Use of lichens as pollution biomonitors in remote areas: comparison of PAhs extracted from lichens and atmospheric particles sampled in and around the Somport tunnel (Pyrenees)

Lichen biomonitoring to assess spatial variability, potential sources and human health risks of polycyclic aromatic hydrocarbons (PAHs) and airborne metal concentrations in Manchester (UK)

Airborne metals and organic pollutants are linked to severe human health impacts, i.e. affecting the nervous system and being associated with cancer. Airborne metals and polycyclic aromatic hydrocarbons (PAHs) in urban environments are derived from diverse sources, including combustion and industrial and vehicular emissions, posing a threat to air quality and subsequently human health. A lichen biomonitoring approach was used to assess spatial variability of airborne metals and PAHs, identify potential pollution sources and assess human health risks across the City of Manchester (UK). Metal concentrations recorded in lichen samples were highest within the city centre area and along the major road network, and lichen PAH profiles were dominated by 4-ring PAHs (189.82 ng g-1 in Xanthoria parietina), with 5- and 6-ring PAHs also contributing to the overall PAH profile. Cluster analysis and pollution index factor (PIF) calculations for lichen-derived metal concentrations suggested deteriorated air quality being primarily linked to vehicular emissions. Comparably, PAH diagnostic ratios identified vehicular sources as a primary cause of PAH pollution across Manchester. However, local more complex sources (e.g. industrial emissions) were further identified. Human health risk assessment found a "moderate" risk for adults and children by airborne potential harmful element (PHEs) concentrations, whereas PAH exposure in Manchester is potentially linked to 1455 (ILCR = 1.45 × 10-3) cancer cases (in 1,000,000). Findings of this study indicate that an easy-to-use lichen biomonitoring approach can aid to identify hotspots of impaired air quality and potential human health impacts by airborne metals and PAHs across an urban environment, particularly at locations that are not continuously covered by (non-)automated air quality measurement programmes.

Lichens as bio-monitors of polycyclic aromatic hydrocarbons: Measuring the impact of features and traffic patterns

The role of road characteristics, including gradient and speed control devices, in influencing emission dynamics remains to be fully elucidated. Most studies have focused on fuel consumption as an indirect indicator of sector emissions instead of directly quantifying specific pollutants, like polycyclic aromatic hydrocarbons (PAHs). This research approach is often due to the complexities involved in capturing these pollutants and their subsequent analysis. Bio-monitors, such as lichens, offer an economically viable method. Their wide distribution across various habitats enables the comparison of PAH levels in diverse environments. Against this background, The present work analyses the ability of tropical lichens to indicate the effect that traffic patterns and geometric design features of roads (traffic activity, road gradient, traffic control devices, and vehicular speed) have on the emission of PAH concentration. Results showed that PAHs in lichens strongly correlated with the road gradient (Spearman correlation, p < 0.005 with R = 0.98 ). Each 1% increase in road gradient implies a rise of 24 ngPAH/gLichen in National Road. Additionally, a trend coherent of PAH concentration with the vehicle speed profile was observed on Panamericana Road. Speed control devices were associated with higher concentrations of PAHs due to acceleration and braking actions that increment fuel consumption. Finally, the results evidenced that lichens helped determine the source of aromatics and their carcinogenic potential using the diagnostic ratio of PAHs and the carcinogenic equivalence sum, respectively.

The Levels of Polycyclic Aromatic Hydrocarbons and Their Derivatives in Plasma and Their Effect on Mitochondrial DNA Methylation in the Oilfield Workers

This study focuses on the components and levels of polycyclic aromatic hydrocarbons (PAHs) and their derivatives (MPAHs and OPAHs) in plasma samples from 19 oil workers, pre- and post-workshift, and their exposure-response relationship with mitochondrial DNA (mtDNA) methylation. PAH, MPAH, OPAH, and platelet mtDNA methylation levels were determined using a gas chromatograph mass spectrometer (GC-MS) and a pyrosequencing protocol, respectively. The total plasma concentrations of PAHs in mean value were, respectively, 31.4 ng/mL and 48.6 ng/mL in pre- and post-workshift, and Phe was the most abundant (13.3 ng/mL in pre-workshift and 22.1 ng/mL in post-workshift, mean value). The mean values of total concentrations of MPAHs and OPAHs in the pre-workshift were 2.7 ng/mL and 7.2 ng/mL, while in the post-workshift, they were 4.5 ng/mL and 8.7 ng/mL, respectively. The differences in the mean MT-COX1, MT-COX2, and MT-COX3 methylation levels between pre- and post-workshift were 2.36%, 5.34%, and 0.56%. Significant (p < 0.05) exposure-response relationships were found between PAHs and mtDNA methylation in the plasma of workers; exposure to Anthracene (Ant) could induce the up-regulation of the methylation of MT-COX1 (β = 0.831, SD = 0.105, p < 0.05), and exposure to Fluorene (Flo) and Phenanthrene (Phe) could induce the up-regulation of methylation of MT-COX3 (β = 0.115, SD = 0.042, p < 0.05 and β = 0.036, SD = 0.015, p < 0.05, respectively). The results indicated that exposure to PAHs was an independent factor influencing mtDNA methylation.

