Particulate matter emissions of different brands of mentholated cigarettes

Inhaling particulate matter (PM) in environmental tobacco smoke (ETS) endangers the health of nonsmokers. Menthol, an additive in cigarettes, attenuates respiratory irritation of tobacco smoke. It reduces perceptibility of smoke and therefore passive smokers may inhale ETS unnoticed. To investigate a possible effect of menthol on PM concentrations (PM₁₀, PM_2.5, and PM₁), ETS of four mentholated cigarette brands (Elixyr Menthol, Winston Menthol, Reyno Classic, and Pall Mall Menthol Blast) with varying menthol content was analyzed. ETS was generated in a standardized way using an automatic environmental tobacco smoke emitter (AETSE), followed by laser aerosol spectrometry. This analysis shows that the tested cigarette brands, despite having different menthol concentrations, do not show differences with regard to PM emissions, with the exception of Reyno Classic, which shows an increased emission, although the menthol level ranged in the midfield. More than 90% of the emitted particles had a size smaller than or equal to 1 µm. Regardless of the menthol level, the count median diameter (CMD) and the mass median diameter (MMD) were found to be 0.3 µm and 0.5 µm, respectively. These results point out that there is no effect of menthol on PM emission and that other additives might influence the increased PM emission of Reyno Classic.

Implications: Particulate matter (PM) in ETS endangers the health of nonsmokers and smokers. This study considers the effect of menthol, an additive in cigarettes, on PM emissions. Does menthol increase the amount of PM? Due to the exposure to secondhand smoke nearly 900,000 people die each year worldwide. The aim of the study is to measure the particle concentration (L^?1), mass concentration (µg m^?3), and dust mass fractions shown as PM₁₀, PM_2.5, and PM₁ of five different cigarette brands, including four with different menthol concentrations and one menthol-free reference cigarette, in a well-established standardized system.     

Plume analysis from field evaluations of a portable air quality monitoring system

ABSTRACT

Near-road measurements in Rochester, NY with a Portable Air Quality Monitoring System indicate a significant plume control of PM_2.5 black carbon (BC) concentrations. This study evaluates the performance of two portable air quality enclosures deployed at collocated research sites to determine their accuracy and usefulness in field deployments, and specifically in pollution plume analysis. One system deployed collocated sensors for measurement of particulate matter mass concentration (Thermo pDR 1500 against Tapered Element Oscillating Microbalance (TEOM) measurement) and the second system deployed sensors for measurement of black carbon (Magee AE33 aethalometer and Brechtel Tricolor Absorption Photometer) in ambient and near-road locations in Rochester, New York, respectively. While the optical PM_2.5 sensors tended to be biased in their determination of concentration by ~15%, they followed changes and trends in concentration very well. The black carbon sensors in the portable systems agreed very well with each other and with the collocated sensor. As a case study to determine the contribution from statistically significant short-lived excursions of pollutant concentration, Morlet wavelet analysis was performed on data from the portable system sensors. Black carbon was found to be strongly influenced by plume behavior with significant plume excursions representing just over 12% of all data points and contributing on average 1 µg/m³ of black carbon above ambient concentrations.

Implications: This paper first evaluates two air pollutant monitoring enclosures with wide applicability including near-road detection of pollutants. Then, we present a novel method to designate isolate statistically significant excursions in air pollution concentration which can be used to determine the impact of pollutant plumes as observed in PM and black carbon behavior near road.     

Plans For APCA’s 53rd Meeting Shaping Up As May Date Nears

A continuous method for the measurement of SO₂ in ambient air at trace levels is described. The principle of detection is based on the anodic oxidation of SO₂ in a galvanic cell. A differential measuring technique with a cell with two anodes and one cathode is used; background and noise current are low and stable. A feature of the measuring system is that the air sample is passed through a porous anode against a head of electrolyte on the other side of the anode. The minimum values for the time constant and the lower detection limit were 3 seconds and about 3µg/m³, respectively. The selectivity of the method was compared with those of other techniques in field testing. Trace concentrations measured by the galvanic method in the range from 12 to 135 µg/m³ were in good agreement with those of the flame photometric and the West-Gaeke method. With a Pt/Ni₂B/graphite anode the mean oxidation efficiency was 94 ± 2% on the basis of 2 faraday/mol of SO₂ within the tested concentration range of 50 to 560 µg/m³. During a field test no decrease in the anode activity was observed over a period of ten months. Examples are given for the galvanic detection of other compounds using porous measuring electrodes.     

