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PubMed2002

Assessment of mutagenicity and toxicity of different-size fractions of air particulates from La Plata, Argentina, and Leipzig, Germany.

Airborne particulates, especially fine particles and bound chemical compounds, are a potential mediator of adverse health effects. In this study an analysis was done of the concentration and size distribution of air particulate matter, the content of bound polycyclic aromatic hydrocarbons (PAHs), and the biological effects of organic extracts from different fractions of dust that had been influenced by urban and industrial emissions from the regions of La Plata, Argentina, and Leipzig, Germany, along with samples from control areas. Air particulate matter was sampled in summer and winter in each region using a high-volume sampler with a six-stage cascade impactor, classifying dust in six size fractions from 10-microm particles to those less than 0.49 microm in size. Organic extracts of dust were tested for mutagenicity (Ames test, Salmonella typhimurium TA98 strain, S9+) and cytotoxicity (Tetrahymena pyriformis test system, growth rate, cell respiration). The content of PAHs was analyzed by high-performance liquid chromatography (HPLC) with diode array and fluorescence detection. Mutagenic and cytotoxic effects were found to be associated with very fine (<0.49 microm) and fine (<1.5 microm) particle-bound compounds, corresponding to a higher content of PAHs. The mutagenic potency (revertants/m(3)) associated with particles less than 0.49 microm from urban areas of La Plata was about 1 order of magnitude higher than in particles in the range of 3.0 to 0.49 microm. Fine fractions from sites with an industrial burden were also found to exhibit high mutagenic potency. A similar tendency was observed in cytotoxicity tests with T. pyriformis. This cell system proved to be very sensitive to toxicants in tested dust fractions. The observed biological effects were found to be correlated significantly with concentrations of total PAH, carcinogenic PAHs, and benzo[a]pyrene.

Air Pollutants↗

PubMed2005

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.

Air Pollutants↗

PubMed2003

DNA binding of polycyclic aromatic hydrocarbons in a human bronchial epithelial cell line treated with diesel and gasoline particulate extracts and benzo[a]pyrene.

Particulate matter of vehicle exhaust is known to contain carcinogenic compounds such as polycyclic aromatic hydrocarbons (PAH) and is suggested to increase lung cancer risk in humans. This study examines the differences in diesel and gasoline-derived PAH binding to DNA in a human bronchial epithelial cell line (BEAS-2B). Particulate matter (PM) of gasoline exhaust was collected from passenger cars on filters and semi-volatile compounds on polyurethane foam (PUF). The soluble organic fraction (SOF) extracted from the particles was used to expose the cells and to perform PAH analysis. Gasoline extracts, benzo[a]pyrene (B[a]P) and reference materials (SRM 1650 and 1587) were used to study dose-dependent adduct formation in BEAS-2B cells. The levels of DNA adducts were in good accord with the 10 DNA adduct-forming PAH concentrations analyzed in the extracts. Gasoline extracts, SRM 1650, SRM 1587 and B[a]P formed DNA adducts dose-dependently in BEAS-2B cells. The time-dependent DNA adduct formation of 5.0 micro M B[a]P was lower than that of 2.5 micro M B[a]P. The results of this study indicate that reformulated and standard diesel fuels formed about 11- and 31-fold more adducts than gasoline, respectively, when PAH-DNA adduct levels were calculated on an emission basis (adducts/mg PM/km), whereas on a particulate basis (adducts/mg PM) no difference between the diesel and gasoline extracts was observed. We conclude that the genotoxicity of diesel fuel is based on higher particulate emission rates compared to gasoline emission and although the concentration of PAH compounds was higher in diesel particulate extracts, DNA binding by the gasoline particulate-bound PAH compounds was more pronounced than that by the diesel particulate-bound PAH compounds.

Air Pollutants↗

PubMed1997

Short-term effects of particulate air pollution on respiratory morbidity in asthmatic children.

