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PubMed1999

Inhalation of diesel engine exhaust affects spermatogenesis in growing male rats.

We conducted experiments to determine whether diesel engine exhaust affects reproductive endocrine function in growing rats. The rats were assigned to three groups: a group exposed to total diesel engine exhaust containing 5.63 mg/m3 particulate matter, 4.10 ppm nitrogen dioxide, and 8.10 ppm nitrogen oxide; a group exposed to filtered exhaust without particulate matter; and a group exposed to clean air. Dosing experiments were performed for 3 months beginning at birth (6 hr/day for 5 days/week). Serum levels of testosterone and estradiol were significantly higher in animals exposed to total diesel exhaust and filtered exhaust (p < 0.05 for each group) as compared to the controls. Follicle-stimulating hormone was significantly decreased in the two groups exposed to diesel exhaust as compared to the control group (p < 0.05). Luteinizing hormone was significantly decreased in the total exhaust-exposed group as compared to the control and filtered groups (p < 0.05). Although testis weight did not show any significant difference among the groups, sperm production and activity of testicular hyaluronidase were significantly reduced in both exhaust-exposed groups as compared to the control group. Histological examination showed decreased numbers of step 18 and 19 spermatids in stage VI, VII, and VIII tubules in the testes of both diesel exhaust-exposed groups. This study suggests that diesel exhaust stimulates hormonal secretion of the adrenal cortex, depresses gonadotropin-releasing-hormone, and inhibits spermatogenesis in rats. Because these effects were not inhibited by filtration, the gaseous phase of the exhaust appears to be more responsible than particulate matter for disrupting the endocrine system.

Administration, Inhalation↗

PubMed1970

Microbial biomass on particulate organic matter in seawater of the euphotic zone.

Microbial biomass on suspended organic matter in seawater of the euphotic zone of Saanich Inlet was investigated. The viable microorganisms were measured by the glucose-uptake method. Microbial carbon on particulate organic matter in seawater was determined to be, on the average, 9.9 mug of C/liter, and there was a regression relationship as y = 0.0062 x - 1.79 with an unbiased variance V(yx) = 0.38, where x = particulate organic carbon in seawater (micrograms of C/liter) and y = logarithm of microbial carbon (micrograms of C/liter).

Journal Article↗

PubMed1999

PCDDs and PCDFs in vehicle exhaust particles in Japan.

Vehicle exhaust particles from gasoline and diesel engine cars were analyzed for PCDDs and PCDFs. The congener patterns of PCDDs and PCDFs in exhaust particles were different between gasoline and diesel engine cars. Suspended particulate matter from electrostatic precipitator connected to a highway tunnel was also analyzed for PCDDs and PCDFs. The congener pattern of suspended particular matter was different from both of gasoline and diesel engine cars. Total amounts of PCDDs/PCDFs sum concentrations in gasoline, diesel and suspended particulate matter were 0.21, 0.87 and 26.0 ng/g, respectively. The I-TEQs levels in gasoline, diesel and suspended particulate matter were 4.2, 11 and 242 pg/g, respectively.

Air Pollutants↗

PubMed1994

Correlation between meteorological conditions and mutagenicity of airborne particulate samples in a tropical monsoon climate area from Kaohsiung City, Taiwan.

