How can contamination be prevented during laboratory analysis of atmospheric samples for microplastics?

Microplastics (MPs) in the air and indoor environments are of growing concern and have led to increased testing for MPs. This study draws attention to the quality and quantitative measures of MP studies by conducting laboratory experiments (on solutions, filters, and blank samples) that were rarely or were not adopted in the airborne and indoor MP literature. Experiments have been conducted to identify contaminations that may come from experimental procedures while determining MPs in the air samples. MPs in different matrices during experiments were counted and categorized by their shapes. Chemical characterization was performed by Raman Spectroscopy. Results showed that laminar flow is the best option over a fume hood or standard laboratory environment for detecting air MPs to reduce blank levels. Blue-green and Black-Grey were the dominant colors; fiber was the predominant type of MPs seen, and most of them fall under the size range from (1-1000 µm) in different indoor environments and blanks. Common MPs seen were PP, PVA, PTFE, PVC, and HDPE. Thermal treatment of fresh unused filters at 450 °C for 4 h was effective as it reduced the MP count by 50%. Working solutions are mainly contaminated, and their pre-filtration is essential. The average deposition of MPs in blank samples during seven days was around 55 MPs. There is an urgent need for studies on developing quality control and quality assurance of airborne and indoor MPs. Hence, a standard protocol needs to be accepted; by harmonizing procedures, comparable results can be found, uncovering the correct levels of MP contamination, as required for risk assessment.

A data-driven analysis of global research trends on dirty-dozen persistent organic pollutants.

The occurrence, distribution, and fate of persistent organic pollutants (POPs) have been extensively studied worldwide; however, the patterns and dynamics of scientific publications on POPs are still unclear. In this study, the research trends on dirty dozen POPs, which are identified under the Stockholm Convention (SC) for immediate action were investigated and evaluated in a broad context to obtain up-to-date information. For this purpose, bibliometric analysis was carried out between 1945 and 2021 using the Web of Science (WoS) database. A total of 197,029 publications were analyzed. "Environmental Sciences" was the most popular research category and the USA was the leading country in dirty dozen POPs studies. The research hotspots are related to the most used keywords such as "Polychlorinated Biphenyls", "Dioxin" and "Persistent Organic Pollutants". In the evaluation of keyword clusters with highlighted research points, 7 clusters were obtained from the publications, which are related to the chemical properties, synthesis, structures, health effects, and analysis methods of dirty dozen POPs. The number of publications and, accordingly, the scientific interest in dirty dozen POPs listed under the SC has not reached equilibrium and continues regardless of the level of development of countries in the world.

Selected Persistent Organic Pollutants in Ambient Air in Turkey: Regional Sources and Controlling Factors.

As a result of its unique location, Turkey receives air masses from Europe, Russia, Middle East, and Africa, making it an important place in terms of long-range atmospheric transport (LRT) of contaminants. Atmospheric levels of 22 organochlorine pesticides (OCPs), 45 polychlorinated biphenyls (PCBs), and 14 polybrominated diphenyl ethers (PBDEs) were measured in two metropolitan cities, Istanbul and Izmir, on a weekly basis from May 2014 to May 2015. Dichlorodiphenyltrichloroethane (DDT) and its derivatives were dominant OCP species, followed by isomers of hexachlorocyclohexane (HCH) at both sites. The annual mean concentration of ∑DDX (sum of o,p'-DDT, p,p'-DDT, o,p'-DDD, p,p'-DDD, o,p'-DDE, and p,p'-DDE) was 82 pg/m3 for Istanbul and 89 pg/m3 for Izmir, while these levels were about 46 pg/m3 for ∑HCHs (sum of α-, ß-, γ-, and δ-HCH) at both of the sites. At both stations, tri- and tetra-PCBs and tetra- and penta-PBDEs were dominant congeners. The temperature dependence indicates that both LRT and local contaminated areas contribute to the elevated levels. A Lagrangian particle dispersion model (FLEXPART) showed a few potential source regions in northern Africa and Middle East, southern-southwestern and eastern Europe including Russia, as well as from local domestic metropolitan areas.

Levels, distribution, and sources of polychlorinated biphenyls in sediments of Lake Eymir, Turkey.