Short-term effects of air pollution (consisting primarily of sulphur dioxide and particulate matter but with low acidity) on respiratory morbidity were studied in asthmatic children from Sokolov, Czech Republic. Eighty nine children with asthma, who recorded daily peak expiratory flow measurements, symptoms and medication use in a diary, were analysed for 7 months during the winter of 1991-1992. Air pollution measurements included: SO2, total suspended particulates (TSPs), inhalable particles, ie. particulate matter of aerodynamic diameter < or = 10 microm, particle strong acidity (PSA) and fine particle sulphate concentration (SO4). Linear and logistic regression analyses estimated the impact of air pollutants adjusted for trend, temperature and weekend and autocorrelated errors. Exposure to elevated levels of air pollution was associated with decreased peak expiratory flow rates, increased respiratory symptoms, increased prevalence of school absence and fever, and increased medication use. Prolonged exposure to particle SO4 showed the largest effect estimates. At the end of January, an air pollution episode occurred, during which respiratory symptoms, prevalence of fever, school absence and asthma medication increased. The association between respiratory symptoms and particulate SO4 was highly dependent on this episode, whilst the associations between lung function and SO4 as well as between fever and SO4 were still observed when this air pollution episode was excluded. Some evidence was found that exposure to air pollution might have enhanced the respiratory symptoms while children were experiencing respiratory infections. In this study, a panel of children with mild asthma experienced small decreases in peak expiratory flow and increased dyspnoea in association with fine particles formed during air pollution episodes.

Adolescent↗

PubMed1978

Inhalation toxicity studies on cigarette smoke (VI). 6-week comparative experiments using modified flue-cured cigarettes: histopathology of the lung.

Rats were exposed twice daily for 6 weeks to diluted smoke derived from cigarettes with a range of deliveries of particulate matter. The inhaled smoke reached the alveolar surface, increased the size and number of free macrophages and provoked epithelial metaplasia but did not appear to alter the lymphoid reaction to spontaneous infection. The hypertrophy of the macrophages was typically alveolar and their hyperplasia was directly proportional to the particulate delivery of cigarettes smoked. Alveolar metaplasia was incipient, developed characteristically near the respiratory bronchiole in close association with macrophage clusters and only in rats exposed to smoke from cigarettes with the highest delivery of particulate matter.

Animals↗

PubMed2001

Detecting organic tracers from biomass burning in the atmosphere.

This is a brief review key to the literature on the determination of organic tracers from biomass burning which are detectable even after long-range global transport in total extracts of atmospheric particles. The major tracers are thermal degradation products from the biopolymer cellulose, namely the didehydromonosaccharide derivatives levoglucosan, galactosan and mannosan and the resin acid derivative dehydroabietic acid, with minor beta-sitosterol. Dehydroabietic acid is emitted primarily from burning of conifer fuel and these tracers are found in most aerosol samples from the North American continent. Particulate matter from the atmosphere over oceanic areas contains organic tracers from both natural and biomass burning emissions. The major biomarker compounds characterized are natural products from continental vegetation consisting primarily of epicuticular wax components and trace components from biomass burning emissions. The presence of these tracers in atmospheric particulate matter over the ocean confirms the long-range transport of smoke from biomass burning off the continents.

Abietanes↗

PubMed2002

The concentration-response relation between PM(2.5) and daily deaths.

Particulate air pollution at commonly occurring concentrations is associated with daily deaths. Recent attention has focused on the shape of the concentration-response curve, particularly at low doses. Several recent articles have reported that particulate matter with aerodynamic diameter < or = 10 microm (PM(10)) was associated with daily deaths with no evidence of a threshold. These reports have used smoothing or spline methods in individual cities and pooled the results across multiple cities to obtain estimates that are more robust. To date, fine particulate matter (aerodynamic diameter Less than or equal to 2.5 microm; PM(2.5)), a component of PM(10), has not been examined in this regard. We examined this association in a hierarchical model in six U.S. cities. In the first stage, we fit log-linear models including smooth functions of PM(2.5) in each city, controlling for season, weather, and day of the week. These smooth functions allowed for nonlinearities in the city-specific associations. We combined the estimated curves across cities using a hierarchical model that allows for heterogeneity. We found an essentially linear relationship down to 2 microg/m(3). The same approach was applied to examine the concentration response to traffic particles, controlling for particles from other sources. Once again, the association showed no sign of a threshold. The magnitude of the association suggests that controlling fine particle pollution would result in thousands of fewer early deaths per year.