Kaohsiung is a city of 1.5 million located in the southern part of Taiwan. It has a serious air pollution problem mainly attributable to much industrial and commercial activity. In order to estimate the effects of traffic, season, and meteorological conditions on the mutagenicity of Kaohsiung City's urban ambient particulate matter, 624 airborne particulate samples were collected on a weekly basis from 12 locations for an entire year. The mutagenic potential of acetone extracts of air samples was evaluated by the Salmonella/microsomal test with S. typhimurium TA98 in the presence and absence of S9 mixtures. The air samples from November 1990 showed the highest direct and indirect mutagenicity among the 12 months, whereas those from June and July 1991 had the lowest direct and indirect mutagenic activity, respectively. The mutagenicity showed a good correlation with amounts of the acetone extractable matter of airborne particulates. The meteorological conditions, monthly mean precipitation, and wind speed also showed a good correspondence with mutagenicity. Wind direction and temperature had a moderate relationship. The major mutagenic fractions of air samples that had the highest mutagenic activity in a month were purified using Sephadex LH-20 column chromatography, and the contents of PAHs, 1-NP, and DNPs were analyzed by HPLC. The characteristic concentration ratios of PAHs indicated that, for the main pollution sources of airborne particulates from Kaohsiung city, the mobile sources were more important than the stationary ones. The total amounts of 1-NP and DNPs in airborne particulates seemed to correspond to their mutagenicity. Although the total amounts of 1-NP and DNPs in the air samples correlated with their mutagenicity, the major mutagenic chemicals in the airborne particulate samples from Kaohsiung City need further investigation.

Air Pollutants↗

PubMed2002

[Effects of traffic-generated ultrafine particles on health].

Epidemiological studies have consistently shown relation between exposure to particulate matter in urban air and cardiovascular and pulmonary morbidity and mortality. Some recent population studies suggest that the ultrafine fraction of particulate matter generated by motorised vehicles is particularly damaging. Animal studies and cell culture experiments support this hypothesis and address the possible mechanisms of action. Inhalation of particulate matter, especially ultrafine particles, causes oxidative stress and inflammation in lung tissue, which affects the lung cells per se, as well as the cardiovascular system.

Air Pollutants↗

PubMed2004

Comparison of fine particle measurements from a direct-reading instrument and a gravimetric sampling method.

Particulate air pollution, specifically the fine particle fraction (PM2.5), has been associated with increased cardiopulmonary morbidity and mortality in general population studies. Occupational exposure to fine particulate matter can exceed ambient levels by a large factor. Due to increased interest in the health effects of particulate matter, many particle sampling methods have been developed In this study, two such measurement methods were used simultaneously and compared. PM2.5 was sampled using a filter-based gravimetric sampling method and a direct-reading instrument, the TSI Inc. model 8520 DUSTTRAK aerosol monitor. Both sampling methods were used to determine the PM2.5 exposure in a group of boilermakers exposed to welding fumes and residual fuel oil ash. The geometric mean PM2.5 concentration was 0.30 mg/m3 (GSD 3.25) and 0.31 mg/m3 (GSD 2.90)from the DUSTTRAK and gravimetric method, respectively. The Spearman rank correlation coefficient for the gravimetric and DUSTTRAK PM2.5 concentrations was 0.68. Linear regression models indicated that log, DUSTTRAK PM2.5 concentrations significantly predicted loge gravimetric PM2.5 concentrations (p < 0.01). The association between log(e) DUSTTRAK and log, gravimetric PM2.5 concentrations was found to be modified by surrogate measures for seasonal variation and type of aerosol. PM2.5 measurements from the DUSTTRAK are well correlated and highly predictive of measurements from the gravimetric sampling method for the aerosols in these work environments. However, results from this study suggest that aerosol particle characteristics may affect the relationship between the gravimetric and DUSTTRAK PM2.5 measurements. Recalibration of the DUSTTRAK for the specific aerosol, as recommended by the manufacturer, may be necessary to produce valid measures of airborne particulate matter.

Aerosols↗

PubMed2000

The impact of polycyclic aromatic hydrocarbons and fine particles on pregnancy outcome.