An Assessment of Source Contributions to Ambient Aerosols in Central Taiwan

Ambient aerosols were sampled at three selected sites in the coastal region of central Taiwan to obtain composition data for use in receptor modeling. All the samples were analyzed for 20 elements with an x-ray fluorescence spectrometer. The mass percentage of sulfates in particle samples was determined by ion chromatography, and mass percentages of elemental carbon (EC) and organic carbon (OC) were determined by an elemental analyzer.

Because the three sampling sites were located within 25 km of each other, the average chemical compositions were similar for particle samples taken at the three sites on the same day. However, the variation in composition from day to day was significantly influenced by wind direction and change in local sources, such as the burning of agricultural wastes. The abundant species in the coarse fraction (2.5&#x0002D;10 µm) were Al (0.5&#x0002D;4.0 µg/m³), Cl (0.1&#x0002D;4.8 µg/m³), Ca (0.2&#x0002D;3.4 µg/m³), Fe (0.2&#x0002D;2.8 µg/ m³), and K (0.1&#x0002D;1.4 µg/m³), while the abundant species in the fine fraction (<2.5 µm) were S (0.3&#x0002D;3.5 µg/m³), Cl (0.01&#x0002D;1.9 µg/ m³), K (0.04&#x0002D;0.98 µg/m³), organic carbon (0.01&#x0002D;10.5 µg/m³), elemental carbon (0&#x0002D;10.7 µg/m³), and sulfates (1.2&#x0002D;15.7 µg/m³).

Calculations for source apportionment were carried out using the CMB7 software developed by the U.S. Environmental Protection Agency (EPA). The main sources for the coarse fraction of ambient aerosols in the region were found to be marine aerosol, coal and fuel oil combustion, burning

of agricultural wastes, and paved road dust. The main sources for the fine fraction were burning of agricultural wastes, diesel exhaust, coal and oil combustion, and sulfates. Source apportionment for the fine fraction was relatively sensitive to the types of sources selected for calculations and the compositions of the sources. The problem can be ameliorated by careful examination of possible sources and by use of local source profiles.     

An Assessment of Source Contributions to Ambient Aerosols in Central Taiwan

Ambient aerosols were sampled at three selected sites in the coastal region of central Taiwan to obtain composition data for use in receptor modeling. All the samples were analyzed for 20 elements with an x&#x002D;ray fluorescence spectrometer. The mass percentage of sulfates in particle samples was determined by ion chromatography, and mass percentages of elemental carbon (EC) and organic carbon (OC) were determined by an elemental analyzer.

Because the three sampling sites were located within 25 km of each other, the average chemical compositions were similar for particle samples taken at the three sites on the same day. However, the variation in composition from day to day was significantly influenced by wind direction and change in local sources, such as the burning of agricultural wastes. The abundant species in the coarse fraction (2.5&#x002D;10 µm) were Al (0.5&#x002D;4.0 µg/m³), Cl (0.1&#x002D;4.8 µg/m³), Ca (0.2&#x002D;3.4 µg/m³), Fe (0.2&#x002D;2.8 µg/ m³), and K (0.1&#x002D;1.4 µg/m³), while the abundant species in the fine fraction (&#x003C;2.5 µm) were S (0.3&#x002D;3.5 µg/m³), Cl (0.01&#x002D;1.9 µg/ m³), K (0.04&#x002D;0.98 µg/m³), organic carbon (0.01&#x002D;10.5 µg/m³), elemental carbon (0&#x002D;10.7 µg/m³), and sulfates (1.2&#x002D;15.7 µg/m³).

Calculations for source apportionment were carried out using the CMB7 software developed by the U.S. Environmental Protection Agency (EPA). The main sources for the coarse fraction of ambient aerosols in the region were found to be marine aerosol, coal and fuel oil combustion, burning of agricultural wastes, and paved road dust. The main sources for the fine fraction were burning of agricultural wastes, diesel exhaust, coal and oil combustion, and sulfates. Source apportionment for the fine fraction was relatively sensitive to the types of sources selected for calculations and the compositions of the sources. The problem can be ameliorated by careful examination of possible sources and by use of local source profiles.     

