China's international trade and air pollution in the United States

Spatially explicit analysis of production and consumption responsibility for the PM2.5-related health burden towards beautiful China

Promoting good health and ensuring responsible production and consumption are essential components of the Sustainable Development Goals (SDGs) established by of the United Nations, as well as the goals of beautiful China. While the health impacts of air pollution have garnered significant attention, there remains a paucity of studies comparing the disparities in responsibility arising from production versus consumption. This paper integrates the Weather Research and Forecasting - Comprehensive Air Quality Model with Extensions (WRF-CAMx) model, the multiregional input‒output (MRIO) model, and the global exposure mortality model (GEMM) to assess the extent of PM2.5-related premature deaths caused by production and consumption activities in 30 Chinese provinces. The findings reveal a spatial mismatch in health burdens between production and consumption. Considering pollutant emissions and their transfer only through the supply chain leads to the finding that the net outflow of emissions from producers is mainly located in most of the northern provinces of China. However, when atmospheric transport and health impacts are included, the producing provinces are mainly located in central China, while the consuming provinces are located in the southeastern coastal and remote western and northern regions. Additionally, the long-range impact of consumption provinces with respect to the health burden is more than twice as large as that of production provinces, and its potential impact on the health burden cannot be ignored. From a sectoral perspective, production emissions from the non-electricity industry and services sectors contribute to 60% of the health burden, while their consumption emissions contribute to over 80% of the health burden. Furthermore, consumption activities in the non-electricity industry and services sectors significantly influence production emissions in the transport, agriculture, and electricity sectors. The geographical separation of consumption and production regions facilitated by trade is a critical yet often overlooked aspect in current regional air quality planning in China. A more comprehensive analysis of life-cycle emissions driven by final consumption could yield greater reductions compared to direct production reductions.

Data-Driven Insights into the Contamination of Polycyclic Aromatic Hydrocarbons in Marine Bays

The synthesis of polycyclic aromatic hydrocarbon (PAH) data allows us to quantify and gain insights into the spatiotemporal dynamics of PAH contamination in marine bays. Here, a data synthesis framework was developed to understand data-driven insights into the spatiotemporal levels, compositional profiles, and potential sources of PAHs in water and sediment of marine bays. PAHs were detected in 69 bays worldwide, with contamination hotspots located in Asian bays. PAH concentrations in pre-2000 were significantly lower than those in the 2000s and post-2010, while the dominant species in water and sediment were 2-3 ring and 4-6 ring PAHs, respectively. The composition patterns of PAHs included 2-3 ring, 3-5 ring, and 4-5 ring dominant categories, but no significant distance decay relationship was found in the composition similarity due to international energy trade. Temporal dynamic patterns of concentrations included Descending-, Ascending-, and Inverted V-type, whereas over longer time spans, the pattern is more similar to the Inverted V-type owing to the reductions in emission intensity. PAHs were derived from both petrogenic and pyrolytic sources, with combustion from both coal and petroleum being the dominant source. These data-driven discoveries provide quantitative insights into the spatiotemporal patterns in the concentration and composition of PAHs, contributing to the mitigation of PAH contamination.

Renewable energy and ecological footprint nexus: Evidence from dynamic panel threshold technique

The escalating phenomenon of environmental degradation is an urgent global concern, imperiling ecosystems and hindering the prospects for sustainable development on a planetary scale. Therefore, this study aims to explore the intricate interplay between renewable energy (RE) and ecological footprint (EF), considering the conditional impact of fiscal capacity (FIC), human development (HDI), institutional quality (IQI), and population density (PDN). Drawing on panel data encompassing 74 developing countries from 2000 to 2022, the study employs a dynamic panel threshold regression method, both with and without an instrumental variable approach. The findings unveil a non-linear nexus between RE and EF, revealing significant threshold values for FIC (1.870), HDI (0.736), and IQI (0.311), above which RE showcases its efficacy in mitigating EF. Conversely, when these predictors dip below the thresholds of FIC (1.391), HDI (0.655), and IQI (0.2545), the impact of RE on FE becomes insignificant. Moreover, the study introduces PDN as an additional threshold variable in the analysis, pinpointing that the effectiveness of RE in reducing EF hinges on PDN being below a threshold value of 263.144; however, above a threshold value of 276.98, the influence of PDN on the RE-FE nexus diminishes. The findings underscore the complexity of policy landscapes in developing countries. They suggest that while promoting renewable energy is pivotal for environmental sustainability, it is equally imperative to bolster existing environmentally friendly fiscal capacity, advance human capital, enhance institutional quality, and craft effective population distribution policies.

