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PubMed1998

Activation of cellular oncogenes in human diploid cell strain (KMB-13) cells by scooter exhaust particulate matter emissions.

Scooter exhaust particulate matter emissions were found to be mutagenic and to induce potential carcinogenicity. To further explore the mechanisms of mutagenicity and potential carcinogenicity of scooter exhaust particulate matter emissions, immunohistochemistry assays were carried out to detect the expression of some oncogenes and tumor suppressor genes in human diploid cell strain (KMB-13) cells, which were morphologically transformed by the organic extracts of scooter exhaust particulate matter emissions. An ABC diagnostic kit was used to investigate the expression of c-myc, p21, p53, and p16 proteins in the transformed cells. The c-myc and p21 proteins showed marked positive staining compared to control. The data suggest that the mutagenicity and potential carcinogenicity of the scooter exhaust particulate matter emissions correlate with the activation of some cellular oncogenes.

Air Pollutants↗

PubMedDate not supplied

Soluble metals as well as the insoluble particle fraction are involved in cellular DNA damage induced by particulate matter.

Exposure to ambient particulate matter has been reported to be associated with increased rates of lung cancer. Previously we showed that total suspended particulate matter (PM) induces oxidative DNA damage in epithelial lung cells. The aim of the present study was to further investigate the mechanism of PM-induced DNA damage, in which soluble iron-mediated hydroxyl radical (.OH) formation is thought to play a crucial role. Using electron spin resonance (ESR) we showed that PM suspensions as well as their particle-free, water-soluble fractions can generate .OH in the presence of hydrogen peroxide (H2O2), an effect which was abrogated by both deferoxamine and catalase. In addition, PM was also found to induce the .OH-specific DNA lesion 8-hydroxydeoxyguanosine (8-OHdG) in the presence of H2O2 as assessed by dot-blot analysis of calf thymus DNA using an 8-OHdG antibody. In human alveolar epithelial cells (A549), both PM suspensions and the particle-free soluble fraction elicited formation of DNA strand breaks (comet-assay). Unlike the acellular DNA assay, in epithelial cells the DNA-damaging capacity of the particle suspensions appeared to be stronger than that of their corresponding particle-free filtrates. In conclusion, our findings demonstrate that the water-soluble fraction of PM elicits DNA damage via transition metal-dependent .OH formation, implicating an important role of H2O2. Moreover, our data indicate that direct 'particle' effects contribute to the genotoxic hazard of ambient particulate matter in lung target cells.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed2004

Chemical speciation of thorium in marine biogenic particulate matter.

Concentrations of particulate thorium in seawater were determined together with the strong organic ligand (SOL) and uranium in particulate matter (PM). The concentrations of particulate Th in surface waters of the western North Pacific and the Sea of Japan ranged from 0.05 to 1.5 pM (1 x 10(-12) M), and showed relatively large temporal and spatial variations. In order to chemically characterize the particulate Th in seawater, the relationship between particulate Th and SOL concentrations in surface PM was examined. The result reveals that particulate Th in surface PM was well correlated with the SOL concentration in PM. The concentrations of particulate Th in surface water were linearly related to those of particulate U. Mass balance analysis suggests that the dominant chemical form of Th(IV), as well as of U, in surface PM is a surface complex with the SOL in PM. Our findings suggest that the SOL in PM is a nonmetal-specific chelator originating from the cell surface of microorganisms.

Particle Size↗

PubMed2005

Size and composition distribution of airborne particulate matter in northern California: I--particulate mass, carbon, and water-soluble ions.

The San Joaquin Valley (SJV) in California has one of the most severe particulate air quality problems in the United States during the winter season. In the current study, measurements of particulate matter (PM) smaller than 10 microm in aerodynamic diameter (PM10), fine particles (PM18), and ultrafine particles (PM0.1) made during the period December 16, 2000-February 3, 2001, at six locations near or within the SJV are discussed: Bodega Bay, Davis, Sacramento, Modesto, Bakersfield, and Sequoia National Park. Airborne PM1.8 concentrations at the most heavily polluted site (Bakersfield) increased from 20 to 172 microg/m3 during the period December 16, 2000-January 7, 2001. The majority of the fine particle mass was ammonium nitrate driven by an excess of gas-phase ammonia. Peak PM0.1 concentrations (8-12 hr average) were approximately 2.4 microg/m3 measured at night in Sacramento and Bakersfield. Ultrafine particle concentrations were distinctly diurnal, with daytime concentrations approximately 50% lower than nighttime concentrations. PMO.1 concentrations did not accumulate during the multiweek stagnation period; rather, PMO.1 mass decreased at Bakersfield as PM1.8 mass was increasing. The majority of the ultrafine particle mass was associated with carbonaceous material. The high concentrations of ultrafine particles in the SJV pose a potential serious public health threat that should be addressed.

