Respirable Dust Samples Research Articles

Assessment of Dust Concentrations Affecting People Working on Roadsides to Mahasarakham University

This study aims to assess possibility of health risk attributed to nuisance dust on people living and working on roadside areas nearby Mahasarakham University (MSU). Nuisance dust was measured during November 2012 to May 2013 covering a school semester and a school break. All samples for Ban Tha Kong Yang roadside area showed high level of ambient aerosol with size less than 10 micron and the level was exceeding the national ambient air quality standard of 0.12 mg m-3 . Approximately half of the samples taken for Ban Kham Riang also show the same result. This suggests significant dust problem in these areas and could potentially cause adverse human health effects. Results from personal respirable dust sampling show that construction worker was exposed to the highest respirable dust concentration among three occupations, including security guard and street-food cooker. The levels were significantly higher with longer time on the road and having earth moving activity nearby. Occupational exposure to respirable dust, however, was not exceeding the US Occupational Safety and Health Administration standard of 5 mg m-3.

Effect of the Quartz Particle Size on XRD Quantifications and Its Implications for Field Collected Samples

The aims of the present study were to assess the effect of the quartz particle size on XRD quantifications, and use it to develop models for correcting the measured quartz concentrations of samples collected from the field. Seven nearly monodispersed pure quartz dusts, with mass median aerodynamic diameters (MMAD) ranging from 0.70 to 10.84 μm, were prepared by a liquid sedimentation device, and their unit XRD intensities (UI) were measured using the NIOSH Method 7500. The results show that UI increases (from 063 to 1.14) along with the rise in MMAD of the pure quartz dust. To examine the impact of the above results on quantifying field collected samples, both total dust and respirable dust samplings were conducted at seven different workplace environments. The results show that the quartz particles contained in all collected total dust samples (MMAD=5.18-16.7 μm, GSD=2.08-2.88) were coarser in their particle sizes than that of the reference quartz standard (NIST-SRM 1878; MMAD=2.16 μm, GSD=1.55), and the measured total quartz particle concentrations (C_m) were 16.6-22.5% lower than the corresponding true concentrations (C_t). However, for respirable dust samples (MMAD=1.37-3.95 μm, GSD=1.978-2.87), since collected quartz particle sizes could be either finer or coarser than that of the reference standard, both underestimation and overestimation were found in the present study (C_m/C_t=0.881-1.09). To correct the measured concentrations of field collected samples, correcting models were developed based on the MMADs of the collected quartz particle samples and their corresponding UIs. This study yields correcting factors for the respirable fraction (CR_f) as CR_f=1.50-0.67×[1-exp(-0.69×MMAD)] (R^2=0.996, n=7). However, the obtained CR_f should be used with caution if the collected samples were found with quartz particle sizes falling outside the size range of the present study.

Gaseous Emissions Monitoring and Ash Analysis of an Industrial Incinerator in Pakistan

A study was conducted on an industrial incinerator located at Kala Shah Kaku, Punjab, Pakistan to monitor and evaluate stack emissions (NOX, SOX, CO, VOCS) and determination of heavy metals in bottom and fly ash of an industrial incinerator burning tobacco dust. Incinerated bottom and fly ash samples were collected. For the purpose of ambient air monitoring three different sides of incinerator were selected. The air emissions monitoring included emissions from right side of the incinerator (A1), emissions from left side of the incinerator (A2) and emissions from the main gate of the incinerator (A3). To determine heavy metals in bottom and fly ash, HACH and Merck procedure via spectrophotometer were used. Respirable Dust Sampler and Flue Gas Analyzer were used to monitor ambient air quality and stack emissions respectively. The results of ambient quality (SOx, NOx, CO, CO2, PM& O2) revealed that the emissions from A2 were comparatively higher than emissions from A1 and A3. With the help of Flue Gas Analyzer it was found that carbon monoxide (CO) emissions were higher than SOX, NOX and VOCS. Bottom ash analysis by spectrophotometer showed that the heavy metals were below the detectable limits. The analysis conducted for heavy metals in fly ash by spectrometry as well confirmed that lead (Pb) and cadmium (Cd) were below the detectable limits and chromium was 1.96 mg/kg of the ash.

