Passive Air Samplers Research Articles

Assessment of human indoor exposure to PAHs during the heating and non-heating season: Role of window films as passive air samplers

The study of indoor organic film on planar surfaces has been shown to be important to assess the transport and fate of organic pollutants in indoor environments. Limited research showed the relationship between equilibrium status of polycyclic aromatic hydrocarbons (PAHs) and the growth days for indoor window films. To accomplish this goal, indoor window film samples were collected in relation to film growth days in Northeast China. PAHs were frequently detected in window films collected during heating season (H-season), with concentrations significantly higher than that of non-heating season (NH-season). Accumulation characteristics of PAH suggested that PAH concentrations (ng/m2 film) were growing near-linearly with time. Partitioning status for PAHs between gas and window films under different accumulation stage from 1 to 11 weeks was investigated during the two seasons. The equilibrium status of PAHs in the films suggested that the octanol–air partition coefficient (logKOA) of the targeted PAHs should be approximately <12 in order to reached the equilibrium stage within 11 weeks of growth. For all the growth days, the proportion of samples that reached equilibrium status for PAHs in the indoor window film samples were further calculated. The total air concentration of the target PAHs were predicted, giving median values of 900 and 240 ng/m3 in H-season and NH-season, respectively. Human health risk posed by PAHs was calculated in this research showing greater risks found for H-season than NH-season. The estimated incremental lifetime cancer risks were considered as safe with values lower than the WHO recommended guideline.

Polycyclic aromatic hydrocarbons and polychlorinated biphenyls in soils and atmosphere of Western Canadian mountains: The role of source proximity, precipitation, forest cover and mountain cold-trapping

Abstract Soil was sampled and XAD-2 based passive air samplers were deployed for one year at several locations on four mountains and a mountain pass in British Columbia (BC), Canada. The mountains, ranging between ca. 1100–1500 m in altitude, varied in their proximity to likely sources of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs). Considered mountain-by-mountain, proximity to sources determines the concentrations of PCBs: Grouse Mountain, immediately to the North of Vancouver, had the highest PCB concentrations in both atmospheric gas phase and soil, while three other mountains in southern BC had levels approximately a factor of three lower. PCB concentrations along the Chilkoot Trail in remote Northern BC were more than an order of magnitude lower. While Grouse Mountain also had the highest PAH concentrations, gas phase concentrations of PAHs elsewhere were only slightly lower and varied little between the different mountains. Soil concentrations of PAHs were highly elevated on urban Grouse Mountain and lowest on Blue Grouse Mountain, which stands out by having the driest climate. On a site-by-site basis, PCB concentrations in the atmospheric gas phase decreased with increasing elevation but show indication of upslope enrichment in the soils of three of the mountains. These include the most urban mountain and two rural mountains, which have more precipitation and forest coverage than the remaining two mountains. There was no difference between congeners in the extent of upslope enrichment, indicating that the temperature gradient along the mountains was not sufficiently large to cause fractionation. Atmospheric gas phase and soil concentrations of PAHs on a mountain decrease with distance from likely sources. Although sources of PAHs are too widespread to observe any trends of mountain cold-trapping, PCBs are clearly experiencing cold-trapping in Western Canadian mountains.

Tree bark as a biomonitor for assessing the atmospheric pollution and associated human inhalation exposure risks of polycyclic aromatic hydrocarbons in rural China

Inhalation exposure to atmospheric polycyclic aromatic hydrocarbons (PAHs) is posing a great threat to human health. Biomass combustion in rural areas contributes greatly to the total PAH emission in China. To conduct a comprehensive risk assessment of ambient PAHs in rural China, a nationwide air sampling campaign was carried out in this study. The 16 U.S. Environmental Protection Agency priority PAHs in tree bark, which was employed as a passive air sampler, were analyzed. The summation of the 16 PAHs ranged from 11.7 to 12,860 ng/m3 in the air of rural China. The national median benzo(a)pyrene equivalent (BaPeq) concentration was 18.4 ng/m3, with the range from 0.334 to 2497 ng/m3. The total inhalation carcinogenic risks of individual PAHs, with the exception for naphthalene, were very low (<1 × 10−6) at most of the sampling sites. The national median excess lifetime lung cancer risk associated with inhalation exposure to atmospheric PAHs was 20.3 × 10−6, corresponding to a population attributable fraction (PAF) of 3.38‰. Our estimations using tree bark were comparable to those reported in other studies and the uncertainties of the variables in the dataset were within the acceptable levels, demonstrating that tree bark is feasible for assessing the atmospheric PAH pollution and associated health risks. We feel that the outputs from this study can assist decision-makers focusing on protecting human health against exposure to atmospheric PAHs in rural China.