Air Movements↗

PubMed1999

Photoinduced particulate matter in a parenteral formulation for bisnafide, an experimental antitumor agent.

This paper assesses the cause of particulate formation in vials of the experimental antitumor agent bisnafide and investigates pharmaceutical techniques to reduce the number of particulates in the product. Solution preparation and particulate isolation were performed under Class 100 laminar air flow. Reversed-phase HPLC and infrared microscopy were used to characterize drug and isolated particulate matter, whereas a Hiac particle counter was used to quantify the particulate matter. Particulate matter was observed following agitation of the drug solutions and was found to be associated with specific lots of drug substance. HPLC of the isolated particulate matter indicated that the particulates consisted largely of bisnafide and impurities that were identified as the products of photodegradation, confirmed to be the result of the photolytic cleavage of bisnafide to form a poorly soluble aldehyde. The aldehyde may, in turn, interact with bisnafide molecules to form the particulate matter as suggested by the observed pH-dependent reversibility of the particulate phenomenon. The particulate matter could be reduced by protecting solutions of bisnafide from light during chemical synthesis and production of the dosage form and, alternatively, by reducing the solution pH to 3.0 or less, addition of surfactants below their critical micelle concentration, and removal of impurities by froth flotation of the bisnafide solutions.

Aldehydes↗

PubMed2003

Evaluation of elemental carbon as a marker for diesel particulate matter.

Elemental carbon (EC) in atmospheric particulate matter originates from a broad range of sources in many urban locations. As health and air quality studies are using elemental carbon measurements to better understand the impact of diesel engines and other combustion sources, there is a great need to clearly understand the relative source contributions to EC concentrations in the atmosphere. However, the different analytical techniques currently used to measure EC do not show good agreement for many particulate matter samples. To this end, studies that use EC as a tracer and integrate different analytical techniques for EC can significantly bias estimates of source contributions to atmospheric particulate matter. In addition, source attribution studies that do not properly address all sources of EC in the atmosphere can also lead to inaccuracies and biases. To better understand the use of EC as a tracer, a review of the distribution of EC in the primary particulate matter emissions from air pollution sources using different analytical methods is discussed. A review of previous apportionment studies of particulate matter is presented to elucidate the fraction of EC that results from emissions from diesel engines in urban locations. These results demonstrate that EC is not a unique tracer for diesel exhaust and efforts to utilize EC as an indicator of diesel exhaust must properly address other sources of EC as well as utilize a consistent measurement technique for EC when comparing source and ambient EC measurements to avoid significant biases.

Air Pollutants↗

PubMed2005

Alterations in bronchoalveolar lavage constituents, oxidant/antioxidant status, and lung histology following intratracheal instillation of respirable suspended particulate matter.

Urban suspended particulate pollutants differ with place of occurrence, meteorological conditions, physicochemical compositions, and the response of the bronchopulmonary apparatus. Lung injury following intratracheal instillation of respirable suspended particulate matter (RSPM) collected in an urban setting in India was investigated in rats. The animals were killed 15 days after exposure to 2.5, 5.0, and 10.0 mg of RSPM. We examined the changes in lung histology, enzymatic activity in the bronchoalveolar lavage (BAL), and the oxidant/ antioxidant status in lung homogenates. The alterations in these parameters were compared with those in rats instilled with quartz particulates, which were used as positive controls. Exposure to RSPM resulted in an increase in the relative weight of lungs and inflammatory changes evidenced by an increase in the total cellularity of the lungs, predominantly polymorphonuclear cells, demonstrable both in the lungs sections and in the bronchoalveolar lavage of the exposed animals. An increase in the protein content and in the lactate dehydrogenase activity in the BAL was found in the RSPM-exposed rats. A marked increase in the output of lipid peroxides and a dose-dependent increase in the formation of reactive nitrogen species (NO) in lung homogenates and BAL, respectively, was found in the RSPM-exposed rats. A significant decrease in the enzymatic lung antioxidants, superoxide dismutase, and catalase was observed. However, the alterations in the levels of glutathione in the lungs of the RSPM-exposed animals were not significant. The inflammatory reaction, oxidative changes, and enzyme release, were more marked in quartz-exposed animals in comparison to the RSPM-exposed rats.