The Global Environmental Impacts of China's Accession to the WTO: A 20-Year Review

Robust empirical assessments of the long-term cumulative global effects of free trade and economic globalization on the environment are limited. This account fills this gap by constructing a dynamic computable general equilibrium model to estimate the environmental effects of a milestone in the recent history of trade liberalization: China's 20-year World Trade Organization (WTO) accession. The modeling shows that China's accession could have resulted in an increase in the global cumulative greenhouse gases (GHGs), sulfur dioxide (SO2), and nitrogen oxide (NOx) emissions by roughly 14,000 Mt CO2-eq, 64 Mt, and 46 Mt, respectively. The global production scale effect contributed to most of these estimated increases. The regional total output composition effect also caused higher emissions. Meanwhile, the sectoral output composition effect helped reduce total emissions to a limited extent. Fortunately, a package of emission abatement measures led to a decrease in emission factors and a drop in the global cumulative emissions of GHGs, SO2, and NOx. The findings suggest that to enjoy the free trade and economic globalization benefits and minimize the induced emission increases, it is vitally important to systemically reduce emissions across the entire economy and nurture a low-carbon trade regime.

Unexpected PM2.5-related emissions and accompanying environmental-economic inequalities driven by "clean" tertiary industry in China

The tertiary industry, led by service sectors, usually have "clean" production processes and thus is ignored by current PM2.5 pollution mitigation strategies in China. Actually, the tertiary industry heavily relies on the supplies from its upstream industries, resulting in pollutant emissions and economic benefits transferring among different regions. With the application of the multiregional input-output (MRIO) model, our study explores the emission contribution from the tertiary industry's consumption activities in China and analyses the accompanying emission-economy relationship. We find that the production process of tertiary industry (with the sector Transportation excluded) contributes only ∼1 % of China's PM2.5-related emissions in 2017. However, its consumption-based emission contributions could increase to 11 %-17 %, among which >95 % are indirectly contributed. More than 40 % of tertiary industry consumption-based emissions, accompanied by 25 % of the consumption-based value added, are transferred via interprovincial trade. The proportion of transferred emissions even exceeds 50 % for the top 10 importers. The spatial pattern of value-added flows is nearly opposite to that of emission flows. Our results also reveal that among the 30 provinces and 870 interprovincial trading pairs, 6 provinces are experiencing environmental-economic win, 7 provinces are experiencing environmental-economic loss, and in detail 326 trading pairs are experiencing environmental-economic win or loss. To reduce the unexpected emissions and inequalities embodied in seemingly "clean" industries, consumption activities should be considered and strengthened in China's new-stage environmental policies.

The impact of smart city construction (SCC) on pollution emissions (PE): evidence from China

Based on panel data from 210 prefecture-level cities in China from 2003 to 2021, this study employs the Time-Varying Differences-in-Differences (Time-Varying DID) approach to systematically examine the impact of smart city construction on pollution emissions and its underlying mechanisms. Additionally, the Propensity Score Matching-Differences-in-Differences method is employed for further validation. The research findings indicate that Smart City Construction (SCC) significantly reduces urban Volume of Sewage Discharge (VSD), sulfur dioxide emissions (SO2), and Emissions of Fumes and Dust (EFD), thereby mitigating pollution emissions (PE) and enhancing environmental quality. Mechanism analysis reveals that SCC achieves these effects through scale effects, structural effects, and technological effects. City heterogeneity analysis shows that provincial capital cities exhibit a stronger suppression effect on pollution emissions compared to non-provincial capital cities. Moreover, cities with lower levels of education attainment demonstrate a stronger ability to curb pollution emissions, while larger cities exhibit a more pronounced impact on mitigating pollution emissions. The marginal contributions of this study mainly consist of three aspects: Firstly, it enriches the literature on environmental impact factors by assessing, for the first time, the influence of SCC on PE. Secondly, a comprehensive approach is employed, integrating VSD, EFD, SO2 data, and economic and pollution data at the city level. Time-Varying DID is used to evaluate the policy effects of SCC. Finally, the study analyzes the impact mechanisms of SCC policy on environmental emissions from various perspectives.

Downscaling of environmental indicators: A review

Environmental indicators at different scales are important for environmental management, daily life, and scientific research. Because of the lack of statistics below a national scale for many environmental indicators, scholars have developed various downscaling methods to obtain finer-scale and diverse forms of data for different environmental indicators. However, the existing downscaling methods for environmental indicators are diverse and fragmented. Here, we reviewed the downscaling methods by reclassifying the environmental indicators from a life cycle perspective into five categories: natural resources use and related attributes; material and energy consumption; environmental discharge; climate change; and environmental footprints. We first provide a general introduction to downscaling theory in the environmental field, including definitions, techniques, and evolution. We then elaborate on downscaling methods and make an inventory of the five categories of environmental indicators. We summarize the downscaling methods commonly applied to specific indicators, scale transformation, the strengths and limitations of corresponding methods, and provide specific examples. Next, we discuss ways to select or construct downscaling methods based on four principles: objective orientation, data accessibility, model feasibility, and model adjustment. Finally, we explore the future direction of downscaling and provide insights for improving downscaling for environmental indicators. In this review, we generalize and clarify the downscaling techniques for environmental indicators, which will help facilitate the appropriate selection of downscaling methods by researchers.

