Preliminary investigation of polychlorinated dibenzo-p-dioxin and dibenzofuran, polychlorinated naphthalene, and dioxin-like polychlorinated biphenyl concentrations in ambient air in an industrial park at the northeastern edge of the Tibet-Qinghai Plateau, China

Urban air PCDD/Fs: Atmospheric concentrations, temporal changes, gas/particle partitioning, possible sources and cancer risks

Polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) are pollutants of concern due to their toxic effects. No active sampling study on PCDD/Fs has been conducted in Bursa. This study aimed to fill this gap by measuring PCDD/F levels in the region. Accordingly, the samples were collected from an urban area in Bursa, covering four seasons between June 2022 and April 2023. The total (gas+particulate) ambient air concentrations were between 312.23 and 829.80 fg/m3 (mean: 555.05 ± 173.62 fg/m3). In terms of toxic equivalents (TEQ), the average concentration was 43.29 ± 9.18 fg WHOTEQ/m3. Based on the concentration values obtained, cancer and non-carcinogenic risk values of PCDD/Fs were calculated for three different age groups. The results indicated negligible health risks for all age groups. In addition, a seasonal assessment was also made and it was observed that PCDD/F concentration values varied with the ambient air temperatures. In general, higher values were measured in colder months compared to warmer months. This was probably due to the additional sources and adverse meteorological conditions. Moreover, the gas/particle partitioning of PCDD/Fs was investigated in detail. The average gas and particulate phase concentrations for PCDD/Fs were 101.81 ± 20.77 and 453.24 ± 172.50, respectively. It was found that an equilibrium state was not reached in the gas/particle partitioning. Two different gas/particle partition models based on adsorption and absorption mechanisms were compared, and the absorption model gave more consistent predictions. The Principal Component Analysis (PCA) was employed to identify the possible PCDD/F sources. The results indicated that the region was influenced by vehicle emissions, residential heating, organized industrial zones and metal recycling facilities. In addition, 72-hour backward air mass trajectory analyses were performed to understand the long-range transported air masses. However, it was found that the transported air masses did not significantly affect the concentration values measured in the sampling site.

Health risk assessment and development of human health ambient water quality criteria for PCBs in Taihu Basin, China

Polychlorinated biphenyls (PCBs) are a class of typical persistent organic pollutants (POPs) with carcinogenicity and extensively found in diverse environmental mediums. The Taihu Basin is one of the most economically developed regions in China, and it has also caused a lot of historical legacy and unconscious emissions of PCBs, posing a threat to the health of people in the region. This study counted the concentrations of PCBs in five environmental media (water, soil, air, dust, and food) in the Taihu Basin from 2000 to 2020 and used Monte Carlo simulation to simulate the multi-channel exposure of PCBs in people of different ages (children, teenagers, and adults), and evaluated their noncarcinogenic and carcinogenic health risks. Finally, the human health ambient water quality standards (AWQC) for PCBs were obtained using regional exposure parameters and bioaccumulation factors. The results showed that the pollution of PCBs in the Taihu Basin was relatively serious in China. The concentration of PCBs in dust is higher than other environmental media. And exposure to water and food is the main exposure pathway for PCBs in the population of the region. Besides, PCBs pose no noncarcinogenic risk to people in this region, but their carcinogenic risk to residents exceeds the safety threshold. Among the three population groups, adults have the highest risk of cancer, and prevention measures need to be taken by controlling the intake of related foods and the concentration of PCBs in water. The following human health AWQC values of the PCBs in Taihu Basin is 3.2 × 10-9 mg/L.

