High Concentrations Of Polycyclic Aromatic Hydrocarbons Research Articles

Global occurrence, food web transfer, and human health risks of polycyclic aromatic hydrocarbons in biota.

Polycyclic aromatic hydrocarbons (PAHs) are widespread organic pollutants that pose significant health risks due to their bioaccumulation in the biota. This study examines the global distribution of PAHs in biota, identifies key factors influencing using boosted regression tree (BRT) models, analyzes their transfer through trophic magnification factors (TMF), and evaluates health risks using the EPA risk assessment model. Research on PAHs has grown from 1978 to 2023, peaking in 2021, with 171 out of 241 studies (71.1%) focusing on marine ecosystems. The highest PAH concentrations are observed in the Mediterranean Sea, Red Sea, and North American coastal regions, primarily influenced by industrial and human activities, such as factory emissions and ship transport. BRT analysis shows region factors and feeding habitats significantly influence PAH levels. TMF analysis shows that biodilution is the main mechanism for PAH attenuation, with concentrations decreasing as trophic levels increase. Additionally, health risk assessment further illustrate that toxicity equivalent (TEQ) values are highest in Egypt and Turkey. Across all populations in Egypt, the United States, Turkey, Portugal, and China, as well as children in Portugal and Sweden, there are potential risks from aquatic product consumption (10-6<CRI<10-4), with CRI values positively correlated with liver cancer incidence. While hazard quotients (HQ)<1 suggest overall safety, higher obesity risks are noted, particularly among women and adolescents.

Polycyclic aromatic hydrocarbons formed during the pyrolysis of dimethoxymethane (DMM). Comparison with other oxygenated additives

The influence of the temperature (1075 – 1475 K) and inlet concentration of fuel (33,333 and 50,000 ppmv) on the formation of the 16 EPA-priority Polycyclic Aromatic Hydrocarbons (PAH) from the pyrolysis of dimethoxymethane (DMM) was analyzed. PAH were detected in different phases (gas phase, adsorbed on soot, and stuck on the reactor walls) and quantified by gas chromatography-mass spectrometry (GC–MS). Additionally, the toxicity of the PAH samples, expressed as B[a]P-eq, was analyzed in all experiments. A comparison with the results obtained from the pyrolysis of other oxygenated compounds was also performed and similar behaviors were observed. The main results showed that, at low temperatures, the highest concentrations of PAH were found in the gas phase, while at high temperatures were found on soot. For both inlet concentrations of DMM, the light PAH, such as naphthalene and acenaphthylene, were found in major concentrations, in all phases and temperatures. The heavy PAH, such as fluoranthene and pyrene, increased its concentration on soot at highest temperatures. The highest formation of soot was obtained at 1475 K and follows the trend: 2,5DMF < tert-butanol < 2MF < 2butanol < iso-butanol < 1-butanol < ethanol < DMC < DMM. The highest formation of PAH was at 1275 K with the tendency: tert-butanol < 2-butanol < 1-butanol < 2,5DMF < 2MF < iso-butanol < ethanol < DMC < DMM. The highest B[a]P-eq value was found in the pyrolysis of 2,5DMF, and the lowest in the pyrolysis of DMM.

Seasonality, sources apportionment, human health risks assessments, and potential implications on the atmospheric chemistry of polycyclic aromatic hydrocarbons in size-segregated aerosols from a Romanian metropolitan area