Pollution in Lucknow City and its health implication on exposed vendors, drivers and traffic policemen

In this pilot study, an exposure–response assessment (aged 16 to 60 years, n = 1,012) was carried out related to eye problems due to vehicular fumes during the winter of 2003. Inhalable particles <PM10 and Pb level were monitored at 12 locations of Lucknow using a Respirable Dust Sampler and EPM 2000 filter. The range of PM10 particles varied from 144 to 305, 211–366 and 141–242 μg/m3 while Pb levels were 0.02–0.93, 0.06–0.90 and 0.07–0.77 μg/m3 during 2002, 2003 and 2004, respectively. The concentrations of PM10 exceeded alarmingly the prescribed standards by a factor of 1.3–3.2. A health survey demonstrated that symptoms were developed such as burning of eyes (in 20 % of drivers, 74.07 % of vendors and 77.47 % of traffic policemen), eye watering (in 51.45 % of drivers, 44 % of vendors and 72.77 % of traffic policemen), constant irritation and redness (in 33.49 % of drivers, 21.29 % of vendors and 26.12 % of traffic policemen) and impaired vision (in 25.01 % of drivers, 20.37 % of vendors and 23.5 % of traffic policemen). The main finding was the prevalence of symptoms of the eyes among the population exposed to automobile fumes.

Quartz Concentration Trends in Metal and Nonmetal Mining

From 1974 through 2010, the Mine Safety and Health Administration (MSHA) collected nearly 147,000 respirable dust samples with a mass of at least 0.1 mg and a minimum of 1% quartz. These samples represent about 50% of all respirable dust compliance samples collected by MSHA. Analysis of these data shows that pockets of high concentrations and overexposure continue to exist. At underground mines, from 2005 to 2010, occupations with >20% of the samples exceeding the permissible exposure limit (PEL) and geometric mean quartz concentrations exceeding the ACGIH threshold limit value of 25 μg/m3 included mucking, crusher operator, general laborer/utility, and front-end loader operator. During the same period, stone and rock saw operators and bagger and packers working at surface mines and mills also had >20% of the samples exceeding the PEL and geometric mean quartz concentrations >25 μg/m3. Regardless of mine type or location, slow but steady improvement in exposure levels is seen in jobs involving crushing operations, which are widespread in the mining industry. Crusher operators are more likely to work in an enclosed area where it is easier to apply dust controls and air conditioning. A downward trend is also observed for vehicle equipment operators who drive load-haul-dumps, front-end loaders, trucks, and similar equipment. Crusher operators and vehicle equipment operators represent occupational categories that are widely sampled by MSHA inspectors. A small but statistically significant reduction in the overall mean respirable quartz dust and quartz concentrations from 1993 to 2010 was observed in most commodity groups. Variability from year to year and between commodities is high. Reduction in respirable quartz dust concentration does not necessarily correspond to a reduction in quartz concentration within the same commodity group. These trends are consistent with those reported in previous studies.

Characterization of Gaseous and Particulate Polycyclic Aromatic Hydrocarbons in Ambient Air of Delhi, India

Three seasonal sampling campaigns were undertaken at an urban site of Delhi for collection of PAHs in particulate and gas phase. Sampling was done by using modified Respirable Dust (PM ≤10μm) sampler attached with polyurethane foam (PUF) plugs and compared with conventional Respirable Dust (PM ≤10 μm) sampler. Total 16 EPA PAH (gaseous + particulate) were determined by Gas Chromatograph-Mass Spectrophotometer (GC-MS). The 3-ring PAH constitutes approximately 90% of the gaseous PAHs with phenanthrene, fluoranthene, acenapthylene, and acenaphthene being the most abundant gaseous PAHs. PAHs with 4- to 6- rings accounted for 92%, 87% and 78% in samples collected during winter, summer and monsoon season respectively. Gaseous PAHs, particulate PAHs and total PAHs were higher during winter as compared to summer and monsoon seasons. The contribution of particulate PAHs were 1.4, 2.1, and 2.5 times higher in winter, summer and monsoon, respectively than of gaseous PAHs. Indeno[123-cd]pyrene, benzo[ghi]perylene, dibenzo[ah]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene and chrysene were found to be the most abundant PAH compounds in the particulate PAHs during all the seasons. The result from application of diagnostic ratio suggests that the higher particulate PAHs emissions were predominantly associated with vehicular emissions along with emissions from biomass burning during winter season.

