Archetypes of Spatial Concentration Variability of Organic Contaminants in the Atmosphere: Implications for Identifying Sources and Mapping the Gaseous Outdoor Inhalation Exposome.

Whereas inhalation exposure to organic contaminants can negatively impact human health, knowledge of their spatial variability in the ambient atmosphere remains limited. We analyzed the extracts of passive air samplers deployed at 119 unique sites in Southern Canada between 2019 and 2022 for 353 organic vapors. Hierarchical clustering of the obtained data set revealed four archetypes of spatial concentration variability in the outdoor atmosphere, which are indicative of common sources and similar atmospheric dispersion behavior. "Point Source" signatures are characterized by elevated concentration in the vicinity of major release locations. A "Population" signature applies to compounds whose air concentrations are highly correlated with population density, and is associated with emissions from consumer products. The "Water Source" signature applies to substances with elevated levels in the vicinity of water bodies from which they evaporate. Another group of compounds displays a "Uniform" signature, indicative of a lack of major sources within the study area. We illustrate how such a data set, and the derived spatial patterns, can be applied to support the identification of sources, the quantification of atmospheric emissions, the modeling of air quality, and the investigation of potential inequities in inhalation exposure.

Atmospheric concentrations of per- and polyfluoroalkyl substances and their emissions at a waste recycling facility producing refuse-derived paper and plastics densified fuel.

To better understand the types and concentrations of per- and polyfluoroalkyl substances (PFAS) emitted into the air from waste recycling facilities that produce refuse-derived paper and plastics densified fuel (RPF) from industrial waste, we conducted an air sampling campaign at a waste recycling facility in Japan. Both passive and active air sampling were conducted, and the samples collected were used to quantify the PFAS emitted into the air during the production of RPF. Overall, few ionic PFAS were detected in the air at the facility; however, high levels of neutral PFAS (8.21-53.4 ng/m3; 20.7-130 pmol/m3) were measured in the air near the heat molding machines. The two neutral PFAS detected at the highest concentrations were 6:2 fluorotelomer alcohol and 6:2 fluorotelomer methacrylate, which are currently unregulated under the Stockholm Convention, suggesting that product manufacturers have shifted away from using regulated PFAS. Small amounts of regulated PFAS such as 8:2 fluorotelomer methacrylate and 8:2 fluorotelomer acrylate were measured in some parts of the facility. Analysis of the concentrations of PFAS in the exhaust gas from the heat molding machines revealed neutral PFAS concentrations (537-2160 ng/m3; 1350-5040 pmol/m3) that were 1-2 orders of magnitude higher than those in the surrounding indoor air. The total emission of neutral PFAS from the facility to the environment was estimated to be 0.066-0.260 g/day (0.168-0.607 mmol/day), depending on whether air volume discharged as exhaust gas or as indoor ventilation was considered. A contribution analysis of the emissions revealed that treating the exhaust gas from the heat molding machines, which constitutes over 94 % of the total emissions, is very effective at reducing PFAS emissions from the facility.

Impact of anthropogenic activities on atmospheric chlorinated paraffins in Ghana using polyurethane foam disk - passive air sampler.

