Assessment of the temporal and spatial distribution of atmospheric PCNs and their air-soil exchange using passive air samplers in Shanghai, East China

Polychlorinated naphthalenes (PCNs) and polychlorinated biphenyls (PCBs) in surface soils and street dusts in Detroit, Michigan

Polychlorinated naphthalenes (PCNs) and polychlorinated biphenyls (PCBs) are toxic contaminants that were produced and used in large quantities for their stability, inertness, and other desirable electrical, cooling, and lubricating properties. Due to their environmental persistence and improper disposal, these contaminants have become broadly distributed in the environment. This study examines the levels, composition, distribution, and potential sources of these compounds in surface soils and street dusts collected at 19 residential and industrial areas in Detroit, Michigan. Each sample was analyzed for 32 PCN and 37 PCB congeners using gas chromatography/mass spectrometry. The geometric mean concentrations of total PCNs and total PCBs were 61 (range:11-1933) and 432 (range: 32-18,637) ng/g, respectively. The most common PCNs were tetra- to hexacongeners and PCN-59 was most prevalent individual congener. For PCBs, hexaPCBs were most common and PCB-158 was dominant. PCN and PCB levels in soils at most sites exceeded health-based guideline levels. Given the short half-lives of PCNs and restrictions on PCN and PCB production, our results imply ongoing or recent releases. Emission sources identified by principal components and other analyses include industrial thermal processes included fuel combustion and electrical waste handling at a scrap metal processor for PCNs and PCBs, respectively. The presence of sources and "hotspots" of these toxic "legacy" contaminants in urban settings like Detroit highlight the potential for human exposure and the need to identify and control sources to prevent further environmental dispersal, exposure and risk.

Spatial distribution and air-soil exchange of short and medium chain chlorinated paraffins in Lahore, Pakistan

This study provides the first systematic data on the distribution of short- (SCCPs) and medium chlorinated paraffins (MCCPs) in the atmosphere and surface soils of Lahore, Pakistan. The spatial distribution of SCCPs and MCCPs in air (n = 12) and soil (n = 15) was investigated from industrial, residential, commercial, conventional e-waste burning and background areas of Lahore. The concentrations ranged from below the limit of detection ( Collapse

Key Words

• Exchange flux
• Fugacity fraction
• Land-use
• Risk assessment
• TOC

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MESH Headings

• Pakistan
• Environmental Monitoring
• Paraffin/analysis
• Soil Pollutants/analysis
• Air Pollutants/analysis
• Hydrocarbons, Chlorinated/analysis
• Soil/chemistry

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Affiliation(s)

Areej Tahir College of Earth and Environmental Sciences, University of the Punjab, Lahore 54590, Pakistan.
Naeem Akhtar Abbasi College of Earth and Environmental Sciences, University of the Punjab, Lahore 54590, Pakistan.
Chang He Queensland Alliance for Environmental Health Science, The University of Queensland, Brisbane 4102, Australia; Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, PR China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, PR China
Sajid Rashid Ahmad College of Earth and Environmental Sciences, University of the Punjab, Lahore 54590, Pakistan

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The long-term spatial and temporal distributions of polychlorinated naphthalene air concentrations in Fildes Peninsula, West Antarctica

The knowledge of polychlorinated naphthalenes (PCNs) in the Antarctic atmosphere is quite limited compared to the Arctic. PCNs are a global concern because of their PBT characteristics (i.e., persistent, bioaccumulative, and toxic) and severe and often deadly biological effects on people and other animals. Therefore, the present study used a passive air sampling method to conduct long-term air monitoring of PCNs for almost a decade from 2013 to 2022, specifically on Fildes Peninsula, situated on King George Island, located in West Antarctica. The median sum of mono-CNs to octa-CN concentration (∑75PCNs) in the Antarctic atmosphere was 12.4 pg/m3. In terms of homologues, mono-CNs to tri-CNs predominated. Among these, the prevalent congeners observed were PCN-1 and PCN-2, originating from mono-CNs, followed by PCN-5/7 from di-CNs, and PCN-24/14 from tri-CNs, respectively. Between 2013 and 2022, the total levels of PCNs were found to have decreased approximately fourfold. Ratio analyses and principal component analysis (PCA) showed that the long-range atmospheric transport and combustion-related sources as the potential PCN sources in the study area. This paper provides the most up-to-date temporal trend analysis of PCNs in the Antarctic continent and is the first to document all 75 congeners (mono-CNs to octa-CN homologue groups).