Global trade-driven transfer of atmospheric polycyclic aromatic hydrocarbon emissions and associated human inhalation exposure risk

Polycyclic aromatic hydrocarbons (PAHs) are of significant public concern because of their toxicity and long-range transport potential. Extensive studies have been conducted to explore the source-receptor relationships of PAHs via atmospheric transport. However, the transfer of trade-driven regional and global PAHs is poorly understood. This study estimated the virtual PAHs emission transfer embodied in global trade from 2004 to 2014 and simulated the impact of international trade on global contamination and associated human inhalation exposure risk of PAHs. Results show that trade-driven PAHs flowed primarily from developed to less-developed regions, particularly in those regions with intensive heavy industries and transportation. As the result, international trade resulted in an increasing risk of lung cancer induced by exposure to PAHs (27.8% in China, 14.7% in India, and 11.3% in Southeast Asia). In contrast, we found decreasing risks of PAHs-induced lung cancer in Western Europe (63.2%) and the United States (45.9%) in 2004. Our findings indicate that final demand and emission intensity are the key driving factors contributing to rising and falling consumption-based PAHs emissions and related health risk respectively. The results could provide a useful reference for global collaboration in the reduction of PAHs pollution and related health risks.

Direct and indirect consumption activities drive distinct urban-rural inequalities in air pollution-related mortality in China

Household consumption in China is associated with substantial PM2.5 pollution, through activities directly (i.e., fuel use) and/or indirectly (i.e., consumption of goods and services) causing pollutant emissions. Urban and rural households exhibit different consumption preferences and living areas, thus their contributions to and suffering from air pollution could differ. Assessing this contrast is crucial for comprehending the environmental impacts of the nation's ongoing urbanization process. Here we quantify Chinese urban and rural households' contributions to ambient PM2.5 pollution and the health risks they suffer from, by integrating economic, atmospheric, and health models and/or datasets. The national premature deaths related to long-term exposure to PM2.5 pollution contributed by total household consumption are estimated to be 1.1 million cases in 2015, among which 56% are urban households and 44% are rural households. For pollution contributed indirectly, urban households, especially in developed provinces, tend to bear lower mortality risks compared with the portions of deaths or pollution they contribute. The opposite results are true for direct pollution. With China's rapid urbanization process, without adequate reduction in emission intensity, the increased indirect pollution-associated premature deaths could largely offset that avoided by reduced direct pollution, and the indirect pollution-associated urban-rural inequalities might become severer. Developing pollution mitigation strategies from both production and consumption sides could help with reducing pollution-related mortality and associated urban-rural inequality.

Impacts of Receiving International Industrial Transfer on China's Air Quality and Health Exceed Those of Export Trade

Benefiting from international economic cooperation on income, technology diffusion, and employment, China also suffers its environmental and health impacts, from both international trade (IT), as is now widely understood, and international industrial transfer (IIT), which has been largely unrecognized. Here, we develop a comprehensive framework to estimate the impacts of exporting IT and receiving IIT. We find that China's emissions of CO2 and almost all air pollutants associated with IIT and IT together grew after 1997 but then declined after 2010, with the peak shares of national total emissions ranging 18-31% for different species. These sources further accounted for 3.8% of nationwide PM2.5 concentrations and 94,610 (76,000-112,040) premature deaths in 2012, and the values declined to 2.6% and 67,370 (52,390-81,810), respectively, for 2017. Separated, the contribution of IIT to those impacts was more than twice that of IT. Scenario analyses suggest that improving emission controls in its less-developed regions would effectively reduce the impact of economic globalization, but such a benefit could be largely offset by strengthened international economic cooperation. The outcomes provide a scientific basis for adjusting China's strategic roles in the international distribution of industrial production and its formulation of relevant environmental policies from a comprehensive perspective.

The economy-employment-environmental health transfer and embedded inequities of China's capital metropolitan area: a mixed-methods study

BACKGROUND

Metropolitan areas have complex trade linkages internally and externally. This complexity stimulates the unequal spatial transfer of environmental health consequences, economy, and employment embodied in internal trade or trade with the outside regions, resulting in unequal exchange. Existing research has rarely discussed this issue at a refined scale, hindering targeted inequity alleviation policies.

METHODS

We conducted a mixed-methods study, focusing on the most polluted metropolitan area in the world, the Beijing-Tianjin-Hebei region of China, and developed an integrated modelling framework to downscale the analysis of the trade-driven unequal transfer of PM2·5- related premature deaths, value added, and job opportunities to the city scale within Beijing-Tianjin-Hebei. The study couples a nested Multi-Regional Input-Output model table containing data from 13 Beijing-Tianjin-Hebei cities and 28 outer provinces in 2017 with a bottom-up emission inventory, value added and employment statistical data, the Weather Research and Forecasting-Comprehensive Air Quality Model with Extensions, the Global Exposure Mortality Model, and human capital methods. We also constructed two indices measuring unequal exchanges between PM2·5-related deaths and economic and employment gains embodied in trades between cities in Beijing-Tianjin-Hebei and trades with outside regions.