Urbanization and industrialization are important transformations shaping the current statement of the society, enhancing significantly the combustion emissions which are threatening the global climate system, air quality, and human health. These emissions contain polycyclic aromatic hydrocarbons (PAHs) which are well known for their high toxicity. The present study is the first assessing the seasonal variation of 17 PAHs in size segregated fractions of atmospheric aerosol particles from a Romanian metropolitan area. In addition to sources apportionment and health risks, the potential role of PAHs on the atmospheric chemistry in the area was also addressed. Higher PAHs concentrations were determined in winter season, the highest values being quantified for benzo[b]fluoranthene, benzo[a]pyrene, and indeno[1,2,3-cd]pyrene. Each analyzed PAH exhibited a dominant peak in the accumulation mode (0.1–1.0 μm), with maxima at 381 nm. Gasoline combustion was identified as a significant contributor to the PAHs levels in the atmospheric aerosols from the area. Biomass-burning contributions were highlighted during the winter and autumn seasons. The positive matrix factorization (PMF) model apportioned four PAHs sources, as follows: vehicular (31%), mixed combustion (33%), biomass and wood burning (19%), and coal and natural gas combustion (18%) sources. Concentration-weighted trajectory (CWT) analysis method revealed clear contributions to PAHs abundances from local and regional air masses. Alveolar region of adults seems to have the highest susceptibility for PAHs deposition. Values exceeding acceptable limits for carcinogenic risk throughout the year are associated with benzo[a]pyrene, benzo[b]fluoranthene, indeno[1,2,3-cd]pyrene, benzo[a]anthracene etc. The present study can be considered as a reference in the region in order measures of mitigation and control for PAHs emission sources to be introduced.

SOURCE APPORTIONMENT OF ATMOSPHERIC AND SEDIMENTARY PAHS FROM KOLKATA, INDIA USING COMPOUND-CLASS-SPECIFIC RADIOCARBON ANALYSIS (CCSRA)

ABSTRACT Polycyclic aromatic hydrocarbons (PAHs) are major air pollutants that are ubiquitously produced by the combustion of organic materials, and it is extremely important to identify their pollution sources. In this study, molecular fingerprinting and compound class-specific radiocarbon dating (CCSRA) were performed on PAHs from canal sediments and air samples collected in Kolkata, India’s third largest city (population approximately 16 million), where PAHs pollution has been a serious problem. Average PAH (Σ12-parent PAHs) concentrations in air samples were 65.1 ng m–3 in summer and 70.9 ng m–3 in winter and in canal sediments were 32.7 µg g–1, which are classified as “very high-level” pollution. Molecular fingerprinting using methyl-PAH/PAH (MPAHs/PAHs) ratios and isomer pair ratios with molecular weights of 178, 202, 228, and 276 suggested that wood and coal combustion were the dominant sources of PAHs in the sediment, and that atmospheric PAHs were influenced by oil combustion in addition to them. The fraction of contemporary carbon (ƒC) of sedimentary PAHs (0.056–0.100), together with the extremely low MPAHs/PAHs ratio results, lead to the conclusion that the major source of the high concentration of PAHs in the canals is from coal combustion. On the other hand, the ƒC of atmospheric PAHs (0.272–0.369) was close to the share of biomass fuels in India’s domestic fuel consumption in 2011 (about 35%). Furthermore, the observed ƒC-discrepancy between atmospheric and sedimentary PAHs in the same urban environment was interpreted to give an insight into the loading pathway of PAHs to canal sediments in Kolkata.

Levels, enrichment characteristics, and health risks of halogenated and parent polycyclic aromatic hydrocarbons in traditional smoked pork

Chinese traditional smoked pork was contaminated with polycyclic aromatic hydrocarbons (PAHs) and chlorinated and brominated PAHs (ClPAHs and BrPAHs; XPAHs) during the smoking process. Therefore, our study investigated the concentrations, enrichment characteristics, and health risks associated with PAHs, as well as ClPAHs and BrPAHs in Chinese traditional smoked pork. The total concentrations of PAHs, ClPAHs and BrPAHs in traditional smoked pork ranged from 90.0 to 79200 ng/g fat weight (fw), 23.6–2340 pg/g fw and 0.550–200 pg/g fw, respectively, which were significantly higher than their levels found in raw pork. Additionally, the concentrations of PAHs and XPAHs in the surface of smoked pork were higher than those in the inner parts. High-ring PAHs exhibited a greater enrichment compared to low-ring PAHs, and BrPAHs exhibited greater enrichment ability than ClPAHs in smoked pork. Furthermore, the ability of individual congeners to migrate from the surface to the inner parts of the smoked pork were varied. When the smoking fuels were similar, a longer smoking time resulted in higher concentrations of PAHs and XPAHs in smoked pork, while casing effectively reduced their concentrations. The correlation between XPAH and parent PAH concentrations indicated that chlorination of PAHs was one of the primary formation mechanisms of some monochlorinated PAHs. Over half of the smoked pork samples posed a potential carcinogenic risk, particularly the surface samples. It is recommended to remove the surface parts when consuming smoked pork and to improve traditional smoking methods to mitigate the health risks.

