freeway in Los Angeles, CA, USA), opening a window is not a viable method to reduce UFPs.

PRACTICAL IMPLICATIONS

Time budget studies show that Americans spend, on average, more than 60 min each day in enclosed vehicles. Smoking inside vehicles can expose the driver and other passengers to high levels of pollutants. Thus, an understanding of the variations and interactions of secondhand tobacco smoke (SHS) and vehicular emissions under realistic driving conditions is necessary. Results of this study indicated that high ventilation rates can effectively dilute ultrafine particles (UFP) inside moving vehicles on urban routes. However, driving with open windows and an increased air exchange rate (AER) are not recommended on tunnels and heavily travelled freeways.

Characterization of PM10 and PM2.5 and associated heavy metals at the crossroads and urban background site in Zabrze, Upper Silesia, Poland, during the smog episodes

The concentrations of seven heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, and Pb) associated with PM10 and PM2.5 at the crossroads and the background sites have been studied in Zabrze, Poland, during smog episodes. Although the background level was unusually elevated due to both high particulate emission from the industrial and municipal sources and smog favorable meteorological conditions, significant increase of the concentration of PM2.5 and PM10 as well as associated heavy metals in the roadside air compared to the urban background has been documented. The average daily difference between the roadside and corresponding urban background aerosol concentration was equal to 39.5 microg m(-3) for PM10 and 41.2 microg m(-3) for PM2.5. The highest levels of the studied metals in Zabrze appeared for iron carried by PM10 particles: 1,706 (background) and 28,557 ng m(-3) (crossroads). The lowest concentration level (in PM10) has been found for cadmium: 7 and 77 ng m(-3) in the background and crossroads site, respectively. Also the concentrations of heavy metals carried by the fine particles (PM2.5) were very high in Zabrze during the smog episodes. Concentrations of all studied metals associated with PM10 increased at the roadside compared to the background about ten times (one order) while metals contained in PM2.5 showed two to three times elevated concentrations (except Fe-five times and Cr-no increase).

Relationship of atmospheric pollution characterized by gas (NO2) and particles (PM10) to microbial communities living in bryophytes at three differently polluted sites (rural, urban, and industrial)

Atmospheric pollution has become a major problem for modern societies owing to its fatal effects on both human health and ecosystems. We studied the relationships of nitrogen dioxide atmospheric pollution and metal trace elements contained in atmospheric particles which were accumulated in bryophytes to microbial communities of bryophytes at three differently polluted sites in France (rural, urban, and industrial) over an 8-month period. The analysis of bryophytes showed an accumulation of Cr and Fe at the rural site; Cr, Fe, Zn, Cu, Al, and Pb at the urban site; and Fe, Cr, Pb, Al, Sr, Cu, and Zn at the industrial site. During this study, the structure of the microbial communities which is characterized by biomasses of microbial groups evolved differently according to the site. Microalgae, bacteria, rotifers, and testate amoebae biomasses were significantly higher in the rural site. Cyanobacteria biomass was significantly higher at the industrial site. Fungal and ciliate biomasses were significantly higher at the urban and industrial sites for the winter period and higher at the rural site for the spring period. The redundancy analysis showed that the physico-chemical variables ([NO(2)], relative humidity, temperature, and site) and the trace elements which were accumulated in bryophytes ([Cu], [Sr], [Pb]) explained 69.3% of the variance in the microbial community data. Moreover, our results suggest that microbial communities are potential biomonitors of atmospheric pollution. Further research is needed to understand the causal relationship underlined by the observed patterns.

Treatment of tunnel wash waters--experiments with organic sorbent materials. Part I: Removal of polycyclic aromatic hydrocarbons and nonpolar oil

Tunnel wash waters characterize all waters that run off after washing procedures of tunnels are performed. These waters represent a wide spectrum of organic and inorganic pollutants, such as polycyclic aromatic hydrocarbons (PAHs) and toxic metals. Removal of such contaminants from water runoff was investigated using laboratory tests after washing procedure was performed on two road tunnels in eastern Norway (Hanekleiv and Bragernes). Due to diverse character of both, treatment media and treated wash waters, the whole investigation was divided into two separate laboratory experiments. The treatment efficiencies were established based on the levels of concentrations and reductions of the measured contaminants in the effluents released from the tested media. In the first part of the article, the contents of nonpolar oil (NPO), 16 individual PAHs, and total PAHs are described. This part revealed that the combination of two organic sorbent materials provided the highest treatment efficiency for wash waters released from the road tunnel and from electrostatic filters. The greatest reduction levels reached 97.6% for NPO, 97.2% for benzo[a]pyrene, and 96.5% for the total PAHs. In the second part of the article, the concentrations and the removal rates of toxic metals are reported.

