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PubMed2000

Air pollution and daily mortality in three U.S. counties.

I used generalized additive models to analyze the time-series of daily total nonaccidental and cause-specific (cardiovascular, cerebrovascular, and chronic obstructive pulmonary disease) deaths over the period 1987-1995 in three major U.S. metropolitan areas: Cook County, Los Angeles County, and Maricopa County. In all three counties I had monitoring information on particulate matter [less than/equal to] 10 microm (PM(10)), carbon monoxide, sulfur dioxide, nitrogen dioxide, and ozone. In Los Angeles, monitoring information on particulate matter [less than/equal to] 2.5 microm (PM(2.5)) was available as well. I present the results of both single and multi-pollutant analyses. Air pollution was associated with each of the mortality end points. With respect to the individual components of the pollution mix, the results indicate considerable heterogeneity of air pollution effects in the different geographic locations. In general, the gases, particularly CO, but not ozone, were much more strongly associated with mortality than was particulate matter. This association was particularly striking in Los Angeles County.

Air Pollutants↗
PubMed1986

Particulate and microbial contamination of intraocular irrigation solutions.

The risk of anterior chamber microbial or particulate contamination or both during extracapsular cataract extraction has increased because of the need for large volumes of irrigating solution during the procedure. I performed a clinical trial using an in-line microfiltration apparatus fitted with a 0.8 micron filter. After passing 500 ml volume bottles of each of six manufacturers' irrigating solutions through individual filters, a variety of particulate matter was observed to be trapped by the filter. In addition, I had samples of 500 ml bottles from each of seven manufacturers' irrigating solutions analyzed independently. This independent analysis involved the determination of particulate counts by Coulter counter analysis and photographic documentation of the particulate matter found in the samples. All the solutions were found to contain some particulate matter. The quantity found ranged from as few as 20 particles per ml to as many as 2,400 particles per ml. The results of this study support the use of an in-line microfiltration apparatus during planned extracapsular and phacoemulsification cataract surgery.

Bacteria↗
PubMed2000

Increase of anaerobic degradation of particulate organic matter in full-scale biogas plants by mechanical maceration.

Different concepts of implementation of mechanical pretreatment for enhancing the biogas potential from fibers in manure feedstock were evaluated by sampling before and after macerators at different biogas plants and from a fiber separation unit. An increase of the biogas potential of up to 25% by pretreatment of the whole feed in the macerator before the reactor was observed. Implementation concepts with a treatment of the fibers alone after separation from the manure showed to be not efficient due to a low recovery of organic matter in the fibers by the separation unit. The low operational costs of a macerator make it attractive to use this pretreatment method for a more complete degradation of particulate organic matter. Investigation of the size distribution of the fibers showed that a change in biogas potential was not correlated to a smaller size of the fibers. Results from the macerators indicate that the biodegradability of the fibers is rather enhanced by shearing which is not necessarily reflected by a change in fiber size.

Bacteria, Anaerobic↗
PubMed1979

Summary of measurements of employee exposure to airborne dust and fiber in sixteen facilities producing man-made mineral fibers.

The results of an industry-wide study to determine the exposure of workers to man-made mineral fibers are summarized. The purpose of the study was to determine current employee exposures to airborne fibers and to utilize results to estimate past exposures. Measured exposures of workers to airborne total particulate matter and fibers are presented; samples were evaluated by phase contrast and electron microscopy. Results of the three year study, which encompassed 16 facilities and over 1500 eight hour samples, show that although there is a wide variation in concentrations of airborne fibers and particulate matter between and within the facilities surveyed, the concentrations of airborne particulate matter and fibers are generally less than 2.5 mg/m3 and 0.5 fibers/cm3, respectively. The norminal fiber size of the fibers manufactured and average airborne fiber concentration were highly correlated.

Air Pollutants↗
PubMed2006

Chemical mass balance source apportionment of PM10 and TSP in residential and industrial sites of an urban region of Kolkata, India.