A Comparison of the Performance of Samplers for Respirable Dust in Workplaces and Laboratory Analysis for Respirable Quartz

The divergent sampling techniques for respirable dust and the analyses for crystalline silica are an important area of interest and discussion among industrial occupational hygienists in Europe. The variety of equipment for air sampling, methods and instrumentation can cause differences between results for the analysis of respirable crystalline silica (RCS). In this study, a Workplace Atmosphere Multi-sampler (WAM), developed by Adhesia, was used to compare respirable dust samplers in the workplace. This rotating device enables the comparison of 12 samplers in a workplace in each run. Seven laboratories participated in the comparison, using six different respirable dust samplers [British Cast Iron Research Association (BCIRA) to the Higgins Dewell (HD) design, Dorr Oliver, Casella SIMPEDS, SKC HD with a polycarbonate filter and polyvinylchloride filter, and the CIP10-R). Each laboratory analysed samples supplied by the samplers and reported the total respirable dust concentration and the RCS concentration. The techniques used were X-ray diffraction direct-on-filter, X-ray diffraction with deposition, infrared direct-on-filter, and infrared with potassium bromide (KBr) discs. The experiments were carried out in four different industries (enamel, sand extraction, foundry and brickworks). Generally, the SKC conductive black plastic sampler is oversampled (y = 1.52x + 0.008) and the CIP10 is undersampled (y = 0.74x + 0.068) when compared with the median air concentration. A pair-wise comparison of the different industries using t-tests indicated significant differences (P < 0.05) between the SKC conductive plastic samplers and the other samplers. The same series of statistical calculations were performed for the results obtained for RCS (quartz) and showed significant differences for the CIP10 techniques and the SKC conductive plastic cyclone analyses when using a polyvinylchloride filter.

PM10 in the ambient air of Chandrapur coal mine and its comparison with other environments

This study compares the ambient air particulate matter (PM10) data of 15 different coal mine environments. For most of these mine environments, the monitoring was carried out by different researchers using respirable dust sampler (RDS) that separates PM10 by centrifugal inertial separation. At two sites--Padmapur and Ghugus (Chandrapur, Maharashtra, India)--mass inertial impaction-based sampler was used for PM10 monitoring. It is observed that the spatiotemporal average value of ambient air PM10 monitored using mass inertial impactor reports relatively higher values (240-372 μg/m(3)) compared to those monitored using RDS (<227 μg/m(3)). In order to realize the severity of mine area pollution, it is compared with PM10 values found in an urban area (Delhi, India). It is found that PM10 values in Delhi (using mass inertial impactor) are much higher (300-400 μg/m(3)) than those reported for the mine environment. The data seems to indicate that the mine environment is relatively cleaner than urban air and therefore raises doubt about the appropriateness of using either mass impactor or RDS for PM10 sampling.

Association Between Proinflammatory Responses of Respirable Silica Dust and Adverse Health Effects Among Dust-Exposed Workers

To evaluate proinflammatory responses induced by respirable silica dust samples and to analyze the role of those responses in explaining adverse health effects among dust-exposed workers in pottery factoryies and tungsten and tin mines. Proinflammatory cytokines of cells were determined after being treated with silica dust samples. Adverse health effects of workers were calculated on the basis of a cohort study. Incidence and mortality of silicosis among tungsten miners were higher than those in other workers. The incidence of interleukin-1β levels was highest in tungsten mines, which was consistent with the incidence of silicosis in tungsten miners. The higher levels of TNF-α and interleukin-6 released from macrophages might be helpful in explaining increased mortalities from lung cancer among tin miners. Interleukin-1β could be a sensitive biomarker in predicting fibrogenic potential of silica dust and the risk of silicosis among dust-exposed workers.