Development and validation of LC-MS/MS method for the determination of Ochratoxin A and its metabolite Ochratoxin α in poultry tissues and eggs

The objective of this study was to develop a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the determination of Ochratoxin A (OTA) and Ochratoxin α (OTα) in poultry tissues and eggs. The two toxins were extracted by a mixture of acetonitrile/water, purified with a reversed phase C18 solid phase extraction column (SPE) and determined by LC-MS/MS. The LC-MS/MS method performances were evaluated in terms of linearity in solvent and in matrix (ranged from 0.5 to 15.10 µg L^?1 for OTA and from 0.60 to 17.85 µg L^?1 for OTα), limit of detection (LOD), limit of quantitation (LOQ), specificity, accuracy and precision in repeatability conditions. Recovery experiments were performed by spiking poultry liver, kidney, muscle and eggs around 1 µg kg^?1 and 10 µg kg^?1. LODs were 0.27 and 0.26 µg kg^?1 while LOQs were fixed at 1.0 and 1.2 µg kg^?1 for OTA and OTα, respectively. Main recoveries for OTA ranged from 82 to 109% and for OTα ranged from 55 to 89%. The values of within-laboratory relative standard deviation (RSD_r) were equal to or below 20%. Considering the results obtained and that all analytical performance criteria were fulfilled, the new extraction and purification method developed for OTA and OTα determination in animal tissues and eggs was found appropriate for control laboratories and research activities designed to ensure food safety.     

1986 APCA Government Agencies Directory

Carbonaceous species (organic carbon [OC] and elemental carbon [EC]) and inorganic ions of particulate matter less than 2.5 μm (PM_2.5) were measured to investigate the chemical characteristics of long-range-transported (LTP) PM_2.5 at Gosan, Jeju Island, in Korea in the spring and fall of 2008–2012 (excluding 2010). On average, the non-sea-salt (nss) sulfate (4.2 µg/m³) was the most dominant species in the spring, followed by OC (2.6 µg/m³), nitrate (2.1 µg/m³), ammonium (1.7 µg/m³), and EC (0.6 µg/m³). In the fall, the nss-sulfate (4.7 µg/m³) was also the most dominant species, followed by OC (4.0 µg/m³), ammonium (1.7 µg/m³), nitrate (1.1 µg/m³), and EC (0.7 µg/m³). Both sulfate and OC were higher in the fall than in the spring, possibly due to more common northwest air masses (i.e., coming from China and Korea polluted areas) and more frequent biomass burnings in the fall. There was no clear difference in the EC between the spring and fall. The correlation between OC and EC was not strong; thus, the OC measured at Gosan was likely transported across a long distance and was not necessarily produced in a manner similar to the EC. Distinct types of LTP events (i.e., sulfate-dominant LTP versus OC-dominant LTP) were observed. In the sulfate-dominant LTP events, air masses directly arrived at Gosan without passing over the Korean Peninsula from the industrial area of China within 48 hr. During these events, the aerosol optical depth (AOD) increased to 1.63. Ionic balance data suggest that the long-range transported aerosols are acidic. In the OC-dominant LTP event, a higher residence time of air masses in Korea was observed (the air masses departing from the mainland of China arrived at the sampling site after passing Korea within 60–80 hr).

Implications:?In Northeast Asia, various natural and anthropogenic sources contribute to the complex chemical components and affect local/regional air quality and climate change. Chemical characteristics of long-range-transported (LTP) PM_2.5 were investigated during spring and fall of 2008, 2009, 2011, and 2012. Based on air mass types, sulfate-dominant LTP and OC-dominant LTP were observed. A long-term variation and chemical characteristics of PM_2.5 along with air mass and satellite data are required to better understand long-range-transported aerosols.     

Outdoor fine and ultrafine particle measurements at six bus stops with smoking on two California arterial highways—Results of a pilot study

As indoor smoking bans have become widely adopted, some U.S. communities are considering restricting smoking outdoors, creating a need for measurements of air pollution near smokers outdoors. Personal exposure experiments were conducted with four to five participants at six sidewalk bus stops located 1.5–3.3 m from the curb of two heavily traveled California arterial highways with 3300–5100 vehicles per hour. At each bus stop, a smoker in the group smoked a cigarette. Gravimetrically calibrated continuous monitors were used to measure fine particle concentrations (aerodynamic diameter ≤2.5 µm; PM_2.5) in the breathing zones (within 0.2 m from the nose and mouth) of each participant. At each bus stop, ultrafine particles (UFP), wind speed, temperature, relative humidity, and traffic counts were also measured. For 13 cigarette experiments, the mean PM_2.5 personal exposure of the nonsmoker seated 0.5 m from the smoker during a 5-min cigarette ranged from 15 to 153 µg/m³. Of four persons seated on the bench, the smoker received the highest PM_2.5 breathing-zone exposure of 192 µg/m³. There was a strong proximity effect: nonsmokers at distances 0.5, 1.0, and 1.5 m from the smoker received mean PM_2.5 personal exposures of 59, 40, and 28 µg/m³, respectively, compared with a background level of 1.7 µg/m³. Like the PM_2.5 concentrations, UFP concentrations measured 0.5 m from the smoker increased abruptly when a cigarette started and decreased when the cigarette ended, averaging 44,500 particles/cm³ compared with the background level of 7200 particles/cm³. During nonsmoking periods, the UFP background concentrations showed occasional peaks due to traffic, whereas PM_2.5 background concentrations were extremely low. The results indicate that a single cigarette smoked outdoors at a bus stop can cause PM_2.5 and UFP concentrations near the smoker that are 16–35 and 6.2 times, respectively, higher than the background concentrations due to cars and trucks on an adjacent arterial highway.