Daily average PM(10) (particulate matter which passes through a size selective impactor inlet with a 50% efficiency cut-off at 10 microm aerodynamic diameter), TSP (total suspended particulate matter) and their chemical species mass concentrations were measured at residential and industrial sites of an urban region of Kolkata during November 2003-November 2004. Source apportionment using chemical mass balance model revealed that the most dominant source throughout the study period at residential site was coal combustion (42%), while vehicular emission (47%) dominates at industrial site to PM(10). Paved road, field burning and wood combustion contributed 21%, 7% and 1% at residential site, while coal combustion, metal industry and soil dust contributed 34%, 1% and 1% at industrial site, respectively, to PM(10) during the study period. The contributors to TSP included coal combustion (37%), soil dust (19%), road dust (17%) and diesel combustion (15%) at residential site, while soil dust (36%), coal combustion (17%), solid waste (17%), road dust (16%) and tyre wear (7%) at industrial site. Significant seasonal variations of the particulate matters have been observed during the study period. In the monitoring sites total carbon, organic carbon and iron were found to be the marker species of road dust, while organic carbon, total carbon, chloride and sulfate have been observed as the marker species of soil dust in TSP.

Air Pollutants↗
PubMed2005

Impact of ambient air pollution on birth weight in Sydney, Australia.

BACKGROUND: Studies in Asia, Europe, and the Americas have provided evidence that ambient air pollution may have an adverse effect on birth weight, although results are not consistent. METHODS: Average exposure during pregnancy to five common air pollutants was estimated for births in metropolitan Sydney between 1998 and 2000. The effects of pollutant exposure in the first, second, and third trimesters of pregnancy on risk of "small for gestational age" (SGA), and of pollutant exposure during pregnancy on birth weight were examined. RESULTS: There were 138,056 singleton births in Sydney between 1998 and 2000; 9.7% of babies (13,402) were classified as SGA. Air pollution levels in Sydney were found to be quite low. In linear regression models carbon monoxide and nitrogen dioxide concentrations in the second and third trimesters had a statistically significant adverse effect on birth weight. For a 1 part per million increase in mean carbon monoxide levels a reduction of 7 (95% CI -5 to 19) to 29 (95% CI 7 to 51) grams in birth weight was estimated. For a 1 part per billion increase in mean nitrogen dioxide levels a reduction of 1 (95% CI 0 to 2) to 34 (95% CI 24 to 43) grams in birth weight was estimated. Particulate matter (diameter less than ten microns) in the second trimester had a small statistically significant adverse effect on birth weight. For a 1 microgram per cubic metre increase in mean particulate matter levels a reduction of 4 grams (95% CI 3 to 6) in birth weight was estimated. CONCLUSION: These findings of an association between carbon monoxide, nitrogen dioxide, and particulate matter, and reduction in birth weight should be corroborated by further study.

Air Pollutants↗
PubMed1981

Particulate evaluation of parenteral nutrition solutions by electronic particle counting and scanning electron microscopy.

The particulate matter contamination of four commercial parenteral nutrition solutions that contained high concentrations of amino acids and dextrose was evaluated. Electron particle counting and scanning electron microscopy (SEM) were used to evaluate the amount of particulate matter over a 24-hour-period. The effect of adding 10 meq calcium and 20 meq phosphate electrolytes on the particulate content of these four solutions was determined also. Both counting methods agreed in the rank order comparison of particulate contamination, in that the Abbott and Travenol solutions contained the fewest particles while the Cutter solutions contained the most. The addition of calcium and phosphate resulted in at least a 50% increase in the mean particle count of all solutions. The SEM analysis showed the mean presence of microscopically large, yet subvisible, particles in the solutions containing phosphate and calcium. All of the solutions followed a previously published relationship between particle number and size. Although all of the solutions contained particulate matter, even the solutions with calcium and phosphate contained fewer particles than allowable by the USP-NF standard.

Drug Contamination↗
PubMed2005

Importance of the personal endotoxin cloud in school-age children with asthma.

BACKGROUND: A number of studies have observed associations between the amount of endotoxin in urban dust and chronic asthma severity, but a direct relationship between personal exposure to household endotoxin and acute asthma worsening has not yet been defined. OBJECTIVE: We sought to investigate the relationship between day-to-day changes in personal endotoxin exposure and asthma severity. METHODS: In the winter and spring of 1999 through 2000, endotoxin exposures were monitored in asthmatic schoolchildren by using portable, as opposed to stationary, monitors designed to measure inhalable and respirable particulate matter less than or equal to 2.5 and 10 microm in diameter. Children were followed with daily measurements of FEV(1) and asthma symptoms. RESULTS: Over a 24-hour period, median daily personal endotoxin exposures ranged from 0.08 EU/m(3) (measured at a particulate matter size range </=2.5 microm in diameter) to 0.37 EU/m(3) (measured at a particulate matter size range </=10 microm in diameter). Personal exposures were significantly (P < .001) higher than endotoxin measurements from either indoor or outdoor stationary monitors. Moreover, individual exposures did not correlate with stationary measurements, suggesting that exposures derived from sources in close proximity to the children's personal activities might be better correlated with disease severity. Increases in personal endotoxin exposures were associated with decreased FEV(1) values and increased symptoms. CONCLUSIONS: These findings demonstrate the importance of using personal monitoring to both measure and correlate endotoxin exposure with asthma severity.