Risks for animal and human health related to the presence of polychlorinated naphthalenes (PCNs) in feed and food

EFSA was asked for a scientific opinion on the risks for animal and human health related to the presence of polychlorinated naphthalenes (PCNs) in feed and food. The assessment focused on hexaCNs due to very limited data on other PCN congeners. For hexaCNs in feed, 217 analytical results were used to estimate dietary exposures for food-producing and non-food-producing animals; however, a risk characterisation could not be performed because none of the toxicological studies allowed identification of reference points. The oral repeated dose toxicity studies performed in rats with a hexaCN mixture containing all 10 hexaCNs indicated that the critical target was the haematological system. A BMDL20 of 0.05 mg/kg body weight (bw) per day was identified for a considerable decrease in the platelet count. For hexaCNs in food, 2317 analytical results were used to estimate dietary exposures across dietary surveys and age groups. The highest exposure ranged from 0.91 to 29.8 pg/kg bw per day in general population and from 220 to 559 pg/kg bw per day for breast-fed infants with the highest consumption of breast milk. Applying a margin of exposure (MOE) approach, the estimated MOEs for the high dietary exposures ranged from 1,700,000 to 55,000,000 for the general population and from 90,000 to 230,000 for breast-fed infants with the highest consumption of breast milk. These MOEs are far above the minimum MOE of 2000 that does not raise a health concern. Taking account of the uncertainties affecting the assessment, the Panel concluded with at least 99% certainty that dietary exposure to hexaCNs does not raise a health concern for any of the population groups considered. Due to major limitations in the available data, no assessment was possible for genotoxic effects or for health risks of PCNs other than hexaCNs.

Seasonal variations and associated health risks of polychlorinated naphthalenes in Markman Canal, Eastern Cape Province, South Africa

This study focused on evaluation of the levels, seasonal variations and human health risks associated with polychlorinated naphthalenes (PCNs) in water and sediment samples of Markman Canal using solid phase and soxhlet extraction methods respectively, followed by clean-up and quantification with gas chromatograph coupled with microelectron capture detector. The sum of eight PCNs congener's (∑₈PCNs) in water and sediments varied from 0.035 to 0.699 μg/L and 0.260 to 6744.16 μg/kg dw, respectively. Highest PCNs concentrations were recorded in water during winter, while sediment samples collected during spring contained maximum levels. The estimated toxic equivalency (TEQ) for water and sediments was 1.19 × 10^-7-1.47 × 10^-4 µg/L and 4.43 × 10^-5-4.19 × 10^-1 µg/kg consecutively. The PCN levels and TEQ values revealed that this waterbody is polluted but constitutes no excess health risk. Efforts should be made to control all the activities contributing to pollution of this canal.

Exposure and Risk Assessment to Airborne dl-PCBs and Dioxins in the Population Living in the Neighborhood of a Cement Plant: A Pilot Study in the Valencian Region of Spain

Emissions from cement manufacturing facilities may increase health risks in nearby populations. For this reason, dioxin-like PCB (dl-PCB), polychlorinated dibenzo-p-dioxin (PCDD), and polychlorinated dibenzofuran (PCDF) concentrations in PM₁₀ samples were assessed in the vicinity of a cement manufacturing plant located in the Valencian Region (eastern Spain). The total concentrations of the sum of dl-PCBs, PCDDs, and PCDFs ranged between 1.85 and 42.53 fg TEQ/m³ at the assessed stations. The average daily inhalation dose (DID) for the sum in adults ranged from 8.93 · 10^-4 to 3.75 · 10^-3 pg WHO TEQ kg^-1 b.w. d^-1, and, for children, the DID ranged from 2.01 · 10^-3 to 8.44 · 10^-3 pg WHO TEQ kg^-1 b.w. d^-1. Risk assessment for adults and children was performed using both daily and chronic exposure. The hazard quotient (HQ) was calculated considering 0.025 pg WHO TEQ kg^-1 b.w. d^-1 to be the acceptable maximum permitted inhalation exposure. The HQ obtained was slightly higher than 1 for PCDD/Fs at one of the stations (Chiva), indicating a possible health risk for the population under study due to inhalation exposure. In the case of chronic exposure, cancer risk (>10^-6) was observed for some samples in one of the assessed sampling sites (Chiva).

