Modeling Global Environmental Fate and Quantifying Global Source-Receptor Relationships of Short-, Medium-, and Long-Chain Chlorinated Paraffins.

Decades-long emissions and long-range transport of chlorinated paraffins (CPs) have resulted in their pervasive presence in the global environment. The lack of an understanding of the global distribution of short-, medium-, and long-chain CPs (SCCPs, MCCPs, and LCCPs) hinders us from quantitatively tracing their origins in remote regions. Using the BETR-Global model and historical emission estimates, we simulate the global dispersion of CPs from 1930 to 2020. Whereas contamination trends in the main contaminated regions (East Asia, Europe, North America, and South Asia) diverge, CP concentrations in the Arctic, Antarctica, and the Tibetan Plateau all increase. By 2020, East Asian, European, and North American emissions contributed 38%, 26%, and 18% of CP contamination in the High Arctic, respectively, while Southern hemispheric emissions and emissions around the Tibetan Plateau primarily contribute to CP contamination in central Antarctica and on the Plateau, respectively. Our results emphasize the important contribution of (i) European and North American emissions to historical CP contamination in remote regions and current MCCP and LCCP contamination in the High Arctic and (ii) East Asian emission to current SCCP and MCCP contamination of all three remote regions. These results can help to evaluate the effectiveness of potential global and regional CP emission-reduction strategies.

Are We Justified in Modeling Human Exposure to Chlorinated Paraffin Mixtures Using the Average Properties of Congeners and Homologues?

Concern over human exposure to chlorinated paraffin (CP) mixtures keeps increasing. The absence of a comprehensive understanding of how human exposure varies with the physicochemical properties of CP constituents has hindered the ability to determine at what level of aggregation exposure to CPs should be assessed. We answer this question by comparing exposure predicted with either a "complex" method that utilizes isomer-specific properties or "simplified" methods that rely on median properties of congener, homologue, or short-/medium-/long-chain CP groups. Our results demonstrate the wide range of physicochemical properties across CP mixtures and their dependence on molecular structures. Assuming unit emissions in the environment, these variances translate into an extensive disparity in whole-body concentrations predicted for different isomers, spanning ∼11 orders of magnitude. CPs with 13-19 carbons and 6-10 chlorines exhibit the highest human exposure potential, primarily owing to moderate to high hydrophobicity and slow environmental degradation and biotransformation. Far-field exposure is dominant for most CP constituents. Our study underscores that using average properties of congener, homologue, or S/M/LCCP groups yields results that are consistent with those derived from isomer-based modeling, thus offering an efficient and practical framework for future risk assessments and human exposure studies of CPs and other complex chemical mixtures.

Exploring long-term global environmental impacts of chlorinated paraffins (CPs) in waste: Implications for the Stockholm and Basel Conventions and the global plastic treaty.

Chlorinated paraffins (CPs), mainly short-chain CPs (SCCPs) and medium-chain CPs (MCCPs), are currently the most produced and used industrial chemicals related to persistent organic pollutants (POPs) globally. These chemicals are widely detected in the environment and in the human body. As the release of SCCPs and MCCPs from products represents only a small fraction of their stock in products, the potential long-term release of CPs from a large variety of products at the waste stage has become an issue of great concern. The results of this study showed that, by 2050, SCCPs and MCCPs used between 2000 and 2021 will cumulatively generate 226.49 Mt of CP-containing wastes, comprising 8610.13 kt of SCCPs and MCCPs. Approximately 79.72 Mt of CP-containing wastes is predicted to be generated abroad through the international trade of products using SCCPs and MCCPs. The magnitude, distribution, and growth of CP-containing wastes subject to environmentally sound disposal will depend largely on the relevant provisions of the Stockholm and Basel Conventions and the forthcoming global plastic treaty. According to multiple scenarios synthesizing the provisions of the three conventions, 26.6-101.1 Mt of CP-containing wastes will be subject to environmentally sound disposal as POP wastes, which would pose a great challenge to the waste disposal capacity of China, as well as for countries importing CP-containing products. The additional 5-year exemption period for MCCPs is expected to see an additional 10 Mt of CP-containing wastes subject to environmentally sound disposal. Thus, there is an urgent need to strengthen the Stockholm and Basel Conventions and the global plastic treaty.