FINDINGS

The Beijing-Tianjin-Hebei region as a single entity shifted 14 985 (95% CI 12 800-16 948) net deaths to regions outside the Beijing-Tianjin-Hebei through trade, most of which occurred in the central region of China. The industrial-based peripheral Beijing-Tianjin-Hebei cities suffered the most serious inequities when trading with other Beijing-Tianjin-Hebei cities and outside regions. While gaining equivalent local jobs, these industrial-based peripheral cities had 250% higher PM2·5-related deaths (10·2 PM2·5-related deaths for obtaining 1000 local jobs) than core cities (2·9 PM2·5-related deaths for obtaining 1000 local jobs) and 57·7% higher PM2·5-related deaths than agricultural-based peripheral cities (6·5 PM2·5-related deaths for obtaining 1000 local jobs). While gaining equivalent value added, industrial-based peripheral cities had 50·6% higher PM2·5-related deaths (¥13·9 of reduced human capital due to PM2·5-related premature deaths to obtain ¥1000 local value added) than core cities (¥9·2 of reduced human capital due to PM2·5-related premature deaths to obtain ¥1000 local value added) and 67·4% higher PM2·5-related deaths than agricultural-based peripheral cities (¥8·3 of reduced human capital due to PM2·5-related premature deaths to obtain ¥1000 local value added).

INTERPRETATION

Treating metropolitan areas as a single entity obscured internal heterogeneity, potentially misleading policy makers into imposing strict regulations on the whole metropolitan area to alleviate the inequities it posed on outside regions. However, several peripheral Beijing-Tianjin-Hebei cities were disadvantaged in their trade with core Beijing-Tianjin-Hebei cities and outside regions. Therefore, policies should be tailored for particular cities within metropolitan areas. Future targeted policies should include, but not be limited to, making ecological compensations and incorporating the environment and health costs into the price of pollution-intensive goods and services.

FUNDING

National Key Research and Devlopment Program of China, National Natural Science Foundation of China, and Jiangsu Natural Science Foundation.

Air pollution health burden embodied in China's supply chains

Product trade plays an increasing role in relocating production and the associated air pollution impact among sectors and regions. While a comprehensive depiction of atmospheric pollution redistribution through trade chains is missing, which may hinder targeted clean air cooperation among sectors and regions. Here, we combined five state-of-the-art models from physics, economy, and epidemiology to track the anthropogenic fine particle matters (PM_2.5) related premature mortality along the supply chains within China in 2017. Our results highlight the key sectors that affect PM_2.5-related mortality from both production and consumption perspectives. The consumption-based effects from food, light industry, equipment, construction, and services sectors, caused 2-22 times higher deaths than those from a production perspective and totally contributed 63% of the national total. From a cross-boundary perspective, 25.7% of China's PM_2.5-related deaths were caused by interprovincial trade, with the largest transfer occurring from the central and northern regions to well-developed east coast provinces. Capital investment dominated the cross-boundary effect (56% of the total) by involving substantial equipment and construction products, which greatly rely on product exports from regions with specific resources. This supply chain-based analysis provides a comprehensive quantification and may inform more effective joint-control efforts among associated regions and sectors from a health risk perspective.

Mismatched Social Welfare Allocation and PM2.5-Related Health Damage along Value Chains within China

Value chains have played a critical part in the growth. However, the fairness of the social welfare allocation along the value chain is largely underinvestigated, especially when considering the harmful environmental and health effects associated with the production processes. We used fine-scale profiling to analyze the social welfare allocation along China's domestic value chain within the context of environmental and health effects and investigated the underlying mechanisms. Our results suggested that the top 10% regions in the value chain obtained 2.9 times more social income and 2.1 times more job opportunities than the average, with much lower health damage. Further inspection showed a significant contribution of the "siphon effect"─major resource providers suffer the most in terms of localized health damage along with insufficient social welfare for compensation. We found that inter-region atmosphere transport results in redistribution for 53% health damages, which decreases the welfare-damage mismatch at "suffering" regions but also causes serious health damage to more than half of regions and populations in total. Specifically, around 10% of regions have lower social welfare and also experienced a significant increase in health damage caused by atmospheric transport. These results highlighted the necessity of a value chain-oriented, quantitative compensation-driven policy.

Does the low-carbon city pilot contribute to the blue sky defense? Evidence from China

China's goal of ecological civilization construction simultaneously faces the dual strategic tasks of pollution control and carbon reduction (PCCR). In addition to carbon reduction, does the low-carbon city pilot (LCCP) further contribute to the blue sky defense? This study investigates the impact of the LCCP on air pollution by employing a multiperiod difference-in-differences (DID) model based on data from 276 Chinese cities. The results show the following: (1) Compared with nonpilot areas, the LCCP reduces PM2.5 levels in pilot areas by approximately 1.50% on average, which is achieved by "industrial restructuring", "government investment in science and technology (S&T)", and "green lifestyle". (2) The LCCP has heterogeneous effects on air quality across cities with different resource endowments and industrial attributes, showing a greater air quality improvement in nonresource-based cities (NREB cities) and old industrial base cities (OIB cities) than in other city types. (3) The positive impact of the LCCP on air improvement in the pilot areas is derived from "pollution control effects" rather than "pollution transfer effects". This study provides useful policy implications for the comprehensive green transition and exploration of synergistic governance for PCCR in China.