The relationship between intrauterine growth retardation (IUGR) and exposure to particulate matter [less than/equal to] 10 microm (PM(10)) and particulate matter [less than and equal to] 2.5 microm (PM(2.5))( )in early pregnancy was recently studied in the highly polluted district of Teplice (Northern Bohemia). From this observation rose the question about the possible role of the carcinogenic fraction of polycyclic aromatic hydrocarbons (c-PAHs), which are usually bound to fine particles. The impact of c-PAHs and fine particles on IUGR was analyzed in Teplice and in Prachatice, a region with similarly high c-PAH but low particle levels. All European, single live births occurring in a 4-year period in Teplice (n = 3,378) and Prachatice (n = 1,505) were included. Detailed personal data were obtained via questionnaires and medical records. Mean PM(10), PM(2.5,) and c-PAHs levels during the 9 gestational months (GM) were estimated for each mother. Adjusted odds ratios (AORs) of IUGR for three levels of c-PAHs (low, medium, and high) and for continuous data were estimated after adjustment for a range of covariates using logistic regression models. In the present 4-year sample from Teplice, previously published results about increasing IUGR risk after exposure to particles in the first GM were fully confirmed, but no such effects were found in Prachatice. The AOR of IUGR for fetuses from Teplice exposed to medium levels of c-PAHs in the first GM was 1.60 [confidence interval (CI), 1.06-2. 15], and to high levels 2.15 (CI, 27-3.63). An exposure-response relationship was established by analyzing the continuous data. For each 10 ng increase of c-PAHs in the first GM, the AOR was 1.22 (CI, 1.07-1.39). About the same relationship was observed in Prachatice in spite of the low particle levels. The results prove that exposure to c-PAHs in early gestation may influence fetal growth. The particulate matter-IUGR association observed earlier may be at least partly explained by the presence of c-PAHs on particle surfaces.

Adult↗

PubMed2002

Processes and modeling of hydrolysis of particulate organic matter in aerobic wastewater treatment--a review.

Carbon cycling and the availability of organic carbon for nutrient removal processes are in most wastewater treatment systems restricted by the rate of hydrolysis of slowly biodegradable (particulate) organic matter. To date, the mechanisms of hydrolysis are not well understood for complex substrates and mixed populations. Most mathematical models use a simple one-step process to describe hydrolysis. In this article, mechanisms of hydrolysis and mathematical models to describe these processes in wastewater treatment processes are reviewed. Experimental techniques to determine mechanisms of hydrolysis and rate constants are discussed.

Bacteria, Aerobic↗

PubMedDate not supplied

Design and implementation of a collaborative study of the mutagenicity of complex mixtures in Salmonella typhimurium.

In 1987, the International Programme on Chemical Safety (IPCS) in collaboration with the U.S. Environmental Protection Agency (U.S. EPA) and the U.S. National Institute of Standards and Technology (U.S. NIST) initiated an international collaborative study of the mutagenicity of complex environmental mixtures in the Ames Salmonella typhimurium mutation assay. The objectives of this study were: (1) to estimate the inter- and intra-laboratory variability associated with the extraction of mixtures for bioassay, (2) to estimate the inter- and intra-laboratory variability associated with the Salmonella typhimurium bioassay when applied to complex mixtures, and (3) to determine whether standard reference complex mixtures would be useful in mutagenicity studies and to evaluate whether reference or certified mutagenicity values determined from this collaborative study should be reported. The complex mixtures used in this study were selected from standard reference materials (SRMs) which had previously been issued by the U.S. NIST as SRM 1597 (coal tar), SRM 1649 (diesel particulate matter) and SRM 1650 (urban air particulate matter) with certified values for polycyclic aromatic hydrocarbons. These SRM complex mixtures are available to scientists as reference standards for analytical chemistry research and are under consideration as SRMs for mutagenicity studies of complex environmental mixtures. This paper briefly describes the final study design, protocol, selection of the complex mixtures, and implementation of this international study.

Laboratories↗

PubMedDate not supplied

Salmonella mutagenicity of three complex mixtures assayed with the microsuspension technique. A WHO/IPCS/CSCM study.

In a collaborative study on complex mixtures, three complex mixtures and two pure compounds were assayed with the Salmonella microsuspension technique. The two pure compounds were benzo[a]pyrene (BaP) and 1-nitropyrene (1-NP). The three complex mixtures were standard reference materials (SRMs) from the U.S. National Institute of Standards and Technology, SRM 1649, SRM 1650 and SRM 1597. The two samples SRM 1649, an urban dust particulate matter, and SRM 1650, a diesel particulate matter, were sonicated with dichloromethane. Sample SRM 1597 was an extract of a coal tar sample with a complex mixture of polycyclic aromatic hydrocarbons. The microsuspension assay was performed with Salmonella strains TA98 and TA100 according to Kado et al. (1983) with minor modifications (Löfroth et al., 1988). The results showed that the microsuspension technique is a more sensitive assay than the plate incorporation method. Depending on sample, strain and metabolic condition the mutagenic responses were 3-37 times higher in the microsuspension assay than in the conventional plate incorporation assay. The microsuspension method is thus useful for environmental samples which are often available in only small amounts.