Spatiotemporal variation of atmospheric nitrated polycyclic aromatic hydrocarbons in semi-arid and petrochemical industrialized Lanzhou City, Northwest China.

Polyurethane foam-based passive air sampler (PUF-PAS) and passive dry deposition sampler (PAS-DD) were adopted, for thefirst timeever in China, to investigate the atmospheric levels and spatial-temporal distributions of air burdens and dry deposition fluxes of 12 nitrated polycyclic aromatic hydrocarbons (NPAHs) during winter and summer seasons in a multiple site field campaign in a petrochemical industrialized capital city in Northwest China. The results showed that the highest air concentration and dry deposition fluxes of ∑12NPAHs occurred at a heavy traffic site among 18 sampling sites in both winter and summer season. The lowest air concentration and dry deposition fluxes were observed at the background site. The mean concentrations of ∑12NPAHs in the ambient air were 8.6 ± 8.1ngm-3 in winter and 15 ± 11ngm-3 in summer. The mean dry deposition fluxes of ∑12NPAHs were 1.8 × 103 ± 1.9 × 103ng(m2day)-1 in winter and 1.4 × 103 ± 1.3 × 103ng(m2day)-1 in summer, respectively. The total concentration of 12 NPAHs was mainly dominated by 1-nitro-naphthalene (1N-NAP) and 2-nitro-naphthalene(2N-NAP) in air, accounting for 32% in winter and 45% in summer of ∑12NPAHs. 7-Nitro-benzo [a] anthracene (7N-BaA) made the largest contribution to dry deposition fluxes of ∑12NPAHs, accounting for 28% in winter and 24% in summer. The ratios of ∑12NPAHs/∑15pPAHs (parent polycyclic aromatic hydrocarbons) were calculated to identify potential sources of NPAHs across the city. The results revealed that the main atmospheric air concentration and dry deposition fluxes of 12 NPAHs could be attributed to the primary emissions in winter and the secondary reaction formation in summer. The sources of primary emissions could be traced back to petrochemical, steel mills, as well as aluminum industries in winter and vehicle exhaust in summer. Higher ∑12NPAH/∑15pPAH concentration ratios in summer indicated that the oxidation of pPAHs contributed to the secondary formation of NPAHs via atmospheric chemical reactions in this petrochemical industrialized mountain-valley city.

Use of XAD®-2 passive air samplers for monitoring environmental trends of PAHs, PCBs and pesticides in three different sites in Strasbourg and its vicinity (east of France)

The continuous release of hazardous chemicals to the atmosphere leads to the importance of their analysis in order to understand ambient air quality. In this study, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and pesticide concentrations in the atmosphere were monitored using XAD®-2 resin-based passive samplers. The study was performed in three sites in the vicinity of and within Strasbourg, France enclosing a rural site (La Wantzenau), an urban site (the botanical garden of the University of Strasbourg) and a suburban site (Robertsau) during four successive years. Sampling was done between April 22 and May 20 in 2013, April 07 and June 02 in 2014, April 28 and June 09 in 2015, and between April 15 and May 27 in 2016. Results showed a different behavior in pollutants accumulation between the rural and the urban sites. For instance, LMW PAHs were found in rural area while HMW PAHs were found in the urban area mainly due to vehicles emissions. For PCBs analyses, “Robertsau” and the “botanical garden” presented higher concentrations and a higher number of detected PCBs than “La Wantzenau”, with total trend for lighter PCBs contribution over the years. Finally, pesticides analyses showed different repartition based on the different pesticides used and arisen from domestic uses of from environmental release and decomposition by the different environmental and meteorological conditions that may have occurred.