Temporal Distribution and Gas/Particle Partitioning of Polycyclic Aromatic Hydrocarbons (PAHs) in the Atmosphere of Strasbourg, France

Gas and particulate phase ambient air concentrations of polycyclic aromatic hydrocarbons (Ʃ16PAHs) were determined in Strasbourg, a large city located in the Alsace region of northeastern France, from May 2018 to March 2020, to study the evolution of their temporal variations and their potential origins. The analysis of PAHs was performed using a global analytical method permitting the quantification of pesticides, PAHs, and polychlorobiphenyls (PCBs). Filters and Carbon doped silicon carbide NMC@SiC foams were extracted by accelerated solvent extraction (ASE) followed by a solid-phase extraction (SPE). Afterwards, extracts were analyzed using gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). Prior to analysis, a pre-concentration step based on solid-phase microextraction (SPME) was used with a polydimethylsiloxane (PDMS) 100 µm fiber. The average total (gas plus particulate) concentration of Ʃ16PAHs varied from 0.51 to 117.31 ng m−3 with a mean of 16.87 ng m−3, with higher concentrations in the cold season of more than 2.5-fold and 6-fold that in the warm season for the gas and particulate phases, respectively. Moreover, low molecular weight (LMW) (2-ring and 3-ring) and medium molecular weight (MMW) (4-ring) PAHs contribute dominantly to the gas phase, while the particulate phase is associated with MMW (4-ring) and high molecular weight (HMW) (5-ring and 6-ring) PAHs. Gas/particle partitioning coefficient (log Kp) was calculated, and values varied between −4.13 and −1.49. It can be seen that the log Kp increased with the molecular weight of the PAHs and that the log Kp is different between cold and warm seasons for HMW PAHs but not for LMW PAHs. Diagnostic ratios of PAHs, which were employed to estimate the primary source of PAHs in Strasbourg, indicate that fuel combustion and biomass/coal burning are the possible origins of PAHs in Strasbourg’s atmosphere.

Polycyclic aromatic hydrocarbon and n-alkane pollution characteristics and structural and functional perturbations to the microbial community: a case-study of historically petroleum-contaminated soil

Characterization of the typical petroleum pollutants, polycyclic aromatic hydrocarbons (PAHs) and n-alkanes, and indigenous microbial community structure and function in historically contaminated soil at petrol stations is critical. Five soil samples were collected from a petrol station in Beijing, China. The concentrations of 16 PAHs and 31 n-alkanes were measured by gas chromatography-mass spectrometry. The total concentrations of PAHs and n-alkanes ranged from 973 ± 55 to 2667 ± 183 μg/kg and 6.40 ± 0.38 to 8.65 ± 0.59 mg/kg (dry weight), respectively, which increased with depth. According to the observed molecular indices, PAHs and n-alkanes originated mostly from petroleum-related sources. The levels of ΣPAHs and the total toxic benzo[a]pyrene equivalent (ranging from 6.41 to 72.54 μg/kg) might exert adverse biological effects. Shotgun metagenomic sequencing was employed to investigate the indigenous microbial community structure and function. The results revealed that Proteobacteria and Actinobacteria were the most abundant phyla, and Nocardioides and Microbacterium were the important genera. Based on COG and KEGG annotations, the highly abundant functional classes were identified, and these functions were involved in allowing microorganisms to adapt to the pressure from contaminants. Five petroleum hydrocarbon degradation-related genes were annotated, revealing the distribution of degrading microorganisms. This work facilitates the understanding of the composition, source, and potential ecological impacts of residual PAHs and n-alkanes in historically contaminated soil.

Associations between land cover categories, gaseous PAH levels in ambient air and endocrine signaling predicted from gut bacterial metagenome of the elderly

There is evidence that polycyclic aromatic hydrocarbons (PAHs) and human gut microbiota are associated with the modulation of endocrine signaling pathways. Independently, studies have found associations between air pollution, land cover and commensal microbiota. We are the first to estimate the interaction between land cover categories associated with air pollution or purification, PAH levels and endocrine signaling predicted from gut metagenome among urban and rural populations. The study participants were elderly people (65-79 years); 30 lived in rural and 32 in urban areas. Semi-Permeable Membrane devices were utilized to measure air PAH concentrations as they simulate the process of bioconcentration in the fatty tissues. Land cover categories were estimated using CORINE database and geographic information system. Functional orthologues for peroxisome proliferator-activated receptor (PPAR) pathway in endocrine system were analyzed from gut bacterial metagenome with Kyoto Encyclopaedia of Genes and Genomes. High coverage of broad-leaved and mixed forests around the homes were associated with decreased PAH levels in ambient air, while gut functional orthologues for PPAR pathway increased along with these forest types. The difference between urban and rural PAH concentrations was not notable. However, some rural measurements were higher than the urban average, which was due to the use of heavy equipment on active farms. The provision of air purification by forests might be an important determining factor in the context of endocrine disruption potential of PAHs. Particularly broad-leaved forests around homes may reduce PAH levels in ambient air and balance pollution-induced disturbances within commensal gut microbiota.

Spatial Distributions, Sources and Risks of Polycyclic Aromatic Hydrocarbons in Sediments from Ziya River System, Northern China

With the development of urbanization and industrialization, Ziya River Plain (ZYRP) had become one of the most polluted regions of polycyclic aromatic hydrocarbons (PAHs) in north China. The distribution of PAHs in sediments were investigated, and then their sources and risks were evaluated. The results showed that the total PAHs varied from 3372 to 92,948 μg/kg, and heavy pollution was found in the upstream. Both the isomer pair ratios of PAH and principal components analysis (PCA) revealed that fossil fuel combustion was the mainly contributes (69.1%), followed by wood and coal combustion (26.7%). The ecological risk for the whole area was moderate, with the highest risk in Niuwei River (NWR). and significant correlation was found between the ecological risk and high-molecular-weight (HMW) of PAHs (r² > 0.99, p < 0.01). Our findings would give insights into the mitigation of sedimentary PAHs pollution in north China.