Air Movements↗

PubMed2003

Analysis of lobar differences in particle deposition in the human lung.

Lung diseases caused by the inhalation of various particulate pollutants have often been reported to occur at specific sites in the lung with some diseases preferentially occurring in one of the lobes. Models for the dosimetry of particulate matter in the lung, therefore, need to be developed at a level of resolution that allows for the study of lobar- and airway-specific patterns of deposition. Using an approach best described as a combination of asymmetric and symmetric approaches to modeling lung geometry, we calculated deposition of particulate matter (PM) ranging from ultrafine to coarse particles in each airway down to the level of the lobar bronchi. Further down the airway tree, we calculated deposition averaged over an airway generation in each lung lobe. We compared our results for regional and lobar deposition with various experimental data as well as with results from other models. The calculated results compared reasonably well with experimental data. Significant variations in deposition were observed among the lobar bronchi as well as among the five lobes. The differences among the lobes were accentuated as one examined generation-specific deposition. Deposition per unit surface area of each lobar bronchus was considerably elevated relative to that calculated for the whole lung. The relative distribution of aerosol deposited per unit surface area among the lobar bronchi was altered by breathing condition and aerosol size. Our observations suggest that a multiple-path model that incorporates the heterogeneous structure of airways in the lung is likely to reduce uncertainties in PM health risk assessments.

Aerosols↗

PubMed1994

The effects of alternative smoking policies on indoor air quality in 27 office buildings.

The effect of alternative smoking policies, which prohibited or restricted smoking, on indoor air quality was studied in 27 air-conditioned office buildings. Carbon monoxide, carbon dioxide, respirable particulates, formaldehyde, ultraviolet particulate matter (u.v.PM), nicotine, air temperature, relative humidity and illumination were measured at eight sample sites in each building. Smoking policy had no effect on carbon monoxide, carbon dioxide, relative humidity, formaldehyde, air temperature or illumination for open office areas. It did have an effect on levels of respirable suspended particulates, ultraviolet particulate matter and nicotine.

Air Conditioning↗

PubMed2003

Environmental impacts of coastal aquaculture in eastern Mediterranean bays: the case of Astakos Gulf, Greece.

GOAL, SCOPE AND BACKGROUND: Over the last decade Greece has become a leading country in the EU as concerns the cage farming of seabream and seabass. A strong debate has risen, however, about the environmental impacts of aquacultures in the coastal areas. The present paper deals with this problem and it is based on measurements of physico-chemical parameters in the water column, particulate matter and sediments in the area of Astakos Gulf, a coastal embayment in western Greece where three big fish farms are currently operating. METHODS: Water samples were collected by using Hydro-Bios sampling bottles, whereas a prototype sediment trap was installed under a fish cage for the collection of particulate matter. Temperature, dissolved oxygen, pH and salinity were measured in situ using portable equipment. Nutrients were determined by standard spectrophotometric methods. Trace metals were determined by Atomic Absorption Spectrometry. Dissolved organic carbon was determined by a Shimadzu 5000A carbon analyzer, whereas organic carbon in sediments was determined titrimetrically. RESULTS AND DISCUSSION: No clear eutrophication incidents have been identified, although the water column near the fish farms was enriched in nutrients and organic carbon. A sludge 'blanket' covers considerable parts of the seabed and is enriched in colloidal organic carbon and trace metals (Cd, Cu, Fe and Zn) that come from unused fish food. The biodegradation of this sludge leads to the development of anoxic conditions followed by the formation of undesirable gases, precipitation or remobilization of metals and the extinction of benthic fauna. CONCLUSION: The operation of fish farms at the coastal area of Astakos Gulf, and probably in similar Mediterranean gulfs, affects the marine environment, particularly in the vicinity of the cages. The most significant influence concerns the near-bottom water layer. The environmental impacts depend on the amount of food given to fishes, the mode of feeding, the fish density in cages, the annual production and the years of unit operation. The hydrology and the geomorphology of the area are also critical factors for its environmental quality. RECOMMENDATION AND OUTLOOK: The success of the fish-farming sector in the Mediterranean is accompanied by environmental and, in some extents, by social and marketing problems. These problems, derived from the rapid development of fish farming, can be solved only through an integrated management, using methods such as environmental impact assessment, risk assessment, economic evaluation, vulnerability assessments, resource accounting, cost-benefit analysis and outcome-based monitoring.