Composition, seasonal variation, and sources of PM10 from world heritage site Taj Mahal, Agra

Air samples for PM(10) (dp < 10 μm in aerodynamic diameter) were collected from March 2007 to February 2008 near Taj Mahal-a historically sensitive site in Agra. Each sample collected on 20.3 × 25.4-cm Whatman quartz microfiber filter using respirable dust sampler was analyzed gravimetrically for mass concentrations and chemically for elements such as Na, Mg, Al, Si, S, Ca, Sc, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Br, Rb, Cd, Ba, and Pb by inductively coupled plasma atomic emission spectroscopy and inorganic ions such as NH (4) (+) , K(+), SO (4) (2-) , NO (3) (-) , F(-), and Cl(-) by ion chromatograph. Annual average of PM(10) 155.47 ± 77.97 μg/m(3) was three times high the annual average NAAQ standard of 50 μg/m(3) for sensitive area. PM(10) as well as K(+), Cl(-), As, and Pb were higher in winter while crust elements and secondary aerosols were higher in summer. The average equivalent ratio of NH (4) (+) to sum up of SO (4) (2-) and NO (3) (-) was greater than unity which indicates high source strength of ammonia and alkaline nature of aerosols in Agra. Source apportionment of PM(10) was carried out by factor analysis using principal component analysis (varimax rotated factor matrix method) of SPSS. Five sources contributing to PM(10) were identified as crust material, vehicular emissions, industrial emissions, coal and biomass burning, and secondary aerosols.

Excessive Exposure to Dust Among Cleaners in the Ethiopian Cement Industry

Personal exposure to dust in cement factories occurs at all stages of the production process and is likely to vary between different stages of the process. Previous studies on cement production have focused on dust exposure among process operators and machine attendants. This study characterizes personal exposure to total and respirable dust among production workers in two cement factories in Ethiopia, with particular focus on cleaners. In Ethiopian cement plants, flow lines are partly open, and cleaning workers use brooms and shovels to remove dust that has settled on floors and machines. Personal full-shift samples of total (n = 150) and respirable dust (n = 36) were taken in the breathing zones of 105 cement workers. Samples of total and respirable dust were collected on 37-mm cellulose acetate filters of closed-face cassettes and in plastic respirable cyclones, respectively. In both factories, cleaners had significantly higher exposures to total and respirable dust than other production workers. Among cleaners, the geometric means for total and respirable dust exposure were 549 and 6.8 mg/m3 in Factory A, and 153 and 2.8 mg/m3 in Factory B. Temporal variability (within-worker) dominated the variability in the cleaners’ total dust exposures. The distance from machines while performing cleaning tasks and the fraction of working hours spent on cleaning explained about 73% of the temporal variability in total dust exposure among cleaners. Only 7% of the production workers used respiratory protective devices. Preventive measures are needed to reduce dust exposure.

A comparison of real-time monitoring of select metal concentrations in a copper smelter workplace compared to standard pump air sampling monitoring methods

This research was conducted to determine if a direct-reading instrument can be used as a guidance tool to estimate the concentrations of arsenic, cadmium, copper and lead in air within a copper smelter workplace based on comparison to standard pump-filter air sampling monitoring methods for these agents. Both respirable and total dust samples were collected using precision flow air sampling pumps and mixed cellulose ester (MCE) filters in sampling cassettes to determine the concentration for each of these metals in air in a smelter workplace. Particulate matter with a diameter of 10 μm or less (PM 10 ) was also sampled by using air sampling pumps and PM 10 impactors. Samples collected in the smelter workplace were submitted to an American Industrial Hygiene Association (AIHA) accredited analytical laboratory, where gravimetric analyses for the total weight of particulates were measured and the concentration of each of the four metals of interest was determined. During the collection of the MCE filters-cassette and PM 10 impactor samples, a Haz-Dust real-time, direct-reading instrument was simultaneously used to measure particulate concentrations in air. A Pearson's Correlation was calculated to determine the strength or degree of association between the direct-reading instrument results and metal concentration for the respirable, total dust and PM 10 concentrations reported by the laboratory. Linear regression was then performed between the direct-reading results and each specific metal concentration reported by the laboratory for total, respirable and PM 10 samples. This comparison of the data from the different monitoring methods provided a correction factor, which was then used to predict the metal concentrations in air based on the direct-reading instrument readings. Pearson's Correlation results showed correlation coefficients from −0.14 for respirable lead to 0.49 for copper PM 10 compared to direct-reading instrument results. Linear regression results found R 2 values ranging from 0.581 for lead PM 10 compared to the direct-reading instrument to 0.821 for copper total dust as compared to the direct-reading instrument aerosol measurements. The direct-reading instrument appears valid and reliable for obtaining general estimates of some metals in a copper smelter workplace, however the method is not sufficiently accurate to replace current accepted, and in some cases required, pump-filter air monitoring methods and should therefore only be used as a guidance tool.