Air Pollutants↗

PubMed2005

Fine particles and meteorological conditions are associated with lung function in children with asthma living near two power plants.

Fine particles are thought to pose a risk to health, especially for vulnerable groups such as children with asthma. These children are also known to be affected by meteorological and seasonal changes. We assessed the association between air pollution and lung function via peak expiratory flow (PEF), controlling for seasonal changes, meteorological conditions and personal physiological, clinical and sociodemographic measurements, in a panel of schoolchildren with asthma living near two power plants in Israel. Two hundred and eighty-five children with confirmed asthma performed PEF tests and completed a respiratory symptoms diary twice a day. Particulate matter <10 microm in diameter (PM10), particulate matter <2.5 microm in diameter (PM2.5) and meteorological conditions were measured at six fixed stations. Data were analysed using time series analysis-generalized linear model and generalized estimating equations. The models were built under the assumption that any health outcome belongs to a multivariate hierarchical system and depends on meteorological, geophysical and sociocultural variables and pollution factors. No significant differences were found in the demographic (age, gender, mean parental education level, parental smoking habits, place of birth and housing density), physiological (body mass index) and clinical factors (illness severity) between the communities participating in the study. A significant direct effect of PM2.5 on the PEF was found in Ashdod (P=0.000). In Sderot, this effect was through an interaction between PM10 and the sequential day of the year (P=0.000). The main conclusion of this study is that children with asthma are at risk from air pollution and geophysical conditions. Policy makers should take these results into consideration when setting thresholds for environmental protection.

Air Pollutants↗

PubMed2006

Carbon in airway macrophages and lung function in children.

BACKGROUND: Epidemiologic studies indirectly suggest that the inhalation of carbonaceous particulate matter impairs lung function in children. Using the carbon content of airway macrophages as a marker of individual exposure to particulate matter derived from fossil fuel, we sought direct evidence of this association. METHODS: Airway macrophages were obtained from healthy children through sputum induction, and the area of airway macrophages occupied by carbon was measured. Lung function was measured with the use of spirometry. We modeled the exposure to primary particulate matter (PM) that is less than 10 mum in aerodynamic diameter (PM10) at or near each child's home address. Linear regression was used to evaluate associations between carbon content of alveolar macrophages and variables that may affect individual exposure. To determine whether lung function that is reduced for other reasons is associated with an increase in the carbon content of airway macrophages, we also studied children with severe asthma. RESULTS: We were able to assess the carbon content of airway macrophages in 64 of 114 healthy children (56 percent). Each increase in primary PM10 of 1.0 microg per cubic meter was associated with an increase of 0.10 microm2 (95 percent confidence interval, 0.01 to 0.18) in the carbon content of airway macrophages, and each increase of 1.0 microm2 in carbon content was associated with a reduction of 17 percent (95 percent confidence interval, 5.6 to 28.4 percent) in forced expiratory volume in one second, of 12.9 percent (95 percent confidence interval, 0.9 to 24.8 percent) in forced vital capacity, and of 34.7 percent (95 percent confidence interval, 11.3 to 58.1 percent) in the forced expiratory flow between 25 and 75 percent of the forced vital capacity. The carbon content of airway macrophages was lower in children with asthma than in healthy children. CONCLUSIONS: There is a dose-dependent inverse association between the carbon content of airway macrophages and lung function in children. We found no evidence that reduced lung function itself causes an increase in carbon content.

Adolescent↗

PubMed2004

Indoor air quality during renovation actions: a case study.