Little information is available on the occurrence and fate of persistent organic pollutants in lakes of Turkey. The present study was performed as a first step to assess the occurrence, spatial distribution, and potential sources of polychlorinated biphenyls (PCBs) in surface sediments of Lake Eymir located in a special protection area. Σ41PCB concentrations range from 1.09 to 2.33 ng g(-1) in 62 sediment samples collected from the lake. The spatial homogeneity of the PCBs along the whole lake suggests the resuspension or redistribution of historic PCB contamination. A chemical mass balance (CMB) receptor model was used to identify the possible sources of PCBs, for which a limited number of congeners are available for modeling purposes. Results indicated Clophen A60 to be the major PCB source in lake sediments. CMB analysis also showed the importance of a number of compounds used for the assessment of source contributions.

Levels and sources of polychlorinated biphenyls in Ankara creek sediments, Turkey.

The spatial distribution, degree of pollution and major sources of polychlorinated biphenyls (PCBs) were evaluated in surficial sediments of Ankara Creek, located in the capital of Turkey and serving as one of the tributaries in the third largest watershed in Turkey. Sediment ΣPCB concentrations analyzed on Aroclor and congener basis (seven indicator congeners) range from 5.5 to 777.6 ng g(-1) and 3.7 to 743.3 ng g(-1) dw as Aroclor and congener based concentrations, respectively. High concentrations of ΣPCBs were observed in the samples located at the downstream sections of the Creek, after discharge from Ankara municipal wastewater treatment plant. Using a chemical mass balance receptor model (CMB), major sources of PCBs affecting the sediments were investigated. The CMB model identified Aroclor 1254 and 1260 to be the major PCB sources affecting sediments. The potential sources for the PCBs were briefly discussed in terms of their use in various industrial applications.

Apportionment of PCB sources near a transformer maintenance and repair facility in Ankara, Turkey.

The concentration and major sources of polychlorinated biphenyls (PCBs) were evaluated in the sediments from a special environmental protection area located near a transformer maintenance and repair facility (TMRF) in Ankara, Turkey. ∑PCB concentrations analyzed on Aroclor and congener basis (seven indicator congeners) ranged from 0.1 to 84.2 and 0.1 to 21.7 ng/g dry weight, respectively. Results show that higher total PCB concentrations were localized around one of the drainage channels of the TMRF. Identity and contribution of PCB sources were predicted using a chemical mass balance (CMB) based receptor model. The CMB model typically identified Aroclor 1260, the PCB mixture frequently used in transformers, as the major PCB source confirming the effect of the TMRF on the area. Poor prediction of some sample congener profiles suggest presence of environmental degradation mechanisms such as volatilization and differential solubilization of lower chlorinated congeners from sediments.

Atmospheric micro (nano) plastics: future growing concerns for human health.

Abstract: Plastics are an integral but largely inconspicuous part of daily human routines. The present review paper uses cross-disciplinary scientific literature to examine and assess the possible effects of nanoplastics (NPs) concerning microplastics (MPs) on human health and summarizes crucial areas for future research. Although research on the nature and consequences of MPs has seen a substantial rise, only limited studies have concentrated on the atmospheric nanosized polymeric particles. However, due to the intrinsic technological complications in separating and computing them, their existence has been difficult to determine correctly. There is a consensus that these are not only existing in the environment but can get directly released or as the outcome of weathering of larger fragments, and it is believed to be that combustion can be the tertiary source of polymeric particles. NPs can have harmful consequences on human health, and their exposure may happen via ingestion, inhalation, or absorption by the skin. The atmospheric fallout of micro (nano) plastics may be responsible for contaminating the environment. Apart from this, different drivers affect the concentration of micro (nano) plastics in every environment compartment like wind, water currents, vectors, soil erosion, run-off, etc. Their high specific surface for the sorption of organic pollutions and toxic heavy metals and possible transfer between organisms at different nutrient levels make the study of NPs an urgent priority. These NPs could potentially cause physical damage by the particles themselves and biological stress by NPs alone or by leaching additives. However, there is minimal understanding of the occurrence, distribution, abundance, and fate of NPs in the environment, partially due to the lack of suitable techniques for separating and identifying NPs from complex environmental matrices. Highlights: Micro (nano) plastics generated may reach the soil, water, and atmospheric compartments.Atmospheric currents serve as a way to transport, leading to micro (nano) plastics pollution.Exposure to micro (nano) plastics may happen via ingestion, inhalation, or absorption by the skin.Nanoplastics may be environmentally more harmful than other plastic particles; the focus should be on defining the exact size range.Visual classification of micro (nano) plastics is poor in reliability and may also contribute to microplastics being misidentified.