Using Polyurethane Foam-Based Passive Air Sampling Technique to Monitor Monosaccharides at a Regional Scale

Monosaccharides are important tracers of pollution aerosol from biomass burning. Air sampling of monosaccharides is often conducted using active samplers. However, applicability of sampling monosaccharides using polyurethane foam passive air samplers (PUF-PASs) has not been investigated, since passive air samplers are often applied to monitor semivolatile organic contaminants in large scale and remote area. Our study successfully collected atmospheric monosaccharides using PUF-PASs, providing a valuable tool for monosaccharides sampling. PUF-PAS sampling rates for individual monosaccharides were calibrated using an active sampler for 92 days, and were 1.1, 1.5, and 1.1 m3/d for levoglucosan, mannosan, and galactosan, respectively. Degradation of monosaccharides in PUF-PAS was demonstrated to be negligible by spike test of 13C-labeled levoglucosan. Furthermore, passive sampling was carried out at 11 sites in the Pearl River Delta of Southern China from January to April and July to September of 2015. Monosaccharide concentrations derived from PUF-PASs were comparable with the reported data obtained by active sampling, demonstrating that the PUF-PAS approach is valid for monosaccharides monitoring. On the basis of our approach, we found that there is a clear correlation between the monosaccharide concentrations and the MODIS fire activities during January-April.

Using Silicone Wristbands to Assess Children's Exposure to Organophosphate Esters and Brominated Flame Retardants

Organophosphate esters (OPEs) are often used as flame retardants and plasticizers and, like brominated flame retardants (BFRs), are frequently detected in indoor environments. Human exposure to semi-volatile organic compounds (SVOCs), including OPEs and BFRs, is widespread, which is particularly concerning for children who often experience higher exposures than adults and are especially vulnerable to long-term negative health impacts. Silicone wristbands have been used as personal passive samplers to examine adult ambient and occupational exposures to a suite of SVOCs and have the potential to be used as a non-invasive and inexpensive method of measuring personal exposures to chemical mixtures. Previously, among adults, OPEs and polybrominated diphenyl ethers (PBDEs, a class of BFRs) on bands have been significantly and positively associated with metabolites in pooled urine samples and serum biomarkers, respectively (rs&amp;#61;0.4-0.7; p&amp;lt;0.01). Here, we examine the utility of wristbands for assessing children&amp;#8217;s exposure to 6 OPEs and several classes of BFRs. Children ages 3-6 and their families were recruited in 2014-16 as part of a study examining children&amp;#8217;s exposures to SVOCs. Paired passive air samplers, hand wipes, and dust from the home were collected and analyzed; OPEs on hand wipes were significantly correlated with biomarkers from pooled urine samples (rs&amp;#61;0.2-0.4, p&amp;lt;0.05). Wristbands (n&amp;#61;75) were also deployed among these children and will be analyzed for OPEs and BFRs. Levels on the bands will also be compared to OPE urinary metabolites, which were previously analyzed in our laboratory, and serum PBDEs. Preliminary analyses among wristbands worn by children in a similar age range indicate that OPEs and BFRs are ubiquitously detectable on the bands (GM&amp;#61;2.6-187.5 ng/g). Results from this study will be used to validate wristbands as a tool for assessing personal exposure among children.

Passive Samplers for the Assessment of Occupational Exposure to Flame Retardants among Canadian E-Waste Dismantlers