Implications: Rules banning smoking indoors have been widely adopted in the United States and in many countries. Some communities are considering smoking bans that would apply to outdoor locations. Although many measurements are available of pollutant concentrations from secondhand smoke at indoor locations, few measurements are available of exposure to secondhand smoke outdoors. This study provides new data on exposure to fine and ultrafine particles from secondhand smoke near a smoker outdoors. The levels are compared with the exposure measured next to a highway. The findings are important for policies that might be developed for reducing exposure to secondhand smoke outdoors.     

Relationship between Sulfate Aerosol and Visibility

A PM₁₀ monitoring network was established throughout the South Coast Air Basin (SOCAB) in the greater Los Angeles region during the calendar year 1986. Annual average PM₁₀ mass concentrations within the Los Angeles metropolitan area ranged from 47.0 µg m^-3 along the coast to 87.4 µg m^-3 at Rubldoux, the furthest inland monitoring station. Measurements made at San Nicolas Island suggest that regional background aerosol contributes between 28 to 44 percent of the PM₁₀ aerosol at monitoring sites In the SOCAB over the long term average. Five major aerosol components (carbonaceous material, NO^- ₃, SO⁼ ₄, NH⁺ ₄, and soil-related material) account for greater than 80 percent of the annual average PM₁₀ mass at all on-land monitoring stations. Peak 24-h average mass concentrations of nearly 300 µg m^-3 were observed at inland locations, with lower peak values (?130–150 µg m^-3) measured along the coast. Peak-day aerosol composition was characterized by increased NO^- ₃ Ion and associated ammonium ion levels, as compared to the annual average. There appears to be only a weak dependence of PM₁₀ mass concentration on season of the year. This lack of a pronounced seasonal dependence results from the complex and contradictory seasonal variations in the major chemical components (carbonaceous material, nitrate, sulfate, ammonium ion and crustal material). At most sites within the Los Angeles metropolitan area, PM₁₀ mass concentrations exceeded both the annual and 24-h average federal and state of California PM₁₀ regulatory standards.     

Fugitive Dust Emission Source Profiles and Assessment of Selected Control Strategies for Particulate Matter at Gravel Processing Sites in Taiwan

Abstract

Particles emitted from gravel processing sites are one contributor to worsening air quality in Taiwan. Major pollution sources at gravel processing sites include gravel and sand piles, unpaved roads, material crushers, and bare ground. This study analyzed fugitive dust emission characteristics at each pollution source using several types of particle samplers, including total suspended particulates (TSP), suspended particulate (PM₁₀), fine suspended particulate (PM_2.5), particulate sizer, and dust-fall collectors. Furthermore, silt content and moisture in the gravel were measured to develop particulate emission factors. The results showed that TSP (<100 µm) concentrations at the boundary of gravel sites ranged from 280 to 1290 µg/m³, which clearly exceeds the Taiwan hourly air quality standard of 500 µg/m³. Moreover, PM₁₀ concentrations, ranging from 135 to 550 µg/m³, were also above the daily air quality standard of 125 µg/m³ and approximately 1.2 and 1.5 times the PM_2.5 concentrations, ranging from 105 to 470 µg/m³. The size distribution analysis reveals that mass mean diameter and geometric standard deviation ranged from 3.2 to 5.7 µm and from 2.82 to 5.51, respectively. In this study, spraying surfactant was the most effective control strategy to abate windblown dust from unpaved roads, having a control efficiency of approximately 93%, which is significantly higher than using paved road strategies with a control efficiency of approximately 45%. For paved roads, wet suppression provided the best dust control efficiencies ranging from 50 to 83%. Re-vegetation of disturbed ground had dust control efficiencies ranging from 48 to 64%.     