Aerosol chemistry over a high altitude station at northeastern Himalayas, India.

BackgroundThere is an urgent need for an improved understanding of the sources, distributions and properties of atmospheric aerosol in order to control the atmospheric pollution over northeastern Himalayas where rising anthropogenic interferences from rapid urbanization and development is becoming an increasing concern.Methodology/Principal FindingsAn extensive aerosol sampling program was conducted in Darjeeling (altitude ∼2200 meter above sea level (masl), latitude 27°01′N and longitude 88°15′E), a high altitude station in northeastern Himalayas, during January–December 2005. Samples were collected using a respirable dust sampler and a fine dust sampler simultaneously. Ion chromatograph was used to analyze the water soluble ionic species of aerosol. The average concentrations of fine and coarse mode aerosol were found to be 29.5±20.8 µg m−3 and 19.6±11.1 µg m−3 respectively. Fine mode aerosol dominated during dry seasons and coarse mode aerosol dominated during monsoon. Nitrate existed as NH4NO3 in fine mode aerosol during winter and as NaNO3 in coarse mode aerosol during monsoon. Gas phase photochemical oxidation of SO2 during premonsoon and aqueous phase oxidation during winter and postmonsoon were the major pathways for the formation of SO4 2− in the atmosphere. Long range transport of dust aerosol from arid regions of western India was observed during premonsoon. The acidity of fine mode aerosol was higher in dry seasons compared to monsoon whereas the coarse mode acidity was higher in monsoon compared to dry seasons. Biomass burning, vehicular emissions and dust particles were the major types of aerosol from local and continental regions whereas sea salt particles were the major types of aerosol from marine source regions.Conclusions/SignificanceThe year-long data presented in this paper provide substantial improvements to the heretofore poor knowledge regarding aerosol chemistry over northeastern Himalayas, and should be useful to policy makers in making control strategies.

Analysis and risk estimates to workers of Brazilian granitic industries and sandblasters exposed to respirable crystalline silica and natural radionuclides

Occupational exposure to respirable crystalline silica and to radiation emitted by natural radionuclides present both in rocks and sands was studied in the Brazilian extractive process and granite product manufacture. Respirable airborne dust samples were collected in working environments, where workers perform different tasks with distinct commercial granites types, and also in places where sandblasters work with sands from different origins. The free crystalline silica contents were determined using X-ray diffraction of the respirable particulate fraction of each sample. Dust samples from granite cutting and sandblasting ambient had the natural radionuclides concentrations measured by gamma spectrometry. Dust concentrations in the workplaces were quite variable, reaching values up to 10 times higher than the respirable particle mass threshold limit value (TLV) set by the American Conference for Governmental Industrial Hygienists of 3 mg m −3 . Also the free crystalline silica concentrations were high, reaching values up to 48 times the TLV of 0.025 mg m −3 . Additionally, our results suggest that the risk of radiation-induced cancer in the granite or marble industries is negligible. However, the combined exposure to dust, gamma radiation, and radon daughter products could result in the enhancement of lung cancer risks associated to sandblasting activities.