PCNs, PCBs, and PCDD/Fs in Soil around a Cement Kiln Co-Processing Municipal Wastes in Northwestern China: Levels, Distribution, and Potential Human Health Risks

To evaluate the impact of the first cement kiln co-processing municipal wastes in northwest China on the surrounding environment, the concentrations of polychlorinated naphthalenes (PCNs), polychlorinated biphenyls (PCBs), and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were determined in 17 soil samples collected around the plant. The concentration ranges of PCNs, PCBs, and PCDD/Fs were 132-1288, 10.8-59.5, and 2.50-5.95 pg/g, and the ranges of toxic equivalents (TEQ) were 1.98-20.8, 2.36-48.0, and 73.2-418 fg/g, respectively. The concentrations of PCNs, PCBs, and PCDD/Fs in this study were generally lower than those in soil around municipal waste incinerators and industrial parks in other areas. An exponential function equation was applied for the relationship between the concentration of the target compounds and the distance from the cement kiln stack, the results showed that PCN and PCB concentrations declined with the increasing of distance from the stack. Furthermore, it was found that the effect of the cement kiln on surrounding soil contaminations with PCNs and PCBs was stronger than that of PCDD/Fs by comparing the PCN, PCB, and PCDD/F homologue profiles in the fly ash sample from the plant and soil samples at different distances. The total carcinogenic risks (CR) of PCNs, PCBs, and PCDD/Fs for children and adults in soil were 1.65 × 10^-8-8.93 × 10^-8 and 1.70 × 10^-8-9.16 × 10^-8, respectively, which was less than the risk threshold (CR = 1 × 10^-6), and there was no health risk.

Determination of polychlorinated naphthalenes in ambient air by isotope dilution gas chromatography-triple quadrupole mass spectrometry

环境空气中的多氯萘(PCNs)一般为痕量水平(pg/m³),要实现其准确定量必然对分析方法的提取、净化和仪器分析提出较高要求。研究通过考察提取溶剂种类、净化流程和色谱-质谱参数,建立了加速溶剂萃取(ASE)-多层硅胶复合中性氧化铝柱的净化方法,并利用同位素稀释气相色谱-三重四极杆质谱(GC-MS/MS)对环境空气中的多氯萘进行测定。同时,通过在采样、提取和进样分析前分别添加同位素内标,开展质量控制和保证。结果表明,在2~100 ng/mL范围内3~8氯萘的平均相对响应因子(RRF)的相对标准偏差(RSD)均小于16%。PCNs同类物的方法检出限为1~3 pg/m³(以样品体积为288 m³计算)。采用基质加标法评价了方法对环境空气样品中PCNs测定的精密度和准确度,低、中、高加标水平下3 ~8氯萘的平均加标回收率分别为89.0%~119.4%、98.6%~122.5%和93.7%~124.5%,测定结果的平均相对标准偏差分别为1.9%~7.0%、1.6%~6.6%和1.0%~4.8%。整个分析过程中,采样内标和提取内标的平均回收率分别为136.2%~146.0%和42.4%~78.1%, RSD分别为5.6%~7.5%和2.7%~17.5%,满足痕量分析的要求且平行性较好。方法的灵敏度和准确度高,精密度良好,适用于环境空气中3~8氯萘的准确定量测定,可在一定程度上缓解多氯萘监测对高分辨气相色谱-高分辨质谱的依赖,为实现多氯萘的国际履约提供方法支持。

Atmospheric concentration, spatial variations, and source identification of persistent organic pollutants in urban and semi-urban areas using passive air samplers in Bursa, Turkey

In this study, the concentration of ambient persistent organic pollutants (POPs) such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) were measured for 12 months in urban and semi-urban areas using a passive air sampler. During the sampling period, a total of 14 PAH (∑₁₄PAH) concentrations measured in urban and semi-urban areas were found to be 54.4 ± 22.6 ng/m³ and 51.7 ± 34.3 ng/m³, respectively. Molecular diagnostic ratios (MDRs) were used to determine PAH sources. According to the MDR values, combustion sources were the most important PAH sources in both sampling areas. However, since the urban area is close to the industrial zone, the combustion sources occurred at high temperatures (> 800 °C), while the sources in the semi-urban area generally consisted of petrogenic fuel combustion. ∑₅₀PCB concentrations measured in the urban and semi-urban areas were found to be 522.5 ± 196.9 pg/m³ and 439.5 ± 166.6 pg/m³, respectively. Homologous group distributions were used to determine the source of PCBs. According to the homologous group distributions, tri-, tetra-, and penta-chlorinated PCBs were dominant in both sampling areas. ∑₁₀OCP concentrations measured in urban and semi-urban areas were found as 242.5 ± 104.6 pg/m³ and 275.9 ± 130.9 pg/m³, respectively. Also, α-HCH/γ-HCH and β-/(α + γ)-HCH ratios were used to determine the source of OCPs. Lindane was the predominant OCP in both sampling areas.