Feasibility of using low-cost portable particle monitors for measurement of fine and coarse particulate matter in urban ambient air

Exposure to ambient particulate matter (PM) is known as a significant risk factor for mortality and morbidity due to cardiorespiratory causes. Owing to increased interest in assessing personal and community exposures to PM, we evaluated the feasibility of employing a low-cost portable direct-reading instrument for measurement of ambient air PM exposure. A Dylos DC 1700 PM sensor was collocated with a Grimm 11-R in an urban residential area of Houston Texas. The 1-min averages of particle number concentrations for sizes between 0.5 and 2.5 µm (small size) and sizes larger than 2.5 µm (large size) from a DC 1700 were compared with the 1-min averages of PM_2.5 (aerodynamic size less than 2.5 µm) and coarse PM (aerodynamic size between 2.5 and 10 µm) concentrations from a Grimm 11-R. We used a linear regression equation to convert DC 1700 number concentrations to mass concentrations, utilizing measurements from the Grimm 11-R. The estimated average DC 1700 PM_2.5 concentration (13.2 ± 13.7 µg/m³) was similar to the average measured Grimm 11-R PM_2.5 concentration (11.3 ± 15.1 µg/m³). The overall correlation (r²) for PM_2.5 between the DC 1700 and Grimm 11-R was 0.778. The estimated average coarse PM concentration from the DC 1700 (5.6 ± 12.1 µg/m³) was also similar to that measured with the Grimm 11-R (4.8 ± 16.5 µg/m³) with an r² of 0.481. The effects of relative humidity and particle size on the association between the DC 1700 and the Grimm 11-R results were also examined. The calculated PM mass concentrations from the DC 1700 were close to those measured with the Grimm 11-R when relative humidity was less than 60% for both PM_2.5 and coarse PM. Particle size distribution was more important for the association of coarse PM between the DC 1700 and Grimm 11-R than it was for PM_2.5.

Implications: The performance of a low-cost particulate matter (PM) sensor was evaluated in an urban residential area. Both PM_2.5 and coarse PM (PM_10-2.5) mass concentrations were estimated using a DC1700 PM sensor. The calculated PM mass concentrations from the number concentrations of DC 1700 were close to those measured with the Grimm 11-R when relative humidity was less than 60% for both PM_2.5 and coarse PM. Particle size distribution was more important for the association of coarse PM between the DC 1700 and Grimm 11-R than it was for PM_2.5.     

Total Anthropogenic Suspended Particulate as Derived from Chemical Analysis of Chloride and Silicate on High-Volume Samples

Extensive chemical analysis of suspended particulate was undertaken by the Bay Area Air Pollution Control District, so that more meaningful interpretation of total mass loading data could be made and more serious problem areas detected. From high-volume samples taken with cellulose paper as the collection medium, analyses were performed for the five heavy metals and nitrate, sulfate, chloride, silicon, and total organics (loss on ignition at 550°C).

Two constituents considered primarily nonanthropogenic, silicate and chloride, were evaluated from eight sampling sites. The data were derived from over 600 individual samples, one sample per week per site. The locations have diverse geographical backgrounds, although they lie in a common air basin. For example, a 21 month average for chlorides ranged from 4.2 µ/m³ at San Francisco to 1.7 µg/m³ at Livermorè some 40 miles inland. Inversely, the total silicates increased from 5.7 µg/m³ at San Francisco to 22.6 µg/m³ at Livermore. The silicate values peak strongly in the dry season, with individual 24 hr silicate component values greater than 60 µg/m³ at inland stations. Wind-generated dust from the bare hills of the Coast Range is the most probable source.

Since the silicates and chlorides are primarily non-anthropogenic, they were excluded from the TSP values to give a total anthropogenic suspended particulate (TASP). The TASP values for the Bay Area show a geographic distribution in much closer conformity to visibility reduction and citizen complaint than do TSP values.     

Detection of free microcystins in the liver and muscle of freshwater fish by liquid chromatography-tandem mass spectrometry

MC analysis of biological tissue is considered to be very difficult due to the lack of validated methods. This is the primary limiting factor for monitoring potential risks in both the flesh of aquatic organisms and the aquatic ecosystem. In this study, an effective method to determine free MCs (MC-LR and MC-RR) in the muscle and liver tissues of freshwater cultured fish was developed using solid-phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC/MS-MS). The extraction solvent, time of extraction, eluent and purification of the extract were optimized. Various SPE cartridges were also investigated. In this optimized analytical procedure, an 85% methanol/water solution (v/v) was selected as the extraction solvent, after which the extracts were purified by removing fats and proteins; a HLB cartridge was chosen for MCs enrichment; and 90% methanol containing 0.02% formic acid/water solution (v/v) was used as the eluent. Under the optimized pretreatment conditions and instrument parameters, good recoveries of MC-LR and MC-RR were obtained at three concentrations (0.5, 1.0 and 2.0 µg g^?1 dry weight (DW)), with values ranging from 92.5 to 98.3% and 92.1 to 98.6%, respectively. The method detection limit (MDL) for muscle samples was 0.5 µg kg^?1 and 0.4 µg kg^?1 (DW) for MC-LR and MC-RR, respectively. The MDL for the liver samples was 0.8 µg kg^?1 (DW) for both MC-LR and MC-RR. The developed procedure was successfully applied to analyze MCs in the muscle and liver of fish samples collected from a Chinese freshwater aquaculture pond during bloom seasons. The MC-LR concentrations ranged from below the MDL to 4.17 µg kg^?1 and the MC-RR concentrations ranged from below the MDL to 2.64 µg kg^?1.     