Air Pollutants↗

PubMed2002

Setting ambient air quality standards for particulate matter.

Ambient air particulate matter (PM), unspecified as to chemical composition, is of concern because of its health effects. Air quality standards for PM have been established in many countries. The earliest standards were based on threshold models and use of a margin of safety. Initially, standards were based on the mass of total suspended material. In the 1980s a shift to a size-specific standard, PM(10), began. PM(10) is the fraction of PM captured with 50% efficiency at 10 microm and greater efficiency at smaller sizes. In the late 1990s, standards were proposed for PM(2.5), which is captured with 50% efficiency at 2.5 microm. The standards for PM are based almost exclusively on human epidemiological data, with laboratory animal and in vitro data used in a supporting role. During the 1990s, new statistical tools began to be used and demonstrated an association between increased PM and an increase in cardiorespiratory morbidity and mortality. The analyses are complicated by the effects of other pollutants such as ozone. Effects have been observed down to 10-20 microg of PM(10) per cubic meter, levels equal to or below background in many parts of the world. In many studies there has been no evidence of a threshold. In the absence of a threshold, a critical issue becomes how to determine how low is low enough? This paper reviews the current literature on PM health effects and suggests research avenues that may yield data which, combined with public policy considerations, may be able to address the issue of 'how low is low enough?'

Air↗

PubMed2005

Sampling results of the improved SKC diesel particulate matter cassette.

Diesel particulate matter (DPM) samples from underground metal/nonmetal mines are collected on quartz fiber filters and measured for carbon content using National Institute for Occupational Safety and Health Method 5040. If size-selective samplers are not used to collect DPM in the presence of carbonaceous ore dust, both the ore dust and DPM will collect on the quartz filters, causing the carbon attributed to DPM to be artificially high. Because the DPM particle size is much smaller than that of mechanically generated mine dust aerosols, it can be separated from the larger mine dust aerosol by a single-stage impactor. The SKC DPM cassette is a single-stage impactor designed to collect only DPM aerosols in the presence of carbonaceous mine ore aerosols, which are commonly found in underground nonmetal mines. However, there is limited data on how efficiently the SKC DPM cassette can collect DPM in the presence of ore dust. In this study we investigated the ability of the SKC DPM cassette to collect DPM while segregating ore dust from the sample. We found that the SKC DPM cassette accurately collected DPM. In the presence of carbon-based ore aerosols having an average concentration of 8 mg/m3, no ore dust was detected on SKC DPM cassette filters. We did discover a problem: the surface areas of the DPM deposits on SKC DPM cassettes, manufactured prior to August 2002 were inconsistent. To correct this problem, SKC modified the cassette. The new cassette produced, with 99% confidence, a range of DPM deposit areas between 8.05 and 8.28 cm2, a difference of less than 3%.

Air Pollution, Indoor↗

PubMed2004

Association of FEV1 in asthmatic children with personal and microenvironmental exposure to airborne particulate matter.