A critical review on plant biomonitors for determination of polycyclic aromatic hydrocarbons (PAHs) in air through solvent extraction techniques

Polycyclic aromatic hydrocarbons (PAHs) are hydrocarbons having two or more fused aromatic rings, released from natural (like forest fires and volcanic eruption) as well as man-made sources (like burning of fossil fuel & wood, automobile emission). They are persistent priority pollutants and continue to last for a long time in the environment causing severe damage to human health owing to their genotoxicity, mutagenicity and carcinogenicity. The study of PAHs in environment has therefore aroused a global concern. PAHs adsorption to plant cell wall is facilitated by transpiration and plant root lipids which help PAHs transfer from roots to leaves and stalks, causing more accumulation of contaminants with the increase in lipid content. Hence, these bioaccumulators can be utilized as biomonitors for indirect assessment of ambient air pollution. Efficacy of specific plants, lichens and mosses as useful biomonitors of airborne PAHs pollution has been discussed in this review along with prevalent classical and modified extraction techniques coupled with proper analytical procedures in order to gain an insight into the assessment of atmospheric PAHs concentrations. Different modern and modified solvent extraction techniques along with conventional Soxhlet method are identified for extraction of PAHs from accumulative bioindicators and analytical methods are also developed for accurate determination of PAHs. Process parameters like choice of solvent, temperature, time of extraction, pressure and matrix characteristics are usually checked. An approach of biomonitoring of PAHs using plants, lichens and mosses has been discussed here as they usually trap the atmospheric PAHs and mineralize them.

Optimized extraction of inorganic arsenic species from a foliose lichen biomonitor

To assess the two most toxicologically relevant species of As, namely arsenite (As(III)) and arsenate (As(V)), chromatographic separations often require two separate chromatographic columns to address the co-elution of arsenobetaine (AsB) with As(III). This issue is typically observed using conventional isocratic methods on anion exchange columns, increasing cost and analysis time. Here, we optimize the extraction of inorganic As from a lichen air biomonitor and develop an isocratic method for the chromatographic separation of five common As species on a PRP X-100 anion exchange column, resulting in the complete baseline separation of all species under study. This method was then applied to lichen biomonitors from an urban and rural site to demonstrate its use. In order of abundance, the various arsenic species in lichens from the urban site in South Africa were As(V) > As(III) > AsB > dimethylarsinic acid (DMA) > monomethylarsonic acid (MMA), and As(V) > AsB > As(III) > DMA > MMA for the rural site, where MMA was present in extremely low, non-quantifiable concentrations in lichens from both sites. Total concentrations of As were higher in samples from the urban site (6.43 ± 0.25 μg/g) than in those from the rural site (1.87 ± 0.05 μg/g), with an overall extraction efficiency of 19% and 40%, respectively. The optimized method utilized relatively inexpensive solvents and is therefore low-cost and eco-friendly in comparison with conventional chromatographic techniques. This is the first study which addresses the optimized extraction and characterization of As species in a South African lichen biomonitor of air pollution. Graphical abstract .

Current knowledge on Parmelia genus: Ecological interest, phytochemistry, biological activities and therapeutic potential

Parmelia Acharius is one of the most representative genera within Parmeliaceae family which is the largest and the most widespread family of lichen-forming fungi. Parmelia lichens present a medium to large foliose thallus and they are distributed from the Artic to the Antartic continents, being more concentrated in temperate regions. According to its current description, the genus encompasses up to 41 different species and it is phylogenetically located within the Parmelioid clade (the largest group in the family). Interestingly, some of its species are among the most common epiphytic lichens in Europe such as Parmelia sulcata Taylor and Parmelia saxatilis (L.) Ach. The present work aims at providing a complete overview of the existing knowledge on the genus, from general concepts such as taxonomy and phylogeny, to their ecological relevance and biological interest for pharmaceutical uses. As reported, Parmelia lichens arise as valuable tools for biomonitoring environmental pollution due to their capacity to bioaccumulate metal elements and its response to acid rain. Moreover, they produce a wide array of specialized products/metabolites including depsides, depsidones, triterpenes and dibenzofurans, which have been suggested to exert promising pharmacological activities, mainly antimicrobial, antioxidant and cytotoxic activities. Herein, we discuss past and recent data regarding to the phytochemical characterization of more than 15 species. Even though the knowledge is still scarce in comparsion to other groups of organisms such as higher plants and other non-lichenized fungi. Reviewed works suggest that Parmelia lichens are worthy of further research for determining their actual possibilities as sources of bioactive compounds with potential therapeutic applications.

Interaction of benzo[a]pyrene with Cu(II)-montmorillonite: Generation and toxicity of environmentally persistent free radicals and reactive oxygen species

This paper presents the interaction of benzo[a]pyrene (B[a]P) with Cu(II)-montmorillonite to investigate the formation, evolution and potential toxicity of environmentally persistent free radicals (EPFRs) under dark and visible light irradiation conditions. Degradation of B[a]P and the generated transformative products on clay mineral are monitored by gas chromatography-mass spectrometry (GC-MS) technique. Hydroxyl-B[a]P and B[a]P-diones are observed during the transformation of B[a]P under dark condition. B[a]P-3,6-dione and B[a]P-6,12-dione are the main products under visible light irradiation. B[a]P transformation is accompanied by the formation of EPFRs, which are quantified by electron paramagnetic resonance (EPR) spectroscopy. With increasing reaction time, the concentrations of the produced EPFRs are initially increased and then gradually decrease to an undetectable level. The deconvolution results of EPR spectra reveal formation of three types of organic radicals (carbon-centered radicals, oxygen-centered radicals, and carbon-centered radicals with a conjugated oxygen), which also co-exist. Correspondingly, visible-light irradiation promotes the formation and the decay of these EPFRs. The produced B[a]P-type EPFRs induce the generation of reactive oxygen species (ROS), such as superoxide (O₂^-) and hydroxide radicals (OH), which may cause oxidative stress to cells and tissues of organisms. The toxicity of degradation products is evaluated by the livability of human gastric epithelial GES-1cells. The toxicity is initially increased and then decreases with the elapsed reaction time, which correlates with the evolution of EPFRs concentrations. The present work provides direct evidence that the formation of EPFRs in interaction of PAHs with metal-contaminated clays may result in negative effects to human health.