Trade-driven changes in China's air pollutant emissions during 2012-2017

Trade plays an important role in driving regional production and the associated pollutant emissions. Revealing the patterns and underlying driving forces of trade may be critical for informing future mitigation actions among regions and sectors. In this study, we focused on the "Clean Air Action" period from 2012 to 2017 and revealed the changes and driving forces in trade-related air pollutant emissions (including sulfur dioxide (SO₂), particulate matter with a diameter equal to or less than 2.5 μm (PM_2.5), nitrogen oxides (NO_x), volatile organic compound (VOC), and carbon dioxide (CO₂)) among regions and sectors in China. Our results showed that emissions embodied in domestic trade decreased considerably in absolute volume nationwide (23-61 %, except for VOC and CO₂), but the relative contribution ratios from consumption in central and southwestern China increased (from 13 to 23 % to 15-25 % for various species), and those for eastern China decreased (from 39 to 45 % to 33-41 % for various species). From the sector perspective, trade-driven emissions from the power sector decreased in relative contribution ratios, while those from other sectors (including chemical, metal, nonmetal and services) were outstanding for specific regions, and became new targeted sectors when seeking mitigation through domestic supply chains. For changes in trade-related emissions, reduction in emission factor dominated the decreasing trends for almost all regions (27-64 % for the national total, except for VOC and CO₂), and optimization in trade and/or energy structures also played marked reduction roles in specific regions, far offsetting the increasing effect of increasing trade volume (26-32 %, except for VOC and CO₂). Our study provides a comprehensive picture of how trade-associated pollutant emissions changed during the "Clean Air Action" period, which may facilitate the formulation of more effective trade-associated policies to mitigate future emissions.

Carbon deficit checks in high resolution and compensation under regional inequity

Carbon compensation is an effective way of reducing carbon emissions. However, previous studies in this field have been limited and have not examined high-precision scientific carbon compensation under regional inequity. The present study examined initial carbon compensation in the grid and developed a new equitable carbon compensation model. Additionally, it modified the carbon compensation value for each province and analysed how land-use change affected carbon compensation. The results show that, after the modification, the entire carbon deficit reached 17.34 × 10⁸ t C in 2015, representing a decrease of 14% compared with the initial carbon deficit. The area with negative carbon deficit values accounted for 36% of the whole area, concentrated mainly in the south, southwest and northwest. Without modification, the initial carbon compensation reached 537 × 10⁸ USD, and only Yunnan, Sichuan and Hainan provinces being eligible to receive compensation. The final modified carbon compensation was approximately 20% of the initial values, and 11 provinces were eligible to obtain compensation. The other provinces responsible for paying the carbon compensation costs were typically concentrated in Central and Eastern China. Land-use changes in 2015 led to increases in the initial carbon compensation and modified carbon compensation of 3.74 × 10⁸ and 0.13 × 10⁸ USD, respectively. The per-unit land-use change caused greater increases in carbon emissions in China's big cities and the provinces in Central and East China. Some policies, such as macro-control by the central government, diversified forms and patterns of compensation, and auxiliary measures should be formulated/proposed.

Trade-driven relocation of ground-level SO2 concentrations across Chinese provinces based on satellite observations

The influence of trade on ground-level SO2 concentrations in China was evaluated based on multiregional input-output (MRIO) analysis, using the ozone monitoring instrument (OMI) SO2 columns and SO2 profiles from an atmospheric chemical and transport model, MOZART-4. The provincial sum of ground-level SO2 concentrations has a good consistency with the provincial SO2 emissions (R = 0.65, p < 0.01). The provincial SO2 concentrations presented strong spatial variations, with a range of 5.1-50.6 μg/m3 and an average of 19.7 μg/m3 across China. The international trade increased the SO2 concentrations in all of the provinces and increased the national population-weighted SO2 (PWM-SO2) concentration by 2.9 μg/m3. Interprovincial trade within China decreased the ambient SO2 concentrations in Beijing, Tianjin, and Chongqing and the provinces in southeast and central China, but increased SO2 in the remaining provinces of China. In general, interprovincial trade decreased the national PWM-SO2 concentration by 5.3 μg/m3.