Concentration of polycyclic aromatic hydrocarbons (PAHs) in bread and health risk assessment across the globe: A systematic review and meta-analysis.

Although bread is the principal food in most countries, polycyclic aromatic hydrocarbons (PAHs) may be present and pose a potential risk to consumers. The aim of this review is to provide a comprehensive report on the concentration and health risks associated with PAHs in bread around the world. Various databases, such as Scopus, PubMed, Science Direct, and Google Scholar, were searched from their beginnings until December 2023 for this systematic review, which included 34 potentially relevant articles with data relating to 1057 bread samples. Utilizing a multilevel regression modeling approach, the study evaluated various factors such as fuel type, bread type, and geographical location. Following the initial evaluation, in 26.47% and 20.28% of all studies, the levels of Bap and PAH4 were higher than the permissible limit values, respectively. Based on the isomer ratios, 55.88% of the studies associated the presence of PAHs in bread samples with pyrogenic/coal combustion sources. According to the carcinogenic risk results, bread consumers in all studies have been exposed to moderate or high levels of carcinogenicity. The most significant risk levels are associated with the consumption of bread in Egypt, Kuwait, Iran, and India. Moreover, meta-regression analysis demonstrated significantly higher toxicity equivalent quotient and cancer risk mean values in bread baked using fossil fuels compared to other sources (p<.05). The high concentrations of PAHs, especially Benzo[a]pyrene, in bread pose a serious public health risk. Stringent regulations and monitoring are crucial to reduce contamination. Further research is necessary to develop safe processing methods to remove PAHs in bread.

Distribution and bioaccumulation status of polycyclic aromatic hydrocarbons (PAHs) in Veraval coastal waters using copepods as bio-indicators.

The study investigates the pollution characteristics of 16 priority PAHs, accumulated in copepods from a major fishing harbour and its adjacent coastal waters of Veraval, west coast of India. The total PAH accumulation is in the range of 922.16-27,807.49ngg-1 dw, with the mean concentration of 5776.59ngg-1 dw. High concentrations of PAHs were present in the copepod samples from inside the harbour. Notably, there was no significant correlation between the lipid content of copepods and the accumulation of PAHs. The molecular diagnostic ratio method (MDR) indicates that the PAH sources are petrogenic in origin, while principal component analysis (PCA) points to petroleum, coal combustion and vehicular emission sources. Total cancerous PAHs (C-PAHs) in the study area dominate by 40% of the total PAHs identified; moreover, the bioaccumulation factor (BAF) is very high in the offshore area, which is also a fishing ground. The global relevance and magnitude of the present study in the Veraval, one of the prime seafood exporting hubs in India, should be dealt with utmost avidity as the accumulation status of PAHs in the zooplankton has never been explored in the Indian coastal waters. Moreover, the current study gives the foremost data on the bioaccumulation status of PAHs in copepods from the tropical waters of India.

Polycyclic Aromatic Hydrocarbons (PAHs) in Grilled Marshmallows.

The aim of this study was to assess potential health risks among children and adolescents consuming various grilled marshmallows using a survey and to determine polycyclic aromatic hydrocarbons (PAHs) in these food products. PAH analysis in grilled marshmallows included a dilution stage with deionized water and liquid-liquid extraction with cyclohexane and solid-phase extraction (SPE). PAH fractions were initially analyzed via high-performance thin-layer chromatography, and PAH concentrations were determined via gas chromatography with a tandem mass detector using the selective reaction monitoring (SRM) mode. This study on the consumption of grilled marshmallows was conducted among approximately 300 children and adolescents. The preliminary results indicated that "raw" marshmallows did not contain PAHs. However, the obtained data suggested the exposure of young people to carcinogenic PAHs from grilled marshmallows (63.5% of them consumed marshmallows). Carcinogenic benzo(a)pyrene (BaP) was determined in all samples. The profile of PAH concentrations in the extracts isolated from various grilled types of marshmallows was similar (r2 > 0.8000), regardless of the grilling method. Compared to the white sugar confection, higher concentrations of PAHs were determined in multicolored marshmallows. The lack of social awareness about exposure to carcinogenic substances is alarming.