Temporal change of the accumulation of persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) in lichens in Switzerland between 1995 and 2014

The aim of this study was to assess the temporal change of atmospheric deposition patterns of persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) in Switzerland between 1995 and 2014 by a passive biomonitoring with lichens. Lichen tissues sampled at 16 representative sites in the same season of 1995 and 2014 were analyzed for a total of 94 individual and 27 sum parameters of POPs and PAHs by means of gas chromatography-mass spectrometry (GC/MS). The comparative analyses showed a decrease of 40 to 80% (medians) for most of the POPs and PAHs concentration in lichens at all site categories. Reduction in tissue concentration of the polychlorinated dibenzo-p-dioxins/furans (PCDD/PCDFs), such as the highly toxic 2,3,7,8-TetraCDD and the TEQ according to WHO (2005) were 66% and 73%, respectively. For the dioxin- and non-dioxin-like PCBs, a decrease of 67% and 58% was found. The average decrease of 30 organochlorine pesticides and insecticides (OCPs) was 65%, with a 94% decrease for lindane. For the 27 PAHs and for benzo(a)pyrene, an average decrease of 58% and 59% was found. Polybrominated diphenyl ethers (PBDE) showed reduced concentrations in lichens at rural and agglomeration sites, but an increase of contamination was observed at industrial and road traffic sites. The direct comparison of changes of POPs and PAHs concentrations in lichens and of emissions between 1995 and 2014 revealed consistent results. The results of this study highlight for the first time in biota the positive effect of emission regulation of POPs in Switzerland.

Tracking the Spatial Fate of PCDD/F Emissions from a Cement Plant by Using Lichens as Environmental Biomonitors

In an area with multiple sources of air pollution, it is difficult to evaluate the spatial impact of a minor source. Here, we describe the use of lichens to track minor sources of air pollution. The method was tested by transplanting lichens from a background area to the vicinity of a cement manufacturing plant that uses alternative fuel and is located in a Natural Park in an area surrounded by other important sources of pollution. After 7 months of exposure, the lichens were collected and analyzed for 17 PCDD/F congeners. The PCDD/F profiles of the exposed lichens were dominated by TCDF (50%) and OCDD (38%), which matched the profile of the emissions from the cement plant. The similarity in the profiles was greatest for lichens located northeast of the plant (i.e., in the direction of the prevailing winds during the study period), allowing us to evaluate the spatial impact of this source. The best match was found for sites located on the tops of mountains whose slopes faced the cement plant. Some of the sites with highest influence of the cement plant were the ones with the highest concentrations, whereas others were not. Thus, our newly developed lichen-based method provides a tool for tracking the spatial fate of industrially emitted PCDD/Fs regardless of their concentrations. The results showed that the method can be used to validate deposition models for PCDD/F industrial emissions in sites with several sources and characterized by complex orography.

Polycyclic aromatic hydrocarbons in caribou, moose, and wolf scat samples from three areas of the Alberta oil sands

Impacts of toxic substances from oil production in the Alberta oil sands (AOS), such as polycyclic aromatic hydrocarbons (PAHs), have been widely debated. Studies have been largely restricted to exposures from surface mining in aquatic species. We measured PAHs in Woodland caribou (Rangifer tarandus caribou), moose (Alces americanus), and Grey wolf (Canis lupus) across three areas that varied in magnitude of in situ oil production. Our results suggest a distinction of PAH level and source profile (petro/pyrogenic) between study areas and species. Caribou samples indicated pyrogenic sourced PAHs in the study area previously devastated by forest fire. Moose and wolf samples from the high oil production area demonstrated PAH ratios indicative of a petrogenic source and increased PAHs, respectively. These findings emphasize the importance of broadening monitoring and research programs in the AOS.

Accumulation of polycyclic aromatic hydrocarbons by lichen transplants: Comparison with gas-phase passive air samplers

This study compared the accumulation of 16 polycyclic aromatic hydrocarbons (PAHs) in samples of the lichen Evernia prunastri exposed for 3 months in and around an industrial area of S Italy with that in co-located passive gas-phase air samplers. The results showed a strong linear correlations (R=0.96, P<0.05) between total PAHs in lichens and in passive samplers, clearly indicating that lichen transplants may provide direct quantitative information on the atmospheric load by total PAHs, allowing translation of lichen values into atmospheric concentrations. To the best of our knowledge this is the first study reporting such a correlation with gas-phase passive air samplers.

Relationship between levels of polycyclic aromatic hydrocarbons in pine needles and socio-geographic parameters

The ability of pine needles to capture polycyclic aromatic hydrocarbons (PAHs) from the surrounding air is well known. In this work the current knowledge of this affinity will be enhanced, investigating the plausible links between the concentrations of PAHs found in pine needles collected in different sites in Portugal, and several socio-geographic variables with environmental relevance. Canonical correlation analysis (CCA) has proven to be a suitable and innovative technique to look for relationships within environmental datasets. In the current work, CCA will simultaneously include chemical information (concentration of PAHs found in pine needles) and socio-geographic information associated to the sampling areas. In order to be more robust in these conclusions, Pinus pinea and Pinus pinaster species were considered separately, allowing an accurate direct comparison between them. The information concerning the different seasons and land occupation was also taken into account. Our results demonstrate how CCA can be a useful tool in environmental impact assessment, and highlight the importance of pine needles as trustful biomonitors of the influence of socio-geographic parameters on the levels of PAHs in a given area.

Linking biochemical perturbations in tissues of the African catfish to the presence of polycyclic aromatic hydrocarbons in Ovia River, Niger Delta region

Petroleum hydrocarbons including polycyclic aromatic hydrocarbons (PAHs) are a pollution issue in the Niger Delta region due to oil industry activities. PAHs were measured in the water column of the Ovia River with concentrations ranging from 0.1 to 1055.6 ng L(-1). Attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy detected alterations in tissues of the African catfish (Heterobranchus bidorsalis) from the region showed varying degrees of statistically significant (P<0.0001, P<0.001, P<0.05) changes to absorption band areas and shifts in centroid positions of peaks. Alteration patterns were similar to those induced by benzo[a]pyrene in MCF-7 cells. These findings have potential health implications for resident local communities as H. bidorsalis constitutes a key nutritional source. The study provides supporting evidence for the sensitivity of infrared spectroscopy in environmental studies and supports their potential application in biomonitoring.