Potential health and economic impacts of shifting manufacturing from China to Indonesia or India

The diversification or decoupling of production chains from China to alternative Asian countries such as India or Indonesia would impact the spatial distribution of anthropogenic emissions, with corresponding economic impacts due to mortality associated with particulate matter exposure. We evaluated these changes using the Community Earth System Model, the Integrated Exposure-Response (IER) model and Willingness To Pay (WTP) method. Significant effects on PM_2.5 related mortality and economic cost for these deaths were seen in many East, Southeast and South Asian countries, particularly those immediately downwind of these three countries. Transferring all of export-related manufacturing to Indonesia resulted in significant mortality decreases in China and South Korea by 78k (5 per 100k) and 1k (2 per 100k) respectively, while Indonesia's mortality significantly increased (73.7k; 29 per 100k), as well as India, Pakistan and Nepal. When production was transferred to India, mortality rates in East Asia show similar changes to the Indonesian scenario, while mortalities in India increased dramatically (87.9k; 6 per 100k), and mortalities in many neighbors of India were also severely increased. Nevertheless, the economic costs for PM_2.5 related mortality were much smaller than national GDP changes in China (0.9 % of GDP vs. 18.3 % of GDP), India (2.7 % of GDP vs. 84.3 % of GDP) or Indonesia (9.4 % of GDP vs. 337 % of GDP) due to shifting all of export-related production lines from China to India or Indonesia. Morally, part of the benefits of economic activity should be used to compensate the neighboring communities where mortality increases occur.

Air pollution-induced health impacts and health economic losses in China driven by US demand exports

Understanding how trade between regions or countries drives the transfer of air pollution has attracted considerable interest recently, but few studies have explored the various transfer pathways or evaluated economic losses due to the health impact of such air pollution. Here, we assess the air pollutant emissions and related health impacts and economic losses in China caused by export trade due to US demand by combining the linked multi-regional input-output (MRIO) model, GEOS-Chem model, integrated exposure-response model, and the willingness to pay method. We show that the air pollutant emissions embedded in China's export due to the US demand reached 5792.38 Kt in 2012 (2.48% of the total), which includes direct exports of intermediate (40.27%) and final (33.61%) products and indirect exports of intermediate products via domestic provinces (16.43%, domestic spillover) and other countries (9.69%, foreign spillover). The resulting increase in PM_2.5 (<2.8 μg m^-3) leads to additional 27,963 deaths in 30 provinces, with a higher death toll in coastal areas and the corresponding economic loss was higher in more developed regions and reached USD 2.08 billion. This study highlights the region-different air pollution and health impacts in China embedded in the US-demand trade, and provides a framework for the analysis of health and economic losses hidden in global trade, particularly between developing and developed countries.

Water-carbon nexus relationship and interaction mechanism analysis within Beijing-Tianjin-Hebei urban agglomeration

As the total water resources consumption control and carbon mitigation continuous improvement, the weak water-carbon incorporate management is increasingly exposed. In this study, a water-carbon nexus assessment framework is proposed to analyze the nexus relationship between water consumption and carbon emission, and distinguishes the coupled water-carbon transmission intensity and the transfer paths under regional and industrial scales. According to the practical input-output table, water consumption, and carbon emission information, the framework is applied to Beijing-Tianjin-Hebei urban agglomeration (BTHUA), a population, resource, and trade intensive area of China. Inter-regional/intra-regional water consumption and carbon emission transfer fluxes between sectors, the pairwise ecological relationship, and the water-carbon nexus were analyzed. Results indicated that the water-carbon transfer indexes from Hebei to Beijing and Tianjin were 161.85 kg/m³ and 113.88 kg/m³ in the study period, along with the most water consumption and carbon emission, and the worst water-carbon nexus. From the industrial perspective, electricity and gas supplying industry provided 7.8% and 29.1% of the total carbon transfer in Tianjin and Hebei, as the most key node sectors on the water-carbon nexus in the BTHUA. The research provides valuably supporting the adjustment of the existing urban agglomeration water-carbon nexus management schemes.

Industrial agglomeration and haze pollution: Evidence from China

The rapid industrialization has contributed to the miracle of economic growth in China, while also caused a series of environmental problems. As one of the most concerning urban disease in China, the aggravation of haze pollution is closely related to the accelerating urbanization and industrialization process in recent years, and the strong spatial diffusion makes the negative externality of haze pollution more harmful. This characteristic of haze pollution is closely related to the spatial structure of industrial sectors, especially the agglomeration of industrial sectors. This paper established a spatial economic framework to investigate the spillover effect of industrial agglomeration on haze pollution based on satellite raster map data of PM_2.5 and location entropy index, and further discuss the question that whether industrial agglomeration can achieve a balanced development for both economic growth and environmental quality. The results indicated that there is an inverted U-shaped relationship between industrial agglomeration and haze pollution, and the indirect effect from spatial spillover dominated this impact. Industrial agglomeration has a single threshold effect on the knowledge spillover and the utilization of pollution disposal infrastructure of industrial sectors. Only when the agglomeration level reaches the threshold value, the scale effect can be realized to promote the air quality. The resource allocation efficiency and knowledge spillovers of industrial agglomeration need to be promoted in order to reach the inflection point and realize the win-win situation.