Chlorinated paraffins (CPs) are a global concern due to their high production, ubiquity in the environment and potential toxicity. In Ghana, there is a significant research gap on the concentration and sources of CPs in the air, as well as insufficient regular monitoring programs to track CP levels over time. This study utilized polyurethane foam-based passive air samplers (PUF-PAS) to examine the concentrations, sources and potential human health risks of CPs in the atmosphere surrounding e-waste sites, urban areas, commercial areas and control/background areas in Ghana. The medium-chain CPs (MCCPs) dominated with an average concentration of 26.0 ± 40.1 ng/m3 and ranged from 1.78 to 240 ng/m3. Short-chain CPs (SCCPs) ranged from 0.05 to 15.2 ng/m3 and had an average concentration of 3.48 ± 3.99 ng/m3. The very short-chain CPs (C9-CPs), had an average concentration of 0.544 ± 0.524 ng/m3 and ranged from 0.091 to 2.14 ng/m3. MCCPs exceeded SCCPs by a factor of 7.5 and C9-CPs by a factor of 48. C14Cl8 was the dominant congener in MCCPs and C10Cl7 was also the dominant congener in SCCPs. E-waste was the main contributor to SCCPs and MCCPs (>30 %) in Ghana. The assessed non-cancer risks associated with CP exposure were within acceptable ranges. For cancer risk, MCCPs indicated high potential health risk but C9-CPs and SCCPs showed low risk. To the best of our knowledge, this is the first study on CPs in Ghana's atmosphere, and e-waste was identified as the country's main source of CPs. This study will help regulatory bodies create policies and procedures to control the use and disposal of chlorinated paraffins.

Temporal, spatial, and seasonal variations in airborne PCDD/F and dl-PCB concentrations around Bien Hoa hot spot, Vietnam, and health risk assessments.

Passive air samplers were used to monitor polychlorodibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorobiphenyls (dl-PCBs) between 2020 and 2022 in four residential areas around Bien Hoa hot spot (BHS) including Trung Dung (TD), Tan Phong (TP), Quang Vinh (QV), and Buu Long (BL). The total toxic equivalents of PCDD/Fs and dl-PCBs (∑TEQs) were highest in the TD area, from 284 to 642 fg TEQ/PUF day. Next was the QV area, where ∑TEQs ranged from 229 to 569 fg TEQ/PUF day. Then, ∑TEQs varied from 205 to 503 fg TEQ/PUF day in the TP area. The lowest ∑TEQs were between 179 and 385 fg TEQ/PUF day in the BL area. The temporal, spatial, and seasonal variations in concentrations of PCDD/Fs and dl-PCBs were related to the prevailing wind direction and the distance from each area to the dioxin hot spot. The average ∑TEQs for all four areas surrounding BHS in the dry season (423 fg TEQ/PUF day) were 1.4 times higher than in the rainy season (303 fg TEQ/PUF day). Health risk assessments from airborne dioxin exposure were estimated using the average daily doses through inhalation (ADDI). The ADDI for residents surrounding BHS ranged from 14.6 to 208 fg TEQ/kg BW/day. The ADDI values by areas were as follows: 23.2-208 fg TEQ/kg BW/day in the TD, 18.7-184 fg TEQ/kg BW/day in the QV, 16.7-163 fg TEQ/kg BW/day in the TP, and 14.6-125 fg TEQ/kg BW/day in the BL. These ADDI values remained within and below the 10% threshold of the WHO-recommended tolerable daily intake (100-400 fg TEQ/kg BW/day). It is necessary to control the excavation activities inside the BHS and cover the temporary storage sites of dioxin-contaminated materials to minimize the emissions of PCDD/Fs and dl-PCB into the ambient air.

Distributions of polycyclic aromatic hydrocarbons in ambient air samples from Hanoi urban areas, Vietnam, and its implications for inhalation exposure.

Sixteen PAHs in ambient air samples collected from residential and roadside areas in the Hanoi metropolitan were investigated. Total PAH concentrations in the ambient air samples ranged from 45.0 to 451 ng/m3. Among PAHs, phenanthrene was found at the most abundant and highest levels. The distributions of PAHs in the ambient air collected in the dry season were on average 26% higher than in the wet season. The PAH concentrations in the air samples collected from the traffic areas were significantly higher (about 2.7 times) than those in the residential areas, indicating that these chemicals originated from motor vehicles. According to vertical, the PAH concentrations found in the ambient air samples collected from the ground floor were significantly higher than on the upper level, however, there was not much difference when going higher (from 24 m (8th floor) to 111 m (37th floor)). The human exposure doses were estimated for two age groups (adults and children) based on the measured PAH concentrations, the inhalation rates, and body weights. The estimated exposure doses to PAHs through inhalation for adults/children were 1.13/2.86 (ng/kg-bw/d) (residential areas) and 3.24/8.18 (ng/kg-bw/d) (traffic areas), respectively. The average lifetime excess cancer risk (ECR) from inhalation exposure to PAHs was 3.0 × 10-4 at the traffic areas and 1.4 × 10-4 at the residential areas. These estimated exposure doses were above the acceptable level of the California Environmental Protection Agency (CalEPA) Office of Environmental Health Hazard Assessment (1*10-6).

