Particulate Air Contaminants Research Articles

An analysis of vehicular exhaust derived nanoparticles and historical Belgium fortress building interfaces

Air pollution monitoring is one of the most important features in contamination risk management. This is because many of the compounds contained within air pollution present a serious risk both for the preservation of open air cultural heritage and for human health. New particle formation is a major contributor to urban pollution, but how it occurs in cities is often puzzling. As more and more people enjoy an increased quality of life through outdoor activity, managing outdoor air quality is vital. This study presents the application of a low-cost system for monitoring the current level of road traffic passengers’ exposure to particulate air contamination. The global rise in tourism also leads to apprehension about its probable destructive influence on various aspects of global preservation. One of the major risks encountered by tourists, stemming from modes of transport, are nanoparticles (NPs) (≤100 ​nm) and ultra-fine particles (UFPs) (100–1000 ​nm) consisting of potentially hazardous elements (PHEs). This study examines Steen Castle, a medieval fortress located in Antwerp, Belgium. Significant NPs with PHEs, were found in the air sampled in this area. The self-made passive sampler (LSPS) described in this study, consisting of retainers specially designed for advanced microscopic analysis, is used for the first time as a simple way to characterize the surrounding atmospheric contamination caused by NPs and UFPs, without the need of other commonly employed more expensive particulate focused active samplers such as cascade impactors. This study aims to assess the result of the utilization of a low-cost, LSPS, to determine outdoor NPs and UFPs in a Belgian urban (Steen Castle) and rural area (Fort van Schoten). This work is the first to detail the usefulness of LSPS for the evaluation of Belgium’s outdoor air for NPs and UFPs, which contain PHEs.

Stochastic environmental research risk assessment

In a briefly approach, sustainability can be defined as the ability to achieve economic prosperity while protecting the natural systems of the planet, and providing a higher quality of life for its people. Nowadays it is a prime and very active area of research, fundamental for human development. Several concepts based on economics, social and environmental concerns have been considered in the development of sustainability indices. The sustainability concept is, not only but necessarily, dependent on “quantification of the environment health”, necessary to determine its effectiveness in achieving or increasing the environmental capacities of ecosystems, as well as to compare alternative plans and policies, to influence decision-makers. Environmental indices are a very important tool for the analysis of some environmental assessment factors, providing quantitative criteria and synthesizing the available information. A good index should be simple to use, transparent, and expandable across other issues. In particular, environmental indices are a useful tool for several audiences, to aid environmental decision making and to allow the media to keep score of and reduce complex information to a smaller, more easily retained, amount of information [Hardi, P., DeSouza-Huletey, J.A., 2000. Issues in analyzing data and indicators for sustainable development. Ecol. Model. 130, 59–65]. The goal of this work is the development of environmental indices, based on stochastically simulated scenarios, using probabilistic approaches. This study was applied to assess the impact of particulate air contamination on the Setúbal Peninsula ecosystems (South of Lisbon, Portugal).

Sources of Fine Particulate Species in Ambient Air over Lake Champlain Basin, VT

This study is a part of an ongoing investigation of the types and locations of emission sources that contribute fine particulate air contaminants to Underhill, VT. The air quality monitoring data used for this study are from the Interagency Monitoring of Protected Visual Environments network for the period of 2001–2003 for the Underhill site. The main source-receptor modeling techniques used are the positive matrix factorization (PMF) and potential source contribution function (PSCF). This new study is intended as a comparison to a previous study of the 1988–1995 Underhill data that successfully revealed a total of 11 types of emission sources with significant contributions to this rural site. This new study has identified a total of nine sources: nitrate-rich secondary aerosol, wood smoke, East Coast oil combustion, automobile emission, metal working, soil/dust, sulfur-rich aerosol type I, sulfur-rich aerosol type II, and sea salt/road salt. Furthermore, the mass contributions from the PMF identified sources that correspond with sampling days with either good or poor visibility were analyzed to seek possible correlations. It has been shown that sulfur-rich aerosol type I, nitrate aerosol, and automobile emission are the most important contributors to visibility degradation. Soil/dust and sea salt/road salt also have an added effect.