The mass of e-waste produced globally is growing dramatically. One hazard, especially for e-waste handlers, are flame retardants (FRs) which are added to electronic and electrical equipment in order to meet flammability standards. FR air concentrations can be measured using active air sampling equipment, but this sampling train can be cumbersome for workers. Passive samplers made from polydimethylsiloxane (PDMS) or silicone rubber, are one option for simplifying the measurement process. Here, we compared PDMS passive air samplers (PDMS-PASs) with active air samplers for the assessment of FR air levels at an e-waste dismantling facility in Ontario, Canada for the purpose of estimating occupational exposure.Sampling was conducted daily over a five days in February 2017. PDMS-PASs were hung at 4 workbenches and a central workplace, and were co-deployed with an active low-volume air sampler which consisted of a GFF followed by a PUF/XAD/PUF sandwich. Each PDMS and low-volume sampler was harvested after 24 hours. Samples were extracted and analysed for 13 FRs, including novel brominated flame retardants (NFRs), polybrominated diphenyl ethers (PBDEs) and organophosphate esters (OPEs), using gas chromatography mass spectrometry (GC-MS).The most abundant FRs were the now-banned PBDEs (BDE-209 accounted for ~70-98 % of FRs collected by PDMS-PASs). Total median concentrations of PBDEs in PDMS-PASs at the central workplace and workbenches were 1930 and 2900 ng/m3, respectively. PDMS-PASs provided comparable estimates of air concentrations to active samplers. The chemical profiles from the PDMS matched those from active sampling, indicating that differences in compound gas-particle partitioning did not affect the sampling efficiency of PDMS.Levels of FRs in air collected from this Canadian e-waste recycling facility suggest PDMS-PASs can be used to estimate occupational exposure to FRs, even for short deployment times at workplaces with elevated levels of these chemicals.

Passive Air Sampling for Gaseous Mercury in Workplace Atmospheres and for Personal Inhalation Exposure Monitoring

Inhalation exposure to gaseous elemental mercury (GEM) continues to be a concern in a number of workplaces. Examples are facilities handling mercury-containing electronic waste, such as compact flu...

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.

Progress on the passive air sampling techniques and occurrence of persistent organic pollutants in remote areas

Persistent organic pollutants can undergo long-range transport and deposit in remote areas (e.g., high mountains, polar areas) through “global distillation effects” or “cold condensation”. This behavior of POPs would pose great risks to the fragile polar ecosystem. Passive air samplers are widely applied to air sampling program at large scales and they are very useful to monitor the pollution levels of legacy POPs in remote areas. They have been widely used to trace the environmental behavior of emerging POPs in the past few decades. The application of PAS has contributed a lot to offer fundamental data to the Stockholm Convention. This study introduced five passive air sampling techniques (SPMD-PAS, PUF-PAS, XAD-2-PAS, SIP-PAS and FTS) and their development history, especially emphasizing on their application and the current pollution of legacy and emerging POPs in remote areas, such as Antarctic, Arctic and Tibetan Plateau. Furthermore, the potential need and future application of PAS were also discussed.

Multidrug Resistant Bacterial Pathogens in the Indoor Air and Floors of Surgical Wards in a University Hospital

Objective: The hospital environment is a major source of&#x0D; nosocomial pathogens. These pathogens could contaminate and colonize surgical&#x0D; wounds leading to infections. This study evaluated the bacteriological quality&#x0D; of air and floors of surgical wards of a University Teaching Hospital in Abuja,&#x0D; Nigeria.&#x0D; &#x0D; Methods: Bacteriological&#x0D; quality of air and floor of surgical wards of the hospital was evaluated using&#x0D; passive air sampling and swabbing methods respectively. The isolates were&#x0D; characterized using rapid test kits and antibiotic susceptibility was&#x0D; determined by the modified Kirby-Bauer disc diffusion method. &#x0D; &#x0D; Results: A&#x0D; total of 121 bacterial isolates comprising eleven species were isolated. In the&#x0D; air and floor of all the surgical wards, Staphylococcus&#x0D; spp. (&amp;gt;42%) was the most prevalent Gram-positive bacterium followed by&#x0D; Bacillus subtilis (20.4%). Among the Gram-negative bacterial isolates, Pseudomonas aeruginosa (13.0%) and Proteus mirabilis (9.0%) were the most&#x0D; prevalent in the air and floor, with occasional detection of Acinetobacter baumannii and other&#x0D; members of the Enterobacteriaceae&#x0D; family. The bacterial isolates exhibited diverse degrees of susceptibility to&#x0D; the commonly prescribed antibiotics. The isolated bacteria were mostly&#x0D; sensitive to fluoroquinolones.&#x0D; &#x0D; Conclusion: This study documented the diverse environmental&#x0D; microbiota of the surgical wards of the hospital. The high resistance of the&#x0D; isolated bacteria to the commonly prescribed antibiotics in the hospital&#x0D; highlighted the need for improved infection control and patient safety&#x0D; protocols in the hospital so as to mitigate the spread of nosocomial infections&#x0D; in the surgical wards of the hospital. J&#x0D; Microbiol Infect Dis 2018; 8(3):108-113