Visualizing indoor ozone exposures via o-dianisidine based colorimetric passive sampler.

In this study, we developed a colorimetric ozone passive sampler (OPS) incorporating o-dianisidine, a redox dye, into a polydimethylsiloxane sheet. The reaction between ozone (O3) and o-dianisidine result in a visible yellowish color change. Unlike previous passive methods that rely on nitrate extraction or the color disappearance of indigotrisulfonate, the OPS offered improved recognition of average O3 exposure. To optimize OPS based on time-weighted average (TWA), we extracted and quantified the amount of reacted o-dianisidine after exposing OPS to O3 by varying concentrations (0-200 ppb) within 8 h. Colorimetric changes of OPS were further analyzed by capturing images, and the effective absorbance of blue scale showed the best fit (EAB, R2 =0.997). OPS validation on visual detection assessed by six parameters: limit of detection, limit of quantification, reproducibility, sampling rate, selectivity to interfering gases, and sensitivity to environmental factors. To enhance visibility, the OPS was assembled with coloration exposure guidelines, and a smartphone app was developed to quantify average O3 exposures. We further conducted field tests that showed the significant disparity between O3 concentrations and personal O3 exposures, which is considered more crucial for assessing health risks. The OPS was optimized to monitor O3 exposure levels and raise awareness among workers and occupants regarding invisible indoor hazards.

Concentrations, phase exchanges and source apportionment of polycyclic aromatic hydrocarbons (PAHs) In Bursa-Turkey.

The present study aimed to determine the pollution levels derived from polycyclic aromatic hydrocarbons (PAHs) in air, plant and soil samples and to reveal the PAH exchange at the soil-air, soil-plant and plant-air interfaces. In this context, air and soil samples were collected in approximately 10-day periods between June 2021 and February 2022 from a semi-urban area in Bursa, an industrial city with a dense population. Also, plant branch samples were collected for the last three months. Total PAH concentrations in the atmosphere (∑16PAH) and soil (∑14PAH) ranged from 4.03 to 64.6 ng/m3 and 13-189.4 ng/g DM, respectively. PAH levels in the tree branches varied between 256.6 and 419.75 ng/g DM. In all air and soil samples, PAH levels were low in the summer and reached higher values in the winter. 3-ring PAHs were the dominant compounds, and their distribution in air and soil samples varied between 28.9%-71.9% and 22.8%-57.7%, respectively. According to the results of diagnostic ratios (DRs) and principal component analysis (PCA), both pyrolytic and petrogenic sources were found to be effective in PAH pollution in the sampling region. The fugacity fraction (ff) ratio and net flux (Fnet) values indicated that the direction of movement of PAHs was from soil to air. In order to better understand the PAH movement in the environment, soil-plant exchange calculations were also achieved. The ratio of ∑14PAH values measured to modeled concentrations (1.19

Regional Distribution of Atmospheric Organophosphate Tri-/Diesters in the Pearl River Delta: Possible Emission, Photo-degradation, and Atmospheric Transportation.