Dynamic Source Distribution and Emission Inventory of a Persistent, Mobile, and Toxic (PMT) Substance, Melamine, in China.

Persistent, mobile, and toxic (PMT) substances are affecting the safety of drinking water and are threatening the environment and human health. Many PMT substances are used in industrial processing or consumer products, but their sources and emissions mostly remain unclear. This study presents a long-term source distribution and emission estimation of melamine, a high-production-volume PMT substance of emerging global concern. The results indicate that in China, approximately 1858.7 kilotonnes (kt) of melamine were released into the water (∼58.9%), air (∼27.0%), and soil systems (∼14.1%) between 1995 and 2020, mainly from its production and use in the decorative panels, textiles, and paper industries. The textile and paper industries have the highest emission-to-consumption ratios, with more than 90% emissions per unit consumption. Sewage treatment plants are the largest source of melamine in the environment for the time being, but in-use products and their wastes will serve as significant melamine sources in the future. The study prompts priority action to control the risk of PMT substances internationally.

[Research Status and Trend Analysis of Environmental and Health Risk and Control of Persistent, Mobile, and Toxic Chemicals].

Persistent, mobile, and toxic or very persistent and very mobile (PMT/vPvM) chemicals have been widely detected in surface water, groundwater, and drinking water around the world and are important emerging contaminants that may significantly affect human health and the environment in the future. According to the identification criteria proposed by the European Union, there are thousands of PMT/vPvM substances in existing chemicals, covering a wide range of applications, including dozens of high-yield industrial chemicals such as melamine. PMT/vPvM chemicals can be discharged into the environment through farmland runoff, industrial wastewater, and domestic sewage, and sewage treatment plants are currently considered to be their main discharge route. It is difficult to effectively remove PMT/vPvM chemicals through the current conventional water treatment technology; they can exist in the water circulation system of the urban human settlement environment for a long time, endangering the safety of drinking water and the ecosystem. The European Union has taken the lead in introducing PMT/vPvM chemicals specifically into the priority areas of the current chemical risk management system. At present, there are still many potential PMT/vPvM chemicals in the environment, and their monitoring methods need to be further improved. It will take time for the identification of substances, the scope of categories, and the establishment of lists. Studies on the environmental fate and exposure of PMT/vPvM in various regions of the world are still very limited, and research on the potential, long-term ecotoxicity, and human health hazard effects remains scarce. At the same time, the research and development of substitute or alternative technologies, as well as environmental engineering treatment technologies such as sewage treatment and contaminated site remediation, will become an urgent need for future PMT/vPvM risk scientific research and management decisions.

Emission and environmental distribution of decabromodiphenyl ethane (DBDPE) in China from 2006 to 2026: Retrospection, forecasting, and implications for assessment and management.

Decabromodiphenyl ethane (DBDPE) is the main alternative to decabromodiphenyl ether (deca-BDE) in commercial use. However, there is increasing evidence show that DBDPE is a potential persistent organic pollutant, and it has been found ubiquitously in environmental media across China in recent years. Monitoring studies have not been able to determine the overall levels and temporal trends of DBDPE contamination in China, and have been unable to explain how emission patterns can affect their environmental distribution. Therefore, this study estimated the temporal variance of DBDPE emissions and environmental concentrations in five regions of China from 2006 to 2026 using the PROduction-To-EXposure (PROTEX) mass balance model. The results showed that Guangdong Province was the greatest DBDPE pollution hotspot in China due to emissions from plastics manufacturing and e-waste disposal; there was also severe pollution in Shandong Province, where almost all the DBDPE in China is produced. The DBDPE concentrations in indoor and outdoor environments increased substantially in all regions during 2006-2021. Furthermore, in Guangdong Province and Shandong Province, the ratio of indoor/outdoor air concentrations was greater than or close to 1, indicative of significant outdoor emission sources of DBDPE. In contrast, the ratios for the Beijing-Tianjin-Hebei region, East China, and Southwest China were below 1 due to the indoor use of electronic equipment containing DBDPE. The temporal trends of these ratios indicated that DBDPE contamination has gradually spread from high-concentration environments with strong emission sources to low-concentration environments. The outcomes of this study have important implications for the risk assessment of DBDPE use in China and can be used to establish contamination-mitigation actions.