Impact of land-use on PAH transfer in sub-surface water as recorded by CaCO3 concretions in urban underground structures (Paris, France)

In densely populated urban areas, the pressure on water resources is considerable and will tend to intensify over the next decades. Preserving water resources therefore seems fundamental, but many questions remain as to the transfer of contaminants to subsurface waters in these largely sealed areas. Because of their toxicity and persistence in the environment, this work focused on the study of polycyclic aromatic hydrocarbons (PAHs), ubiquitous pollutants mainly produced by human activities. To better understand the main factors leading to the retention or transport of these pollutants in urban environments, vertical transects, from the surface to several meters down, were established on three study sites in or near Paris (France), selected according to an urbanization gradient. Soil samples collected at the surface and urban secondary carbonate deposits (USCD), similar to cave speleothems, sampled underground in quarries and aqueducts were analyzed. As the hydrophobic properties of PAHs favor their sorption onto organic matter, the latter was also studied using organic carbon analysis and UV fluorescence spectroscopy. The USCD located closest to the urbanized surface contained high concentrations of PAHs (76.8 ± 5.3 ng g−1), while the USCD located at greater depth with organic soil on the surface contained the lowest amount of PAHs (2.9 ± 0.4 ng g−1), and no PAHs with log KOC > 5. The results highlight the predominant role played by the presence of organic topsoil at the surface in retaining and storing large amounts of PAHs (1914–2595 ng. gsoil−1), particularly the most hydrophobic ones (i.e. 60% of the 15 PAHs are characterized by a Log KOC >5), which are also the most toxic. The lithology and thickness of the bedrock (between the surface and the USCD) also play an important role in the retention of PAHs, particularly those adsorbed on the particulate phase.

Pollution characteristics, source apportionment and absorption spectra of size-resolved PAHs in atmospheric particles in a cold megacity of China

Polycyclic aromatic hydrocarbons (PAHs) have the capability for solar radiation absorption related to climate forcing. Herein, pollution characteristics and absorption spectra of size-resolved PAHs in atmospheric particles in a cold megacity were comprehensively investigated. The mean concentrations of Σ18PAHs in all the 11 particle size ranges were 3.95 ± 4.77 × 104 pg/m3 and 2.17 ± 1.54 × 103 pg/m3 in heating period (HP) and non-heating period (NHP), respectively. Except for most PAHs with 2 and 3 benzene rings in NHP, most other PAHs showed a unimodal distribution pattern with the peak at 0.56–1.0 µm in both periods, which was caused by PAH emission sources. The PAH-related climate forcing was mainly caused by the solar radiation absorptions at ∼325 (∼330) nm and ∼365 nm. In general, the absorption intensities were higher in HP than NHP. The absorption intensity in the particle size range of 0.56–1.0 µm was the highest, and benzo[e]pyrene was the dominant contributor. In colder periods in HP, higher PAH concentrations caused more intensive PAH-related climate forcing. This study provided new insights for pollution characteristics and absorption spectra of size-resolved PAHs in atmospheric particles, which will be useful for better understanding PAH-related climate forcing.