Simultaneous determination of pesticides,mycotoxins, tropane alkaloids,growth regulators,and pyrrolizidine alkaloids in oats and whole wheat grains after online clean-up via two-dimensional liquid chromatography tandem mass spectrometry

In this study, a two-dimensional liquid chromatography tandem mass spectrometry method was developed and validated for the determination of pesticide residues and contaminants in whole wheat grains and oats. The samples were extracted with a mixture of acetonitrile and water and were injected into the two-dimensional LC-MS/MS system without any further clean-up or sample preparation. Samples were analyzed with four different matrix matched calibrations. Matrix effects were evaluated by comparing analyte signals in the respective matrix matched standard with the neat solvent standards. The final method was validated according to the current Eurachem validation guide and SANTE document. The number of successfully validated analytes throughout all three validation levels in oats and wheat, respectively, were as follows: 330 and 316 out of 370 pesticides, 6 and 13 out of 18 pyrrolizidine alkaloids and 7 out of 9 regulated mycotoxins. Moreover, both plant growth regulators mepiquat and chlormequat as well as the tropane alkaloids atropine and scopolamine met the validation criteria. The majority of pesticides showed limits of detection below 1?µg kg^?1, pyrrolizidine alkaloids below 0.7?µg kg^?1, tropane alkaloids below 0.2?µg kg^?1, growth regulators below 0.7?µg kg^?1 and mycotoxins below 8?µg kg^?1 in both matrices.     

Concentration,size, and density of total suspended particulates at the air exhaust of concentrated animal feeding operations

Total suspended particulate (TSP) samples were seasonally collected at the air exhaust of 15 commercial concentrated animal feeding operations (CAFOs; including swine finishing, swine farrowing, swine gestation, laying hen, and tom turkey) in the U.S. Midwest. The measured TSP concentrations ranged from 0.38 ± 0.04 mg m^?3 (swine gestation in summer) to 10.9 ± 3.9 mg m^?3 (tom turkey in winter) and were significantly affected by animal species, housing facility type, feeder type (dry or wet), and season. The average particle size of collected TSP samples in terms of mass median equivalent spherical diameter ranged from 14.8 ± 0.5 µm (swine finishing in winter) to 30.5 ± 2.0 µm (tom turkey in summer) and showed a significant seasonal effect. This finding affirmed that particulate matter (PM) released from CAFOs contains a significant portion of large particles. The measured particle size distribution (PSD) and the density of deposited particles (on average 1.65 ± 0.13 g cm^?3) were used to estimate the mass fractions of PM₁₀ and PM_2.5 (PM ≤10 and ≤2.5 μm, respectively) in the collected TSP. The results showed that the PM₁₀ fractions ranged from 12.7 ± 5.1% (tom turkey) to 21.1 ± 3.2% (swine finishing), whereas the PM_2.5 fractions ranged from 3.4 ± 1.9% (tom turkey) to 5.7 ± 3.2% (swine finishing) and were smaller than 9.0% at all visited CAFOs. This study applied a filter-based method for PSD measurement and deposited particles as a surrogate to estimate the TSP’s particle density. The limitations, along with the assumptions adopted during the calculation of PM mass fractions, must be recognized when comparing the findings to other studies.

Implications: The concentration, size, and density of TSP samples varied greatly with animal species, housing facility type, feeder type, and season, suggesting that PM emission data derived from limited measurements may not be readily applied to estimate the overall emission from concentrated animal feeding operations (CAFOs). This study also affirmed that particles released from CAFOs is of relatively high density (~1.65 g cm^?3) and with diameter mostly larger than 10 µm, indicating that regular PM abatement devices, such as cyclones, fabric filters, or even a simple downward-facing exhaust duct, may be employed to mitigate the TSP emission with acceptable efficiency.     

