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

Dissent in the sediment? Lake sediments as archives of short- and long-range impact of anthropogenic activities in northeastern Germany

The suitability of lake sediment cores to reconstruct past inputs, regional pollution, and usage patterns of pesticides has been shown previously. Until now, no such data exist for lakes in eastern Germany. Therefore, 10 sediment cores (length 1 m) of 10 lakes in eastern Germany, the territory of the former German Democratic Republic (GDR), were collected and cut into 5-10-mm layers. In each layer, concentrations of trace elements (TEs) As, Cd, Cr, Cu, Ni, Pb, S, and Zn, as well as of organochlorine pesticides (OCPs), i.e., dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH), were analyzed. A miniaturized solid-liquid extraction technique in conjunction with headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) was used for the latter. The progression of TE concentrations over time is uniform. It follows a trans-regional pattern and is indicative of activity and policy making in West Germany before 1990 instead of those in the GDR. Of OCPs, only transformation products of DDT were found. Congener ratios indicate a mainly aerial input. In the lakes' profiles, several regional features and responses to national policies and measures are visible. Dichlorodiphenyldichloroethane (DDD) concentrations reflect the history of DDT use in the GDR. Lake sediments proved to be suitable to archive short- and long-range impacts of anthropogenic activity. Our data can be used to complement and validate other forms of environmental pollution long-term monitoring and to check for the efficiency of pollution countermeasures in the past.

Trace metals, polycyclic aromatic hydrocarbons and polychlorinated biphenyls in the surface sediments from Sanya River, China: Distribution, sources and ecological risk

The urban inland river ecosystems are now facing comprehensive pollution and governance pressures. Up to now, few works related to the multiple pollution assessment of trace metals, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) for the urban inland river sediments have been reported in China. Our study investigated the spatial distribution, ecological risk and potential sources of trace metals, PAHs and PCBs in surface sediment collected from 20 sampling sites of Sanya River, Hainan Province, China. The pollution status and potential ecological risk of trace metals were evaluated using the contamination indexes including geoaccumulation index (I_geo), individual potential ecological risk (E_rⁱ), potential ecological risk index (RI) and pollution load index (PLI). Considering the carcinogenicity and toxicity of PAHs and PCBs to human health and the ecological environment, we also analyzed the distributions, sources and adverse biological effects of PAHs and PCBs according to the sediment quality guidelines (SQGs), principal component analysis (PCA) and other source analysis. This study revealed that the surface sediments in Sanya River were extremely slight pollution and showed a very low ecological risk according to I_geo, E_rⁱ, PLI and RI results for trace metals. Besides, PAHs and PCBs pollution detected may not pose considerable adverse biological effect to ecological environment in a foreseeable period on the basis of comprehensive research results. The overall surface sediments quality of the Sanya River not seem to pose a serious pollution and ecological risk based on the evaluation results of multiple pollution factors. The study provided detailed information on the multiple pollution status and location of surface sediments, one of the key environmental indicators of international tourism cities, in the Sanya River, which would be useful for the water quality improvement of Sanya River and the environmental remediation of the other coastal ecosystems from different regions.

A study of the spatial distribution patterns of airborne polycyclic aromatic hydrocarbons in crowberry (Empetrum nigrum) in Ilulissat, Greenland

Polycyclic aromatic hydrocarbons (PAHs) are produced by anthropogenic activities, such as traffic and domestic heating. Due to their adverse effects to humans and natural habitats, the presence of PAHs in the environment needs to be monitored. Plants are known as natural accumulators of persistent organic pollutants (POPs) and can therefore be used for the monitoring of PAHs emitted into the environment. Contamination by PAHs also occurs in the Arctic such as Greenland due to long-range transport through air. However, as anthropogenic activities in the Arctic are increasing, there is a need to investigate the distribution of PAHs due to local emission sources. In this study, we present a systematic sampling approach to identify the influence of PAH sources in an area next to the town of Ilulissat in Greenland. Composite crowberry samples have been collected north of Ilulissat, where the town itself, an incineration site and Ilulissat airport are possible emission sources for PAHs. Matrix solid-phase extraction was used for the extraction of PAHs and the chemical analysis was performed by gas chromatography with mass spectrometry detection (GC-MS). In total, 18 out of 19 investigated PAHs could be detected in Empetrum nigrum in a concentration range of 0.69 to 93.01 μg/kg_{dry weight}. Higher concentrations for most of the targeted PAHs were found close to the suspected emission sources and also along the road connecting them. For pyrene, the correlation between the concentration and the distance from the emission sources could be modelled and visualized using a two-dimensional exponential variogram and ordinary kriging. The range in which the samples were spatially correlated was approximately 500 m. Our results show that local emission sources contribute to the spatial distribution patterns of PAHs. Monitoring of pollution by airborne PAHs is therefore needed even in areas far from major pollution sources such as Ilulissat, Greenland. E. nigrum showed to be a feasible species for biomonitoring of PAHs due to its large abundance in the sampling area and its widespread availability in the Artic region.