Polycyclic aromatic hydrocarbons in the dagang oilfield (china): distribution, sources, and risk assessment

The levels of 16 polycyclic aromatic hydrocarbons (PAHs) were investigated in 27 upper layer (0-25 cm) soil samples collected from the Dagang Oilfield (China) in April 2013 to estimate their distribution, possible sources, and potential risks posed. The total concentrations of PAHs (∑PAHs) varied between 103.6 µg·kg(-1) and 5872 µg·kg(-1), with a mean concentration of 919.8 µg·kg(-1); increased concentrations were noted along a gradient from arable desert soil (mean 343.5 µg·kg(-1)), to oil well areas (mean of 627.3 µg·kg(-1)), to urban and residential zones (mean of 1856 µg·kg(-1)). Diagnostic ratios showed diverse source of PAHs, including petroleum, liquid fossil fuels, and biomass combustion sources. Combustion sources were most significant for PAHs in arable desert soils and residential zones, while petroleum sources were a significant source of PAHs in oilfield areas. Based ontheir carcinogenity, PAHs were classified as carcinogenic (B) or not classified/non-carcinogenic (NB). The total concentrations of carcinogenic PAHs (∑BPAHs) varied from 13.3 µg·kg(-1) to 4397 µg·kg(-1) across all samples, with a mean concentration of 594.4 µg·kg(-1). The results suggest that oilfield soil is subject to a certain level of ecological environment risk.

Sample pretreatment to differentiate between bioconcentration and atmospheric deposition of polycyclic aromatic hydrocarbons in mosses

In this first approach a comparison using different sample pretreatment methodologies has been made to differentiate between total atmospheric deposition and bioconcentration of polycyclic aromatic hydrocarbons (PAHs) in moss samples (Brachythecium rutabulum). Samples were collected in a densely polluted urban area in Barakaldo (Biscay, Basque Country) and submitted to different cleaning procedures with the aim to remove as many deposited atmospheric particles as possible. Analysis by means of Scanning Electron Microscopy coupled to Energy Dispersive Spectroscopy (SEM-EDS) allowed to quantify the removal efficiency of each cleaning procedure and to chemically characterise particles still present in the pre-cleaned sample. Cleaning moss samples twice with deionised water in an ultrasound bath showed up as the most suitable way to remove solid particles deposited on their surface. Discerning between bioconcentration and atmospheric deposition is therefore possible after GC-MS quantitative analysis of non-washed and washed moss samples.

Patterns of traffic polycyclic aromatic hydrocarbon pollution in mountain areas can be revealed by lichen biomonitoring: a case study in the Dolomites (Eastern Italian Alps)

In mountain areas of touristic interest the evaluation of the impact of human activities is crucial for ensuring long-term conservation of ecosystem biodiversity, functions and services. This study aimed at verifying the biological impact of polycyclic aromatic hydrocarbon (PAH) emissions due to traffic along the roads leading to seven passes of the Dolomites (SE Alps), which were recently declared a UNESCO World Heritage Site. Thalli of the epiphytic lichen Pseudevernia furfuracea, collected at increasing distances from the roads, were used as biomonitors. Our study revealed a gradient of decreasing PAH pollution within 300 m from the roads. Differences among passes were evident mainly for samples collected nearest to the roads, but PAH concentrations at 300 m were almost always higher than those of undisturbed reference sites, indicating that traffic PAH pollution may impact natural ecosystems and lichen diversity at relatively long distances from the emission source.

Novel biospectroscopy sensor technologies towards environmental health monitoring in urban environments

Biospectroscopy is an emerging inter-disciplinary field that exploits the application of sensor technologies [e.g., Fourier-transform infrared spectroscopy, Raman spectroscopy] to lend novel insights into biological questions. Methods involved are relatively non-destructive so samples can subsequently be analysed by more conventional approaches, facilitating deeper mechanistic insights. Fingerprint spectra are derived and these consist of wavenumber-absorbance intensities; within a typical biological experiment, a complex dataset is quickly generated. Biological samples range from biofluids to cytology to tissues derived from human or sentinel sources, and analyses can be carried out ex vivo or in situ in living tissue. A reference range of a designated normal state can be derived; anything outside this is potentially atypical and discriminating chemical entities identified. Computational approaches allow one to minimize within-category confounding factors. Because of ease of sample preparation, low-cost and high-throughput capability, biospectroscopy approaches herald a new greener means of environmental health monitoring in urban environments.

Guidelines for biomonitoring persistent organic pollutants (POPs), using lichens and aquatic mosses--a review

During the last decades, awareness regarding persistent organic pollutants (POPs), such dioxins and furans (PCDD/Fs) and polycyclic aromatic hydrocarbons (PAHs), has become a cutting-edge topic, due to their toxicity, bioaccumulation and persistency in the environment. Monitoring of PCDD/Fs and PAHs in air and water has proven to be insufficient to capture deposition and effects of these compounds in the biota. To overcome this limitation, environmental biomonitoring using lichens and aquatic mosses, have aroused as promising tools. The main aim of this work is to provide a review of: i) factors that influence the interception and accumulation of POPs by lichens; ii) how lichens and aquatic bryophytes can be used to track different pollution sources and; iii) how can these biomonitors contribute to environmental health studies. This review will allow designing a set of guidelines to be followed when using biomonitors to assess environmental POP pollution.

A step towards the use of biomonitors as estimators of atmospheric PAHs for regulatory purposes

One of the main drawbacks of using lichens to monitor atmospheric PAHs has been reported as the inexistence of studies aiming to translate PAH values in lichens into the atmospheric equivalents ones, in order to use this information for regulatory purposes. In this work, PAH concentrations in lichens were compared with PAH concentrations measured in a conventional active sampler in an outdoor environment for a 9-month span. Significant positive correlations between HMW-PAHs, Σ16 EPA-PAHs, and BaP equivalent concentrations in lichens and those in air (TSP) were found. Concentrations of Σ16 EPA-PAHs in lichens and air showed a seasonal variation, with highest values during winter and lowest values during summer. Meteorological variables - temperature, atmospheric pressure, relative humidity, and wind speed - showed to significantly influence PAH concentrations in both lichens and air. Based on the significant linear correlations, equations for translating PAH concentrations measured in lichens into equivalent ones for air were proposed for the first time, allowing a broader use of lichens' information regarding PAHs in monitoring schemes and decision-making.