Animals↗

PubMed2000

Examining impacts of visibility and PM strategies before implementation.

One of the major challenges facing the world today is defining paths to sustainable futures. Part of the challenge is developing a national energy strategy that promotes an adequate energy supply for the United States, while enhancing environmental quality and maintaining U.S. competitiveness in the world economy. To assist in this challenge, we have developed a screening technique to analyze the effectiveness of different proposed emissions reduction strategies. The technique, referred to as the visibility assessment screening technique (VAST), is designed to examine possible impacts on visibility of emission changes of sulfur oxides, nitrogen oxides, volatile organic compounds (i.e., SO2, NOx, and VOC) and fine and coarse particulate matter (PM). The influence of relative humidity, natural aerosols, and the chemical interconnections among sulfur and nitrogen components of aerosols in determining the effectiveness of Clean Air Act Amendment and other projected energy-related emissions changes on eastern and western visibility are explored. The effectiveness of these strategies on particulate matter impacts and potentially on ozone is also noted.

Air Pollution↗

PubMed1986

Genotoxicity and polynuclear aromatic hydrocarbon analysis of environmental tobacco smoke samples from restaurants.

Acetone-extracted samples of airborne particulate matter collected in three restaurants were analysed for their content of polynuclear aromatic hydrocarbons (PAH) and related polynuclear aromatic compounds (PAC) as well as for genotoxic activity using the Salmonella/microsome assay (strains TA98 and TA100) and sister chromatid exchange (SCE) induction in Chinese hamster ovary (CHO) cell cultures. The total particulate matter varied considerably in the restaurants, being 1.37 mg/m3 at the highest; in the same restaurant the highest amount of total PAHs (168 ng/m3) was also detected. Altogether, 13-22 individual PACs were identified in the samples, ranging from phenanthrene to benzothionaphthene. All of the six samples caused significant increases both in bacterial revertant and SCE frequencies. In the Salmonella assay, the mutagenic activity detected was primarily with metabolic activation. However, in the CHO cell cultures the induction of SCEs was also seen without an exogenous metabolic activation system. The cytotoxicity of the extracts limited the concentration range tested in the SCE assay. Only a partial correspondence of the total PAH content with the genotoxic activity of the samples was found. The genotoxicity of restaurant air exceeded by one to two orders of magnitude the previously reported activities detected by similar methods in urban outdoor and indoor air samples.

Animals↗

PubMed2002

Airborne particles in the Miyagi Museum of Art in Sendai, Japan, studied by electron probe X-ray microanalysis and energy dispersive X-ray fluorescence analysis.