Development of Emission Factors for Quantification of Blasting Dust at Surface

Environmental impact assessment (EIA) and environmental management plan (EMP) is a statutory requirement for execution of new mining projects or for expansion of the operating projects. For this purpose, quantification of blasting dust emission is required. This can be done by developing emission factors for blasting. The concept is similar to that of specific charge in blasting. For mining operations other than blasting, quantification of dust can be done using emis- sion factors. Emission estimation techniques are very limited for blasting. In this study, the emission factors were de- veloped by carrying out a detailed field study at one of the largest opencast coal mines of India in all four seasons. Da- ta on atmospheric and meteorological conditions were generated by installing sodar and automatic weather station at the mine site. Respirable dust samplers were installed for monitoring of the dust emitted during coal or overburden bench blasting. Emission factors for dust concentrations were developed in gram per cubic meter of rock excavated. The developed emission factors were used to estimate dust emissions for adjacent mines due to similarity in mining and meteorological conditions. Seasonal variations in moisture contents in benches, where dust was monitored, indicated the lowest emission factors in monsoon due to high moisture in the bench materials. Similar field studies were also conducted at another coalfield of India for two seasons. It was found that the emission factors are site-specific.

Atmospheric Particulate Pollutants and their Relationship with Meteorology in Ahmedabad

Urban air pollution is rapidly becoming an environmental problem of public concern worldwide. It can influence public health and local/regional weather and climate. In the present study, airborne particulate pollutants data were collected for a period of 4 years (2005–2008) at 13 locations in Ahmedabad, a mega city in Gujarat State in western India. The particulate pollutants data were collected by the Gujarat Pollution Control Board with respirable dust samplers (RDSs). The observed Suspended Particulate Matter (SPM) concentrations varied from 66.0 to 786.0 µg/m3, and concentrations of Particulate Matter of aerodynamic diameters less than 10 microns (PM10) ranged between 17.0 to 327.0 µg/m3. The seasonal- and annual-average concentrations of the two pollutants were mostly above Indian air quality standards and were generally comparable with those observed in most other Indian urban areas. During this study period, there was a continuous decrease of particulate pollutants concentrations within Ahmedabad; however, the concentrations were just above the permissible limits set by the Central Pollution Control Board (CPCB). These particulate pollutants concentrations were compared with meteorological variables such as rainfall, humidity, temperature, and wind speed. Both SPM and PM10 showed significant negative correlations with rainfall. An Air Quality Index (AQI) was calculated for all stations for all months. AQI values varied from 25 to 193.3. AQI was high in summer season and low in monsoon season. AQI values varied from Good (0–50) to Hazardous (300–500). On the basis of the AQI scale, it is found that the atmospheric environment of Ahmedabad is moderately polluted to unhealthy range.

Beryllium Aerosol Characteristics in the Magnesium and Aluminum Transformation Industry in Quebec: A Comparison of Four Different Sampling Methodologies

To examine the influence of the sampling method on beryllium (Be) exposure assessment, a study was conducted in foundries and smelters to contrast the performance of five different dust sampling devices. Six sampling surveys were conducted in four different settings, and both personal and fixed station samples were collected using the following sampling heads: IOM samplers (inhalable dust), 35-mm plastic cassettes (total dust), aluminum SKC cyclones (respirable dust), 8-stage Sierra cascade impactors, and 12-stage MOUDI impactors. In total, beryllium concentrations were determined for 66/68 inhalable dust samples, 62/62 total dust samples, 56/57 respirable dust samples, 54/64 8-stage Sierra samples, and 19/25 12-stage MOUDI samples. In the magnesium foundry and aluminum smelters, the concentrations obtained during specific tasks could exceed the actual permissible exposure limit of the province of Québec (0.15 μg/m 3 ) or of the ACGIH threshold limit value (TLV) (0.05 μg/m 3 ). The median of median dust concentration ratios computed from the sampling heads at the fixed station decreased as follows: IOM (1.00) > Sierra (0.76) > 37-mm cassette (0.61) > MOUDI (0.48) > respirable (0.12). The same trends were observed with the ratios of the median of median Be concentrations at the fixed station but with a larger scattering within sampling heads as follows: IOM (1.00) > Sierra (0.69) > 37-mm cassette (0.64) > MOUDI (0.54) > respirable (0.19). The median of median ratios of dust (IOM (1.00) > Sierra (0.56) > 37-mm cassette (0.35) > respirable (0.06)) and Be (IOM (1.00) > Sierra (0.66) > 37-mm cassette (0.48) > respirable (0.11)) in dust were lower, and there was less scattering for the 37-mm cassette and SKC cyclone used during breathing zone sampling than for the same sampling heads at the fixed station. Inhalable aerosol measurements should remain the tool for estimating the risk of exposure to beryllium in these settings until a clear dose response is established for these sampling heads.