Facile fabrication and application of poly(ortho-phenetidine) nanocomposite coating for solid-phase microextraction of carcinogenic polycyclic aromatic hydrocarbons from wastewaters

The waters and wastewaters around industrial areas are heavily polluted and have adverse effects on the ecosystems. The present study is mainly focused on the electropolymerization of ortho-phenetidine and co-deposited on a steel wire along with graphene oxide nanosheets as a novel coating for solid-phase microextraction of polycyclic aromatic hydrocarbons (PAHs) from aqueous media prior to gas chromatography-mass spectrometry. PAHs are composed of multiple aromatic rings which have been linked to skin, lung, bladder and liver. Cancer is a primary human health risk of exposure to PAHs. To obtain a firm and stable coating, several empirical factors relevant to the electrochemical process were investigated. Characterization for chemical structure and surface morphology of the synthesized nanocomposite was conducted with FT-IR spectroscopy and FE-SEM, respectively. XRD and TGA were applied to study the other properties of the nanocomposite. Some essential items involved in microextraction process were also checked in details. Under optimized case, validation parameters were assessed. Wide linearity (0.005-5.0 ng mL^-1), low detection limits (0.4-4.3 pg mL^-1) and good repeatability (3.6-9.5%) and reproducibility (7.6-11.8%) were achieved. The developed method was utilized to analyze contaminated real samples such as wastewater samples from coal processing industries and agricultural water samples collected from the vicinity of the industry in different seasons and high recoveries were obtained, finally.

High spatial resolution analysis of polybrominated diphenyl ethers (PBDEs) using transplanted lichen Evernia prunastri: A case study in central Italy

The ability of transplanted lichen Evernia (E.) prunastri (L.) to act as a high spatial biomonitoring tool for 14 polybrominated diphenyl ethers (PBDEs) was evaluated at 23 monitoring sites in a very polluted area in central Italy. The selected area is characterized by the presence of numerous emission sources, such as waste-to-energy plant, steel plant, vehicular traffic, and domestic heating. Transplanted E. prunastri proved to be a useful tool to biomonitor PBDEs, due to its ability to bioaccumulate individual congeners in varying concentrations in relation to the strength of the emission sources present over the territory. PBDEs levels widely ranged from 132 to 24,237 ng kg^-1 dry weight, according to the sources of emission located around the monitoring sites. The highest concentrations were detected at the sites close to the municipal solid waste incinerator, steel plant, and high busy roads, confirming their important role as PBDEs emissions sources.

Recalibration and validation of the Swiss lichen bioindication methods for air quality assessment

The aim of this study was to recalibrate the Swiss lichen bioindication methods, developed and calibrated with air pollution data 30 years ago. Since then, levels of air pollution have considerably decreased, and the mix of pollutants has changed due to successful emission control in Switzerland and neighboring countries. In particular, there has been a change from a sulfur- and acid-dominated to a more nitrogen-dominated pollution mix of NH₃/NO_x and ozone, resulting in increased pH levels. This allowed a recolonization and change in abundance and composition of the epiphytic lichen vegetation, indicating an improved air quality in Switzerland. The existing indices of atmospheric pollution or purity IAP₁₈ and IAP_BR developed 30 years ago showed good longitudinal correlations with air pollutant levels until the end of the last century, but a growing drift was observed in some regions over the last 15 years. This called for a method recalibration with more recent air pollution data. Data from a total of 7178 trees from 22 Swiss regions grouped into 1331 homogenous plots and covering the period 1994 to 2017 were averaged by year within plots. Three pollutant-specific lichen indices were newly established, one for primary pollutants (NO₂, PM10, SO₂), one for ozone (AOT40f), and one for ammonia (NH₃). These pollutant-specific lichen indices were derived from linear regression models with lichen variables and a linear time trend variable as predictors, using time-dependent coefficients. Parameters were selected using the Lasso method. The primary pollutant lichen index showed a coefficient of determination R² of 0.86 in the model with NO₂, PM10, and SO₂ as predictor variables, whereas corresponding models with other predictor variables (i.e., NH₃, AOT40f, and meteorological variables) were of considerably lower fit. Regionalized lichen models for three larger Swiss regions revealed even better results, compared with the unified Swiss models. The best regionalized ozone and ammonia lichen indices reached an R² of 0.88 and 0.71, respectively.

New classes of organic pollutants in the remote continental environment - Chlorinated and brominated polycyclic aromatic hydrocarbons on the Tibetan Plateau

Halogenated polycyclic aromatic hydrocarbons are carcinogenic and ubiquitous environmental organic pollutants. The abundance and sources of these compounds have not been studied in remote environments. We collected and analyzed air, soil, lichen, and moss samples from the Tibetan Plateau. Concentrations of chlorinated polycyclic aromatic hydrocarbons were 0.78-4.16 pg/m³ in air, 3.11-297 pg/g in soil, 260-741 pg/g in lichens, and 338-934 pg/g in mosses. Concentrations of brominated polycyclic aromatic hydrocarbons were 0.15-0.59 pg/m³ in air, 0.61-72.3 pg/g in soil, 33.5-64.9 pg/g in lichens, and 20.5-72.5 pg/g in mosses. The dominant congeners were 9- and 2-chlorophenanthrene, 1-chloropyrene, 3-chlorofluoranthene, and 1-bromopyrene. We found correlations between congener concentrations in lichens and in air, and lichens effectively predicted near-ground atmospheric concentrations of the pollutants. The enrichment of photochemically stable compounds in high-altitude environments is influenced by their physicochemical properties. Principal component analysis with multivariate linear regression of chlorinated polycyclic aromatic hydrocarbons measured in lichens provided an assessment of the relative source contributions, and suggested that in Medog County of Tibetan Plateau, 48% was likely from long-range combustion sources, 26% was from local burning sources, and 26% was from photochemical formation.