The regional characteristics of atmospheric organophosphate triesters (OPEs) and organophosphate diesters (Di-OPs) in the Pearl River Delta (PRD) were investigated by passive air samplers mounting quartz fiber filters. The analytes were found on a regional scale. Atmospheric OPEs, semi-quantified using sampling rates of particulate-bonded PAHs, were in the range of 537-2852 pg/m3 in spring and in the range of 106-2055 pg/m3 in summer, with tris(2-chloroethyl)phosphate (TCEP) and tris(2-chloroisopropyl)phosphate as the main components. While atmospheric Di-OPs were semi-quantified using sampling rates of SO42-, in the range of 22.5-5576 pg/m3 in spring and in the range of 66.9-1019 pg/m3 in summer, with di-n-butyl phosphate and diphenyl phosphate (DPHP) being the main Di-OPs. Our results indicated that OPEs were mainly distributed in the central part of the region, which might be ascribed to the distribution of industry related to OPE-containing products. In contrast, Di-OPs were scattered in the PRD, suggesting local emission from their direct industrial application. Significantly lower levels of TCEP, triphenyl phosphate (TPHP), and DPHP were detected in summer than in spring, implying that these compounds might be partitioned off particles as the temperature increased and due to possible photo-transformation of TPHP and DPHP. The results also suggested the long-distance atmospheric transportation potential of Di-OPs.

Polycyclic aromatic hydrocarbons (PAHs) levels in PM10 and bulk deposition using Mosspheres: A pilot study in an urban environment.

Study air polycyclic aromatic hydrocarbons (PAHs) capturing the spatial variability of their concentrations is not economically feasible with conventional methods. In the present work we tested, for the first time and under real conditions, the suitability for intensive monitoring and mapping these contaminants of innovative, cost-effective passive air samplers known as "Mosspheres". The Mosspheres, filled with a devitalised Sphagnum palustre L. moss clone, were placed in a 575 m. grid in a medium-sized European city for three months. Concentrations in the moss tissues of 15 priority PAHs, including benzo(a)pyrene, were determined and converted into PM10 and bulk deposition with the equations proposed in a recent study. Low concentrations of PAHs were detected, with only a few enriched points never exceeding the legal thresholds, near industrial areas and busy roads. Despite these low PAH concentrations, Mosspheres were able to detect spatial structure for several PAHs and high-resolution pollution maps were constructed for these compounds. The results prove the high sensitivity and suitability of Mosspheres for mapping PAH levels and for quantitative (i.e. PAHs with 4 or more rings) and qualitative (3-ring PAHs) monitoring. Thus, this study supports their widespread application and its potential inclusion in European Directives on air quality control.

Vehicular influence on atmospheric concentrations and source apportionment of polycyclic aromatic hydrocarbons in some major cities in three regions of Ghana using epiphytic lichens.

The present study employed epiphytic lichens as biomonitor and passive air sampler for the assessment of fifteen (15) atmospheric polycyclic aromatic hydrocarbons (PAHs) in some major cities in three regions of Ghana. A total of 36 composite lichen samples were collected and analysed using Gas Chromatography - Tandem Mass Spectrometry (GC-MS-MS). The total PAH recorded ranged between 1909.9 ng/kg (A36) and 250,091.4 ng/kg (W15). Due to the inherent deficiencies in using a single source apportionment tool, multiple source apportionment methods including diagnostic ratios, principal component analysis/absolute principal component scores (PCA-APCS) and APCS with automatic linear model (APCS-ALM) were used to ascertain the source of PAHs in the lichens. The diagnostic ratios revealed a mix source of wood/grass and petrol/petroleum fuel combustion, with the major source ascribing to wood/grass combustion. The source apportionment confirmatory statistical test conducted with the PCA-APCS and APCS-ALM, were in good agreement with the diagnostic ratio. Both PCA-APCS and APCS-ALM suggested two significant sources (p < 0.0), with wood/grass combustion as the major (contributing 77.8%) and mix petroleum related sources being the other with 22.2% contribution of PAHs to the receptor sites. The study found PCA-APCS and especially APCS-ALM to be an effective statistical tool for PAH source apportionment in passive air samplers. To our knowledge, this is the first use of lichens for PAH monitoring in the country. Therefore, this study could serve as an inexpensive and real time bio-monitoring tool for air quality assessment in the African sub-region and the world at large.