Optimization of Emission Reduction Target in the Beijing-Tianjin-Hebei Region: An Atmospheric Transfer Coefficient Matrix Perspective

In recent years, the problem of atmospheric pollution has been concerning in the Beijing-Tianjin-Hebei region, due to the frequent haze. It has become a significant issue to improve regional air quality through appropriate emission reduction measures. In this study, considering the regional atmospheric transmission of air pollutants, the WRF/CALPUFF model (the Weather Research and Forecasting model coupled with the California Puff air quality model) was used to describe the impact of each city's pollutant emissions on the concentrations of every city. Then, a new optimization model was designed to calculate the maximum allowable emissions of every city. The results showed that NOx and PM_2.5 emissions need to be reduced by 44% and 48%, respectively, in the traditional mitigation scenario (any city's pollutant emissions are not allowed to increase). However, in the optimized scenario, NOx and PM_2.5 emissions should be reduced by 23% and 46%, respectively, to meet the national secondary standard. The emissions of cities with low transfer coefficients, such as Zhangjiakou, Qinhuangdao, and Chengde, could even be appropriately increased. This means that the optimized scenario could reduce the pressure on emission reduction. Although the optimization results are theoretical and idealistic, this research study provides a new idea for formulating emission mitigation policies in various regions to reduce the impact on the economy.

Exports Widen the Regional Inequality of Health Burdens and Economic Benefits in India

Both the ever-complex international and subnational supply chains could relocate health burdens and economic benefits across India, leading to the widening of regional inequality. Here, we simultaneously track the unequal distribution of fine particle matter (PM_2.5) pollution, health costs, and value-added embodied in inter- and intranational exports for Indian states in 2015 by integrating a nested multiregional input-output (MRIO) table constructed based on EXIOBASE and an Indian regional MRIO table, Emissions Database for Global Atmospheric Research (EDGAR), the Community Multi-Scale Air Quality (CMAQ) model, and a concentration-response function. The results showed that the annual premature deaths associated with PM_2.5 pollution embodied in inter- and intranational exports were 757,356 and 388,003 throughout India, accounting for 39% and 20% of the total premature deaths caused by PM_2.5 pollution, respectively. Richer south and west coastal states received around half of the national Gross Domestic Product (GDP) induced by exports with a quarter of the health burden, while poorer central and east states bear approximately 60% of the health burden with less than a quarter of national GDP. Our findings highlight the role of exports in driving the regional inequality of health burdens and economic benefits. Therefore, tailored strategies (e.g., air pollution compensation, advanced technology transfer, and export structure optimization) could be formulated.

Phyto-cleaning of particulate matter from polluted air by woody plant species in the near-desert city of Jodhpur (India) and the role of heme oxygenase in their response to PM stress conditions

Particulate matter (PM) is one of the most dangerous pollutants in the air. Urban vegetation, especially trees and shrubs, accumulates PM and reduces its concentration in ambient air. The aim of this study was to examine 10 tree and shrub species common for the Indian city of Jodhpur (Rajasthan) located on the edge of the Thar Desert and determine (1) the accumulation of surface and in-wax PM (both in three different size fractions), (2) the amount of epicuticular waxes on foliage, (3) the concentrations of heavy metals (Cd and Cu) on/in the leaves of the examined species, and (4) the level of heme oxygenase enzyme in leaves that accumulate PM and heavy metals. Among the investigated species, Ficus religiosa L. and Cordia myxa L. accumulated the greatest amount of total PM. F. religiosa is a tall tree with a lush, large crown and leaves with wavy edge, convex veins, and long petioles, while C. myxa have hairy leaves with convex veins. The lowest PM accumulation was recorded for drought-resistant Salvadora persica L. and Azadirachta indica A. Juss., which is probably due to their adaptation to growing conditions. Heavy metals (Cu and Cd) were found in the leaves of almost every examined species. The accumulation of heavy metals (especially Cu) was positively correlated with the amount of PM deposited on the foliage. A new finding of this study indicated a potentially important role of HO in the plants' response to PM-induced stress. The correlation between HO and PM was stronger than that between HO and HMs. The results obtained in this study emphasise the role of plants in cleaning polluted air in conditions where there are very high concentrations of PM.

Dairy Trade Helps to Alleviate Global Carbon Emission Pressure

Global dairy production, consumption, and trade are growing rapidly, driven by population and per capita income growth and increasing health concerns mainly from developing countries, which has aroused concerns about the related carbon emission (mostly in the form of methane) increase. If all of the dairy products consumed were produced locally/domestically in the developing countries/economies (a counterfactual scenario), the carbon emissions in 2018 would be 28 Mt CO₂-equiv higher than its status quo (a factual scenario). The present study indicates that unlike in many global trade cases in which carbon leakages are from developed to developing countries, global dairy trade is characterized by net embodied carbon flows from developed to developing countries/economies due to the fact that there is an overwhelming one-way-flow of dairy products from developed to developing countries/economies. The differences in the carbon emission factors between the developed and developing countries/economies provide an opportunity that global dairy trade and production specialization can help to reduce carbon emissions from increasing dairy product demand, and the total reduction potential is estimated to be about 414 Mt CO₂-equiv from 2018 to 2030. Free trade agreements such as the Regional Comprehensive Economic Partnership will incentivize larger carbon emission reduction benefits through promoting dairy trade.