Time Variant Exposure Analysis (TVEA): A Measurement Tool for Characterizing Particulate Exposure Determinants in Construction

A work sampling-based approach, time variant exposure analysis (TVEA), was developed for assessment of determinants for particulate air contaminants in dynamic construction environments. To use TVEA, the field researcher records observations at fixed intervals to systematically survey over 30 potential determinants that could affect exposure to three types of particulate matter: quartz-containing dusts, diesel exhaust, and a general grouping of “other particles” that includes welding fume and wood dust. Two field studies were conducted to address questions of inter-rater reliability (n = 20) and coding interval appropriateness (n = 21) for the TVEA method. At least substantial inter-rater agreement (kappa > 0.60) was obtained for the TVEA variables related to tool or machine use, process, material, source intensity, and source orientation. Kappa values for source direction (0.22–0.38) and number of sources (0.38–0.60) showed comparatively lower agreement for all particulate types. Observation interval appropriateness was analyzed using linear regression to compare a 5-min observation interval “gold standard” with alternate intervals. Regression statistics indicated that while 30 min is an acceptable interval for exposure assessment, 15 min optimizes precision and practicality by ensuring that 95% of all observations differ less than ten percentage points from the “true” values. TVEA is a useful exposure assessment tool for the dynamic construction environment. It is flexible in that only those determinants that are of interest need be coded and the coding interval can be adjusted to accommodate the level of precision desired.

Reductions in volatile organic compounds, aldehydes, and particulate air contaminants in an IVF laboratory by centralized and stand-alone air filtration systems

To determine the effects of a dedicated central air-handling system and a stand-alone air filtration system on volatile organic compounds (VOC), aldehydes, and particulate concentrations in an IVF laboratory. Prospective, descriptive measurements of air quality. The IVF laboratory at Albany IVF is supplied by a dedicated central air-handling system which includes HEPA filtration, and high-activity charcoal and potassium permanganate filters. The hallway outside of the laboratory is supplied by an unfiltered air system. The central air-handling system in the laboratory was turned off and the air vents and doors to the laboratory were sealed with plastic sheeting. Base-line air samples were then taken in the hallway and the laboratory over 4 hours for the determination of VOC, aldehydes and particulates. A free-standing air-filtration system (Coda Tower, IVFonline/genX) was installed in the laboratory for 24 hours, and the air in the laboratory was again sampled. Air samples were analyzed for VOC by cryoconcentrated gas chromatography/mass spectrometry, and for aldehydes by high-performance liquid chromatography. The size and number of particulates were determined by dispersion of laser light. A total of 28 VOC and 6 aldehydes, were detected in the baseline samples taken from the hallway and the laboratory. Of these, 24 were at lower concentration in the laboratory, 9 were at higher concentration in the laboratory, and one was at the same concentration in the hallway and laboratory. Total baseline particulate concentrations were 2.8 times higher in the laboratory than in the hallway. After 24 hours of operation of the Coda Tower, the concentrations of 14 VOC and 6 aldehydes in the laboratory decreased (range 13 to 100%), the concentrations of 4 were unchanged, and the concentrations of 3 (acetonitrile, dichlorodifluoromethane (CFC 12), and n-heptane) increased. The concentrations of six size classes of particulates in the laboratory decreased (range 37 to 98%) during the 24 hours of operation of the Coda Tower. The results indicate that a dedicated central air-handling system can reduce the concentrations of VOC, aldehydes, and particulates in an IVF laboratory. However, the Coda Tower produced further decreases in the concentrations of VOC, aldehydes, and particulates. The increase in the concentration of acetonitrile in the laboratory was probably due to off-gassing from the plastic sheeting used to seal the air vents and doors. These results suggest that a stand-alone air treatment system can improve air quality over that produced by a dedicated central air-handling system.