Monitoring concentrations of select metals in workplace smelter airborne particulates using a Grimm 1.109 Real-time Portable Aerosol Spectrometer

Particulates containing hazardous metals and metal fumes are common in the metal smelting industry. Exposure of workers to these smelter particulates has been documented to lead to adverse health effects. In this study, select metals contained in respirable, PM10, and total dust samples where correlated to readings of a Grimm 1.109 aerosol measuring instrument in an effort to see if with the use of correction factors the metals can be accurately determined when compared to metal concentrations reported by the laboratory analysis of respirable, PM10, and total dust samples. In all, there were 16 sampling events, with three respirable, three PM10, and three total dust samples collected during each sampling event. The four metals of particular interest analyzed by the laboratory were cadmium, arsenic, lead, and copper. To more accurately and precisely determine metal concentrations when using the Grimm 1.109 with correction factors, further sampling is needed with the collection of process variables such as ore feedstock metal concentrations, process operation parameters, and weather conditions that can be included into linear regression models. Statistical model results suggest that this methodology of using metal specific correction factors to adjust Grimm 1.109 measured particulate matter concentrations to determine the selected metal concentrations in a smelter environment are within statistically accepted criteria and can be used to determine the metal concentrations in the smelter industry.

Concentrations, sources, and exposure profiles of polycyclic aromatic hydrocarbons (PAHs) in particulate matter (PM10) in the north central part of India

Airborne particulates (PM(10)) from four different areas within Agra city (a semi-arid region) were collected using respirable dust samplers during the winter season (Nov. 2005-Feb 2006) and were then extracted with methylene chloride using an automated Soxhlet Extraction System (Soxtherm). The extracts were analyzed for 17 target polycyclic aromatic hydrocarbons (PAHs) and the heterocycle carbazole. The average concentration of total PAH (TPAH) ranged from 8.04 to 97.93 ng m(-3). The industrial site had the highest TPAH concentration followed by the residential, roadside, and agricultural sites. Indeno(1,2,3-cd)pyrene, benzo(g,h,i)perylene, and benzo(b)fluoranthene were the predominant compounds found in the samples collected from all of the sites. The average B(a)P-equivalent exposure, calculated by using toxic equivalent factors derived from literature and the USEPA, was approximately 7.6 ng m(-3). Source identification using factor analysis identified prominent three, four, four, and four probable factors at industrial, residential, roadside, and agricultural sites, respectively.

Aerosols near by a coal fired thermal power plant: Chemical composition and toxic evaluation

Industrial processes discharge fine particulates containing organic as well as inorganic compounds into the atmosphere which are known to induce damage to cell and DNA, both in vitro and in vivo. Source and area specific studies with respect to the chemical composition, size and shape of the particles, and toxicity evaluations are very much limited. This study aims to investigate the trace elements associated with the aerosol particles distributed near to a coal burning thermal power plant and to evaluate their toxicity through Comet assay. PM 10 (particles determined by mass passing an inlet with a 50% cut-off efficiency having a 10-μm aerodynamic diameter) samples were collected using respirable dust samplers. Twelve elements (Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb, Se, Hg, and As) were analyzed using ICP-AES. Comet assay was done with the extracts of aerosols in phosphate buffered saline (PBS). Results show that Fe and Zn were found to be the predominant elements along with traces of other analyzed elements. Spherical shaped ultrafine particles of <1 μm aerodynamic diameter were detected through scanning electron microscope. PM 10 particles near to the coal burning power plant produced comets indicating their potential to induce DNA damage. DNA damage property is found to be depending upon the chemical characteristics of the components associated with the particles besides the physical properties such as size and shape.