A temporary renovation activity releases considerably high concentrations of particulate matter, viable and non-viable, into air. These pollutants are a potential contributor to unacceptable indoor air quality (IAQ). Particulate matter and its constituents lead, sulfate, nitrate, chloride, ammonium and fungi as well as fungal spores in air were evaluated in a building during renovation action. Suspended dust was recorded at a mean value of 6.1 mg m(-3) which exceeded the Egyptian limit values for indoor air (0.15 mg m(-3)) and occupational environments (5 mg m(-3)). The highest particle frequency (23%) of aerodynamic diameter (dae) was 1.7 microm. Particulate sulfate (SO(4)(2-)), nitrate (NO(3)(-)), chloride (Cl(-)), ammonium (NH(4)(+)) and lead components of suspended dust averaged 2960, 28, 1350, 100 and 13.3 microg m(-3), respectively. Viable fungi associated with suspended dust and that in air averaged 1.11 x 10(6) colony forming unit per gram (cfu g(-1)) and 92 colony forming unit per plate per hour (cfu p(-1) h(-1)), respectively. Cladosporium(33%), Aspergillus(25.6%), Alternaria(11.2%) and Penicillium(6.6%) were the most frequent fungal genera in air, whereas Aspergillus(56.8%), Penicillium(10.3%) and Eurotium(10.3%) were the most common fungal genera associated with suspended dust. The detection of Aureobasidium, Epicoccum, Exophiala, Paecilomyces, Scopulariopsis, Ulocladium and Trichoderma is an indication of moisture-damaged building materials. Alternaria, Aureobasidium, Cladosporium, Scopulariopsis and Nigrospora have dae > 5 microm whereas Aspergillus, Penicillium and Verticillium have dae < 5 microm which are suited to penetrate deeply into lungs. Particulate matter from the working area infiltrates the occupied zones if precautionary measures are inadequate. This may cause deterioration of IAQ, discomfort and acute health problems. Renovation should be carefully designed and managed, in order to minimize degradation of the indoor and outdoor air quality.

Air Pollution, Indoor↗

PubMed1989

Mutagenicity of airborne particles from a nonindustrial town in Italy.

The mutagenic activity of airborne particulate matter collected in Pisa, a small nonindustrial town located in Italy, has been monitored over 1 year using the Ames Salmonella Test. Airborne particulate was collected on fibreglass filters using a Hi-Vol sampler and extracted by sonication and Soxhlet acetone extraction in sequence. TA 98 and TA 100 salmonella strains gave positive results with the great majority of samples. The mutagenicity trend fits with a harmonic regression with a peak during December/January and inversely correlates with the temperature. No correlations were observed with other meteorological conditions such as wind, cloud, rainfall, atmospheric pressure, and humidity. The ratio between mutagenicity/microgram of particulate matter with S9 and that without S9 remains more or less constant regardless of seasonal fluctuations, suggesting that during cold months quantitative increases of mutagens onto particulate matter have probably occurred. The comparison of air mutagenicity in different sites suggests that motor vehicle exhaust fumes are the major source of air pollution. Finally, because of high-traffic volume, air mutagenicity at street level is comparable to that observed in several metropolitan areas all over the world.

Air Pollutants↗

PubMed1995

Effects of Suspended Particulates on the Frequency of Transduction among Pseudomonas aeruginosa in a Freshwater Environment.

Transduction has been shown to play a significant role in the transfer of plasmid and chromosomal DNA in aquatic ecosystems. Such ecosystems contain a multitude of environmental factors, any one of which may influence the transduction process. It was the purpose of this study to show how one of these factors, particulate matter, affects the frequency of transduction. In situ transduction rates were measured in lake water microcosms containing either high or low concentrations of particulate matter. The microcosms were incubated in a freshwater lake in central Oklahoma. Transduction frequencies were found to be enhanced as much as 100-fold in the presence of particulates. Our results suggest that aggregations of bacteriophages and bacterial cells are stimulated by the presence of these suspended particulates. This aggregation increases the probability of progeny phages and transducing particles finding and infecting new host cells. Consequently, both phage production and transduction frequencies increase in the presence of particulate matter.