Driver exposure to combustion particles in the U.S. Trucking industry

A large study of combustion particle exposures for drivers of diesel-powered trucks was conducted in collaboration with an epidemiologic study of lung cancer outcomes for workers in the trucking industry. Three components of diesel exhaust combustion particles (PM(2.5), elemental carbon, and organic carbon) were measured inside the driver cabs of diesel-powered trucks from 36 different trucking terminals across the United States between 2001 and 2005. In-cab particle exposures for drivers assigned to both short and long distance trips were observed, as well as information on the smoking status of the driver, truck characteristics such as age and model, and weather conditions during the sampling session. This article summarizes these findings and describes the relationship between exhaust particles and various determinants of exposure. The results suggest that in-cab particle exposures are positively related to smoking, ambient particle concentrations, truck age, and open windows, with other significant modifying factors such as weather. This study represents the largest and most comprehensive exposure assessment of drivers in the trucking industry, encompassing a 4-year period of observations on diesel and exhaust particle exposures nationwide. The results are relevant not only to the occupational group of truck drivers being examined but also to the general population that live, commute, or work within proximity to diesel-fueled traffic or trucking terminals.

Error and bias in determining exposure potential of children at school locations using proximity-based GIS techniques

BACKGROUND

The widespread availability of powerful tools in commercial geographic information system (GIS) software has made address geocoding a widely employed technique in spatial epidemiologic studies.

OBJECTIVE

The objective of this study was to determine the effect of the positional error in geocoding on the analysis of exposure to traffic-related air pollution of children at school locations.

METHODS

For a case study of Orange County, Florida, we determined the positional error of geocoding of school locations through comparisons with a parcel database and digital orthophotography. We used four different geocoding techniques for comparison to establish the repeatability of geocoding, and an analysis of proximity to major roads to determine bias and error in environmental exposure assessment.

RESULTS

RESULTS INDICATE THAT THE POSITIONAL ERROR IN GEOCODING OF SCHOOLS IS VERY SUBSTANTIAL: We found that the 95% root mean square error was 196 m using street centerlines, 306 m using TIGER roads, and 210 and 235 m for two commercial geocoding firms. We found bias and error in proximity analysis to major roads to be unacceptably large at distances of < 500 m. Bias and error are introduced by lack of positional accuracy and lack of repeatability of geocoding of school locations.

CONCLUSIONS

These results suggest that typical geocoding is insufficient for fine-scale analysis of school locations and more accurate alternatives need to be considered.

Statistical analysis of atmospheric trace metals and particulate fractions in Islamabad, Pakistan

Airborne suspended particulate matter was collected on glass fibre filters in urban atmosphere of Islamabad, Pakistan, using high volume sampler. The particulate samples were analysed for 10 selected metals (Fe, Na, Zn, K, Pb, Mn, Cr, Ni, Co and Cd) by FAAS method. Maximum mean contribution was noted for Fe (1.761microg/m(3)), followed by Na (1.661microg/m(3)), Zn (1.021microg/m(3)), K (0.488microg/m(3)) and Pb (0.128microg/m(3)). The particle size determination on vol.% basis for nine fractions (PM(<1.0), PM(1.0-2.5), PM(2.5-5), PM(5-10), PM(10-15), PM(15-25), PM(25-50), PM(50-100) and PM(>100)) was carried out using Mastersizer. PM(5.0-10) were found to be most abundant in the local atmosphere followed by PM(2.5-5.0) and PM(15-25) while coarse/giant particles (PM(50-100) and PM(>100)) showed lower contribution. The trace metals were found to be mainly associated with smaller particulate fractions up to PM(10-15). Among the climatic parameters temperature has significant relationship with fine particles and airborne metal levels while relative humidity showed negative correlation. The source identification was carried out by principal component analysis and cluster analysis. Five metal sources were identified: industrial, vehicular emissions, metallurgical operations, garbage incineration and soil derived dust. The metal levels were also compared with those reported for other rural and urban parts around the world.