Environmental contamination and human exposure of polychlorinated biphenyls (PCBs) in China: A review

Polychlorinated biphenyls (PCBs), together with 11 other organic compounds, were initially listed as persistent organic pollutants (POPs) by the Stockholm Convention because of their potential threat to ecosystems and humans. In China, many monitoring studies have been undertaken to reveal the level of PCBs in environment since 2005 due to the introduced stricter environmental regulations. However, there are still significant gaps in understanding the overall spatial and temporal distributions of PCBs in China. This review systematically discusses the occurrence and distribution of PCBs in environmental matrices, organisms, and humans in China. Results showed that PCB contamination in northern and southern China was not significantly different, but the PCB levels in East China were commonly higher than those in West China, which might have been due to the widespread consumption of PCBs and intensive human activities in East China. Serious PCB contamination was found in e-waste disassembling areas (e.g., Taizhou of Zhejiang Province and Qingyuan and Guiyu of Guangdong Province). Higher PCB concentrations were also chronicled in megalopolises and industrial clusters. The unintentionally produced PCBs (UP-PCBs) formed during industrial thermal processes may play an increasingly significant role in PCB pollution in China. Low PCB levels were recorded in rural and underdeveloped districts, particularly in remote and high-altitude localities such as the Tibetan Plateau and the South China Sea. However, these data are limited. Human exposure to PCBs is closely related to the characteristics of environmental pollution. This review also discusses existing issues and future research prospects on PCBs in China. For instance, the accumulation characteristics and migration regularities of PCBs in food webs should be further studied. More investigations should be undertaken to assess the quantitative relationship between external and internal exposure to PCBs. For example, bioaccessibility and bioavailability studies should be supplemented to evaluate human health risks more accurately.

Occurrence, Human Exposure, and Risk Assessment of Polybrominated Dibenzo-p-Dioxins and Dibenzofurans, Polychlorinated Naphthalenes, and Metals in Atmosphere Around Industrial Parks in Jiangsu, China

Air samples were collected around industrial parks in Jiangsu, China, to allow the concentrations, profiles, and risk assessment of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), polychlorinated naphthalenes (PCNs), and metals to be investigated. The concentrations of ΣPBDD/Fs and ΣPCNs were 1324.26-2080.98 fg/m³ (11.35-42.57 fg I-TEQ/m³) and 10,404.9-29,322.9 fg/m³ (1.32-7.19 fg I-TEQ/ m³), respectively. The highest concentration of ΣPBDD/Fs and ΣPCNs were observed at site C. PBDD/Fs were mainly dominated by PBDFs. The main contributor to the ΣPBDD/Fs in all samples was 1,2,3,4,6,7,8-HpBDF, which accounted for 25.75%-39.4%. For PCNs, the predominating homologues were tetra-, tri- and penta-CNs, which contributed 30.7%-43.3%, 24.7%-31.0%, and 10.6%-21.6%, respectively. As for metals, the pollution of As, Mn, Cr, and Ni in most samples exceeded National Ambient Air Quality Standards of China. Assessing the risk of inhalation exposure showed that there were potential carcinogenic risks to local residents.

