Air pollution is a common problem in mega-cities in Asia, resulting in high levels of particulate matter (PM). In this study, 24 h samples of airborne particulate matter (PM
2.5 and PM
10) was ...collected for two weeks in urban locations in Kabul and Mazar-e Sharif, Afghanistan. The samples were analyzed for twenty
n-alkanes, fifteen polycyclic aromatic hydrocarbons (PAHs) and eighteen oxygenated PAHs (oxy-PAHs). The results were compared to a reference location in Umeå, Sweden. The main objectives were: to characterize the organic fraction in PM
2.5, with focus on oxy-PAHs, PAHs and
n-alkanes, assess relationships between compound groups, and investigate possible source categories. Mean PM
10, levels were 260 μg m
−3, and 334 μg m
−3 and mean PM
2.5 levels were 86 μg/m
3and 68 μg m
−3 in Kabul and Mazar-e Sharif, respectively. The higher ratio of PM
2.5 to PM
10 in Kabul than Mazar-e Sharif or Umeå was reflected in the high number of small particles, as collected by a particle counter. Kabul and Mazar-e Sharif had high levels of PAHs and oxy-PAHs compared to Umeå and previously reported data from Western countries. Generally, the highest individual levels of oxy-PAHs were found for ketones (0.27–33 ng m
−3), whereas the quinone levels were lower (0.027–3.1 ng m
−3). High correlations (
r > 0.96) between PAHs and oxy-PAHs were found at both locations. Diagnostics for
n-alkanes, such as the carbon preference index, and the most abundant species,
C
max, and the presence of unresolved complex mixture indicated a higher contribution from coal and petroleum sources in Kabul. Models generated by principal component analysis (PCA) and positive matrix factorization (PMF) both suggested separate sources for lower molecular weight
n-alkanes and higher molecular weight
n-alkanes. The PAHs and the oxy-PAHs were not separated in either the PCA or the PMF models, indicating that they had similar sources and are perhaps relatively unspecific as source markers. Nevertheless, the PAHs and oxy-PAHs were good markers for bad air quality in the urban locations in Afghanistan in comparison to data from Western countries. Based on the models and diagnostic ratios it is suggested that traffic and combustion of coal and biomass were the dominating sources of the high levels of particle-bound organic compounds.
► Size-distribution data reveal high number of small particles in Kabul. ► Concentrations of particle-bound PAHs and oxy-PAHs were high in Kabul and Mazar-e Sharif. ► Evaluation by source apportionment tools indicated a high load from traffic, coal and biomass. ► PAHs and oxy-PAHs were highly correlated and inseparable by principal component analysis.
The reactive gases perfluoroisobutene and carbonyl fluoride are highly toxic and difficult to analyze in air. For this paper, the available sampling and analysis methods involving gas ...chromatography/mass spectrometry were investigated for their potential to give unambiguous identification and quantification of perfluoroisobutene and carbonyl fluoride, for which no such methods exist. Although high concentrations of perfluoroisobutene could be analyzed directly by manual split injection, sorbent sampling followed by thermal desorption GC/MS allowed lower concentrations to be analyzed. However, a significant degradation of perfluoroisobutene observed after thermal desorption analysis inspired the use of derivatization of perfluoroisobutene with 3,4‐dimercaptotoluene. The use of Tenax TA sorbent tubes spiked with 3,4‐dimercaptotoluene and trimethylamine in a molar ratio of 1:8 proved successful for the quantification of a unique perfluoroisobutene derivative, and the method was validated for atmospheres in the range of 0.13–152 ppb with a relative standard deviation of less than 20% and an accuracy of 90%. Although carbonyl fluoride was less stable than perfluoroisobutene, direct analysis was possible at high concentrations but the response was not linear. The 3,4‐dimercaptotoluene derivatization method developed was also applicable for quantification of carbonyl fluoride atmospheres.