Day–night variation, size distribution, source identification, and health risk of polycyclic aromatic hydrocarbons in particulate matter in Ulsan, South Korea

Particulate matter (PM) in 11 different sizes was collected at a semi-rural site in Ulsan, a multi-industrial city in South Korea, over one year from 2019 to 2020 to investigate the temporal patterns in size distribution and potential sources of polycyclic aromatic hydrocarbons (PAHs). The mean concentration of Σ21 PAHs was higher in winter (0.29 and 0.45 ng/m3 for coarse and fine PM, respectively) than in summer (0.06 and 0.07 ng/m3). Although there was no statistically significant difference between day and night for the concentration of individual PAHs in both coarse and fine PM, the concentrations were generally higher during the day than at night. During the day, Σ21 PAHs had two distinct peaks (0.056–0.10 μm and 3.20–5.60 μm) in winter, but they tended to partition to larger particles (1.00–1.80 μm and >18.0 μm) in summer. This result suggests that the volatilization of PAHs in smaller particles was enhanced by high-temperature conditions in summer, followed by their condensation onto larger particles. At night, Σ21 PAH peaks were mainly around the size of 0.7 μm (droplet mode), suggesting the importance of heterogeneous-aqueous reactions. The results of the conditional bivariate probability function and concentration-weighted trajectory indicate that the high concentrations of PAHs in summer and winter were more affected by local pollution and long-range atmospheric transport, respectively. The results of the health risk assessment demonstrate that PAHs in fine PM contributed significantly to cancer risk compared to those in coarse PM. In conclusion, investigating the size distribution of PAHs in particles is necessary to understand their environmental behaviors and evaluate potential health risks.

A systematic toxicologic study of polycyclic aromatic hydrocarbons on aquatic organisms via food-web bioaccumulation

Pollution-induced declines in fishery resources restrict the sustainable development of fishery. As a kind of typical environmental pollutant, the mechanism of polycyclic aromatic hydrocarbons (PAHs) facilitating fishery resources declines needs to be fully illustrated. To determine how PAHs have led to declines in fishery resources, a systematic toxicologic analysis of the effects of PAHs on aquatic organisms via food-web bioaccumulation was performed in the Pearl River and its estuary. Overall, PAH bioaccumulation in aquatic organisms was correlated with the trophic levels along food-web, exhibiting as significant positive correlations were observed between PAHs concentration and the trophic levels of fishes in the Pearl River Estuary. Additionally, waterborne PAHs exerted significant direct effects on dietary organisms (P < 0.05), and diet-borne PAHs subsequently exhibited significant direct effects on fish (P < 0.05). However, an apparent block effect was found in dietary organisms (e.g., zooplankton) where 33.49 % of the total system throughput (TST) was retained at trophic level II, exhibiting as the highest PAHs concentration, bioaccumulation factor (BAF), and biomagnification factor (BMF) of ∑15PAHs in zooplankton were at least eight-fold greater than those in fishes in both the Pearl River and its estuary, thereby waterborne PAHs exerted either direct or indirect effects on fishes that ultimately led to food-web simplification. Regardless of the block effect of dietary organisms, a general toxic effect of PAHs on aquatic organisms was observed, e.g., Phe and BaP exerted lethal effects on phytoplankton Chlorella pyrenoidosa and zooplankton Daphnia magna, and decreased reproduction in fishes Danio rerio and Megalobrama hoffmanni via activating the NOD-like receptors (NLRs) signaling pathway. Consequently, an assembled aggregate exposure pathway for PAHs revealed that increases in waterborne PAHs led to bioaccumulation of PAHs in aquatic organisms along food-web, and this in turn decreased the reproductive ability of fishes, thus causing decline in fishery resources.

Personal exposure monitoring to polycyclic aromatic hydrocarbons bound to size-segregated aerosol