Air Pollutants↗
PubMed2005

Influence of algal and bacterial particulate organic matter on benzo[a]pyrene bioaccumulation in Daphnia magna.

In order to better asses the influence of organic matter on the bioavailability of hydrophobic organic contaminants, the effect of algae and POM of bacterial origin on the bioaccumulation of benzo[a]pyrene in Daphnia magna was evaluated. The bioaccumulation was monitored with increasing concentrations of particulate organic matter (POM) and dissolved organic matter (DOM). In all experiments, the presence of POM greatly reduced the bioaccumulation of benzo[a]pyrene. The reduction was more pronounced in the presence of algae, for which we observed a 99%-reduction effect in the presence of 6 x10 (5) cell/mL (equivalent to 5.3 mg C/L). The bioaccumulation of benzo[a]pyrene was decreased by 49% by organic matter of bacterial origin at 4.7 mg C/L. Assuming that benzo[a]pyrene was partitioned between water, DOM and POM and supposing that D. magna accumulated free benzo[a]pyrene via respiration and POM-bond benzo[a]pyrene via ingestion, bioaccumulation data allowed to estimate the dietary uptake rate of benzo[a]pyrene as well as partitioning coefficients K(POC) and K(DOC). Despite the ingestion of contaminated particles, we could not observe any dietary uptake of benzo[a]pyrene in daphnids. We verified, as usually supposed, that the bioaccumulation of benzo[a]pyrene to D. magna occurs mainly via direct contact. Very high partitioning coefficients (log K(POC) between 5.2 and 6.2) were estimated. This study pointed out the great influence of biogenic organic matter on the fate and the bioavailability of benzo[a]pyrene in aquatic ecosystems.

Animals↗
PubMedDate not supplied

[Suspense-dust-, lead- and benzpyrene emissions in the city of Zurich].

Levels of particulate matter, lead and benzo(a)pyrene were measured during 1971--1976 at different monitoring stations in Zurich. Annual averages in city proper ranged between 90 and 180 microgram/m3 for particulate matter, 2 and 3 microgram/m3 for lead and between 6 and 7 ng/m3 for benzo(a)pyrene. Corresponding values for the suburbs as well as for the village of Netstal were about 1/3 to 1/2. Winter levels were higher than the summer ones at all the sites. These differences were more obvious in case of calms. Ambient concentrations of particulate matter and lead measured in the city center were similar to those measured in german cities and were in the same range as air quality standards. Primary attention should be paid to the reduction of emissions, as surveillance of space heating and incineration equipment, and the reduction of lead in fossil fuels.

Air Pollution↗
PubMed2004

Measurement of contemporary and fossil carbon contents of PM2.5 aerosols: results from Turtleback Dome, Yosemite National Park.

The impact of aerosol particulate matter of mean mass aerodynamic diameter < or = 2.5 microm (PM2.5 aerosols) on health, visibility, and compliance with the U.S. EPA's regional haze regulations is a growing concern. Techniques that can help better characterize particulate matter are required to better understand the constituents, causes, and sources of PM2.5 aerosols. Measurement of the 14C/C ratio of the PM2.5 aerosols, the absence of 14C in fossil carbon materials, and the known 14C/C levels in contemporary carbon materials allow the use of a two-component model to derive contemporary and fossil carbon contents of the particulate matter. Such data can be used to estimate the relative contributions of fossil fuels and biogenic aerosols to the total aerosol loading. Here, the methodology for performing such an assessment using total suspended particulate hi-vol aerosol samplers to collect PM2.5 aerosols on quartz fiber filters and the technique of accelerator mass spectrometry to measure 14C/C ratios is presented and illustrated using PM2.5 aerosols collected at Yosemite National Park.

Aerosols↗
PubMed2005

Particle size distribution and atmospheric metals measurements in a rural area in the South Eastern USA.