Exposure to particulate matter (PM) air pollution has been shown to exacerbate children's asthma, but the exposure sources and temporal characteristics are still under study. Children's exposure to PM is likely to involve both combustion-related ambient PM and PM related to a child's activity in various indoor and outdoor microenvironments. Among 19 children with asthma, 9-17 years of age, we examined the relationship of temporal changes in percent predicted forced expiratory volume in 1 sec (FEV1) to personal continuous PM exposure and to 24-hr average gravimetric PM mass measured at home and central sites. Subjects were followed for 2 weeks during either the fall of 1999 or the spring of 2000, in a southern California region affected by transported air pollution. FEV(subscript)1(/subscript) was measured by subjects in the morning, afternoon, and evening. Exposure measurements included continuous PM using a passive nephelometer carried by subjects; indoor, outdoor home, and central-site 24-hr gravimetric PM2.5 (PM of aerodynamic diameter < 2.5 microm) and PM10; and central-site hourly PM10, nitrogen dioxide, and ozone. Data were analyzed with linear mixed models controlling for within-subject autocorrelation, FEV1 maneuver time, and exposure period. We found inverse associations of FEV1 with increasing PM exposure during the 24 hr before the FEV1 maneuver and with increasing multiday PM averages. Deficits in percent predicted FEV1 (95% confidence interval) for given PM interquartile ranges measured during the preceding 24-hr were as follows: 128 microg/m3 1-hr maximum personal PM, -6.0% (-10.5 to -1.4); 30 microg/m3 24-hr average personal PM, -5.9% (-10.8 to -1.0); 6.7 microg/m3 indoor home PM2.5, -1.6% (-2.8 to -0.4); 16 microg/m3 indoor home PM10, -2.1% (-3.7 to -0.4); 7.1 microg/m3 outdoor home PM2.5, -1.1% (-2.4 to 0.1); and 7.5 microg/m3 central-site PM2.5, -0.7% (-1.9 to 0.4). Stronger associations were found for multiday moving averages of PM for both personal and stationary-site PM. Stronger associations with personal PM were found in boys allergic to indoor allergens. FEV1 was weakly associated with NO2 but not with O3. Results suggest mixed respiratory effects of PM in asthmatic children from both ambient background exposures and personal exposures in various microenvironments.

Adolescent↗

PubMed2004

[Advances on the immunotoxicity of airborne fine particulate matter (PM2.5)].

Exposure to airborne fine particulate matter (PM2.5) is an health risk factor, and immune system is one of the target tissues. Fine particulate matter had an effect on the host specific immune and nonspecific immune. The immune effect has two side, it can cause the damage to body, on the other hand it can also clean up the particulate matter. Immunotoxicity of PM2.5 is also associated with the other biological effect such as genotoxicity. Damage of fine particulate is through oxidant stress, inflammation and neurogenic inflammation and so on, but the detail of the mechanism for them is lacking. This review describes the immunotoxicity of PM2.5 from different aspects and levels.

Air Pollutants↗

PubMed2006

Airborne particulate matter inhibits alveolar fluid reabsorption in mice via oxidant generation.

Ambient particulate matter is increasingly recognized as a significant contributor to human cardiopulmonary morbidity and mortality in the United States and worldwide. We sought to determine whether exposure to ambient particulate matter would alter alveolar fluid clearance in mice. Mice were exposed to a range of doses of a well-characterized particulate matter collected from the ambient air in Düsseldorf, Germany through a single intratracheal instillation, and alveolar fluid clearance and measurements of lung injury were made. Exposure to even very low doses of particulate matter (10 microg) resulted in a significant reduction in alveolar fluid clearance that was maximal 24 h after the exposure, with complete resolution after 7 d. This was paralleled by a decrease in lung Na,K-ATPase activity. To investigate the mechanism of this effect, we measured plasma membrane Na,K-ATPase abundance in A549 cells and Na,K-ATPase activity in primary rat alveolar type II cells after exposure to particulate matter in the presence or absence of the combined superoxide dismutase and catalase mimetic EUK-134 (5 microM). Membrane but not total protein abundance of the Na,K-ATPase was decreased after exposure to particulate matter, as was Na,K-ATPase activity. This decrease was prevented by the combined superoxide dismutase/catalase mimetic EUK-134. The intratracheal instillation of particulate matter results in alveolar epithelial injury and decreased alveolar fluid clearance, conceivably due to downregulation of the Na,K-ATPase.

Air Pollutants↗

PubMed1999

Measured and modelled concentrations and vertical profiles of airborne particulate matter within the boundary layer of a street canyon.