Air pollution is a global problem, where impaired air quality significantly damages human health and the environment. Twenty-four hours of personal exposure to size-segregated airborne particulate matter (PM) and associated polycyclic aromatic hydrocarbons (PAHs) were measured in 129 non-smoking residents living in two Czech cities, Ostrava (an industrial area with high levels of air pollution) and Ceske Budejovice (an agricultural area with lower air pollution level) in various seasons between years 2018–2020. Particulate matter (PM) was sampled by cascade impactors based on their aerodynamic diameter (dae, μm) and divided into size fractions: coarse (2.5 < dae), fine (0.25 < dae < 2.5) and ultrafine (<0.25). Size distributions of 20 priority PAHs adsorbed on these PM fractions were analyzed by gas chromatography coupled to tandem mass spectrometry in electron ionization (GC-EI-MS/MS). The total concentration of ∑20PAHs to which residents were exposed ranged from 0.09 ng/m3 to 47.18 ng/m3. A higher level of PAHs was detected in Ostrava (mean: 5.59 ng/m3) than in Ceske Budejovice (mean: 1.96 ng/m3). Statistically significant concentration differences between PAHs in individual seasons were observed in both sampled localities, with higher concentrations measured in winter than in summer. Fine and ultrafine particles predominated in the mass composition of the particulate matter. The ultrafine particle size contained 67–80% of total PAHs. Respiratory health risk was estimated based on inhalation cancer risk (ICR). Cancer risk attributable to personal inhalation exposure ranged from 2.8 × 10−8 to 4.3 × 10−4. In winter, higher cancer risk were found in Ostrava, mainly caused by a high concentration of carcinogenic PAHs bound to ultrafine particles. Overall, the personal monitoring data confirmed a higher air pollution burden in the industrial area and the winter season and highlighted the importance of focusing on ultrafine particles as the main carriers of potentially mutagenic and carcinogenic substances, such as PAHs. In addition, personal monitoring data provided more detailed and accurate information on individual-level exposures, revealing significant differences in exposure concentrations in people living in the same area.

Effect of different smoking times and temperatures on polycyclic aromatic hydrocarbon concentrations in smoked sausages

Smoked pork and chicken sausages were prepared using three different time-temperature combinations; 60 &amp;deg;C for 4 hours, 75 &amp;deg;C for 3 hours, and 90 &amp;deg;C for 2 hours. The amount of polycyclic aromatic hydrocarbons (PAHs) present in these smoked products was estimated using liquid chromatography-mass spectrometry (LC-MS). The PAH compounds were identified using multiple reaction monitoring (MRM) and the retention time of that particular compound. The most potent carcinogenic PAH compound, benzo(a)pyrene (BaP), was not detected in any of the treatments analyzed. The pork and chicken sausages were found to contain the following PAH compounds: Flu, BaA, Chr, BbF, and BkF. Chrysene was found in all samples in the range from 27.38 to 45.08 &amp;micro;g/kg. It was observed that a higher smoking temperature (90 &amp;deg;C) resulted in more PAH compounds in the sausages. Furthermore, the chicken sausages were found to have higher concentrations of PAHs, particularly Chr and BaA, than the pork sausages.

Historical trend of polycyclic aromatic hydrocarbons in a sediment core from Osaka Bay during the Meghalayan

Polycyclic aromatic hydrocarbons (PAHs) are produced by incomplete combustion of biomass and fossil fuel, yet PAHs have been rarely analyzed in coastal sediment cores as a tracer for human activities before industrialization. The aim of this study was to assess if the historical trend of PAHs can be related to past human activities. To this end, we have determined the concentrations of PAHs in a 9 m-long sediment core from Osaka Bay, which records history of the last 2400 years. The concentration of PAHs before the beginning of the 17th century CE, the beginning of the peaceful Edo period, was consistently low (&lt;100 ng g−1) and mainly comprised of smoke-derived PAHs reflecting the natural background. A relative higher abundance of 4−6 ring PAHs from the early 17th century CE and a higher PAH concentration from the early 18th century CE until approximately 1800 CE agreed with a population increase, Cu smelting activities and increasing combustion of charcoal. The constant PAH concentration until the late 19th century CE overlapped with a decline in the population in the Osaka area. An increasing PAH concentration from the late 19th century CE marked the beginning of industrialization in the Modern age. The peak in PAH concentration in 1945 CE was likely caused by burning of wooden structures due to air raids on Osaka City. A second peak around 1980 CE indicated the introduction of cleaner energies. We conclude that PAHs in coastal sediment cores can be used to reconstruct past human activities.