Atmospheric particle mass concentrations were measured at a site adjacent to Lake Hartwell, GA, during six dry sampling events in February-March 2003. The overall average PM2.5 mass concentration was 9.5 microg/m3 and the overall average total suspended particles mass concentration was 19.1 microg/m3. Particulate matter was collected on a deposition plate mounted onto a specially designed wind vane and was subsequently analyzed to determine the particle size distribution. The average geometric particle diameter was found to be 2.8 microm. Particulate matter collected was found to be closely approximately at log-normal distribution, with a count median diameter of 1.5 mum and a geometric standard deviation of 1.8. Individual metal concentrations present in airborne particulate matter were determined for cadmium, chromium, copper, iron, lead, manganese, nickel, and zinc using inductively coupled plasma-mass spectrometry analysis of samples collected on Teflon filters. Ambient metal concentrations were found to range from 0.8 ng/m3 for cadmium to 512 ng/m3 for iron. The dry deposition flux of metals was estimated to be in the range of 0.17 mg/(m2 year) for cadmium to 102 mg/(m2 year) for iron. More samples need to be collected and analyzed, both temporally and spatially, in order to establish atmospheric metals fluxes onto surfaces.

Air↗
PubMed2001

Direct ultrasonic agitation for rapid extraction of organic matter from airborne particulate.

Direct ultrasonic extraction (DUE) is proposed as simple and rapid sample pretreatment method. This new approach is applied to the extraction of particulate organic matter (POM) from airborne particulate by using dichloromethane (DCM) or DCM/methanol (90/10, v/v) as extractant. The analytical determination was carried out by weighing the extractable POM on an electrobalance. Total recovery for POM could be obtained when the sample was extracted three times with 25-50 mL extractant each for about 5 min at 50 W ultrasonic power. In comparison with conventional Soxhlet extraction, less extraction time (total 15 min only) and solvent consumption (100 mL) were required by DUE. The efficiency of the DUE was similar or even higher than the routine Soxhlet method. Additionally, the new extractor is very simple and easy to use and can accelerate the extraction procedures of organic components from various solid samples.

Air↗
PubMed1997

[Respiratory symptoms and cough reflex in populations exposed to different degrees of environmental pollution].

BACKGROUND: Santiago is a city with a high degree of environmental pollution caused by particulate matter and ozone, producing adverse effects in the respiratory system. AIM: To compare respiratory symptoms and cough reflex in adults from Santiago and from a rural area with low levels of environmental pollution. SUBJECTS AND METHODS: One hundred twenty six non-smoker adults from Santiago and 116 from a rural area with low levels of pollution answered a respiratory symptom questionnaire. Of these 101 subjects from Santiago and 116 from the rural area inhaled doubling concentrations of capsaicin from 0.5 to 500 microM or until five coughs were elicited. The lowest concentration eliciting 2 or more coughs (CD2) or 5 or more coughs (CD5) was recorded. Levels of environmental particulate matter were also recorded in both locations. RESULTS: Levels of particulate matter were 102 +/- 41 and 64 +/- 24 micrograms/m3 in Santiago and the rural area respectively. People from Santiago had higher rates of throat clearing, cough and phlegm. CD2 geometric mean and confidence limits in Santiago and the rural area were 6.9 (5.2-7.4) and 2.8 (2.7-2.9) respectively (p < 0.001). No differences in CD5 were observed between both locations. Multivariate analysis disclosed the variable location (city) as the only independent predictor of respiratory symptoms. CONCLUSIONS: The increased CD2 found in Santiago suggests that the higher rates of respiratory symptoms related to air pollution can be associated to a decreased sensitivity of the cough reflex.

Adolescent↗
PubMed1996

Comparing the presence, potency, and potential hazard of genotoxins extracted from a broad range of industrial effluents.