The spatial-temporal chemical footprint of pesticides in China from 1999 to 2018.

The massive use of pesticides brings considerable environmental and human health impacts. This study conducted an overall assessment of the ecological impact of the extensive pesticide use in China from 1999 to 2018 through the Chemical Footprint (ChF) calculation. The results demonstrated that the primary ecological impacts caused by pesticides occurred in the most central and eastern regions in China, e.g., provinces of Shandong, Henan, Hubei, Anhui, and Jiangsu. The northeastern, some southern and central provinces, e.g., Heilongjiang, Jilin, Liaoning, Yunnan, Guangxi, Guangdong, Ningxia, and Shaanxi, got moderate impacts, whereas the northwest regions, e.g., Qinghai, Xinjiang, and Tibet, had much lighter impacts relatively. The agricultural soil in inland areas and surface sea waters in coastal provinces bore the major impacts of the pesticide pollution in China, shared above 80% of the ChF across all environmental compartments. Chlorpyrifos, pymetrozine, fenpropathrin, pyridaben, atrazine, etc., were the pesticides that had the greatest impacts on the ecosystem, which contributed over 95% of the total ChF of pesticides used in China, although the use amount of these pesticides accounted for less than 10% of the total use amount of all pesticides annually. The study also indicated that the overall ChF of pesticide use in China has been declining since 2010, which was corresponding with the control actions of highly hazardous pesticides, especially the elimination of high toxic organophosphorus insecticides during the past decade.

Global Historical Production, Use, In-Use Stocks, and Emissions of Short-, Medium-, and Long-Chain Chlorinated Paraffins.

The last few decades have seen ubiquitous and increasing contamination of chlorinated paraffins (CPs) worldwide. Here, we develop the first global inventories of production, use, in-use stocks, and emissions of total CPs, including the short-, medium- and long-chain components (SCCPs, MCCPs, and LCCPs) during 1930-2020 using a dynamic substance flow analysis model named Chemical in Products Comprehensive Anthroposhpheric Fate Estimation. The model estimates that a total of ∼33 million metric tons of CPs have been produced and used globally, ∼40% of which still resided in in-use products by 2020 and is available for long-term emissions in the next decades. Global cumulative emissions of CPs have increased to ∼5.2 million metric tons by 2020, with SCCPs, MCCPs, and LCCPs accounting for ∼30, 40, and 30%, respectively. While the production, use, and emissions of CPs started declining in regions such as Western Europe, they remain high in China. The model also suggests that homologues with 10, 14, and 22-23 carbons were predominant in the cumulatively produced and emitted SCCPs, MCCPs, and LCCPs, respectively. The emission estimates were evaluated by generating environmental concentrations that are comparable to literature-reported environmental monitoring data. Our estimates provide opportunities to link the environmental fate and occurrence of CPs to emission sources and lay the basis for future risk-reduction strategies of CPs around the world.

Distribution and Emission Estimation of Short- and Medium-Chain Chlorinated Paraffins in Chinese Products through Detection-Based Mass Balancing.