Components and dispersion characteristics of organic and inorganic odorous gases in a large-scale dairy farm

The rapid development of large-scale livestock husbandry has caused serious air pollution problems (e.g., The Tuzuoqi demonstration farm belonging to the Yili Group. The farm is located in the suburb of Hohhot City in northern China). In this study, the gases in typical areas of a large-scale dairy farm were sampled and measured for volatile organic compounds (VOCs), hydrogen sulfide, and ammonia concentrations. Fifty-two species of VOCs were identified. The VOCs emitted from the cowshed mainly consisted of halogenated hydrocarbons (16,960 µg/m³), ketones (15,700 µg/m³), esters (9889 µg/m³), and sulfur compounds (3677 µg/m³). The VOCs from the oxidation pond were mainly composed of halogenated hydrocarbons (21,940 µg/m³) and ketones (3589 µg/m³). The VOCs from the solid–liquid separation tank comprised halogenated hydrocarbons (32,010 µg/m³), ketones (7169 µg/m³), and sulfur compounds (1003 µg/m³). The highest concentrations of ammonia and hydrogen sulfide were obtained from the milking parlor and solid–liquid separation tank, respectively. The ammonia concentration declined gradually due to the superposition of ammonia emitted from the cowshed and milking parlor. Analysis results of the influences of distance and meteorological factors on the dispersion of ammonia and hydrogen sulfide suggested that the dilution factors decreased with increasing distance from the emission source. Within distance ranges of 0–10 and 10–25 m, the concentration dilution factors were positively correlated with wind speed and temperature but negatively correlated with humidity and atmospheric pressure. The results of our work can provide a theoretical basis for the prevention and control of odorous gases in large-scale livestock farms.

Implications: Gases in typical areas of a large-scale dairy farm were sampled, and a total of 52 species of VOCs were identified. The highest concentrations of ketones, sulfur compounds, and esters were obtained at the cowshed (15,700, 3677, and 9889 µg/m³, respectively). Within the distance ranges of 0–10 and 10–25 m, the concentration dilution factors were positively correlated with wind speed and temperature.     

Calculation of Smoke Plume Opacity from Particulate Air Pollutant Properties

Calculation of smoke plume opacity from the properties of the particulate emission is facilitated with the use of a parameter K (specific particulate volume cm³/m³/extinction coefficient m^?1) computed from theory. Graphs of K vs. the geometric mass mean particle radius at geometric standard deviations from 1 (monodisperse) to 10 are presented for particle refractive indices of 1.96–0.66i (carbon), 2.80–0.02i, 1.33 (water) and 1.50 at a wavelength of light of 550 nm. Experimental data of K for various sources are reported. Application to the estimation of the Ringelmann number is discussed and illustrated with an example.     

Applications of GPS-tracked personal and fixed-location PM2.5 continuous exposure monitoring

Continued development of personal air pollution monitors is rapidly improving government and research capabilities for data collection. In this study, we tested the feasibility of using GPS-enabled personal exposure monitors to collect personal exposure readings and short-term daily PM_2.5 measures at 15 fixed locations throughout a community. The goals were to determine the accuracy of fixed-location monitoring for approximating individual exposures compared to a centralized outdoor air pollution monitor, and to test the utility of two different personal monitors, the RTI MicroPEM V3.2 and TSI SidePak AM510. For personal samples, 24-hr mean PM_2.5 concentrations were 6.93 μg/m³ (stderr = 0.15) and 8.47 μg/m³ (stderr = 0.10) for the MicroPEM and SidePak, respectively. Based on time–activity patterns from participant journals, exposures were highest while participants were outdoors (MicroPEM = 7.61 µg/m³, stderr = 1.08, SidePak = 11.85 µg/m³, stderr = 0.83) or in restaurants (MicroPEM = 7.48 µg/m³, stderr = 0.39, SidePak = 24.93 µg/m³, stderr = 0.82), and lowest when participants were exercising indoors (MicroPEM = 4.78 µg/m³, stderr = 0.23, SidePak = 5.63 µg/m³, stderr = 0.08). Mean PM_2.5 at the 15 fixed locations, as measured by the SidePak, ranged from 4.71 µg/m³ (stderr = 0.23) to 12.38 µg/m³ (stderr = 0.45). By comparison, mean 24-h PM_2.5 measured at the centralized outdoor monitor ranged from 2.7 to 6.7 µg/m³ during the study period. The range of average PM_2.5 exposure levels estimated for each participant using the interpolated fixed-location data was 2.83 to 19.26 µg/m³ (mean = 8.3, stderr = 1.4). These estimated levels were compared with average exposure from personal samples. The fixed-location monitoring strategy was useful in identifying high air pollution microclimates throughout the county. For 7 of 10 subjects, the fixed-location monitoring strategy more closely approximated individuals’ 24-hr breathing zone exposures than did the centralized outdoor monitor. Highlights are: Individual PM_2.5 exposure levels vary extensively by activity, location and time of day; fixed-location sampling more closely approximated individual exposures than a centralized outdoor monitor; and small, personal exposure monitors provide added utility for individuals, researchers, and public health professionals seeking to more accurately identify air pollution microclimates.