The Effect of Inhalation Resistance on Facepiece Leakage

Air purifying respirators use filters to remove particulate air contaminants. Resistance to airflow generally increases as the filter loads and a “filter cake” is formed. It has been recommended by ANSI and the Occupational Safety and Health Administration that filters should be replaced when the wearer notices they are hard to breathe through. Repeated faceseal leak rate measurements were made during respirator wear over a range of simulated breathing resistances from 5.6 to 19.6 mm (0.22 to 0.77 inches) of water. The measured faceseal leak rates increased as the breathing resistance increased and varied depending on the initial leak rate at the 5.6 mm pressure. The increase in faceseal leak rate from 5.6 to 19.6 mm breathing resistance was as high as a factor of 4. Theoretically, a person with an initial respirator penetration of 2.5% could have that value increase to 10% as filter loading increased breathing resistance by 14 mm. Some research has shown that breathing resistances between 60 and 140 mm of water would be “noticeable but well tolerated.” It is not known if workers would be able to detect an increase in breathing resistance that would lead to a significant increase in faceseal leakage. These data suggest a need to establish a replacement schedule for all filters used in the workplace. How often a filter should be replaced is difficult to determine. Breathing resistance would vary depending on the individual filter and aerosol loading characteristics, the concentration of the aerosol in the workplace, and breathing rates.

The Effect of Inhalation Resistance on Facepiece Leakage

Air purifying respirators use filters to remove particulate air contaminants. Resistance to airflow generally increases as the filter loads and a “filter cake” is formed. It has been recommended by ANSI and the Occupational Safety and Health Administration that filters should be replaced when the wearer notices they are hard to breathe through. Repeated faceseal leak rate measurements were made during respirator wear over a range of simulated breathing resistances from 5.6 to 19.6 mm (0.22 to 0.77 inches) of water. The measured faceseal leak rates increased as the breathing resistance increased and varied depending on the initial leak rate at the 5.6 mm pressure. The increase in faceseal leak rate from 5.6 to 19.6 mm breathing resistance was as high as a factor of 4. Theoretically, a person with an initial respirator penetration of 2.5% could have that value increase to 10% as filter loading increased breathing resistance by 14 mm. Some research has shown that breathing resistances between 60 and 140 mm of water would be “noticeable but well tolerated.” It is not known if workers would be able to detect an increase in breathing resistance that would lead to a significant increase in faceseal leakage. These data suggest a need to establish a replacement schedule for all filters used in the workplace. How often a filter should be replaced is difficult to determine. Breathing resistance would vary depending on the individual filter and aerosol loading characteristics, the concentration of the aerosol in the workplace, and breathing rates.

The Effect of Inhalation Resistance on Facepiece Leakage

Air purifying respirators use filters to remove particulate air contaminants. Resistance to airflow generally increases as the filter loads and a "filter cake" is formed. It has been recommended by ANSI and the Occupational Safety and Health Administration that filters should be replaced when the wearer notices they are hard to breathe through. Repeated faceseal leak rate measurements were made during respiratory wear over a range of simulated breathing resistances from 5.6 to 19.6 mm (0.22 to 0.77 inches) of water. The measured faceseal leak rates increased as the breathing resistance increased and varied depending on the initial leak rate at the 5.6 mm pressure. The increase in faceseal leak rate from 5.6 to 19.6 mm breathing resistance was as high as a factor of 4. Theoretically, a person with an initial respirator penetration of 2.5% could have that value increase to 10% as filter loading increased breathing resistance by 14 mm. Some research has shown that breathing resistances between 60 and 140 mm of water would be "noticeable but well tolerated." It is not known if workers would be able to detect an increase in breathing resistance that would lead to a significant increase in faceseal leakage. These data suggest a need to establish a replacement schedule for all filters used in the workplace. How often a filter should be replaced is difficult to determine. Breathing resistance would vary depending on the individual filter and aerosol loading characteristics, the concentration of the aerosol in the workplace, and breathing rates.