Century-long source apportionment of PAHs in Athabasca oil sands region lakes using diagnostic ratios and compound-specific carbon isotope signatures

Evaluating the impact that airborne contamination associated with Athabasca oil sands (AOS) mining operations has on the surrounding boreal forest ecosystem requires a rigorous approach to source discrimination. This study presents a century-long historical record of source apportionment of polycyclic aromatic hydrocarbons (PAHs) in dated sediments from two headwater lakes located approximately 40 and 55 km east from the main area of open pit mining activities. Concentrations of the 16 Environmental Protection Agency (EPA) priority PAHs in addition to retene, dibenzothiophene (DBT), and six alkylated groups were measured, and both PAH molecular diagnostic ratios and carbon isotopic signatures (δ(13)C) of individual PAHs were used to differentiate natural from anthropogenic inputs. Although concentrations of PAHs in these lakes were low and below the Canadian Council of Ministers of the Environment (CCME) guidelines, diagnostic ratios pointed to an increasingly larger input of petroleum-derived (i.e., petrogenic) PAHs over the past 30 years concomitant with δ(13)C values progressively shifting to the value of unprocessed AOS bitumen. This petrogenic source is attributed to the deposition of bitumen in dust particles associated with wind erosion from open pit mines.

Use of bioindicators to evaluate air quality and genotoxic compounds in an urban environment in Southern Brazil

Biological indicators are widely used to monitor genotic compounds and air quality in urban environments. Parmotrema tinctorum and Teloschistes exilis have been used to verify the presence of pollutants and analyze morphophysiological alterations in the thallus of species caused by their action. Species were exposed for seven months, in an urban area, in southern Brazil. Mutagenicity and cytotoxicity of PM10 organic extracts were assessed in the Salmonella/microsome assay at two stations. High concentrations of S, Pb, Cr, Zn and Hg were registered in the last period of exposure and more significant morphophysiological damages were verified in the lichens. Generally a higher mutagenic activity is observed in organic extracts of airborne particulate matter during the first months and in the third period of exposure of lichens. In addition, nitro compounds was detected through nitro-sensitive strains. Lichens and mutagenic biomarkers enabled the evaluation of air quality and the presence of environmentally-aggressive compounds.

Influence of organic matter content and human activities on the occurrence of organic pollutants in antarctic soils, lichens, grass, and mosses

Banned pesticides such as HCB and p,p'-DDE, and other legacy and ongoing pollutants such as PCBs and PAHs, were measured in different vegetation types and soil samples collected at selected areas from Antarctic Peninsula (Deception and Livingstone Islands, Southern Shetlands). Two Antarctic expeditions (in 2005 and 2009) were carried out to assess POPs levels at remote areas, and close to current and abandoned Antarctic research settlements, to assess potential sources of pollutants. Overall, the patterns in lichens, mosses, and grass were dominated by low molecular PCB congeners and PAHs and the presence of HCB and p,p'-DDE rather than heavier compounds, suggesting the importance of long-range atmospheric transport of POPs as the main vector for the introduction of these chemicals to Antarctica. Statistically significant correlations (p-level < 0.05) between concentrations in vegetation of PCBs, p,p'-DDE, and the more volatile PAHs with lipid content were found with r(2) of 0.22-0.52 for PCBs, 0.42 for p,p'-DDE, and 0.44-0.72 for the more volatile PAHs. Thus, lipid content is an important factor controlling POPs in Antarctic lichens, mosses, and grass. A strong significant dependence of HCB (r(2) = 0.83), p,p'-DDE (r(2) = 0.60), and PCBs (r(2) = 0.36-0.47) concentrations in soil on its organic carbon content was also observed, indicating the important role of soil organic matter (SOM) in the retention of PCBs and OCPs in Polar Regions, where SOM content is low. Penguin colonies enhance the SOM content in some areas which is reflected in higher concentrations of all POPs, especially of persistent compounds such as p,p'-DDE. Higher concentrations of PCBs and PAHs found at the currently active Byers Camp (in an Antarctic Specially Protected Area) were explained by higher SOM content, thus indicating that Antarctic regulations are being successfully fulfilled in this small research area. On the other hand, PAHs in soils proximate to current Juan Carlos I research station show that even small human settlements are an important source of PAHs to the local environment. Therefore, even though the concentrations in Antarctica are low, there is evidence of local hotspots of contamination.

Rinodina sophodes (Ach.) Massal.: a bioaccumulator of polycyclic aromatic hydrocarbons (PAHs) in Kanpur City, India

The aim of this study is to determine the possibility of using Rinodina sophodes (Ach.) Massal., a crustose lichen as polycyclic aromatic hydrocarbons (PAHs) bioaccumulator for evaluation of atmospheric pollution in tropical areas of India, where few species of lichens are able to grow. PAHs were identified, quantified and compared to evaluate the potential utility of R. sophodes. The limit of detection for different PAHs was found to be 0.008-0.050 μg g( - 1). The total PAHs in different sites were ranged between 0.189 ± 0.029 and 0.494 ± 0.105 μg g( - 1). The major sources of PAHs were combustion of organic materials, traffic and vehicular exhaust (diesel and gasoline engine). Significantly higher concentration of acenaphthylene and phenanthrene indicates road traffic as major source of PAH pollution in the city. Two-way ANOVA also confirms that all PAHs content showed significant differences between all sampling sites (P 1%). This study establishes the utility of R. sophodes in monitoring the PAHs accumulation potentiality for development of effective tool and explores the most potential traits resistant to the hazardous environmental conditions in the tropical regions of north India, where no such other effective way of biomonitoring is known so far.