Land Use Regression Approach to Model NO2–Concentrations in a Swedish Medium-City

In order to visualize the geographical distribution of air pollution concentration realistically, we applied the Land Use Regression (LUR) model in the urban area of Gothenburg, Sweden. The concentration of NO2 was obtained by 25 passive air samplers during 7-20 May, 2001. Explanatory variables were estimated by GIS in buffers ranging from 50 to 500 m-radii. Linear regression was calculated, and the most robust were attained to the multiple linear regression. Additionally, the LUR model was compared with a dispersion model. The final model explained 81.7% of the variance of NO2 concentration with presence of sum of traffic within 150 m and altitude as predictor variables. Mann-Whitney Test did not exhibit significant difference between yearly concentrations of NO2 measured by regulatory measurement sites and measurements from passive samplers, thus LUR model was extrapolated for later years and mapped. The extrapolation indicated more elevated levels of pollution for the years 2003, 2006 and 2010. The results highlight the contribution of traffic on air quality and suggest that LUR modelling may explain the variations of atmospheric pollution with good accuracy. In addition, the model puts focus on spatial and temporal variability needed to describe retrospective exposure to air pollution in studies that evaluate health effects.

Characterizing Spatial Diversity of Passive Sampling Sites for Measuring Levels and Trends of Semivolatile Organic Chemicals.

Passive air sampling of semivolatile organic compounds (SVOCs) is a relatively inexpensive method that facilitates extensive campaigns with numerous sampling sites. An important question in the design of passive-sampling networks concerns the number and location of samplers. We investigate this question with the example of 17 SVOCs sampled at 14 background sites across the Czech Republic. More than 200 time series (length 5-11 years) were used to characterize SVOC levels and trends in air between 2003 and 2015. Six polychlorinated biphenyls (PCBs), 6 polyaromatic hydrocarbons (PAHs), and 5 organochlorine pesticides (OCPs) at 14 sites were assessed using data from the MONET passive sampling network. Significant decreases were found for most PCBs and OCPs whereas hexachlorobenzene (HCB) and most PAHs showed (mostly insignificant) increases. Spatial variability was rather low for PCBs and OCPs except for dichlorodiphenyltrichloroethane (DDT) and rather high for PAHs. The variability of the SVOC levels and trends depends on characteristics of the sites including their remoteness, landscape, population, and pollution sources. The sites can be grouped in distinct clusters, which helps to identify similar and, thereby, potentially redundant sites. This information is useful when monitoring networks need to be optimized regarding the location and number of sites.

Investigating NOx Concentrations on an Urban University Campus Using Passive Air Samplers and UV–Vis Spectroscopy

Gas-phase nitrogen oxides are important in the formation of tropospheric ozone. NOx (NO and NO2) as well as tropospheric ozone have been shown to have negative effects on human health. Therefore, accurately measuring NOx concentrations in the atmosphere is important. In this laboratory experience, students measured ambient NOx concentrations using a relatively simple and inexpensive passive sampling/UV–vis spectroscopy technique. The students used two different types of spectrophotometers to determine limits of detection and ambient NOx concentrations. Data demonstrated both spectrometers behaved similarly, proving laboratories utilizing different spectrophotometers could accurately perform the experiment. Although not statistically verified due to the limited number of passive samplers employed in the pilot experiment, measured NOx concentrations were similar to those calculated by a local air quality model (within approximately 50 parts per billion). At the end of the laboratory experience, students compared their measured NO2 concentrations to the United States Environmental Protection Agency’s primary and secondary standard of 53 parts per billion (annual mean). The initial learning goals of the experiment included the following: the successful creation of calibration curves, the determination of spectrophotometer limit of detection, and the calculation of ambient NOx concentrations. The experiment is appropriate for students enrolled in analytical and environmental chemistry courses.