Dioxins and dioxin-like PCBs in the ambient air of the Valencian Region (Spain): Levels, human exposure, and risk assessment

Dioxins (polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF), as well as dioxin-like PCBs (dl-PCBs), are listed as persistent organic pollutants in the Stockholm Convention. In this study, we measured their concentrations in the particulate phase (PM10) of the ambient air in seven monitoring stations of the Valencian Community (Spain). A total of 82 samples were collected from different sampling sites: four industrial, two urban, and one remote, from February to December 2019. The total concentrations of the sum of PCDD, PCDF, and dl-PCBs ranged from 2.90 fg TEQ/m³ to 317.98 fg TEQ/m³. Risk assessment for adults and children was performed using both daily and chronic exposure. Each station showed its specific dioxin profile, related to the main productive activities in each area. The daily inhalation dose (DID) in adults and children was lower than the tolerable daily intake (TDI) of 1-4 pg WHO TEQ kg^-1 b.w. d^-1 for dioxins. In the case of chronic exposure, the cancer risk for dioxins and dl-PCBs was estimated at values ranging from 5.27 E-07 to 5.52 E-05. The cancer risk for dioxins and PCBs estimated at the 95th percentile was higher than 1.0 E-06 in all of the industrial and urban areas.

Qualitative and quantitative changes in traffic and waste incineration PCDD/Fs in urban air and soils under different seasonal conditions (Metropolitan Area of Barcelona)

A sampling and analysis scheme was implemented to discriminate between inputs of polychlorodibenzo-p-dioxins and polychlorodibenzofurans (PCDD/Fs) at low concentrations in urban areas. Ambient air and soils were sampled and analyzed in five stations in the Metropolitan area of Barcelona (2018-2019); one located in a reference urban traffic site and four in the area of influence of an integrated waste management facility (IWMF) that included a solid waste incinerator. Seasonality was the main factor determining the PCDD/F composition, and involved lower values in the warmer months. This seasonal effect was related to enhanced photooxidation of PCDDs compared to PCDFs and faster depletion of the less chlorinated congeners due to volatility at higher ambient temperature; consistent with the compounds' octanol-air partition coefficients. The ratio 2,3,7,8-tetrachlorobenzofuran/1,2,3,4,6,7,8-heptachlorobenzofuran allowed, for the first time, identifying cases of preferential contributions of IWMF and traffic inputs, i.e. values of 0.06 and 0.32, respectively. Combination of this ratio with the airborne PCDD/F levels illustrated that the quantitative PCDD/F levels were not a useful criterion for elucidation between IWMF and traffic inputs. PCDD/Fs levels in soils ranged between 9.0 and 22 pg WHO-TEQ/g in the two sites closest to the IWMF, while the other sites, including the traffic site, showed values between 0.8 and 1.9 pg WHO-TEQ/g. The levels in the former group were higher than those observed in other urban areas and above 5 pg WHO-TEQ/g, which is a limit reference value in several European countries. The C₇ and C₈ observed congener distributions in all soils examined were different from those in the air samples and similar to those reported in sewage sludge from waste water treatment plants, not showing influences from IWMF or traffic PCDD/F inputs.

Short-chain chlorinated paraffins in soils indicate landfills as local sources in the Tibetan Plateau

Background contamination levels of contemporary persistent organic pollutants (POPs) may be elevated due to local discharges, and hence it is of high importance to assess and monitor them in alpine and Polar Regions. This study investigated the role of waste disposal in the Tibetan plateau as the local source of short-chain chlorinated paraffins (SCCPs). SCCPs were determined in soils from the urban landfill and rural dumpsites, with a concentration range of 56.8-1348 ng/g dw. The gradient descent of SCCP levels from Lhasa landfill to the surrounding soils with increasing distances suggested a significant SCCP release from waste disposal. The transport pattern was well fitted by the Boltzmann equation after normalization in terms of soil organic carbon contents. Compared to the landfill cells closed in early years, the recently closed cells contained higher concentrations but lower proportions of the short-chain congener groups, likely reflecting the SCCP use history in Tibet. In open-burning dumpsites, higher SCCP levels and dominance of lighter congener groups indicates that such crude waste treatment process might cause an extra release of volatile SCCPs. This study elucidates local SCCP inputs to the background environment, and demonstrates that both urbanization and badly-managed landfill have been contributing to the presence of contemporary POPs in the Tibetan Plateau.