Accumulations and equilibrium conditions of organophosphate esters (OPEs) in the indoor window film and the estimation of concentrations in air.

The study of the fate of organophosphate esters (OPEs) in the interior environment is vital because of the growing use of OPEs. Organic films on glass are both sink and sources of indoor pollutants. Indoor window films have been employed as passive air samplers to collect OPEs in the indoor air. Nevertheless, little is known about the development and equilibrium condition of OPEs on indoor window films during the film formation process. In this study, the concentrations of twelve OPEs in indoor window films from different buildings on a university campus and the growth thickness of the films as a function of sampling time were investigated in different seasons. Ten out of the 12 OPEs were detected in window film with >50 % frequency. Tris (2-chloroethyl) phosphate (TCEP) and tris (1-chloro-2-propyl) phosphate (TCPP), which are chlorinated and toxic OPEs, were the dominant OPEs found in the winter. The majority of OPEs in window films exhibited linear growth patterns within 77 days. Temperature, humidity, ventilation, and seasonality all affected the concentrations of various OPEs in the window films. Low molecular weight OPEs, such as tri-n-butyl phosphate and TCEP, attained equilibrium between indoor air and window films within 49 or 77 days. The indoor air concentrations of OPEs were estimated from their film concentrations based on the theoretical approach for the passive air sampler. In winter, the predicted gas-phase air concentrations of OPEs (3.7 ng/m3 for TECP) were significantly lower than or comparable to summer (11 ng/m3, p < 0.05). To the best of our knowledge, this is the first attempt to combine uncertainty and sensitivity analysis to understand the behaviors of OPEs in indoor film and air.

Spatial and temporal variation, source identification, and toxicity evaluation of brominated/chlorinated/nitrated/oxygenated-PAHs at a heavily industrialized area in eastern China.

Some derivatives of polycyclic aromatic hydrocarbons (PAHs) such as chlorinated and brominated PAHs (Cl/BrPAHs), nitrated and oxygenated PAHs (N/OPAHs) have attracted significant concern due to their high toxicity. Knowledge of the profiles, formation mechanisms, and potential sources of these toxic chemicals near the industrial complexes is essential for their pollution control and management. In this study, we monitored Cl/BrPAHs, N/OPAHs, and PAHs at 24 sampling sites near a heavily industrialized area (steel, chemical, and rubber plants) using passive air samplers during the heating period (7 December 2019 to 15 April 2020) and the non-heating period (2 June 2020 to 4 October 2020). The total average concentrations of 16 BrPAHs, 8 ClPAHs, 17 NPAHs, 6 OPAHs, and 18 PAHs during both sampling periods were 471 pg/m3, 229 pg/m3, 312 pg/m3, 2120 pg/m3, and 63.1 ng/m3, respectively. Except for NPAHs, BrPAHs, ClPAHs, OPAHs, and PAHs all showed higher levels during the heating period. The spatial distributions of Cl/BrPAHs, N/OPAHs, and PAHs exhibited a similar pattern, with the highest concentrations detected in the vicinity of the steel industry. Congener profiles of PAH derivatives indicated that mono-substituted low molecular weight compounds (2-3 rings) were dominant. The major formation mechanisms of halogenated PAHs were discussed by correlation analysis and relative Gibbs free energies, and direct bromination of parent PAHs could be the major formation mechanism of BrPAHs in this study. Diagnostic ratios showed that NPAHs were mainly derived from primary emissions, but the contribution of secondary formation was increased at heavily contaminated sites. The positive matrix factorization model extracted four Cl/BrPAHs, three N/OPAHs, and four PAHs factors, and the result showed that PAHs and their derivatives mainly derived from industrial and combustion sources, photochemical reactions, vehicle emissions, and crude oil volatilization, etc.