Influence of geocoding quality on environmental exposure assessment of children living near high traffic roads

Background

The widespread availability of powerful geocoding tools in commercial GIS software and the interest in spatial analysis at the individual level have made address geocoding a widely employed technique in epidemiological studies. This study determined the effect of the positional error in street geocoding on the analysis of traffic-related air pollution on children.

Methods

For a case-study of a large sample of school children in Orange County, Florida (n = 104,865) the positional error of street geocoding was determined through comparison with a parcel database. The effect of this error was evaluated by analyzing the proximity of street and parcel geocoded locations to road segments with high traffic volume and determining the accuracy of the classification using the results of street geocoding. Of the original sample of 163,886 addresses 36% were not used in the final analysis because they could not be reliably geocoded using either street or parcel geocoding. The estimates of positional error can therefore be considered conservative underestimates.

Results

Street geocoding was found to have a median error of 41 meters, a 90^th percentile of 100 meters, a 95^th percentile of 137 meters and a 99^th percentile of 273 meters. These positional errors were found to be non-random in nature and introduced substantial bias and error in the estimates of potential exposure to traffic-related air pollution. Street geocoding was found to consistently over-estimate the number of potentially exposed children at small distances up to 250 meters. False positives and negatives were also found to be very common at these small distances.

Conclusion

Results of the case-study presented here strongly suggest that typical street geocoding is insufficient for fine-scale analysis and more accurate alternatives need to be considered.

Modeling particle exposure in U.S. trucking terminals

Multi-tiered sampling approaches are common in environmental and occupational exposure assessment, where exposures for a given individual are often modeled based on simultaneous measurements taken at multiple indoor and outdoor sites. The monitoring data from such studies is hierarchical by design, imposing a complex covariance structure that must be accounted for in order to obtain unbiased estimates of exposure. Statistical methods such as structural equation modeling (SEM) represent a useful alternative to simple linear regression in these cases, providing simultaneous and unbiased predictions of each level of exposure based on a set of covariates specific to the exposure setting. We test the SEM approach using data from a large exposure assessment of diesel and combustion particles in the U.S.trucking industry. The exposure assessment includes data from 36 different trucking terminals across the United States sampled between 2001 and 2005, measuring PM2.5 and its elemental carbon (EC), organic carbon (OC) components, by personal monitoring, and sampling at two indoor work locations and an outdoor "background" location. Using the SEM method, we predict the following: (1) personal exposures as a function of work-related exposure and smoking status; (2) work-related exposure as a function of terminal characteristics, indoor ventilation, job location, and background exposure conditions; and (3) background exposure conditions as a function of weather, nearby source pollution, and other regional differences across terminal sites. The primary advantage of SEMs in this setting is the ability to simultaneously predict exposures at each of the sampling locations, while accounting for the complex covariance structure among the measurements and descriptive variables. The statistically significant results and high R2 values observed from the trucking industry application supports the broader use of this approach in exposure assessment modeling.

Air particulate pollution due to bushfires and respiratory hospital admissions in Brisbane, Australia

To examine the impact of bushfire smoke on hospital admission rates for respiratory disease, a time series study was conducted in Brisbane, Australia. Data on particles of 10 microns or less in aerodynamic diameter (PM10) per cubic metre, bushfire events, meteorological conditions, and daily respiratory hospital admissions were obtained for the period of 1 July 1997 to 31 December 2000. A generalized linear model with the negative binomial distribution was used to estimate the effects of bushfire smoke on respiratory hospital admissions. The results of this study show that daily respiratory hospital admission rates consistently increased with increasing levels of PM10 for both bushfire and non-bushfire periods. This relationship appeared stronger during bushfire periods than non-bushfire periods, especially for the current day. The findings suggest that bushfire smoke was statistically significantly associated with an increased risk of respiratory hospital admissions in Brisbane (p < 0.05). The health impact assessment needs to be considered in the control and management of bushfires.