Journal Article↗

PubMed2005

Assessment of Godavari estuarine mangrove ecosystem through trace metal studies.

Trace metals (Fe, Mn, Cu, Co, Ni. Pb, Cd and Cr) analyses in particulate matter and sediments were carried out at 16 different stations in the Godavari mangrove ecosystem covering the three regions viz., Kakinada (KKD) bay, Goutami-Godavari estuary (GGE) and Coringa and Gaderu mangrove environments (CGME). Higher concentrations of trace metals in particulate matter and in sediments were noticed in the mangrove environment compared to the KKD bay and GGE region. The significant correlations observed between several couples of metals in different regions as well as between numbers of heavy metals (Fe, Mn, Zn) with Total Suspended Matter (TSM) in particulate organic matter could be an indication of the role of the complexation with organic matter in the distribution pattern of these metals. Further significant correlations between organic carbon (OC) and Cr, Co, Pb, Cu and Mn in sediments of all the three regions indicate that organic matter acts as a metal carrier. The values of Pollution Load Index (PLI) were low and varied between 0.34 and 0.68 in KKD bay, 0.47 and 0.49 in GGE and, from 0.62 to 1.03 in CGME area, which indicate that the estuarine ecosystem is not of pollution concern under the present scenario.

Avicennia↗

PubMed1996

Decreased Carbon and Nutrient Input to Boreal Lakes from Particulate Organic Matter Following Riparian Clear-Cutting

The plankton communities of oligotrophic Canadian Shield lakes are strongly regulated by the allochthonous supply of total phosphorus (TP) and dissolved organic carbon (DOC), a proportion of both of which originate from particulate organic matter. Although decreased inputs of allochthonous leaf litter have been documented for small streams whose riparian forests have been removed, no such data exist for boreal lakes. Through estimates of airborne litter input from forested and clear-cut shorelines and laboratory measurements of concentrations released from leaf leachate, we determined that riparian deforestation resulted in reductions of DOC from 17.8 to 0.4 g/m shoreline/yr and of TP from 2.9 to 0.3 g/m shoreline/yr. Previous predictive models indicate that such reductions may be substantial enough to decrease basic metabolic processes of lake plankton communities by as much as 9% in primary production and 17% in respiration.

Journal Article↗

PubMed2001

Number concentration and size of particles in urban air: effects on spirometric lung function in adult asthmatic subjects.

Daily variations in ambient particulate air pollution are associated with variations in respiratory lung function. It has been suggested that the effects of particulate matter may be due to particles in the ultrafine (0.01-0.1 microm) size range. Because previous studies on ultrafine particles only used self-monitored peak expiratory flow rate (PEFR), we assessed the associations between particle mass and number concentrations in several size ranges measured at a central site and measured (biweekly) spirometric lung function among a group of 54 adult asthmatics (n = 495 measurements). We also compared results to daily morning, afternoon, and evening PEFR measurements done at home (n = 7,672-8,110 measurements). The median (maximum) 24 hr number concentrations were 14,500/cm(3) (46,500/cm(3)) ultrafine particles and 800/cm(3) (2,800/cm(3)) accumulation mode (0.1-1 microm) particles. The median (maximum) mass concentration of PM(2.5) (particulate matter < 2.5 microm) and PM(10) (particulate matter < 10 microm in aerodynamic diameter) were 8.4 microg/m(3) (38.3 microg/m(3)) and 13.5 microg/m(3) (73.7 microg/m(3)), respectively. The number of accumulation mode particles was consistently inversely associated with PEFR in spirometry. Inverse, but nonsignificant, associations were observed with ultrafine particles, and no associations were observed with large particles (PM(10)). Compared to the effect estimates for self-monitored PEFR, the effect estimates for spirometric PEFR tended to be larger. The standard errors were also larger, probably due to the lower number of spirometric measurements. The present results support the need to monitor the particle number and size distributions in urban air in addition to mass.

Adult↗