Personal Passive Air Samplers for Chlorinated Gases Generated from the Use of Consumer Products.

Various chlorine-based disinfectants are being used during the COVID-19 pandemic; however, only a few studies on exposure to harmful gases resulting from the use of these disinfectants exist. Previously, we developed a personal passive air sampler (PPAS) to estimate the exposure level to chlorine gas while using chlorinated disinfectants. Herein, we investigated the color development of the passive sampler corresponding to chlorine exposure concentration and time, which allows the general population to easily estimate their gas exposure levels. The uptake and reaction rate of PPAS are also explained, and the maximum capacity of the sampler was determined as 1.8 mol of chlorine per unit volume (m3) of the passive sampler. Additionally, the effects of disinfectant types on the gas exposure level were successfully assessed using passive samplers deployed in a closed chamber. It is noteworthy that the same level of chlorine gas is generated from liquid household bleach regardless of dilution ratios, and we confirmed that the chlorine gas can diffuse out from a gel-type disinfectant. Considering that this PPAS reflects reactive gas removal, individual working patterns, and environmental conditions, this sampler can be successfully used to estimate personal exposure levels of chlorinated gases generated from disinfectants.

Regional characteristics of atmospheric δ34S-SO42- over three parts of Asia monitored by quartz wool-based passive samplers.

A new method is presented for measuring atmospheric contents and δ34S-SO42- in airborne particulate matter using quartz wool disk passive air samplers (Pas-QW). The ability of Pas-QW samplers to provide time-integrated measurements of atmospheric SO42- was confirmed in a field calibration study. The average sampling rate of SO42- measured was 2.3 ± 0.3 m3/day, and this was not greatly affected by changes in meteorological parameters. The results of simultaneous sampling campaign showed that the average SO42- contents in Pakistan and the Indochina Peninsula (ICP) were relatively lower than that of China. The spatial distribution of SO42- concentrations was largely attributed to the development of the regional economies. The range of δ34S values observed in Pakistan (4.3 ± 1.4‰) and the ICP (4.5 ± 1.2‰) were relatively small, while a large range of δ34S values was observed in China (3.9 ± 2.5‰). The regional distribution of sulfur isotope compositions was significantly affected by coal combustion. A source analysis based on a Bayesian mixing model showed that 80.4 ± 13.1% and 19.6 ± 13.1% of artificial sulfur dioxide (SO2) sources in China could be attributed to coal combustion and oil combustion, respectively. The two sources differed greatly between regions, and the contribution of oil combustion in cities was higher than previously reported data obtained from emission inventories. This study confirmed that the Pas-QW is a promising tool for simultaneously monitoring atmospheric δ34S-SO42- over large regions, and that the results of the isotope models can provide a reference for the compilation of SO2 emission inventories.

Development of a personal passive air sampler for estimating exposure to effective chlorine while using chlorine-based disinfectants.

With an increasing use of indoor disinfectants such as chlorine (Cl2 ) and hypochlorous acid, a convenient sampler for estimating exposure to oxidants, such as effective chlorine, is necessary. Here, we developed a personal passive air sampler (PPAS) composed of a redox dye, o-dianisidine, in a polydimethylsiloxane (PDMS) sheet. o-Dianisidine readily reacts with gaseous oxidants generated by bleach usage, and its color changes as the reaction progresses; hence, personal exposure to effective chlorine could be easily detected by the naked eye, while cumulative exposure could be determined by measuring concentrations of o-dianisidine reacting with it. The PPAS was calibrated, and a sampling rate of 0.00253 m3 /h was obtained using a small test chamber. The PPAS was tested with the help of ten volunteers whose personal exposure to Cl2 -equivalent gas was estimated after bathrooms were cleaned using spray and liquid-type household disinfection products, and the accumulated exposure-gas concentrations ranged from 69 to 408 ppbv and 148 to 435 ppbv, respectively. These PPAS-derived exposure concentrations were approximately two orders lower than those estimated using ConsExpo, suggesting a significant overestimation by prevailing screening models, possibly due to the ignorance of transformation reactions.