Exhaled breath (EB) contains various volatile organic compounds (VOCs) that can indicate specific biological or pathological processes in the body. Analytical techniques like gas chromatography-mass ...spectrometry (GC-MS) can be used to detect and measure these exhaled biomarkers. In this study, the objective was to develop a non-invasive method of EB sampling in animals that were awake, as well as to analyze EB for volatile biomarkers specific for chlorine exposure and/or diagnostic biomarkers for chlorine-induced acute lung injury (ALI). To achieve this, a custom-made sampling device was used to collect EB samples from 19 female Balb/c mice. EB was sampled both pre-exposure (serving as internal control) and 30 min after exposure to chlorine. EB was collected on thermal desorption tubes and subsequently analyzed for VOCs by GC-MS. The following day, the extent of airway injury was assessed in the animals by examining neutrophils in the bronchoalveolar lavage fluid. VOC analysis revealed alterations in the EB biomarker pattern post-chlorine exposure, with eight biomarkers displaying increased levels and six exhibiting decreased levels following exposure. Four chlorinated compounds: trichloromethane, chloroacetone, 1,1-dichloroacetone and dichloroacetonitrile, were increased in chlorine-exposed mice, suggesting their specificity as chlorine EB biomarkers. Furthermore, chlorine-exposed mice displayed a neutrophilic inflammatory response and body weight loss 24 h following exposure. In conclusion, all animals developed an airway inflammation characterized by neutrophil infiltration and a specific EB pattern that could be extracted after chlorine exposure. Monitoring EB samples can readily and non-invasively provide valuable information on biomarkers for diagnosis of chlorine-induced ALI, confirming chlorine exposures.
Metal organic frameworks based on zirconium nodes (Zr-MOFs) have impressive adsorption capacities, and many can rapidly hydrolyze toxic organophosphorus nerve agents. They could thus potentially ...replace commonly used adsorbents in respiratory filters. However, current test methodologies are poorly adapted to screen the large number of available MOFs, and data for nerve agent adsorption by MOFs are scarce. This paper presents a miniaturized method for assessing the capacity of Zr-MOFs for dynamic gas phase adsorption and degradation of sarin (GB) into the primary hydrolysis product isopropyl methyl phosphonic acid (IMPA). The method was validated by comparing the dynamic adsorption capacities of activated carbon (AC) and NU-1000 for GB under dry and humid conditions. Under dry conditions, unimpregnated AC had a greater capacity for GB uptake (0.68 ± 0.06 g/g) than pelletized NU-1000 (0.36 ± 0.03 g/g). At 55% relative humidity (RH), the capacity of AC was largely unchanged (0.72 ± 0.10 g/g) but that of NU-1000 increased slightly, to 0.46 ± 0.10 g/g. However, NU-1000 exhibited poor water retention at 55% RH. For both adsorbents, the degree of hydrolysis of GB into IMPA was significantly greater at 55% RH than under dry conditions, but the overall degree of hydrolysis was limited in both cases. Further tests at higher relative humidities are needed to fully evaluate the ability of NU-1000 to degrade GB after adsorption from the gas phase. The proposed experimental setup uses very small amounts of both adsorbent material (20 mg) and toxic agent, making it ideal for assessing new MOFs. However, future methodological challenges are reliable generation of sarin at higher RH and exploring sensitive methods to monitor degradation products from nerve agents in real-time.
Picric acid (PA) is a severe environmental and security risk due to its unstable, toxic, and explosive properties. It is also challenging to detect in trace amounts and in situ because of its highly ...acidic and anionic character. Here, we assess sensing of PA under nonlaboratory conditions using surface-enhanced Raman scattering (SERS) silver nanopillar substrates and hand-held Raman spectroscopy equipment. The advancing elasto-capillarity effects are explained by molecular dynamics simulations. We obtain a SERS PA detection limit on the order of 20 ppt, corresponding attomole amounts, which together with the simple analysis methodology demonstrates that the presented approach is highly competitive for ultrasensitive analysis in the field.
Polycyclic aromatic hydrocarbons (PAHs) and their oxygenated analogues (OPAHs) are ubiquitous air pollutants known to cause adverse health effects. PAH air levels are commonly monitored by active ...sampling but passive sampling has become popular because of its lower cost and simplicity, which facilitate long-term sampling and increased spatial coverage. However, passive samplers are less suitable for short-term sampling and are in general less accurate than active samplers because they require reliable sampling rate (Rs) measurements for individual analytes under diverse environmental conditions. In this study a small passive sampler designed to sample both particle-bound and gaseous compounds was evaluated and calibrated for PAHs and OPAHs in a traffic environment by co-deployment with active samplers for two weeks. Despite the relatively low average air concentrations of PM10 (20 μg/m3), PM2.5 (5 μg/m3), total PAHs (4.2 ng/m3), and OPAHs (2.3 ng/m3) at the site, detectable quantities (on average 24 times above blank values) of the full range of PAHs and OPAHs were captured, with low variability (average RSD of 16%). This was accomplished by using a Tenax® TA-modified glass fiber substrate that is compatible with highly sensitive thermal desorption GC-MS analysis, which made it possible to achieve detection limits per sample in the pg range. Experiments with inverted samplers revealed that the relative contribution of gravitational settling to the sampling of particles carrying PAHs and OPAHs was around 3.5 times larger than other deposition mechanisms. Average Rs values for individual OPAHs and PAHs were 0.046 ± 0.03 m3/day and 0.12 ± 0.07 m3/day, respectively, with no appreciable difference between the values for particle-associated and gaseous compounds. Furthermore, the Rs values were competitive with other currently used passive samplers if normalized for substrate area. Overall, the new sampler’s performance, simplicity and ability to generate relatively time-resolved data make it a promising candidate for diverse SVOC monitoring studies.