Concentrations and vertical profiles of various fractions of airborne particulate matter (suspended particulate matter (SPM), PM10 and PM2.5) have been measured over the first three metres from ground in a street canyon. Measurements were carried out using automated near real-time apparatus called the Kinetic Sequential Sampling (KSS) system. KSS system is essentially an electronically-controlled lift carrying a real-time particle monitor for sampling air sequentially, at different heights within the breathing zone, which includes all heights within the surface layer of a street canyon at which people may breathe. Data is automatically logged at the different receptor levels, for the determination of the average vertical concentration profile of airborne particulate matter. For measuring the airborne particle concentration, a Grimm Dust Monitor 1.104/5 was used. The recorded data also allows for time series analysis of airborne particulate matter concentration at different heights. Time series data and hourly-average vertical concentration profiles in the boundary layer of the confines of a street are thought to be mainly determined by traffic emissions and traffic associated processes. Hence the measured data were compared with results of a street canyon emission-dispersion model in time and space. This Street Level Air Quality (SLAQ) model employs the plume-box technique and includes modules for simulating vehicle-generated effects such as thermally- and mechanically-generated turbulence and resuspension of road dust. Environmental processes, such as turbulence resulting from surface sensible heat and the formation of sulphate aerosol from sulphur dioxide exhaust emissions, are taken into account. The paper presents an outline description of the measuring technique and model used, and a comparison of the measured and modelled data.

Air Pollutants↗

PubMed2005

Differential pressure as a measure of particulate matter emissions from diesel engines.

A diesel particulate matter analyzer capable of direct, real-time measurement of engine exhaust particulate is necessary to effectively institute source control technology currently being used on diesel equipment and to ensure that the control measures are working. To investigate the potential of a differential pressure monitor to measure diesel particulate matter in undiluted exhaust, samples were collected from three different diesel engines--Kubota, Isuzu, and Deutz--running under 12 different RPM and load scenarios. These measurements were compared to elemental carbon concentrations in the sampled exhaust as determined by using the NIOSH 5040 analytical method. Elemental carbon is used as a surrogate measurement for diesel particulate matter. The results of the two data sets were then compared using a linear regression analysis. The coefficient of determination (or R2) was calculated to be 0.98, 0.94, and 0.74 for the Kubota, Deutz, and Isuzu engines, respectively. R2 values of this magnitude indicate that this method can be successful in estimating elemental carbon emissions in the engines tested. In addition, for replicate samples, the coefficient of variation ranged from 7.1% to 10.2% with an average of 8.5%. These data indicate that this method could prove useful to mechanics as they work to maintain engines and DPM control technologies.

Carbon↗

PubMed2002

Source apportionment of secondary airborne particulate matter in a polluted atmosphere.

Secondary airborne particulate matter formed from gas-phase pollutants contributes significantly to the most severe particulate air quality events that occur in the United States each year. In this study, a mechanistic air quality model is demonstrated that can predict source contributions to the size distribution of secondary airborne particulate matter. Calculations performed for a typical air quality episode in Southern California show that NOx released from diesel engines and catalyst-equipped gasoline engines account for the majority of the secondary particulate nitrate aerosol measured at inland locations. NH3 released from catalyst-equipped gasoline engines, farm animals, and residential sources account for the majority of the secondary particulate ammonium ion at inland locations in the region. When both tailpipe and road dust emissions are considered, transportation sources dominate the size distribution of total (primary plus secondary) airborne particulate matter in the South Coast Air Basin during the episode studied. These findings suggest that the public health risk associated with air pollution released from transportation sources is significant relative to other public health threats such as traffic accidents.

Air Pollutants↗

PubMed1989

[Determination of particulate matter in small volume antibiotic injections].

Amounts of particulate matter present in 17 small volume antibiotic injections marketed in Japan were determined using light obscuration particle analyzer (HIAC). The vial volume range of each batch of product was 7-20 ml, and each vial contained 1 g as antibiotic potency. In 4 products, contents of particles between 2.5 and 10 microns in diameter were counted 2,000-7,000 per vial, and particles in other products were counted less than 2,000 per vial. Numbers of particles greater than or equal to 10 microns in diameter were much less than the USP XXI criteria for particulate matter in small volume injections. The product of the highest counts for particles between 10 and 25 microns in diameter showed counts amounted to 0.13% of the USP XXI criteria. In the 25-50 microns particulate diameter range, particulate matters were detected only in 2 products, and they were less than 0.2% of the USP XXI criteria. Particles over 50 microns in diameter were not detected in any products. These results showed that 17 small volume antibiotic injections marketed in Japan had good qualities regarding contents of particulate matter.