Characteristics of Polycyclic Aromatic Hydrocarbons in Size-Resolved Particles in the Roadside Environment of Beijing: Seasonality, Source, and Toxicological Effects

The polycyclic aromatic hydrocarbons (PAHs) in size-resolved particles emitted from diverse sources are required for quantification to reduce the emissions in order to protect public health. Twenty-four PAHs in size-segregated particles in the roadside environment of Beijing were observed from 1 October 2021 to 30 September 2022. The size distributions of PAHs were bimodal, with peak concentrations ranging from size fractions of 0.43 to 0.65 μm and 4.7 to 5.8 μm in all four seasons, respectively. The highest concentration of PAHs in fine particles (PM2.1) was 35.3 ng m−3 in winter, followed by 16.0 ng m−3 in autumn, 15.3 ng m−3 in spring, and 6.5 ng m−3 in summer. Conversely, the concentration of PAHs in coarse particles (PM2.1–9) ranged from 6.8 ng m−3 (summer) to 20.5 ng m−3 (winter) from low to high. The size fractions of 0.43–2.1 μm PAHs increased most from clear to polluted days, which could be ascribed to the heterogeneous reactions. Source apportionment using positive matrix factorization showed that four sources, namely biomass combustion, coal combustion, diesel vehicles, and gasoline vehicles accounted for PAHs with the estimation of 17.4%, 22.1%, 26.4%, and 23.2% to PAHs in PM2.1; and 19.6%, 24.3%, 23.6%, and 20.1% in PM2.1–9, respectively. Furthermore, we used the human alveolar epithelial cell (BEAS-2B) to assess the toxicological effects of size-resolved atmospheric PAHs. The results showed that the cell survival rate caused by fine particles was lower than that of coarse particles with the same concentrations of PAHs, which is mainly related to the higher content of highly toxic PAHs in fine particles.

Characterization of polycyclic aromatic hydrocarbon from open burning of disposable COVID-19 facemask: Spatial distribution and risk assessment

The use of facemasks as a preventive measure against infection of the COVID-19 virus has some associated environmental impacts, especially in Subs-Saharan African countries where the used facemasks are being disposed of using open burning. Hence this study characterized Polycyclic Aromatic Hydrocarbons (PAHs) emissions from different COVID-19 facemask materials and determined the associated risk of open burning of facemask. Facemasks of different materials were sourced from open dump sites. Each material was combusted in an open reactor and the emissions were collected using A filter-sorbent sampling system. Analysis of PAHs in the sample was carried out using GCMS. The associated health risk was assessed using Incremental Life Cancer Risk (ILCR) and Hazard Quotient (HQ). The result showed the concentration of PAHs emission ranged ∑ PAHs 73.33 –368.16 µg/m3 while carcinogenic PAHs ranged ∑ CarPAHs 26.79–179.74 µg/m3. The result also showed the surgical and N95 facemask emits the highest concentration of PAHs. The modeled annual ground-level PAHs Isopleth reveals the presence of a high concentration of PAHs around the vicinity of the burning site after a year. Proper disposal of these facemask using controlled medical incinerator is highly recommended.

Sources, Occurrences, and Risks of Polycyclic Aromatic Hydro-Carbons (PAHs) in Bangladesh: A Review of Current Status

Polycyclic aromatic hydrocarbons (PAHs) pollution has emerged as a significant environmental issue in Bangladesh in the recent years, driven by both economic and population growth. This review aims to investigate the current trends in PAHs pollution research, covering sediments, water, aquatic organisms, air particles, and associated health risks in Bangladesh. A comparative analysis with PAHs research in other countries is conducted, and potential future research directions are explored. This review suggests that the research on PAHs pollution in Bangladesh is less well studied and has fewer research publications compared to other countries. Dominant sources of PAHs in Bangladesh are fossil fuel combustion, petroleum hydrocarbons, urban discharges, industrial emissions, shipbreaking, and shipping activities. The concentrations of PAHs in sediments, water, air particles, and aquatic organisms in Bangladesh were found to be higher than those in most of the other countries around the world. Therefore, coastal sediments showed higher PAHs pollution than urban areas. Health risk assessments reveal both carcinogenic and non-carcinogenic risks to residents in Bangladesh due to the consumption of aquatic organisms. According to this investigation, it can be concluded that there are considerably higher PAHs concentrations in different environmental compartments in Bangladesh, which have received less research attention compared with other countries of the world. Considering these circumstances, this review recommends that future PAHs pollution research directions should focus on aquatic ecosystems, shipbreaking areas, air particles, and direct exposure to human health risks. Therefore, this study recommends addressing the identification of PAH sources, bioaccumulation, biomagnification in the food web, and biomarker responses of benthic organisms in future PAHs pollution research.