Atmospheric Concentrations and Health Implications of PAHs, PCBs and PCDD/Fs in the Vicinity of a Heavily Industrialized Site in Greece

Background: Thriassion Plain is considered the most industrialized area in Greece and thus a place where emissions of pollutants are expected to be elevated, leading to the degradation of air quality. Methods: Simultaneous determination of polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), and polychlorinated biphenyls (PCBs) was performed in PM10 samples. SPSS statistical package was employed for statistical analysis and source apportionment purposes. Cancer risk was estimated from total persistent organic pollutants’ (POPs) dataset according to the available literature. Results: POPs concentrations in particulate matter were measured in similar levels compared to other studies in Greece and worldwide, with mean concentrations of ΣPAHs, ΣPCDD/Fs, dioxin like PCBs, and indicator PCBs being 7.07 ng m−3, 479 fg m−3, 1634 fg m−3, and 18.1 pg m−3, respectively. Seasonal variations were observed only for PAHS with higher concentrations during cold period. MDRs, D/F ratios, and principal component analysis (PCA) highlighted combustions as the main source of POPs’ emissions. Estimation of particles’ carcinogenic and mutagenic potential indicates the increased toxicity of PM10 during cold periods, and cancer risk assessment concludes that 3 to 4 people out of 100,000 may suffer from cancer due to POPs’ inhalation. Conclusions: Increased cancer risk for citizens leads to the necessity of chronic POPs’ monitoring in Thriassion Plain, and such strategies have to be a priority for Greek environmental authorities.

Concentrations, Sources, and Potential Human Health Risks of PCDD/Fs, dl-PCBs, and PAHs in Rural Atmosphere Around Chemical Plants in Jiangsu Province, China

Concentrations and sources of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (dl-PCBs), and polycyclic aromatic hydrocarbons (PAHs) in a rural atmosphere near industrial zones in Jiangsu, China were determined and the associated risks were assessed. The concentrations of ΣPCDD/Fs, ΣPCBs, and ΣPAHs ranged from 11.9-57.7 pg·m^-3, 0.58-2.71 pg m^-3, and 11-18 ng m^-3, respectively. Principal component analysis suggested that the contamination of air with PCDD/Fs and PCBs mainly originated from industrial activities and combustion processes. In contrast, the major source of PAHs was the combustion of petroleum, coal, and biomass. These data were used to estimate the exposure of the population living nearby to these persistent organic pollutants and to evaluate the non-carcinogenic and carcinogenic risks associated with their inhalation. Our study are likely to be helpful for developing and implementing regulation strategies for PCDD/Fs, dl-PCBs, and PAHs in the atmosphere around industrial and surrounding residential areas.

Polychlorinated Naphthalene Congener Profiles in Common Vegetation on the Tibetan Plateau as Biomonitors of Their Sources and Transportation

Polychlorinated naphthalenes (PCNs) are globally transported, carcinogenic, persistent organic pollutants (POPs) that were recently added to the Stockholm Convention with 184 parties. The Tibetan Plateau plays an important role in the global transportation and distribution of POPs. Knowledge of PCN sources and transportation on the Tibetan Plateau is important for their control globally. In this study, we quantified the congener-specific concentrations of PCNs in lichen, moss, soil, and air samples collected on the Tibetan plateau and found that common lichens were effective biomonitors for predicting atmospheric PCNs in this area. The physiochemical properties of the PCNs, the temperatures, and the lichen lipid contents were identified as important factors influencing PCN partitioning between lichens and air. Lichen-air partitioning equations were established and used to predict PCN concentrations in air in Southeast Tibet. The lichens could be used as PCN biomonitors to clarify their spatial variations, sources, and transportation in the southeast of the plateau. PCN concentrations in lichens increased with altitude, suggesting that high-mountain cold-trapping influenced the PCN transportation behavior. Principal component analysis and linear discriminant analysis showed that the major source of PCNs in this region was long-range atmospheric transportation via the Indian monsoon in summer and wind from Southwest Asia in winter. This study provides a novel method using PCN congener profiles as fingerprints and statistical models for studying the geochemical effects of conditions in high-mountain regions on the contamination behaviors of 75 congeners of the notorious PCNs.