A Thermo-Cavitation Method to Determine Organochlorine Pesticides in Gas and Particle Phases Collected in Polyurethane Foam Used in Passive Air Samplers

Persistent organic pollutants (POPs) are globally dispersed substances considered to have adverse effects on health and ecosystems. Organochlorine pesticides (OCPs) are POPs. OCPs can be collected from the air by passive samplers using polyurethane foam (PUF). POPs in PUF are generally extracted by Soxhlet, considered as reference extraction method. We offer a different methodology approach to extract 16 OCPs from the PUF. This technology extracts, filters, collects the sample and evaporates the solvent, without sample transfer. It is a modification of the ultrasound-assisted extraction micro-scale cell (M-UAE-MSC) previously patented by our group. A full factorial experimental design (23 centred) was used to optimise the extraction conditions. The most desirable conditions were 50 °C, 40% ultrasound potency and 20-min extraction time, two extractions. OCP recoveries ranged from 67 to 110%. OCP recoveries were equivalent by M-UAE-MSC and Soxhlet techniques. The method was not suitable for five OCPs, and further refinement is needed. Method linearity (r2) was ≥ 0.98. Limits of detection were observed between 1.2 and 4.6 ng PUF−1, while limits of quantification were found between 3.9 and 15.2 ng PUF−1. The method was applied to determine OCPs collected by PUF passive samplers in Mexico. Endosulfan I was the OCP most frequently observed. The M-UAE-MSC optimised extraction conditions, decreased the extraction time from several hours to less than 1 h and reduced three times the solvent consumption with respect to Soxhlet. This afforded a decrease in the waste generation and a reduction in the OCP-extraction cost up to 80%. The results of this study reveal an efficient and consistent procedure, as well as a simpler, faster, cost-saving and more environmentally friendly method to determine OCPs collected by PUF in passive samplers compared to Soxhlet extraction.

New brominated flame retardants and dechlorane plus in the Arctic: Local sources and bioaccumulation potential in marine benthos

The aim of the present study was to investigate the presence and bioaccumulation of new flame retardants (nBFRs), polybrominated diphenyl ethers (PBDEs) and dechlorane plus (DDC-CO) in the marine environment close to an Arctic community. Passive sampling of air and water and grab sampling of sediment and amphipods was used to obtain samples to study long-range transport versus local contributions for regulated and emerging flame retardants in Longyearbyen, Svalbard. BDE-47 and -99, α- and β-tetrabromoethylcyclohexane (DBE-DBCH), syn- and anti-dechlorane plus (DDC-CO) were detected in all investigated matrices and the DDC-COss at higher concentrations in the air than reported from other remote Arctic areas. Water concentrations of ΣDDC-COSs were low (3 pg/L) and comparable to recent Arctic studies. ΣnBFR was 37 pg/L in the water samples while ΣPBDE was 3 pg/L. In biota, ΣDDC-COSs dominated (218 pg/g ww) followed by ΣnBFR (95 pg/g ww) and ΣPBDEs (45 pg/g ww). When compared with other areas and their relative distribution patterns, contributions from local sources of the analysed compounds cannot be ruled out. This should be taken into account when assessing long-range transport of nBFRs and DDC-COs to the Arctic. High concentrations of PBDEs in the sediment indicate that they might originate from a small, local source, while the results for some of the more volatile compounds such as hexabromobenzene (HBBz) suggest long-range transport to be more important than local sources. We recommend that local sources of flame retardants in remote areas receive more attention in the future.