Characterization, source identification and apportionment of selected metals in TSP in an urban atmosphere

To understand the metal distribution characteristics in the atmosphere of urban Islamabad, total suspended particulate (TSP) samples were collected on daily 12 h basis, at Quaid-i-Azam University campus, using high volume sampler. The TSP samples were treated with HNO(3)/HClO(4) based wet digestion method for the quantification of eight selected metals; Fe, Zn, Pb, Mn, Cr, Co, Ni and Cd by FAAS method. The monitoring period ran from June 2001 to January 2002, with a total of 194 samples collected on cellulose filters. Effects of different meteorological conditions such as temperature, relative humidity, wind speed and wind direction on selected metal levels were interpreted by means of multivariate statistical approach. Enhanced metal levels for Fe (930 ng/m(3)), Zn (542 ng/m(3)) and Pb (210 ng/m(3)) were found on the mean scale while Mn, Cr, Co and Ni emerged as minor contributors. Statistical correlation study was also conducted and a strong correlation was observed between Pb-Cr (r=0.611). The relative humidity showed some significant influence on atmospheric metal distribution while other meteorological parameters showed weak relationship with TSP metal levels. Regarding the origin of sources of heavy metals in TSP, the statistical procedure identified three source profiles; automobile emissions, industrial/metallurgical units, and natural soil dust. The metal levels were also compared with those reported for other parts of the world which showed that the metal levels in urban atmosphere of Islamabad are in exceedence than those of European industrial and urban sites while comparable with some Asian sites.

A review of traffic-related air pollution exposure assessment studies in the developing world

Exposure assessment studies in the developing world are important. Although recent years have seen an increasing number of traffic-related pollution exposure studies, exposure assessment data on this topic are still limited. Differences among measuring methods and a lack of strict quality control in carrying out exposure assessment make it difficult to generalize and compare findings between studies. In this article, exposure assessment studies carried out in the developing world on several traffic-related air pollutants are reviewed. These pollutants include particulate matter (PM), carbon monoxide (CO), nitrogen dioxide (NO(2)), volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs). In addition, it discusses advantages and disadvantages of various monitoring methods (ambient fixed-site monitoring, microenvironment monitoring, and personal exposure assessment using portable samplers) for these pollutants in exposure assessment studies. Also included in this paper is a brief introduction of standards for these pollutants in ambient air or in occupational settings established by the United States Environmental Protection Agency (USEPA), the United States Occupational Safety and Health Administration (OSHA) and the World Health Organization (WHO). The review ends with a summary of the limitations and gaps in recent studies and suggestions for future research in the developing world.

Measurements of particle number and mass concentrations and size distributions in a tunnel environment

Particulate matter emissions were measured in two bores of the Caldecott Tunnel in Northern California during August and September 2004. One bore (Bore 1) is open to both heavy- and light-duty vehicles while heavy-duty vehicles are prohibited from entering the second bore (Bore 2). Particulate matter number and mass size distributions, chemical composition, and gaseous copollutants were recorded for four consecutive days near the entrance and exit of each bore. Size-resolved emission factors were determined for particle number, particle mass, elemental carbon, organic carbon (OC), sulfate, nitrate, and selected elements. The size distributions in both the bores showed a single large mode at roughly 15-20 nm in mobility diameter, with occasional smaller modes around 100 nm. The PM10 mass emission factor for heavy-duty vehicles was 14.5 times higher than that of light-duty vehicles. The particles derived from diesel are more abundant in elemental carbon, 70.9% of PM10 emissions, as compared to the light-duty vehicles. Conversely, a greater percentage of OC was found in light-duty emissions than heavy-duty emissions. In comparison to previous studies at the Caldecott Tunnel, less particle mass but more particle numbers are emitted by vehicles than was the case 7 years ago.

Metal contamination and solid phase partitioning of metals in urban roadside sediments