The presented work provides baseline data on the existing airborne conditions in the Miyagi Museum of Art in Sendai, Japan, during the summer of 2000. The chemical composition, size and indoor and outdoor origin of the suspended particulate matter were identified using a number of advanced X-ray techniques, such as Electron Probe X-Ray Microanalysis (EPXMA) and Energy Dispersive X-Ray Fluorescence Analysis (EDXRF). Our results, to the best of our knowledge, represent the first detailed study of the chemical nature of the indoor particulate matter in a Japanese museum and, as such, may contribute to future improvements of the air quality inside museums and to the lasting conservation of works of art.

Journal Article↗

PubMed2005

Gene-particulate matter-health interactions.

Inter-individual variation in human responses to air pollutants suggests that some subpopulations are at increased risk to the detrimental effects of pollutant exposure. Extrinsic factors such as previous exposure and nutritional status may influence individual susceptibility. Intrinsic (host) factors that determine susceptibility include age, gender, and pre-existing disease (e.g., asthma), and it is becoming clear that genetic background also contributes to individual susceptibility. Environmental exposures to particulates and genetic factors associated with disease risk likely interact in a complex fashion that varies from one population and one individual to another. The relationships between genetic background and disease risk and severity are often evaluated through traditional family-based linkage studies and positional cloning techniques. However, case-control studies based on association of disease or disease subphenotypes with candidate genes have advantages over family pedigree studies for complex disease phenotypes. This is based in part on continued development of quantitative analysis and the discovery and availability of simple sequence repeats and single nucleotide polymorphisms. Linkage analyses with genetically standardized animal models also provide a useful tool to identify genetic determinants of responses to environmental pollutants. These approaches have identified significant susceptibility quantitative trait loci on mouse chromosomes 1, 6, 11, and 17. Physical mapping and comparative mapping between human and mouse genomes will yield candidate susceptibility genes that may be tested by association studies in human subjects. Human studies and mouse modeling will provide important insight to understanding genetic factors that contribute to differential susceptibility to air pollutants.

Air Pollutants↗

PubMed2003

Effects of ambient air pollution on symptom severity and medication use in children with asthma.

BACKGROUND: Exposure to air pollutants has been investigated as a possible cause of asthma attacks in children. OBJECTIVE: To investigate the short-term effects of air pollutants on a panel of 133 children with asthma who enrolled in the Childhood Asthma Management Program. METHODS: During screening, the children completed daily diary cards for an average of 58 days to indicate their medication use and asthma severity. We used ordinal logistic regression to compare the odds of a more serious relative to a less serious asthma attack, and we used a Poisson model to analyze medication use. In both analyses we accommodate dependence in the data and different periods of observation for study subjects. RESULTS: Our results indicate that a 10-microg/m3 increase in particulate matter less than or equal to 2.5 microm (PM2.5) lagged 1 day was associated with a 1.20 times increased odds of having a more serious asthma attack [95% confidence interval (CI), 1.05 to 1.37] and a 1.08-fold increase in medication use (95% CI, 1.01 to 1.15). A 10-microg/m3 increase in particulate matter less than or equal to 10 microm (PM10) increased the odds of a more serious asthma attack (odds ratio = 1.12; 95% CI, 1.04 to 1.22) and also increased medication use (relative risk = 1.05; 95% CI, 1.00 to 1.09). CONCLUSIONS: Increases in PM2.5 and PM10 are significantly associated with an increased risk of more severe asthma attacks and medication use in Seattle area children with asthma. We also found associations with carbon monoxide, but we believe that carbon monoxide is a marker for exposure to combustion byproducts.

Adolescent↗

PubMed1999

A centrifugal particle concentrator for use in inhalation toxicology.