First insight into polybrominated diphenyl ethers in car dust in Turkey: concentrations and human exposure implications.

The presence of polybrominated diphenyl ethers (PBDEs) in the car is due to their use as a flame retardant additive in various car components such as dashboard, plastic parts, seat and headliner cushion foams, insulated cables, and electronic circuits. Ingestion of dust inadvertently or dermal contact to dust are significant pathways of human exposure to pollutants including PBDEs. There are no studies documenting presence of car dust associated flame retardants in Turkey. In the current study, a total of 13 PBDEs congeners were investigated in 62 car dust samples collected from Bursa province of Turkey using glass-fiber filters and a vacuum cleaner. Results of the study showed that congener concentrations were within the range of

Removal of cadmium from aqueous solutions using clinoptilolite: influence of pretreatment and regeneration.

In this study, Cd removal from aqueous solutions via clinoptilolite was investigated in terms of the effect of pretreatment and regeneration. Four different chemicals (NaCl, KCl, CaCl2 and HCl) were tested for this purpose. Samples treated by a total of 20 bed volume (BV) of 1M NaCl solution prepared in tap water with no pH adjustment were found to perform satisfactorily. Five exhaustion and regeneration cycles were then carried out, revealing an increasing Cd removal capacity, coupled with constant Cd elution efficiency in progressing cycles. Furthermore, the change of pH and the presence of exchangeable (Na, K, Ca and Mg) and framework cations (Si and Al) in the aqueous phase were investigated. Subsequently, these were discussed in terms of progressive conversion of clinoptilolite to its homoionic Na-form, and the presence of different Cd removal mechanisms in the system. This study emphasizes the potential of clinoptilolite to be a part of sustainable wastewater treatment technologies, enabling the recovery of both the sorbent and the metal, via demonstration of effective Cd removal and clinoptilolite recovery, besides successful concentration of metal in the regenerant solution.

Positive Matrix Factorization dynamics in fingerprinting: A comparative study of PMF2 and EPA-PMF3 for source apportionment of sediment polychlorinated biphenyls.

Receptor models were typically used in air pollution studies and few publications are available for Positive Matrix Factorization (PMF) that consider the details of parameters and procedures in evaluating the trace organic pollutants in sediments. In this study, environmental fate and source composition of Lake Eymir sediments contaminated by polychlorinated biphenyls (PCBs) were explored by applying two PMF models, Paatero's PMF2 and United States Environmental Protection Agency's (US EPA) EPA-PMF3. PMF2 and EPA-PMF3 rely on different algorithms; Paatero's algorithm and multilinear engine algorithm, respectively. Here, the approaches of two PMF models were compared for the identification of PCB patterns taking into consideration the effects of various uncertainty matrices, residual matrices and goodness-of fit parameters. As a result of the study, it was understood that both models resolved five factors and indicated Clophen A60 as the source of PCBs. These results were consistent with the results resolved by Chemical Mass Balance model applied to the same data set in a previous study. However, source contributions identified by two models differed in quantity, but with similar patterns. This study indicates a way in understanding behavior, fate and global source of persistent organic pollutants in sediment by applying and comparing with a special data including high percentage of below detected value (38.2%) to understand the dynamics of PMF model parameters.

Inventory development for perfluorooctane sulfonic acid (PFOS) in Turkey: challenges to control chemicals in articles and products.