Atmospheric concentration, source identification, and health risk assessment of persistent organic pollutants (POPs) in two countries: Peru and Turkey.

It is known that some persistent organic pollutants (POPs) are used worldwide, and these pollutants are dangerous for human health. However, there are still countries where measurements of these pollutants have not been adequately measured. Although many studies have been published for determining the concentrations of POPs in Turkey, there are limited studies in Latin American countries like Peru. For this reason, it is essential both to conduct a study in Peru and to compare the study with another country. This study is aimed at determining the atmospheric POPs such as polycyclic aromatic hydrocarbon (PAH), organochlorine pesticide (OCP), and polychlorinated biphenyl (PCB) concentrations using passive air samplers in Yurimaguas (Peru) and Bursa (Turkey). Molecular diagnosis ratios and ring distribution methods were used to determine the sources of PAHs. According to these methods, coal and biomass combustions were among the primary sources of PAHs in Peru, while petrogenic and petroleum were the primary sources of PAHs in Turkey. Then, α-HCH/γ-HCH and ß-/(α+γ)-HCH ratios were used to determine the sources of OCPs. According to the α-HCH/γ-HCH ratios, the primary sources of OCPs in both countries were lindane. Similarly, according to ß-/(α+γ)-HCH ratios, the HCHs have been historically used in Peru while they were recently utilized in Turkey. Finally, homologous group distributions were used to determine the sources of PCBs. Similar distributions of homologous groups were observed in the sampling sites in both countries. Also, the homologous group distributions obtained have been determined that industrial activities could be effective in the sampling areas in both countries. When the cancer risks that could occur via inhalation were evaluated, no significant cancer risk has been determined in both countries.

Occurrence of polycyclic aromatic hydrocarbons (PAHs) in air and soil surrounding a coal-fired thermal power plant in the south-west coast of India.

This investigation focused on the potential sources of polycyclic aromatic hydrocarbons (PAHs) in different matrices and their temporal variations surrounding a coal-fired thermal power plant in India. Samples were collected in different seasons for 1 year. Gas chromatography-mass spectroscopy (GC-MS) was used to perform the measurement of 16 priority PAHs. Average PAH concentrations were ranged from 0.71 to 2.99 ng/m3 in air and 1.59-22.7 ng/g in soil respectively. High levels of PAHs were found in soil compared to air, which indicated deposition in soil. This could be because of the fallout of high-molecular-weight compounds. During the monsoons, PAH concentrations in the air were the lowest compared to the other seasons because of the dilution effect. Phenanthrene, fluoranthene, and pyrenes were dominant in the air, contributing up to 32.5%, 22.7%, and 19.2% of total PAHs, respectively. On the other hand, soils contained fluoranthene (12.3%), pyrene (10.7%), benzo[b]fluoranthene (10%), chrysene (9.82%), and indeno[123-c,d]pyrene (9.64%) compounds. The occurrence of indeno[1,2,3-cd]pyrene (9.14 ng/g) indicated that the soil is contaminated from fly ash and diesel emissions from the thermal power plant and vehicular emission. The diagnostic ratios, thematic maps, and principal component analysis revealed that the fly ash, diesel emissions from the thermal power plant, vehicles, and biomass burning were the probable sources of PAHs in the study area. The human health risk assessment studies reveal that the soil samples are more prone to carcinogenicity than air samples. As per our knowledge, this is the first report on the impact of PAHs on air and soil in this region.

Spatial and temporal variations of volatile organic compounds using passive air samplers in the multi-industrial city of Ulsan, Korea.