•Excellent detectability and repeatability at short exposure time in a low concentration environment.•Very sensitive analytical protocol based on TD-GC-MS.•Sampling rates for OPAHs and PAHs of 0.046 ± 0.03 and 0.12 ± 0.07 m3/day, respectively.•No apparent difference in sampling rates for particle-associated and gaseous compounds.•Gravitational settling is the dominant uptake mechanism for particles carrying PAHs and OPAHs.
The sampler’s performance, simplicity, and ability to generate short-term data for PAHs and OPAHs make it a promising candidate for a vast variety of SVOC air monitoring studies.
Abstract
Over the past 10 years, a number of safety measures for reducing firefighters’ exposure to combustion particles have been introduced in Sweden. The most important measure was the reduction ...in the time firefighters wear suits and handle contaminated equipment after turn-outs involving smoke diving. This study was divided into two parts, those being to investigate the level of protection obtained by multiple garment layers and to assess exposure during a standardized smoke diving exercise. First, realistic work protection factors (WPFs) were calculated by comparing air concentrations of the full suite of gaseous and particle-bound polycyclic aromatic hydrocarbons (PAHs) inside and outside structural ensembles, including jacket and thick base layer, during a tough fire extinguishing exercise using wood as the fuel. Second, during a standardized smoke diving exercise, exposure was assessed by measuring PAH skin deposition and levels of eight urinary PAH metabolites in 20 volunteer student firefighters before and after the exercise. The average WPF for the sum of 22 PAHs was 146 ± 33 suggesting a relatively high protective capacity but also indicating a substantial enrichment of contaminants with a risk of prolonged dermal exposure. Accordingly, in the second exercise, the median levels of skin-deposited Σ14-PAHs and urinary 1-hydroxypyrene significantly increased 5-fold (21 to 99 ng/wipe) and 8-fold (0.14 to 1.1 µmol mol−1 creatinine), respectively, post exposure. Among the PAH metabolites investigated, 1-hydroxypyrene proved to be the most useful indicator of exposure, with significantly elevated urinary levels at both 6 h and 20 h after the exercise and with the strongest correlation to dermal exposure. Metabolites from two-ring and three-ring PAHs were eliminated faster while levels of 3-hydroxy-benzoapyrene did not meet the detection criteria. The results from correlation studies indicated that dermal uptake was a major route of exposure in accordance with previous findings. To summarize, this study shows that some of the newly adopted protective measures were correctly implemented, and should continue to be followed and be more widely adopted.
In urban areas, inhalation of fine particles from combustion sources such as diesel engines causes adverse health effects. For toxicity testing, a substantial amount of particulate matter (PM) is ...needed. Conventional sampling involves collection of PM onto substrates by filtration or inertial impaction. A major drawback to those methodologies is that the extraction process can modify the collected particles and alter their chemical composition. Moreover, prior to toxicity testing, PM samples need to be resuspended, which can alter the PM sample even further. Lastly, the choice of the resuspension medium may also impact the detected toxicological responses. In this study, we compared the toxicity profile of PM obtained from two alternative sampling systems, using in vitro toxicity assays. One system makes use of condensational growth before collection in water in an impinger – BioSampler (CG‐BioSampler), and the other, a Dekati® Gravimetric Impactor (DGI), is based on inertial impaction. In addition, various methods for resuspension of DGI collected PM were compared. Tested endpoints included cytotoxicity, formation of cellular reactive oxygen species, and genotoxicity. The alternative collection and suspension methods affected different toxicological endpoints. The water/dimethyl sulfoxide mixture and cell culture medium resuspended particles, along with the CG‐BioSampler sample, produced the strongest responses. The water resuspended sample from the DGI appeared least toxic. CG‐BioSampler collected PM caused a clear increased response in apoptotic cell death. We conclude that the CG‐BioSampler PM sampler is a promising alternative to inertial impaction sampling.
Inhaling air pollution fine particles, such as from diesel engines, poses health risks. Particulate matter (PM) toxicity testing requires a significant amount of PM mass. This study compares PM toxicity in vitro from two sampling systems condensational growth before collection in water in an impinger – BioSampler (CG‐BioSampler) and Dekati® Gravimetric Impactor (DGI). Also, different resuspension methods of DGI collected PM were studied. The employed resuspension methods affected toxicological endpoints differently.