Short- and medium-chain chlorinated paraffins (SCCPs and MCCPs, respectively) have raised environmental concern due to their potential for persistence, long-range transport, bioaccumulation, and toxicity. However, little is known about the production, use, and environmental emissions of SCCPs and MCCPs in China, the world's largest producer and consumer. In this study, we estimated the amounts of SCCPs and MCCPs produced and used in China in 2018-2019 based on a nationwide survey and measurements of concentrations in products, from which we estimated the environmental emissions of SCCPs and MCCPs in China. Our results show that 225.2 and 236.4 metric kilotons (kt) of SCCPs and 428.5 and 450.2 kt of MCCPs were used in China in 2018 and 2019, respectively, with poly(vinyl chloride) (PVC) products dominating SCCP and MCCP usage. Moreover, a total of 3.9 and 4.2 kt SCCPs and 3.8 and 4.1 kt MCCPs were emitted into China's environment in 2018 and 2019, respectively. Although less MCCPs are released into the air relative to SCCPs, their level exceeds the emission of SCCPs into soil. Finally, detailed mass balance calculation indicates that, although emissions from the use of PVC products dominate SCCP and MCCP inputs into the air, emissions from the use of polyurethane foam adhesives are more closely related to input into surface waters for SCCPs and MCCPs. For input into soil, the main emission sources are the use of polyurethane foam adhesives (for SCCPs) and rubber products (for MCCPs). This study provides a preliminary overview of the distributions of SCCPs and MCCPs in products and insight into the mass balance of SCCPs and MCCPs from their production and use to emission in China. This assessment also provides an important foundation for better understanding the environmental risks and fates associated with SCCPs and MCCPs in China and around the world.

Comparison of fluorotelomer alcohol emissions from wastewater treatment plants into atmospheric and aquatic environments.

Recent studies have revealed that wastewater treatment plants (WWTPs) are an important source of fluorotelomer alcohols (FTOHs) in the environment. However, it remains unclear whether volatilization to the atmosphere or discharge with wastewater effluent into receiving water bodies is the dominant pathway through which FTOHs enter the environment; it also remains unclear how the relative importance of these two emission pathways varies among seasons and homologs. Here, we estimated the emissions of 6:2 and 8:2 FTOHs through these two pathways from a typical WWTP in Beijing, China, by measuring height-dependent air concentrations above the wastewater surface; we also measured wastewater concentrations among the four annual seasons. Our results showed that atmospheric emissions dominate total annual FTOH emissions, but are not dominant in every single season. Emission to the aquatic environment is dominant during seasons with less wind (i.e., summer and fall). While the abundance of 6:2 FTOH has increased in recent years, 8:2 FTOH remains the major FTOH homolog released into the environment in China. This study provides comprehensive information regarding FTOH emissions from WWTPs to the environment and practical guidance for future monitoring practices.

Stocks, flows and emissions of DBDPE in China and its international distribution through products and waste.

Decabromodiphenyl ethane (DBDPE) is an alternative to the commercial decabromodiphenyl ether (deca-BDE) mixture but has potentially similar persistence, bioaccumulation potential and toxicity. While it is widely used as a flame retardant in electrical and electronic equipment (EEE) in China, DBDPE could be distributed globally on a large scale with the international trade of EEE emanating from China. Here, we performed a dynamic substance flow analysis to estimate the time-dependent mass flows, stocks and emissions of DBDPE in China, and the global spread of DBDPE originating in China through the international trade of EEE and e-waste. Our analysis indicates that, between 2006 and 2016, ∼230 thousand tonnes (kt) of DBDPE were produced in China; production, use and disposal activities led to the release of 196 tonnes of DBDPE to the environment. By the end of 2016, ∼152 kt of the DBDPE produced resided in in-use products across China. During the period 2000-2016, ∼39 kt of DBDPE were exported from China in EEE products, most of which (>50%) ended up in North America. Based on projected trends of China's DBDPE production, use and EEE exports, we predict that, by 2026, ∼74 and ∼14 kt of DBDPE originating in China will reside in in-use and waste stocks, respectively, in regions other than mainland China, which will act as long-term emission sources of DBDPE worldwide. This study discusses the considerable impact of DBDPE originating in China and distributed globally through the international trade of EEE; this is projected to occur on a large scale in the near future, which necessitates countermeasures.

Global environmental fate of short-chain chlorinated paraffins: Modeling with a single vs. multiple sets of physicochemical properties.