Implications: Personal air pollution monitoring technology is advancing rapidly. Currently, personal monitors are primarily used in research settings, but could they also support government networks of centralized outdoor monitors? In this study, we found differences in performance and practicality for two personal monitors in different monitoring scenarios. We also found that personal monitors used to collect outdoor area samples were effective at finding pollution microclimates, and more closely approximated actual individual exposure than a central monitor. Though more research is needed, there is strong potential that personal exposure monitors can improve existing monitoring networks.     

Advances in the Analysis of Air Contaminants Comments

Abstract

Methylcyclopentadienyl manganese tricarbonyl (MMT) is an organometallic compound used as an octane improver in unleaded gasoline. The combustion of MMT leads to the formation of manganese (Mn) oxides, mainly Mn₃O₄. The objective of this study is to assess the variations over time and space of respirable (Mn_R) and total (Mn_T) Mn in the urban atmosphere and to evaluate human exposure by inhalation. Two sampling sites were selected on the island of Montreal based on their local traffic density (municipal botanical garden, C^-= 10,000–15,000 vehicles d^-1; Montreal Waterworks, C⁺= 100,000–130,000 vehicles d^-1). Air samplings were made during the day at stations located 10 m from the road using portable pumps, some of which were equipped with a cyclone. Mn_R and Mn_T and other metals were measured on Teflon filters by neutron activation. Mn exposure doses by inhalation were calculated using Monte–Carlo simulations. Mn_R and Mn_T average concentrations were significantly higher at site C⁺ (Mn_R = 0.024 µg m^-3; Mn_T = 0.050 µg m^-3) than at site C^- (Mn_R= 0.015 µg m^-3; Mn_T= 0.027 µg m^-3). Temporal profiles at sites C⁺ and site C^-were similar, with a coefficient of correlation of 0.24 for Mn_R and 0.26 for Mn_T. Trend analyses (ARIMA) also showed that the period of the week (work days vs. off days) was significantly related to Mn_R and Mn_T variations at both sites. The average exposure dose by inhalation to Mn_R and Mn_T ranged from 0.001 to 0.030 µg kg^-1 day^-1 and 0.001 to 0.05 µg kg^-1 day^-1. Mn_R and Mn_T concentrations reflected a positive relationship with traffic density. However, it remains difficult to attribute these results directly to the combustion of MMT in unleaded gasoline. On average, the Mn_R and Mn_T inhalation doses were 2 to 15 times lower than the reference dose (RfC) proposed by the U.S. Environmental Protection Agency (EPA) for the general population.     

Development,validation, and application of a method for the GC-MS analysis of fipronil and three of its degradation products in samples of water,soil, and sediment

A method for the identification and quantification of pesticide residues in water, soil, and sediment samples has been developed, validated, and applied for the analysis of real samples. The specificity was determined by the retention time and the confirmation and quantification of analyte ions. Linearity was demonstrated over the concentration range of 20 to 120 µg L^?1, and the correlation coefficients varied between 0.979 and 0.996, depending on the analytes. The recovery rates for all analytes in the studied matrix were between 86% and 112%. The intermediate precision and repeatability were determined at three concentration levels (40, 80, and 120 µg L^?1), with the relative standard deviation for the intermediate precision between 1% and 5.3% and the repeatability varying between 2% and 13.4% for individual analytes. The limits of detection and quantification for fipronil, fipronil sulfide, fipronil-sulfone, and fipronil-desulfinyl were 6.2, 3.0, 6.6, and 4.0 ng L^?1 and 20.4, 9.0, 21.6, and 13.0 ng L^?1, respectively. The method developed was used in water, soil, and sediment samples containing 2.1 mg L^?1 and 1.2% and 5.3% of carbon, respectively. The recovery of pesticides in the environmental matrices varied from 88.26 to 109.63% for the lowest fortification level (40 and 100 µg kg^?1), from 91.17 to 110.18% for the intermediate level (80 and 200 µg kg^?1), and from 89.09 to 109.82% for the highest fortification level (120 and 300 µg kg^?1). The relative standard deviation for the recovery of pesticides was under 15%.