The use of electronic cigarettes (E‐cigs) is rapidly increasing. The latest generation of E‐cigs is highly customizable, allowing for high heating coil temperatures. The aim of this study was to ...assess the toxic potential of a fourth‐generation E‐cig. Aerosols generated from E‐liquid with (24 mg/mL) and without nicotine, using a fourth‐generation E‐cig, were chemically analysed and compared with cigarette smoke (K3R4F). Human lung epithelial cell lines and distal lung tissue explants were exposed to E‐cig vapour extract (EVE) and cigarette smoke extract for 24 hours and assessed for viability, inflammation, oxidative stress and genotoxicity. E‐cig aerosols contained measurable levels of volatile organic compounds, aldehydes and polycyclic aromatic hydrocarbons, in general, to a much lesser extent than cigarette smoke. Higher levels of certain carbonyls, e.g. formaldehyde, were detected in the E‐cig aerosols. EVEs decreased cell viability of BEAS‐2B cells, whereas little effect was seen in A549 cells and distal lung tissue. The nicotine‐containing EVE caused a greater decrease in cell viability and significant increase in DNA damage than the nicotine‐free EVE. Increased cytotoxicity, reactive oxygen species production and genotoxicity were seen with cells and tissue exposed to cigarette smoke extract compared with EVEs. Although E‐cig aerosols were less toxic than cigarette smoke, it was not benign. Moreover, the EVE containing nicotine was more toxic than the nicotine‐free EVE. More research is needed on the short‐ and long‐term health effects of vaping and the usage of newly emerging E‐cig devices to evaluate better the potential negative effects of E‐cigs on human health.
There are few data on the toxic potential of new‐generation electronic cigarette (E‐cig) models. Aerosols generated from a fourth‐generation E‐cig contained volatile organic compounds, aldehydes and polycyclic aromatic hydrocarbons but to a lesser extent than cigarette smoke. E‐cig aerosol extracts were cytotoxic to BEAS‐2B cells, and caused increased cell death and DNA strand breaks when containing nicotine. More research is needed on the short‐ and long‐term health effects of vaping.
Metal oxide fumes form at high temperatures, for instance, during welding or firing ammunition. Inhalation exposure to high levels of airborne metal oxide particles can cause metal fume fever, ...cardiovascular effects, and lung damage in humans, but the associated underlying pathological mechanisms are still not fully understood. Using human alveolar epithelial cells, vascular endothelial cells, and whole blood model systems, we aimed to elucidate the short‐term effects of well‐characterized metal particles emitted while firing pistol ammunition. Human lung epithelial cells exposed to gunshot smoke particles (0.1–50 μg/ml) produced reactive oxygen species (ROS) and pro‐inflammatory cytokines (interleukin 8 (IL‐8), granulocyte‐macrophage colony‐stimulating factor (GM‐CSF)) that activate and recruit immune cells. Particles comprising high copper (Cu) and zinc (Zn) content activated human endothelial cells via a non‐ROS‐mediated mechanism that triggered immune activation (IL‐8, GM‐CSF), leukocyte adhesion to the endothelium (soluble intercellular adhesion molecule 1 (sICAM‐1)), and secretion of regulators of the acute‐phase protein synthesis (interleukin 6 (IL‐6)). In human whole blood, metal oxides in gunshot smoke demonstrated intrinsic properties that activated platelets (release of soluble cluster of differentiation 40 ligand (sCD40L), platelet‐derived growth factor B‐chain homodimer(PDGF‐BB), and vascular endothelial growth factor A (VEGF‐A)) and blood coagulation and induced concomitant release of pro‐inflammatory cytokines from blood leukocytes that further orchestrate thrombogenesis. The model systems applied provide useful tools for health risk assessment of particle exposures, but more studies are needed to further elucidate the mechanisms of metal fume fever and to evaluate the potential risk of long‐term cardiovascular diseases.
Inhalation exposure to metal fumes emitted during pistol firing can cause metal fume fever in humans. The mechanisms behind short‐term toxic responses to metal fumes were investigated in exposure systems using lung epithelium, vascular endothelium, and whole blood. Gunshot smoke particles elicited toxic responses and immune activation in lung epithelial cells, vascular endothelial cells, and white blood cells and activated thrombocytes that orchestrate thrombogenesis, creating a milieu that contributes to metal fume fever and potentially accelerates the development of cardiovascular diseases.
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