We examined the genotoxicity of dichloromethane extracts from 50 final effluent samples collected from 42 industries, including pulp and paper, chemical manufacturing, metal refining, metal surface treatment, and municipal waste water treatment. Effluents were initially fractionated into dissolved substances, and substances adsorbed to suspended particulate matter. Acid/base partitioning was used to further fractionate aqueous extracts. Genotoxicity of extracts was found to be related to sample type, industry type, metabolic activation status, and extract fluorescence (380 nm excitation, 430 nm emission). S9 metabolic activation reduced genotoxic potency in over 90% of the extracts examined. Expression of potency values per equivalent unit of original sample revealed that effluent particulate matter is, on average, almost four orders of magnitude more potent than aqueous filtrates. Suspended particulate matter from organic and inorganic chemical production, petroleum and metal refining, and from metal surface treatment facilities, provided extracts that were significantly more genotoxic than those from sewage treatment and pulp and paper facilities. Aqueous filtrates from inorganic and organic chemical production, metal refining, and surface treatment facilities were significantly more genotoxic than those emitted by aluminum and petroleum refineries. Overall, the results suggest that pulp and paper mills emit mostly soluble genotoxins, while petroleum and aluminum refineries emit predominantly particle-associated genotoxins. Although some extracts elicited a strong SOS response, the potency of the extractable residues was low when compared to highly potent pure substances such as benzo(alpha) pyrene. On average, a mg of dichloromethane-extractable residue has an SOS genotoxicity equivalent to 0.1-1.0 microg of benzo(alpha) pyrene. Predicted Ames mutagenic potency values corresponded reasonably well with industrial waste mutagenic potency values corresponded reasonably well with industrial waste mutagenic potency values published by other researchers. Genotoxic loading values were calculated to quantify the total daily genotoxic emission and potential hazard of each industry. Highest loadings were from sewage treatment, pulp and paper, and metal refining facilities. Highest loading values were the SOS genotoxic equivalent of over 30 kg of benzo(alpha)pyrene per day. The ultimate hazard of genotoxic emissions is not known. Actual hazard assessment is complicated by a poor understanding of the postemission behavior of genotoxins. Exposure of downstream biota is likely substantial.

Analysis of Variance↗
PubMedDate not supplied

Determination of exposure to environmental tobacco smoke in restaurant and tavern workers in one US city.

Approximately 173 subjects employed as waiters, waitresses, or bartenders in the Knoxville, TN, Standard Metropolitan Statistical Area collected a sample of air from their breathing zone while at their workplace for one shift. In addition, area samples were placed near the work spaces of many of the subjects. Collected samples were analyzed for respirable suspended particulate matter (RSPM), ultraviolet-absorbing and fluorescing particulate matter, solanesol, 3-ethenyl pyridine (3-EP), and nicotine. Saliva samples were collected from the subjects prior to and within 24 h following their work shift, to confirm their non-smoking status. The range of concentrations of environmental tobacco smoke (ETS) constituents encountered was considerable, e.g., for nicotine, from undetectable to more than 100 microg/m3. However, the highest RSP levels observed were considerably lower than OSHA workplace standards. Distributions of ETS concentrations suggest that there are two "ETS exposure" types of bartenders: those that work in single room bars and those that work in larger, multiroom restaurant/bars. Personal exposure to ETS of the former group was ca. 10x greater than those of the latter group, who were exposed to ETS levels more comparable to those encountered by wait staff. Exposure (concentration x duration) differences between wait staff and workers in other types of unrestricted smoking environments reported in other studies suggest that exposures in the restaurant environment may be more difficult to assess than originally considered. Salivary cotinine levels indicated that for those subjects living in smoking homes, ETS exposures outside the workplace are at least as important as those in the workplace.

Adolescent↗
PubMed1993

Quantitative assessment of cancer risk from exposure to diesel engine emissions.

Quantitative estimates of lung cancer risk from exposure to diesel engine emissions were developed using data from three chronic bioassays with Fischer 344 rats. Human target organ dose was estimated with the aid of a comprehensive dosimetry model. This model accounted for rat-human differences in deposition efficiency, normal particle clearance rates, transport of particles to lung-associated lymph nodes, respiration rates, and lung surface area, as well as high-dose inhibition of particle clearance. Recent evidence indicates that the inert carbon core of the diesel particulate matter is likely to be the primary source of carcinogenicity. The epithelial tissue lining the alveoli and lower airways is the primary target site for induction of lung tumors. Dose was therefore based upon the concentration of carbon particulate matter per unit lung surface area. Unit risk estimates were developed using either a time-to-tumor or a linearized multistage model. The unit risk estimates, defined as the 95% upper confidence limit of the cancer risk from continuous lifetime exposure to 1 microgram/m3 of diesel exhaust particulate matter, varied from 1.0 to 4.6 x 10(5) with a geometric mean of 1.7 x 10(5).

Animals↗