While short-chain chlorinated paraffins (SCCPs) comprise a myriad of components whose physicochemical properties are extremely diverse, many previous studies characterized the SCCP mixtures collectively using a single set of physicochemical properties when modeling the global environmental fate and risk. In this work, we explore whether a discrepancy exists between simulations based on a single set of physicochemical properties and multiple component-specific ones in global fate and risk modeling, and the environmental condition (e.g., proximity to emission source vs. temperature) in which such a discrepancy is most notable. We simulated the environmental concentrations and compartmental distribution of SCCPs, using a mechanistic fugacity-based multimedia BETR-Global model. We observed a discrepancy between modeled concentrations based on a single and multiple sets of properties, which is more notable in regions with a low temperature and negligible emissions, e.g., the remote and cold background Arctic region. The modeled compartmental distribution differs slightly between simulations based on different sets of physicochemical properties. While using a single set of properties minimizes input data required for model-based evaluation of the risk of SCCPs, it tends to underestimate the environmental occurrence and risk in remote and cold regions, which are vulnerable and hence deserve a more conservative evaluation conclusion, and prevents us from drawing conclusions on which SCCP component is of greatest concern. The current work can be a relevant step towards improving the methodology for global environmental modeling and risk assessment of SCCPs and other complex halogenated chemical mixtures.

Global distribution potential and regional environmental risk of F-53B.

Recent years have witnessed increases in emissions and environmental contamination by F-53B, a chlorinated polyfluorinated ether sulfonate used as a mist suppressant in the Chinese electroplating industry. In this study, based on a national industrial survey and statistics, we estimated the annual release of F-53B across China during the period 2006-2015. We evaluated the global transport and distribution of F-53B using the Globo-POP model, and assessed its environmental risk in regions of China using the EUSES model. Our calculations indicate that approximately 10-14 metric tons (t) of F-53B are released annually into the environment, mainly in East China. Our Globo-POP calculations demonstrate that a limited fraction (0.02-0.50%) of the cumulative F-53B emissions can reach the Arctic via oceanic advection. Despite its low long-range transport potential, F-53B can accumulate in Chinese local waters. Our EUSES calculations predict that the F-53B concentration in fresh water (South China) currently approaches 0.7 mg/L and will reach 2.3 mg/L by 2020 in the region surrounding chromium-plating plants if its use remains uncontrolled. Such an increase in concentration implies a potential risk to aquatic environments. This study highlights the risk if F-53B is proposed to be used as a substitute for perfluorooctanesulfonic salt-based mist suppressants.

Effects of habitual t'ai chi exercise on adiponectin, glucose homeostasis, lipid profile, and atherosclerotic burden in individuals with cardiovascular risk factors.

OBJECTIVES: A single bout of t'ai chi (TC) exercise was previously found to be associated with a significant increase in post-exercise adiponectin levels in individuals with cardiovascular risk factors. The objective of this study was to examine the long-term effects of 24-month habitual TC exercise on adiponectin levels, glucose homeostasis, lipid profile, and atherosclerotic burden in individuals with cardiovascular risk factors. DESIGN: This was a prospective observational study. SETTINGS/LOCATION: The study was conducted at a regional hospital in south Taiwan. SUBJECTS: Participants of a TC exercise program held by the clinics of cardiology and cardiovascular surgery for individuals with cardiovascular diseases were recruited to the TC group. Individuals who did not join the program were recruited as controls. All study subjects had at least one cardiovascular risk factor. INTERVENTIONS: Ninety-minute session of Yang's style TC at least once a week. OUTCOME MEASURES: Measurements on adiponectin, glucose homeostasis, lipid profile, and atherosclerotic burden were made at three time points-baseline, 12 months, and 24 months. Two-way repeated-measures general linear model was used to assess the changes over the study period between the TC and control groups. RESULTS: Thirty-seven patients in both the TC and control groups completed the study. The TC group showed a greater increase in natural logarithmic transformed (Ln) adiponectin values than the control group over the study period (interaction effect p=0.009). Glucose homeostasis, lipid profile, risk of atherosclerosis, and atherosclerotic burden did not showed significant changes with TC compared with the controls over the 24-month period. CONCLUSIONS: The results of the present study indicate that for individuals with at least one cardiovascular risk factor, engaging in habitual TC exercise could lead to favorable changes in levels of adiponectin. The association between habitual TC and cardiovascular events and diabetic complications will require further investigations.