Perfluorooctane sulfonic acid (PFOS) and related substances have been listed as persistent organic pollutants (POPs) in the Stockholm Convention. Countries which have ratified the Convention need to take appropriate actions to control PFOS use and release. This study compiles and enhances the findings of the first inventory of PFOS and related substances use in Turkey conducted within the frame of the Stockholm Convention National Implementation Plan (NIP) update. The specific Harmonized Commodity Description and Coding System (Harmonized System (HS)) codes of imported and exported goods that possibly contain PFOS and 165 of Chemical Abstracts Service (CAS) numbers of PFOS-related substances were assessed for acquiring information from customs and other authorities. However, with the current approaches available, no useful information could be compiled since HS codes are not specific enough and CAS numbers are not used by customs. Furthermore, the cut-off volume in chemical databases in Turkey and the reporting limit in the HS system (0.1 %) are too high for controlling PFOS. The attempt of modeling imported volumes by a Monte Carlo simulation did not also result in a satisfactory estimate, giving an upper-bound estimate above the global production volumes. The replies to questionnaires were not satisfactory, highlighting that an elaborated approach is needed in the communication with potentially PFOS-using stakeholders. The experience of the challenges of gathering information on PFOS in articles and products revealed the gaps of controlling highly hazardous substances in products and articles and the need of improvements.

A preliminary investigation of the environmental impact of a thermal power plant in relation to PCB contamination.

PURPOSE: The most significant application of polychlorinated biphenyls (PCBs) is in transformers and capacitors. Therefore, power plants are important suspected sources for entry of PCBs into the environment. In this context, the levels and distribution of PCBs in sediment, soil, ash, and sludge samples were investigated around Seyitömer thermal power plant, Kütahya, Turkey. Moreover, identity and contribution of PCB mixtures were predicted using the chemical mass balance (CMB) receptor model. METHODS: United States Environmental Protection Agency methods were applied during sample preparation, extraction (3540C), cleanup (3660B, 3665A, 3630C), and analysis (8082A). RESULTS: ΣPCB concentrations in the region ranged from not detected to 385 ng/g dry weight, with relatively higher contamination in sediments in comparison to soil, sludge, and ash samples collected from around the power plant. Congener profiles of the sediment and soil samples show penta-, hexa-, and hepta-chlorobiphenyls as the major homolog groups. The results from the CMB model indicate that PCB contamination is largely due to Clophen A60/A40 and Aroclor 1254/1254(late)/1260 release into the sediment and sludge samples around the thermal power plant. CONCLUSIONS: Since there are no other sources of PCBs in the region and the identity of PCB sources estimated by the CMB model mirrors PCB mixtures contained in transformers formerly used in the plant, the environmental contamination observed especially in sediments is attributed to the power plant. Release of PCBs over time, as indicated by the significant concentrations observed even in surface samples, emphasizes the importance of the need for better environmental management.

Assessment of temporal variation and sources of PCBs in the sediments of Mediterranean Sea, Mersin Bay, Turkey.

Information on temporal distribution of polychlorinated biphenyls (PCBs) in the coastal sediments of Mediterranean Sea, Mersin was compiled using data published between 1980 and 2009, and the present study. The first congener specific PCB results from the region yield concentration levels of Σ(41)PCBs in sediments ranging from 0.61 to 1.04 ng g(-1). Sediment profiles show penta-, hexa- and hepta-chlorobiphenyls, specifically, #149 and 153 as the most abundant congeners in all samples. Comparison of total PCB concentrations over time suggests no recent PCB input to the region. Using congener specific PCB data for the region, identity and contribution of PCB sources were also predicted using a chemical mass balance -based (CMB) receptor model. The CMB model identified Aroclor 1260 to be the major PCB source in coastal sediments. The potential sources for the PCBs were briefly discussed in terms of their use in various industrial applications.

Spatial distribution and source apportionment of PCBs in sediments around Izmit industrial complexes, Turkey.

The spatial distribution, degree of pollution and major sources of PCBs were evaluated in surficial sediments within the heavily urbanized and industrialized Izmit Bay and its main freshwater inputs. ΣPCB concentrations range from 2.90 to 85.4ngg(-1) in marine sediments and from ND to 47.7ngg(-1) in freshwater sediments. Results suggest that high concentrations of ΣPCBs were localized around a chlor-alkali plant and an industry that handles bulk liquid, dry and drummed chemicals, and petroleum products in the Bay. Using a chemical mass balance receptor model (CMB), major sources of PCBs in the region were investigated. The CMB model identified Aroclor 1254 and 1260 to be the major PCB sources in marine sediments and the less chlorinated Aroclor 1248 and 1242 as the major PCB sources in freshwater sediments. The potential sources for the PCBs were briefly discussed in terms of their use in various industrial applications.