The occurrence of brominated flame retardants in the atmosphere of Gauteng Province, South Africa using polyurethane foam passive air samplers and assessment of human exposure

Polyurethane foam passive samplers were deployed between May 2016 and January 2017 to evaluate concentrations of polybrominated diphenyl ethers (PBDEs), selected alternative flame retardants (AFRs) and total hexabromocyclododecane (HBCDD) (sum of α-, β-, and γ-HBCDD). The PUF air samplers were deployed in semi–urban, urban, industrial and landfill sites in Gauteng Province, South Africa. The acquired results presented a clear semi urban–industrial–urban–landfill concentration gradient for all BFRs measured. Taking into account 2 sampling periods (cold and warm periods) (n = 16), the atmospheric concentrations of ∑9PBDEs, HBCDDs and ∑AFRs were 100–2820 pg m−3, 12–117 pg m−3 and 41–4660 pg m−3, respectively, for the sparsely populated residential area, densely populated residential area, industrial area and the landfill area. In all cases, BDE 47, 99, and 209 were the most dominant congeners with high detection frequencies. The highest calculated daily exposure dose in Gauteng Province atmosphere was 0.61 and 1.54 ng kg −1 – bw d −1 for adults and children respectively. The estimated total intake of PBDEs was 0.47–33.4 ng kg −1 – bw d −1, which was generally below the lowest adverse effect limit (LOAEL), suggesting that the residents of Gauteng Province may not be significantly affected as a result of their exposure to these pollutants through inhalation. However, this does not necessarily suggest that the pollutants are harmless to human health, since they have the tendency to bioaccumulate in biological systems. Incidentally, this is the first study from Africa to report on the atmospheric concentrations of PBDEs, HBCDDs and AFRs in urban, landfill and industrial areas. The findings from this study further highlight the contributory role of landfills as potential sources of BFRs into the atmosphere.

Occurrence, distribution, and air-water exchange of organophosphorus flame retardants in a typical coastal area of China

Organophosphorus flame retardants (OPFRs) have been detected ubiquitously in the air and water worldwide, but no study has focused on their air-water exchange process. Here, we investigated the concentrations, distributions, and seasonal variations of OPFRs in the coastal air and water of Dalian, China. The total concentrations of 10 OPFRs in the air based on passive air sampling ranged from 0.50 to 20.0 ng/m3, while the concentrations of OPFRs in the water dissolved phase ranged from 48.3 to 681 ng/L. Relatively high concentrations were mainly discovered near the industry areas or river estuaries, suggesting that point sources along the coastline may significantly influence the local OPFR concentrations. Tris(2-chloroisopropyl) phosphate (TCIPP) was the most dominant congener followed by tris(2-chloroethyl) phosphate (TCEP), which was consistent with their high production and persistence. The air-water gaseous exchanges of OPFRs were estimated for the first time according to their concentrations in gaseous and dissolved phases. Generally, the gaseous exchange fluxes varied with sampling site and period. TCIPP showed the highest gaseous deposition flux of −395 ± 1211 ng/(m2 d), while TCEP showed the highest emission flux of 1414 ± 2093 ng/(m2 d). The dry deposition fluxes of OPFRs (0.05–822 ng/(m2 d)) were also calculated based on their particle fractions in the air. The result suggested that both gaseous exchange and particle deposition processes significantly influenced the air-water transport of OPFRs in this area.

Spatiotemporal distribution and dynamic modeling of atmospheric gaseous polycyclic aromatic hydrocarbons in a rapidly urbanizing city: Nanjing, China.

Multiple studies have evaluated the concentration and lung cancer risk of polycyclic aromatic hydrocarbons (PAHs). However, the monitoring and dynamic modeling of PAHs with a high resolution were relatively insufficient. We investigated the spatiotemporal distribution of gaseous PAH concentrations using passive air samplers with high sampling density in an industrial city of Nanjing, China (January and October 2015) and found that the gaseous PAH concentrations in western Nanjing were higher than those in eastern Nanjing, mainly because of emission source distribution and wind action. There were notable seasonal changes in PAH concentrations: winter > autumn > spring > summer. We developed an atmospheric PAH dynamic model with a high resolution of 1km2 based on the advection-diffusion equation and coupled with an emissions inventory and atmospheric transportation processes. Acenaphthene was selected as a proxy for gaseous PAHs. The modeled acenaphthene concentrations were similar to the concentrations measured. Moreover, we used the model to identify the impact of meteorological factors on gaseous PAHs via scenario analysis and found that a narrow-range temperature change and even heavy rainfall may not significantly affect atmospheric gaseous PAH concentrations, whereas the wind played an important part in transferring PAHs and changing their geographic distribution.