This study was undertaken to assess the anthropogenic impact on metal concentrations of urban roadside sediments (N = 633) in Seoul city, Korea and to estimate the potential mobility of selected metals (Zn, Cu, Pb, Cr, Ni, and Cd) using sequential extraction. Comparison of metal concentrations in roadside sediments with mean background values in sediments collected from first- or second-order streams in Korea shows that Zn, Cu and Pb are most affected by anthropogenic inputs. The 206Pb/207Pb ratios of roadside sediments (range = 1.1419-1.1681; mean 1.1576 +/- 0.0068) suggest that Pb is mainly derived from industrial sources rather than from leaded gasoline. A five-step sequential extraction of roadside sediments showed that Zn, Cd and to a lesser degree Ni occur predominantly in the carbonate bound fraction, while Pb is highest in the reducible fraction, Cu in the organic fraction, and Cr in the residual fraction. It was found that the concentrations in the readily available exchangeable fraction were generally low for most metals examined, except for Ni whose exchangeable fraction was appreciable (average 15.2%). Considering the proportion of metals bound to the exchangeable and carbonate fractions, the comparative mobility of metals probably decreases in the order of Zn > Ni > Cd > Pb > Cu > Cr. As potential changes of redox state and pH may remobilize the metals bound to carbonates, reducible, and/or organic matter, and may release and flush them through drain networks into streams, careful monitoring of environmental conditions appears to be very important. With respect to ecotoxicity, it is apparent the Zn and Cu pollution is of particular concern in Seoul city.

Lead and cadmium in indoor air and the urban environment

The present study was conducted to find potential terrestrial biomonitors for heavy metals in indoor air in an urban environment. TSP, PM(10), and PM(2.5) were collected in three retirement facilities in the urban area of Vienna. In addition, particulate matter and soil, vegetation, and isopods (Porcellio scaber L.) were collected in the adjacent garden areas. Aerosols were sampled with a low-volume air sampler. The sampled materials were wet ashed and total lead and cadmium contents were determined. Water-soluble heavy metal concentrations were measured in aqueous extracts from air exposed filters, soil, and vegetation. Lead and cadmium were analyzed by graphite furnace AAS. Lead contents in the vegetation were inferred from water-soluble lead in soils. Lead in isopods generally reflected the contents in vegetation. Cadmium in plants probably derived from soil solutions as well as from atmospheric input. Isopods reflected the total cadmium contents in soils. Particulate matter was dominated by PM(2.5), both with respect to mass concentrations and to heavy metal contents. The indoor aerosol was found to be influenced by human activity, indoor sources, and outdoor particles. Relationships between indoor airborne heavy metals and the contents in vegetation (lead and cadmium: positive) and isopods (lead: negative) were identified to have the potential for biomonitoring indoor air quality.

Emissions of metals associated with motor vehicle roadways

Emissions of metals and other particle-phase species from on-road motor vehicles were measured in two tunnels in Milwaukee, WI during the summer of 2000 and winter of 2001. Emission factors were calculated from measurements of fine (PM2.5) and coarse (PM10) particulate matter at tunnel entrances and exits, and effects of fleet composition and season were investigated. Cascade impactors (MOUDI) were used to obtain size-resolved metal emission rates. Metals were quantified with inductively-coupled plasma mass spectrometry (ICP-MS) and X-ray fluorescence (XRF). PM10 emission rates ranged from 38.7 to 201 mg km(-1) and were composed mainly of organic carbon (OC, 30%), inorganic ions (sulfate, chloride, nitrate, ammonium, 20%), metals (19%), and elemental carbon (EC, 9.3%). PM10 metal emissions were dominated by crustal elements Si, Fe, Ca, Na, Mg, Al, and K, and elements associated with tailpipe emissions and brake and tire wear, including Cu, Zn, Sb, Ba, Pb, and S. Metals emitted in PM2.5 were lower (11.6% of mass). Resuspension of roadway dust was dependent on weather and road surface conditions, and increased emissions were related to higher traffic volumes and fractions of heavy trucks. Emission of noble metals from catalytic converters appeared to be impacted by the presence of older vehicles. Elements related to brake wear were impacted by enriched road dust resuspension, but correlations between these elements in PM2.5 indicate that direct brake wear emissions are also important. A submicrometer particle mode was observed in the emissions of Pb, Ca, Fe, and Cu.