粒子状大気汚染物質の発生源同定と寄与率の推定

粒子状大気汚染物質の発生源同定と寄与率の推定

Advances in instrumentation for atmospheric aerosol measurement

Instruments for airborne particle sampling and measurement are important tools for the study of particulate air contaminants. As such they are important in air quality, air pollution and industrial hygiene studies. Particle measuring instruments are important also for various industrial processes, such as clean room monitoring and contaminant measurement in clean process gases used in semiconductor manufacturing. This paper reviews the advances in particle measuring and sampling instruments, with particular emphasis on instruments for atmospheric studies. Devices for particle generation needed for instrument calibration and experimental purposes are also covered in this review.

Particle Size-Selective Sampling in Establishing Threshold Limit Values

Abstract The principal deposition and retention sites of inhaled particulate air contaminants are governed by particle aerodynamic size and are critical factors in the nature and severity of resulting injury or disease. Inhaled substances may deposit in the alveolar or gas exchange region, in the thoracic conducting airways or tracheobronchial region, and/or in the oral pharynx or nasopharyngeal region (mouth or nose breathing). Examination of specific air contaminants and specific diseases associated with particular regions of the respiratory tract indicates that size-selective sampling is critical to a meaningful evaluation of the inhalation hazard to the worker. Different particle size distributions of the same contaminant will cause major changes in deposition in different regions of the respiratory tract, markedly changing the relative quantity of material deposited within the region and so determining the probability and nature of the associated disease processes. A procedure for determining particl...

Photoperiod and cell mediated immunity of clinically normal dogs

Abstract Previously, the authors have reported seasonal variations in cell mediated immunity in the dog during the period July, 1977 ‐ October 1978 as measured by whole blood lectin‐induced lymphocyte transformation. Peak activity occurred in the summer, suggesting association with photoperiodicity. Here the authors report on immune response of dogs kept indoors ‐ under controlled physical environment ‐ with a natural (outdoor) photoperiod or under a 12:12 h (LD) regime, and a control group kept in outdoor kennels. Peak immune activity in 1979 occurred in the winter, in both indoor groups as well as the outdoor groups subject to natural photoperiod. Since the indoor dogs were kept at a constant temperature and humidity in clean (filtered) air, photoperiod, temperature, and particulate air contaminants probably are not associated with seasonal variations in immunity. The underlying cause for either the seasonal variations or the shift from peak activity in the summer of 1978 to winter of 1979 is unknown. D...

Particulate air contamination in Puerto Rico: A student involvement project

The results of a 114-day study of the air pollution in Ponce, Puerto Rico are presented. Techniques of instrument calibration and statistical analysis are also discussed. (AIP)

Identification and quantitative analysis of particulate air contaminants by x-ray diffraction spectrometry.

Because of the synergistic effects which take place from the mixing of gases and particulates in ambient air, it is important that the determination of air contaminants be carried out on the sample in its native state without imposing any further chemical recombination during the analysis. Since x-ray diffraction provides a chemically passive method of analysis and yields molecular rather than elemental information, we have undertaken the siudy of, and have successfully employed crystal diffraction lines as a qualitative and quantitative means for determining such materials as lime, calcium carbonate, road salt, coke dust, and aerosol from sinter emissions as well as several other less common industrial particulates in samples obtained from dustfall as dispersed in a matrix of powdered amorphous glass. Correlative to the above investigation this method was also extended to the study of such gases as sulfur dioxide which may be selectively fixed to an active surface.

A quantitative study of full crown preparation debris

A laboratory study was designed to sort and quantitate the dental aerosol cloud created during ten full crown preparation precedures with the use of a tapered diamond stone as the cutting instrument in the air-turbine handpiece. The quantitative evaluation presents data that may be useful in predicting hazardous levels of particulate air contamination in dental or clinical operatories.

Activation Analysis of Particulate Air Contaminants

A procedure is described for the activation analysis of particulate air contaminants collected on filter papers. Results are included from the identification of several radioactive species in a series of samples. The samples, together with a filter paper control, were irradiated in a reactor. Measurements of BETA activity were made with a proportional counter and gamma activities were measured with a pulse height analyzer equipped with a scintillation detector. Some samples were also analyzed with a multichannel analyzer. Data are included on the activation history of the samples and the radioisotopes identified. (C.H.)