Assessing human exposure to polycyclic aromatic hydrocarbons (PAH) in a petrochemical region utilizing data from environmental biomonitors

Polycyclic aromatic hydrocarbons (PAH) are toxic compounds that have been classified by the International Agency for Research on Cancer as probable or possible human carcinogens. Human exposure to PAH is usually assessed by considering data from a single air monitoring station as being representative of a large region; however, air pollution levels change on small spatial scales and thus also affect environmental exposure. The use of environmental biomonitors is a useful tool to assess the levels of PAH with high spatial resolution. The aims of this study were to (1) assess human exposure to PAH in a petrochemical region in Portugal, integrating data from environmental biomonitors (lichens), air, and soil in a regional area, and (2) determine the health risks associated with exposure to PAH with high spatial resolution. Bearing this in mind, benzo[a]pyrene (BaP) equivalent concentrations in samples of soil, air, and lichens collected in the study region were used to assess human exposure through different pathways, including inhalation of air and soil particles, ingestion of soil, and dermal contact with soil. Human health risk was calculated through the Incremental Lifetime Cancer Risk (ILCR). BaP equivalent concentrations found in the region ranged from 6.9 to 46.05 ng BaPeq/g in lichens, from 16.45 to 162.02 ng BaPeq/g in soils, and from 0.02 to 0.16 ng BaPeq/m³ in air, indicative of high variability in this regional area. Human exposure to PAH varied between 976 and 42,877 ng BaPeq/d. When considering all exposure pathways, ILCR values were between 10⁻⁴ and 10⁻³. Considering only inhalation, ILCR values were between 10⁻⁶ and 10⁻⁵. The main risk seemed to arise from soil (either ingestion or inhalation of resuspended soil particles). The high spatial resolution of our environmental data allowed for detection of critical exposure levels at unexpected sites. Our results identified important areas where health studies on local populations need to be focused, and where environmental levels of PAH need to be monitored over time in order to protect human health.

Distribution and sources of PAHs using three pine species along the Ebro River

Needles of three pine species (Pinus halepensis, Pinus pinea and Pinus nigra) were analysed to assess the occurrence of polycyclic aromatic hydrocarbons (PAHs) in 34 sites located throughout the Ebro River, in Northeast Spain. Overall, the concentration varied between 55 and 808 ng g(-1) (dry weight). The three- and four-ring PAHs were the most representative, with phenanthrene having 43% of the total PAH load and naphthalene showing a high incidence in rural areas. Despite matrix apparent similarities, P. halepensis needles revealed higher entrapment levels than P. nigra and P. pinea, the latter showing the lowest levels. The assessment of possible sources using PAH ratios (phenanthrene/anthracene and fluoranthene/pyrene) did not reveal a clear tendency regarding the distinction of petrogenic and pyrogenic sources in general, reflecting heterogeneous sources of PAHs in the Ebro area.

Comparison of lichen, conifer needles, passive air sampling devices, and snowpack as passive sampling media to measure semi-volatile organic compounds in remote atmospheres

A wide range of semivolatile organic compounds (SOCs), including pesticides and polycyclic aromatic hydrocarbons (PAHs), were measured in lichen, conifer needles, snowpack and XAD-based passive air sampling devices (PASDs) collected from 19 different U.S. national parks in order to compare the magnitude and mechanism of SOC accumulation in the different passive sampling media. Lichen accumulated the highest SOC concentrations, in part because of its long (and unknown) exposure period, whereas PASDs accumulated the lowest concentrations. However, only the PASD SOC concentrations can be used to calculate an average atmospheric gas-phase SOC concentration because the sampling rates are known and the media is uniform. Only the lichen and snowpack SOC accumulation profiles were statistically significantly correlated (r = 0.552, p-value <0.0001) because they both accumulate SOCs present in the atmospheric particle-phase. This suggests that needles and PASDs represent a different composition of the atmosphere than lichen and snowpack and that the interpretation of atmospheric SOC composition is dependent on the type of passive sampling media used. All four passive sampling media preferentially accumulated SOCs with relatively low air-water partition coefficients, while snowpack accumulated SOCs with higher log K(OA) values compared to the other media. Lichen accumulated more SOCs with log K(OA) > 10 relative to needles and showed a greater accumulation of particle-phase PAHs.

The direct influence of ship traffic on atmospheric PM2.5, PM10 and PAH in Venice

The direct influence of ship traffic on atmospheric levels of coarse and fine particulate matter (PM(2.5), PM(10)) and fifteen polycyclic aromatic hydrocarbons (PAHs) has been estimated in the urban area of Venice. Data analysis has been performed on results collected at three sites over the summer, when ship traffic is at a maximum. Results indicate that monitoring of the PM daily concentrations is not sufficiently detailed for the evaluation of this contribution, even though it could be useful for specific markers such as PAHs. Therefore a new methodology, based on high temporal resolution measurements coupled with wind direction information and the database of ship passages of the Harbour Authority of Venice has been developed. The sampling sites were monitored with optical detectors (DustTrack(®) and Mie pDR-1200) operating at a high temporal resolution (20s and 1s respectively) for PM(2.5) and PM(10). PAH in the particulate and gas phases were recovered from quartz fibre filters and polyurethane foam plugs using pressurised solvent extraction, the extracts were then analysed by gas chromatography- high-resolution mass spectrometry. Our results shows that the direct contribution of ships traffic to PAHs in the gas phase is 10% while the contribution to PM(2.5) and to PM(10) is from 1% up to 8%.

Occurrence of PAH in the seasonal snowpack of the Eastern Italian Alps

PAH concentrations have been determined in 47 seasonal snowpack samples collected in the Valbelluna valley and in the Bellunesi Dolomites National Park, in the Italian North-Eastern Alps, during the winter of 2005. The SigmaPAH concentration in high-altitude alpine sites (above 1700 m) was 32+/-20 ng/kg while in valley bottom urban areas it was 165+/-54 ng/kg with maximum values of 290 ng/kg. The GIS mapping technique was employed to produce a PAH spatial distribution. The urbanized Valbelluna valley, and in particular the SW part, had the highest accumulation of all PAH, with values an order of magnitude more than those in rural and alpine areas. This behaviour is consistent with urban air quality data, and is due to geo-morphological and meteorological factors such as the deeper shape of the valley at the position of the town of Feltre and the low altitude of the boundary layer during the winter season.