The source-receptor relationship of volatile organic compounds (VOCs) is an important environmental concern, particularly in large industrial cities; however, only a few studies have identified VOC sources using high spatial resolution data. In this study, 28 VOCs were monitored in Ulsan, the biggest multi-industrial city in Korea. Passive air samplers were seasonally deployed at eight urban and six industrial sites. The target compounds were detected at all sites. No significant seasonal variations of VOCs were observed probably due to the continuous emissions from major industrial facilities. Benzene, toluene, ethylbenzene, xylenes, and styrene accounted for 66-86% of the concentration of Σ28 VOCs. The spatial distribution of the individual VOCs clearly indicated that petrochemical, automobile, non-ferrous, and shipbuilding industries were major VOC sources. Seasonal wind patterns were found to play a role in the spatial distribution of VOCs. Diagnostic ratios also confirmed that the industrial complexes were the dominant VOC sources. The results of principal component analysis and correlation analyses identified the influence of specific compounds from each industrial complex on individual sites. To the best of our knowledge, this is the first comprehensive report on the seasonal distribution of VOCs with high spatial resolution in a metropolitan industrial city in Korea.

Passive indoor air sampling for consumer product chemicals: a field evaluation study.

Innovative exposure measurement methods are needed for large environmental health studies, particularly for semivolatile organic compounds (SVOCs). Active air sampling methods are costly to implement, but passive air sampling presents a viable method. To expand and improve the use of passive air samplers (PAS) for indoor SVOC monitoring, we designed a unique, compact sampler using commercially available polyurethane foam (PUF) disks housed within durable, easy-to-setup, low-profile enclosures. We evaluated the new design using co-located active air samplers (AAS) and analyzed for SVOCs. Most of the targeted SVOCs found using active sampling (27 of 33) were also detected using passive sampling. We found good agreement (R2 = 0.88) between active and passive sampling methods for characterizing the relative abundance of each chemical, and the measured active sampler concentrations and passive sampler masses were significantly positively correlated for 14 of 21 chemicals, for which correlations could be estimated. We found that measurements of many SVOCs originating from consumer products and typically found in the gas-phase (log KOA < 10) can be reliably ranked-and thus appropriate for epidemiological studies-using this PAS design. These SVOCs include diethyl phthalate, AHTN, HHCB, tris(2-chloroethyl) phosphate, dibutyl phthalate, and tris(1-chloro-2-propyl) phosphate, as well as methyl paraben, benzophenone, and benzophenone-3, which have not previously been measured by passive sampling. This PAS can be used in epidemiological studies involving consumer product chemicals and complements other novel exposure tools.

Polydimethylsiloxane (silicone rubber) brooch as a personal passive air sampler for semi-volatile organic compounds.

Exposure assessments conducted using a personal sampler include the contribution of human activities to exposure that is neglected when using a stationary air sampler. This study evaluated the uptake characteristics and application of the polydimethylsiloxane (PDMS or silicone rubber) brooch as a personal passive air sampler (PPAS) for measuring concentrations of two groups of semi-volatile organic compounds (SVOCs), namely phthalates and organophosphate esters (OPEs), indoors in proximity to the breathing zone. Uptake rates of the PDMS brooch were calibrated against a personal low volume active air sampler (PLV-AAS) co-deployed on each of five study participants working in offices for 8 hs daily for four days. Sampling rates measured here ranged from 0.41 ±â€¯0.33 to 1.33 ±â€¯0.34 m3 day-1 dm-2 with an average value of 0.86 ±â€¯0.29 m3 day-1 dm-2. Personal air concentrations of 1211 to 2640 ng m-3 for ∑5 phthalates and 254 to 663 ng m-3 for ∑5 OPEs were measured for three study participants who used the PDMS brooches continuously for seven days. These concentrations resulted in estimated inhalation exposures of 19,400 to 42,400 ng day-1 for ∑5 phthalates and 4,070 to 10,600 ng day-1 for ∑5 OPEs. This study demonstrated that the PDMS brooch can be used to assess inhalation exposure when worn for at least 24 h indoors, for compounds present in >4 ng m-3 in air such as individual phthalates and OPEs tested here.