Anti-Bacterial Agents↗

PubMed2003

Chemical analysis of World Trade Center fine particulate matter for use in toxicologic assessment.

The catastrophic destruction of the World Trade Center (WTC) on 11 September 2001 caused the release of high levels of airborne pollutants into the local environment. To assess the toxicity of fine particulate matter [particulate matter with a mass median aerodynamic diameter < 2.5 microm (PM2.5)], which may adversely affect the health of workers and residents in the area, we collected fallen dust samples on 12 and 13 September 2001 from sites within a half-mile of Ground Zero. Samples of WTC dust were sieved, aerosolized, and size-separated, and the PM2.5 fraction was isolated on filters. Here we report the chemical and physical properties of PM2.5 derived from these samples and compare them with PM2.5 fractions of three reference materials that range in toxicity from relatively inert to acutely toxic (Mt. St. Helens PM; Washington, DC, ambient air PM; and residual oil fly ash). X-ray diffraction of very coarse sieved WTC PM (< 53 microm) identified calcium sulfate (gypsum) and calcium carbonate (calcite) as major components. Scanning electron microscopy confirmed that calcium-sulfur and calcium-carbon particles were also present in the WTC PM2.5 fraction. Analysis of WTC PM2.5 using X-ray fluorescence, neutron activation analysis, and inductively coupled plasma spectrometry showed high levels of calcium (range, 22-33%) and sulfur (37-43% as sulfate) and much lower levels of transition metals and other elements. Aqueous extracts of WTC PM2.5 were basic (pH range, 8.9-10.0) and had no evidence of significant bacterial contamination. Levels of carbon were relatively low, suggesting that combustion-derived particles did not form a significant fraction of these samples recovered in the immediate aftermath of the destruction of the towers. Because gypsum and calcite are known to cause irritation of the mucus membranes of the eyes and respiratory tract, inhalation of high doses of WTC PM2.5 could potentially cause toxic respiratory effects.

Air Pollutants↗

PubMed2000

Toxic evaluation of organic extracts from airborne particulate matter in Puerto Rico.

In recent years, several hypotheses have emerged to explain the toxicologic activity of particulate matter. Organic compounds, ultrafine particles, biologic components, and transition metals are some of the constituents that reportedly exert some type of adverse effect on human health. A considerable fraction of the urban particulate matter consists of carbon compounds, which originate mostly from anthropogenic sources. The toxicity of organic fractions from particulate matter have been mainly evaluated by considering their mutagenic activity. This research expands on the toxicologic profile of organic compounds adsorbed to particulate matter, specifically in Puerto Rico, by using the cytotoxic neutral red bioassay (NRB). The NRB uses normal human epidermal keratinocytes or other types of cells to measure the effect on cell viability when exposed to organic compounds associated to the particles in the air. We validated the NRB for particulate matter by using a standard reference material (SRM 1649). We used the NRB to determine toxicologic differences of extracts between an urban industrialized site with anthropogenic activity versus a coastal region with less human activity. The cytotoxicity associated with organic compounds in particulate matter collected at the urban industrialized site was detected in both the particulate matter (3/4) 10 microm in aerodynamic diameter (PM(10)) and particulate matter (3/4) 100 microm in aerodynamic diameter (PM(100)). Greater toxic effects were observed in PM(10) extracts than in PM(100) extracts, but PM(10) toxic effects were not significantly different from those in PM(100). The extracts from the industrialized site were more cytotoxic than the extracts from coastal reference site, although in the summer, extracts from both sites were significantly cytotoxic to normal human epidermal keratinocytes. In addition, the nonpolar extracts of both PM(10) and PM(100) exerted the greatest cytotoxicity, followed by the polar, and, finally, the moderately polar extract. This study demonstrates that extracts from the Guaynabo industrialized site were more toxic than similar extracts obtained from a reference coastal site in Fajardo, Puerto Rico.

Air Pollutants↗