Using Polychlorinated Naphthalene Concentrations in the Soil from a Southeast China E-Waste Recycling Area in a Novel Screening-Level Multipathway Human Cancer Risk Assessment

Polychlorinated naphthalene (PCN) concentrations in the soil at an e-waste recycling area in Guiyu, China, were measured and the associated human cancer risk due to e-waste-related exposures was investigated. We quantified PCNs in the agricultural soil and used these concentrations with predictive equations to calculate theoretical concentrations in outdoor air. We then calculated theoretical concentrations in indoor air using an attenuation factor and in the local diet using previously published models for contaminant uptake in plants and fruits. Potential human cancer risks of PCNs were assessed for multiple exposure pathways, including soil ingestion, inhalation, dermal contact, and dietary ingestion. Our calculations indicated that local residents had a high cancer risk from exposure to PCNs and that the diet was the primary pathway of PCN exposure, followed by dermal contact as the secondary pathway. We next repeated the risk assessment using concentrations for other carcinogenic contaminants reported in the literature at the same site. We found that polychlorinated dibenzodioxins and dibenzofurans (PCDD/Fs) and PCNs caused the highest potential cancer risks to the residents, followed by polychlorinated biphenyls (PCBs). The relative importance of different exposure pathways depended on the physicochemical properties of specific chemicals.

Occurrence of dioxin-like POPs in soils from urban green space in a metropolis, North China: implication to human exposure

Urban green space is a special space for urban life and natural contact and has an important impact on human health. However, little information is available on dioxin-like persistent organic pollutants (POPs) in the soils from the specific areas. We measured the concentrations of polychlorinated naphthalenes (PCNs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and polychlorinated biphenyls (PCBs) in the soils from urban green space in a metropolis, North China, and found total concentrations of PCDD/Fs, PCBs, and PCNs in the range of 11.5-91.4, 14.7-444, and 82.5-848 pg/g, respectively. It was worth to notice that the concentrations of PCDD/Fs in public park soil from urban center were significantly higher than those in the road greenbelts and resident lawns (Kruskal-Wallis test, p = 0.004). The source analysis indicated that sewage sludge from wastewater treatment plants were important sources of PCNs and PCDD/Fs in urban green land soils, and atmospheric deposition from municipal solid waste incinerator (MSWI) also play an important role in PCDD/F sources. The rough exposure risk evaluation showed that the residents were at a safe level with the daily doses being 0.172-3.144 fg/kg BW/day for children and 0.022-0.406 fg/kg BW/day for adult. Due to the complex and variable sources of PCDD/Fs in urban areas, dioxin-like POPs in urban green land should be given more attention to weaken human exposure.

Distribution, composition, and ecological risk of surface sedimental polychlorinated naphthalenes in the East China Sea

To reveal the pollution levels and estimate the ecological risks of polychlorinated naphthalenes (PCNs) in the East China Sea (ECS), seventy-five surface sediment samples were collected and analyzed by high-resolution mass spectrometry. PCN contents ranged from below detection limit to 261.71 ng/g dry weight (d.w.), with an integrally seaward decreasing trend. Mono-, tetra-, and hepta-CNs were the dominant homologs, and CN-2, CN-73, and CN-75 were the major individual components in most samples. CN-2 presented an obvious boundary with lower contents (16.48 ± 3.40 ng/g d.w.) in the center of the study area and higher contents (50.88 ± 10.39 ng/g d.w.) in the north and south of the boundary. The toxic equivalent (TEQ) contents ranged from 0 to 0.212 ng/g, and CN-2 and CN-73 were the predominant contributors to the TEQ.