Comparison of Clinical Features between Typical and Atypical Takotsubo Cardiomyopathy: A Single Center, Retrospective, Case-Controlled Study.

BACKGROUND: The incidence and possible differences between typical and atypical Takotsubo cardiomyopathy (TTC) in Taiwanese patients have not yet been assessed. METHODS: We reviewed the records of 2171 patients who underwent left heart catheterization for suspected acute coronary syndrome (ACS) between January 2003 and March 2011 to identify TTC. Demographic, clinical presentations, laboratory data, and electrocardiographic, echocardiographic and angiographic findings were assessed in all patients. RESULTS: We found that fourteen patients had typical TTC, and six had atypical TTC. There were no differences in the clinical presentations, ejection fraction and in-hospital course of illness between patients with typical TTC (the TT group) and patients with atypical TTC (the AT group). However, the patients in the AT group were relatively younger than those in the TT group (mean ages 60 vs. 73 years, respectively, p = 0.018), and fewer patients had hypertension in the AT group than in the TT group (33% vs. 86%, respectively, p = 0.037). In electrocardiography, ST segment elevation was noted less frequently in the AT group than in the TT group (33% vs. 86%, respectively, p = 0.037). CONCLUSIONS: Atypical TTC and typical TTC may be the same syndrome with different manifestations. They seemed to have different patient characteristics and electrocardiographic changes. KEY WORDS: Acute coronary syndrome; Takotsubo cardiomyopathy; Transient left ventricular apical ballooning.

Takotsubo cardiomyopathy as an underlying mediator of myocardial infarction with normal coronary arteries.

OBJECTIVE: The purpose of the present study was to describe our experience with myocardial infarction with normal coronary arteries (MINCA) with regards to the prevalence, clinical characteristics, possible underlying etiologies (including Takotsubo cardiomyopathy, TCM) and the short- and long-term outcomes associated with this condition. METHODS: We retrospectively analyzed the records of 596 consecutive patients presenting with acute myocardial infarction over a 4-year period and identified 24 patients (14 female, 10 male) with angiographically normal coronary arteries. Demographic and clinical variables and outcomes were reviewed. RESULTS: Mean patient age was 59 +/- 20 years. The presumed MINCA mechanism was TCM in 10 patients (41.7%), probable myocarditis in 5 (20.8%), coronary spasm in 4 (16.7%), coronary thrombus in 3 (12.5%) and aortic dissection in 2 patients (8.3%). After a mean follow-up of 19 +/- 14 months, 2 patients with probable myocarditis had died of cardiovascular causes, 1 patient with aortic dissection had died due to sepsis after surgery and 1 patient with TCM had died of noncardiovascular causes 2 years after discharge. CONCLUSION: In this study, we found that MINCA occurred in 4% of patients with acute myocardial infarction undergoing emergent coronary angiography, with the most frequent underlying mechanism being TCM.

Isolated right ventricular intracavitary metastasis of hepatocellular carcinoma in a 74-year-old woman.

A 74-year-old woman with a history of chronic hepatitis C and transcatheter arterial chemoembolization for an unresectable hepatocellular carcinoma (HCC) 2 years previously presented with progressive exertional dyspnea of 1 month's duration. Two-dimensional echocardiography revealed a huge right ventricular mass with right atrial and right ventricular outflow tract extension. Palliative resection of the tumor and adjunctive chemotherapy was performed. However, the right ventricular mass recurred 1 month later and the patient died 4 months after the operation. To our knowledge, this is the oldest patient reported with isolated right ventricular intracavitary metastasis of HCC, and this report reemphasizes the lower surgical indication in patients with metastatic cardiac tumors.