Source apportionment of suspended particulate matter (PM1, PM2.5 and PM10) collected in road and tram tunnels in Krakow, Poland.

Here, we present the results of a comprehensive study of air quality in two tunnels located in the city of Krakow, southern Poland. The study comprised three PM fractions of suspended particulate matter (PM1, PM2.5 and PM10) sampled during campaigns lasting from March 14 to April 24, 2016 and from June 28 to July 18, 2016, in the road tunnel and the tram tunnel, respectively. The collected samples had undergone comprehensive chemical, elemental and carbon isotope analyses. The results of these analyses gave the basis for better characterization of urban transport as a source of air pollution in the city. The concentrations of particulate matter varied, depending on the analysed PM fraction and the place of sampling. For the tram tunnel, the average concentrations were 53.2µg·m-3 (PM1), 73.8µg·m-3 (PM2.5), 96.5µg·m-3 (PM10), to be compared with 44.2µg·m-3, 137.7µg·m-3, 221.5µg·m-3, respectively, recorded in the road tunnel. The isotope-mass balance calculations carried out separately for the road and tram tunnel and for each PM fraction, revealed that 60 to 79% of carbon present in the samples collected in the road tunnel was associated with road transport, to be compared with 15-33% obtained in the tram tunnel. The second in importance were biogenic emissions (17-21% and 41-49% in the road and tram tunnel, respectively. Sixteen different polycyclic aromatic hydrocarbons (PAHs) have been identified in the analysed samples. As expected, much higher concentrations of PAHs were detected in the road tunnel when compared to the tram tunnel. Based on the analysed PAHs concentrations, health risk assessment was determined using 3 different types of indicators: carcinogenic equivalent (CEQ), mutagenic equivalent (MEQ) and toxic equivalent (TEQ).

The perturbation of PAHs on mosses in Aberdeen, Scotland, as a consequence of social restrictions imposed during the COVID-19 pandemic

Air quality and the concentration of polycyclic aromatic hydrocarbons (PAHs) in urban environments are increasingly becoming a concern. Measuring air quality and PAHs, and linking these to specific activities, requires deploying and recovering sampling devices to capture and measure any changes. From May 2020 to June 2021, during the “lockdown” period of the COVID-19 pandemic, acrocarpous and pleurocarpous mosses were collected from five types of site in Aberdeen, United Kingdom, and the concentration of PAHs measured to track changes in PAHs as travel-related activities changed. The predominant types of PAHs found on mosses were of the four- and five-ring varieties, with the four-ring variety of PAH (medium molecular weight) becoming more dominant as the lockdown was lifted. However, for most sites, the concentration of PAHs was evidently perturbed by the transient lifting, reimposing, and then lifting of lockdown conditions, which either directly limited travel or changed people’s motivations to travel by car. Molecular diagnostic ratios or molecular marker parameters used to infer the source of PAHs varied little and were nearly always consistent with PAHs deriving from combustion in vehicle engines. Thus, even when travel was limited, PAHs were still derived from vehicle usage, although the overall concentrations on mosses were much lower. On average, the lowest PAH concentrations were found on mosses collected from a recreational park located the furthest from traffic. The highest PAH concentrations were observed on mosses collected from residential car parks during periods when the lockdown had been lifted. However, mosses from the same residential car parks had very low PAH concentrations during periods of travel restrictions, strongly suggesting that, for mosses, local factors and patterns of vehicle usage strongly determine their exposure to PAHs. Therefore, mosses within urban environments can be used for monthly monitoring of PAHs as they are able to detect changes induced by human behaviour.