Levels and sources of PAHs in selected sites from Portugal: biomonitoring with Pinus pinea and Pinus pinaster needles

Pine needle samples from two pine species (Pinus pinaster Ait. and Pinus pinea L.) were collected at 29 sites scattered throughout Portugal, in order to biomonitor the levels and trends of 16 polycyclic aromatic hydrocarbons (PAHs). The values obtained for the sum of all PAHs ranged from 76 to 1944 ng/g [dry weight (dw)]. Despite the apparent matrix similarities between both pine species, P. pinaster needles revealed higher mean entrapment levels than P. pinea (748 and 399 ng/g (dw) per site, respectively). The urban and industrial sites have the highest average of PAH incidence [for P. pinea, 465 and 433 ng/g (dw) per site, respectively, and for P. pinaster, 1147 and 915 ng/g (dw)], followed by the rural sites [233 ng/g and 711 ng/g (dw) per site, for P. pinea and P. pinaster, respectively]. The remote sites, both from P. pinaster needles, show the least contamination, with 77 ng/g (dw) per site. A predominance of 3-ring and 4-ring PAHs was observed in most samples, with phenanthrene having 30.1% of the total. Naphthalene prevailed in remote sites. Rainfall had no influence on the PAHs levels, but there was a relationship between higher wind speeds and lower concentrations. PAH molecular ratios revealed the influence of both petrogenic and pyrogenic sources.

Lichens as an integrating tool for monitoring PAH atmospheric deposition: a comparison with soil, air and pine needles

The aim of this study was to validate lichens as biomonitors of PAH atmospheric deposition; for that, an inter-comparison between the PAH profile and concentrations intercepted in lichens with those of air, soil and pine needles was performed. The study was conducted in a petro-industrial area and the results showed that PAH profiles in lichens were similar to those of the air and pine needles, but completely different from those of soils. Lichens accumulated higher PAH concentrations when compared to the other environmental compartments and its concentrations were significantly and linearly correlated with concentrations of PAHs in soil; we showed that a translation of the lichen PAHs concentrations into regulatory standards is possible, fulfilling one of the most important requirements of using lichens as biomonitors. With lichens we were then able to characterize the air PAHs profile of urban, petro-industrial and background areas.

Correlations between physicochemical properties of PAHs and their distribution in soil, moss and reindeer dung at Ny-Alesund of the Arctic

Concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in soil, moss and reindeer dung collected at Ny-Alesund of the Arctic were measured to investigate their accumulation trends and distribution in the three compartments. Compared with the other regions, the proportions of 2 + 3 ring PAHs to the total PAHs were higher, whereas the proportions of 5 + 6 ring PAHs were lower in the three compartments at Ny-Alesund. Significant log/log-linear relationship was observed between the sub-cooled liquid vapor pressure (p(L)( degrees )) and the soil/moss quotient (Q(SM)). The relation was similar to the relationship between the gas/particle partition coefficient (K(P)) and p(L)( degrees ) of PAHs, implying Q(SM) would be a "mirror image" of K(P). Excellent log/log-linear relationships were observed between Q(SM) and K(OA) as well as between the moss/dung quotient (Q(MD)) and K(OW). The results presented here indicate the physicochemical properties are suitable for characterizing the distribution of PAHs in soil, moss and reindeer dung.

Spatial modeling of PAHs in lichens for fingerprinting of multisource atmospheric pollution

PAHs are toxic compounds emitted by several anthropogenic sources, which have a great impact on human health. We show, for the first time, how spatial models based on PAHs intercepted by lichens can be used for fingerprinting multisource atmospheric pollution in a regional area. Urban-industrial areas showed the highest atmospheric deposition of PAHs followed by urban > industrial > agricultural > forest Multivariate analysis of lichen data showed, for the first time, a clear distinction between various sources of PAHs in the same area: urban are dominated by 4-ring PAHs, forest by 3-ring PAHs, and industrial by 5- and 6-ring PAHs or by 2-ring PAHs (petrogenic or pyrogenic, respectively). Heavy metals were also used for supporting the fingerprinting of PAH sources, reinforcing the industrial origin of 5- and 6-ring PAHs and revealing their particular nature. The spatial structure of the models for different PAHs seems to be dependent on the following factors: size and hydrophilic character of different PAHs, type of emission sources (point or nonpoint), and dispersion associated with particulates of different sizes. Based on the long-term integration of PAHs in lichens, these spatial models will significantly improve our knowledge on the impact of PAH chronic-exposure to humans and ecosystems.

Polycyclic aromatic hydrocarbon (PAH) accumulation in lichen, Phaeophyscia hispidula of DehraDun City, Garhwal Himalayas

The distribution and origin of polycyclic aromatic hydrocarbons (PAHs) in the lichen, Phaeophyscia hispidula (Ach.) Essl., collected from nine different road crossings of DehraDun, capital city of Uttaranchal (Garhwal Himalayas) were studied. The origin of PAHs was also assessed using the Phe/Ant, Flu/Pyr, Ant/Ant+Phe, Flu/Flu+Pyr and Naph/Phen concentration ratios. The total concentration of 16 PAHs ranged from 3.38-25.01 mug g(-1) with an average concentration of 12.09 +/- 9.38 (SD). The PAH ratios clearly indicates that PAH were of mixed origin, a major characteristic of urban environment. Significantly higher concentration of phenanthrene, pyrene and acenaphthylene indicates road traffic as major source of PAH pollution in the city. The study establishes the utility of P. hispidula as an excellent biomonitoring organism in monitoring of PAH from foot hill to sub temperate area of the Garhwal Himalayas.