Health impacts of frequent heavy automobile traffic on children and adolescents

This paper assesses the extent to which particulate, elemental and organic carbon emissions from heavy traffic in urban city roads affect the health of children and the adolescent health. Although the health effects of exposures may be cumulative, it is in the adolescence that the manifestations are realized. This paper therefore, assesses the best way forward for monitoring and preventing the environmental health impacts of heavy traffic on children and adolescents who live within the vicinity of urban city transportation systems. Major urban cities such as Houston, New York, and California are cited as examples of cities where health-related problems have already been reported. The particulate, elemental and organic carbon emissions are reviewed as the sources by which heavy traffic and the hazardous chemical emissions affect the health of the populace. The role of accessory loading and engine speed on idling emissions in direct health risks of children and adolescents is evaluated. The association of particulate, elemental, and organic carbon emission with respiratory effects (including, allergies and asthma), and the related behavior problems in children and the adolescents are discussed. The best strategies in preventing the effects of heavy traffic in the urban cities are suggested by introducing new effective monitoring techniques and exposure assessment methods. It is visualized that a more comprehensive research is needed to develop robust regulatory systems that would control the efficiency of automobiles and prevent the adverse health effects relating to heavy traffics in urban city roads. Strong city environmental health authorities-community partnerships relevant to exposure information should be encouraged.

Variations in the source, metal content and bioreactivity of technogenic aerosols: a case study from Port Talbot, Wales, UK

Atmospheric aerosol samples were collected during different prevailing wind directions from a site located close to a busy motorway, a major steelworks, and the town of Port Talbot (Wales, UK). A high-volume collector was used (1100 l/min), enabling relatively large amounts of particulate matter (PM(10-2.5) and PM(2.5)) samples to be obtained on a polyurethane foam [PUF, H(2)N-C(O)O-CH(2)CH(3)] substrate over periods of 2-7 days. Four samples were chosen to exemplify different particle mixtures: SE- and NE-derived samples for particles moving along and across the motorway, a NW-derived sample from the town, and a mixed SW/SE-derived sample containing a mixture of particles from both steelworks and motorway. The latter sample showed the highest average collection rate (0.9 mg/h, 13 microg/m(3)) and included a prominent pollution episode when rainy winds were blowing from the direction of the steelworks. Both NW and SE samples were collected under dry conditions and show the same collection rate (0.7 mg/h, 10 microg/m(3)), whereas the NE sample was collected during wetter weather and shows the lowest rate (0.3 mg/h, 5 microg/m(3)). Scanning electron microscopy (SEM) and energy-dispersive X-ray microanalysis system (EDX) analyses show all samples are dominated by elemental and organic carbon compounds (EOCC) and nitrates, with lesser amounts of sulphates, felsic silicates, chlorides and metals. ICP-MS analyses show the SW/SE sample to be richest in metals, especially Fe, Zn, Ni, and Mn, these being attributed to an origin from the steelworks. The SE sample, blown along the motorway corridor, shows enhanced levels of Pb, V, Ti, As, and Ce, these metals being interpreted as defining a traffic-related chemical fingerprint. The NW sample shows a very low metal content. DNA plasmid assay data on the samples show TM(50) values varying from 66 to 175 microg/ml for the adjusted whole sample and 89 to 203 microg/ml for the soluble fraction. The SW/SE-mixed metalliferous sample is the most bioreactive (both whole and soluble) and the soluble fraction of the metal-depleted NW sample is the least bioreactive. The metal content of the aerosol samples, especially soluble metals such as Zn, is suggested to be the primary component responsible for oxidative damage of the DNA, and therefore most implicated in any health effects arising from the inhalation of these particulate cocktails.

The measurements of ambient particulates (TSP, PM2.5, PM2.5-10), chemical component concentration variation, and mutagenicity study during 1998-2001 in central Taiwan

During June 1998 and February 2001, the experiments of this study were conducted at four sampling sites (THUPB, THUC, HKIT and CCRT) with different characters (suburban, rural and traffic). The chemical components (Cl-, Na+, K+, Mg2+, Ca2+, Fe, Zn, Pb, Ni) in suspended particle were also analyzed simultaneously. The particulate mass concentrations are higher in the traffic site (CCRT) than the other sampling sites in this study. This is because that high traffic density flow characterized CCRT sampling site. Besides, the fine particle (PM2.5) concentration was the dominant species out of the total suspended particles in central Taiwan, Taichung. The same phenomenon is found in most of cities around the world. Moreover, chloride, nitrate sulfate and ammonium are higher in Taiwan than other sampling sites in the world. The results also indicated that the control of acidic and secondary aerosol pollutants have become an important issue in Taiwan. In addition, mutagenic assays on the organic extracts of airborne particulates at different sampling sites were also conducted in central Taiwan. The data obtained here also reflected that the mutagenicity of the suspended particulates are significantly higher in winter period than it occurred in summer period.