Epidemiologic studies have provided strong evidence that episodic exposure to ambient particulate matter is associated with increases in morbidity and mortality. These adverse effects have been demonstrated at concentrations far below the National Ambient Air Quality Standard (NAAQS), and thus, the biological plausibility of these effects has been questioned. For the purpose of exposing test animals to relevant and reproducible exposure concentrations of ambient particulate matter (PM), we have developed a simple and inexpensive concentrator system that can concentrate ambient particles 10-fold. A high-volume blower is used to deliver ambient air to the inlet manifold of a centrifugal concentrator and the entrained particles travel along a concentric annulus formed by a stationary solid outer cylinder and a porous inner cylinder rotating at high speed (up to 12,500 rpm). Suction applied at one end of the porous shaft causes the dispersion medium (air) to pass through the porous cylinder and into the shaft. Since the rotational velocity of airborne particles is comparable to that of the rotating cylinder near its surface, the particles move radially outward due to the centrifugal force, in addition to their motion laterally along the cylinder and inward due to the suction of air into the rotating porous cylinder. The particles reach their highest concentration near the outlet manifold, where they enter the exposure chamber under positive pressure ( approximately 0.4 cm H2O). Except for coarse particle loss due to impaction and diffusional loss of ultrafine particles in the concentrator, the increase in particle concentration is the ratio of the flow rates for the inlet air and the air delivered to the exposure chamber. We have used the centrifugal concentrator to deliver concentrated ambient urban PM to a nose-only exposure chamber and examined the concentrating effect across ambient particle sizes.

Air↗

PubMed2006

Air pollution and infant death in southern California, 1989-2000.

OBJECTIVE: We evaluated the influence of outdoor air pollution on infant death in the South Coast Air Basin of California, an area characterized by some of the worst air quality in the United States. METHODS: Linking birth and death certificates for infants who died between 1989 and 2000, we identified all infant deaths, matched 10 living control subjects to each case subject, and assigned the nearest air monitoring station to each birth address. For all subjects, we calculated average carbon monoxide, nitrogen dioxide, ozone, and particulate matter < 10 microm in aerodynamic diameter exposures experienced during the 2-week, 1-month, 2-month, and 6-month periods before a case subject's death. RESULTS: The risk of respiratory death increased from 20% to 36% per 1-ppm increase in average carbon monoxide levels 2 weeks before death in early infancy (age: 28 days to 3 months). We also estimated 7% to 12% risk increases for respiratory deaths per 10-microg/m3 increase in particulate matter < 10 microm in aerodynamic diameter exposure experienced 2 weeks before death for infants 4 to 12 months of age. Risk of respiratory death more than doubled for infants 7 to 12 months of age who were exposed to high average levels of particulates in the previous 6 months. Furthermore, the risk of dying as a result of sudden infant death syndrome increased 15% to 19% per 1-part per hundred million increase in average nitrogen dioxide levels 2 months before death. Low birth weight and preterm infants seemed to be more susceptible to air pollution-related death resulting from these causes; however, we lacked statistical power to confirm this heterogeneity with formal testing. CONCLUSIONS: Our results add to the growing body of literature implicating air pollution in infant death from respiratory causes and sudden infant death syndrome and provide additional information for future risk assessment.

Air↗

PubMed1999

Assessing the human health risk of atmospheric particles.

The health implications of atmospheric particulate matter have become a topic of much interest on both sides of the Atlantic, but especially in the USA, where they were at the centre of the debate over the Environmental Protection Agency's (EPA) revision of the National Ambient Air Quality Standard in 1997. Much of this debate revolves around claims that particulate matter (usually represented by PM10) in the atmosphere directly influences mortality, hospital admissions with respiratory diseases, and so on. In this paper, we take a critical look at one of these issues, the influence of PM10 on deaths in the elderly population. Two data sets are considered, one from Birmingham (Alabama) and the other from Chicago. In both cases we find a significant PM10-mortality relationship in some of the models fitted, but not in others. Other issues considered include the existence of a threshold below which PM10 has no discernible influence, the interaction with other pollutants and the mortality displacement or harvesting effect (the theory that the direct effect of PM10 is limited to a very small subset of the population who are already critically ill and whose death is only advanced by a few hours or days as a result of air pollution). Overall, our conclusion is that there are too many uncertain issues to allow us to make definitive statements about a causal relationship between PM10 and mortality.

Air Pollution↗