Long-term trends and affecting factors in the concentrations of criteria air pollutants in South Korea

Here, we used a novel approach to analyze the trends in the concentrations of six national criteria air pollutants, carbon monoxide (CO), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), PM₁₀, PM_2.5, and surface ozone (O₃), between 2001 and 2018, and the factors affecting the concentrations of CO and SO₂ at the district level in South Korea (Korea) between 2011 and 2016. We considered four factors affecting the concentrations of CO and SO₂: (1) concentration-to-emission ratio, (2) air pollutant-to-CO₂ emission ratio, (3) carbon intensity, and (4) area-weighted energy supply. We found that the most influencing factors determining the concentrations of CO and SO₂ in Korea were the air pollutant-to-CO₂ emission ratio and the concentration-to-emission ratio. The annual mean concentrations of CO, SO₂, PM₁₀, PM_2.5, and NO₂ generally decreased, while O₃ levels showed an increasing trend, over the last 18 years in Korea. We also found that NO₂ concentration had strong positive and negative correlations with PM_2.5 and O₃ concentrations, respectively. However, the relationship between O₃ and NO₂ levels showed an inverted U shape under NO₂ super-rich condition (e.g., > 55 ppb in Seoul), and the daily maximum 8-h values (MDA8O₃) increased in proportion to the NO₂ level under poor NO₂ conditions (e.g., < 25 ppb in Seoul).

Global trade drives transboundary transfer of the health impacts of polycyclic aromatic hydrocarbon emissions

International trade leads to a redistribution of pollutant emissions related to the production of goods and services and subsequently affects their severe health impacts. Here, we present a framework of emissions inventories, input-output model, numerical atmospheric chemistry model, and estimates of the global burden of disease. Specifically, we assess emissions and health impacts of polycyclic aromatic hydrocarbons (PAH), a carcinogenic byproduct of production activities, and consider income, production, final sale, and consumption stages of the global supply chain between 2012 and 2015. We find that in 2015, global anthropogenic PAH emissions were 304 Gg (95% CI: 213~421 Gg) and estimated related lifetime lung cancer deaths were 6.9 × 10⁴ (95% CI: 1.8 × 10⁴~1.5 × 10⁵ deaths). The role of trade in driving the PAH-related health risks was greater than that in driving the emissions. Our findings indicate that international cooperation is needed to optimise the global supply chains and mitigate PAH emissions and health impacts.

Interprovincial Metal and GHG Transfers Embodied in Electricity Transmission across China: Trends and Driving Factors

With the increasing proportion of low-carbon power in electricity generation mix, power generation will be transformed from carbon-intensive to metal-intensive. In this context, metal and GHG transfers embodied in electricity transmission of China from 2015 to 2019 are quantified by the Quasi-Input-Output model. Combined with complex network theory, we have distinguished whether metal and GHG transfers show different trends as electricity trade changes. Driving factors contributing to forming the metal and GHG transfers are also explored based on the Quadratic Assignment Procedure. The results show that the electricity trade change has strengthened the metal transfer network significantly, while several key links in the GHG transfer network have weakened. Moreover, we find provincial differences in low-carbon electricity investment contributing to the metal transfer while affecting the GHG transfer little. The above facts imply an expanding embodied metal transfer in the future and shed light on policy making for power system decarbonization.

Analysis of Atmospheric CO2 and CO at Akedala Atmospheric Background Observation Station, a Regional Station in Northwestern China

Air samples were collected by flasks and analyzed via a Picarro G2401 gas analyzer for carbon dioxide (CO₂) and carbon monoxide (CO) at the Akedala Atmospheric Background Station in Xinjiang, China, from September 2009 to December 2019, to analyze the changes in the characteristics of atmospheric CO₂ and CO and determine the sources. The results show that the annual average CO₂ concentration showed an increasing trend (growth rate: 1.90 ppm year⁻¹), ranging from 389.80 to 410.43 ppm, and the annual average CO concentration also showed an increasing trend (growth rate: 1.78 ppb year⁻¹), ranging from 136.30 to 189.82 ppb. The CO₂ concentration and growth rate were the highest in winter, followed by autumn, spring, and summer. The CO concentration and growth rate were also the highest in winter due to anthropogenic emissions, ecosystem effects, and diffusion conditions. The main trajectories of CO₂ and CO determined by the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model were parallel to the Irtysh River valley and then passed through the Old Wind Pass. Furthermore, the main source regions of CO₂ and CO at the Akedala Station were eastern Kazakhstan, southern Russia, western Mongolia, and the Xinjiang Tianshan North Slope Economic Zone of China. This study reflects the characteristics of long-term changes in CO₂ and CO concentrations at the Akedala station and provides fundamental data for the studies on environmental changes and climate change in Central Asia.

Embedded Health Risk from Arsenic in Globally Traded Rice

International food trade is fundamental to global food security but with often negative consequences in the producing country. We propose a method of quantifying flows of inorganic arsenic (iAs) and embedded increased lifetime cancer risks (EHR) at a global scale, where negative impacts are felt on the importing country. Computations were made for 153 countries. Vietnam exports the most iAs embedded in rice (796 kg/year) followed by India (788 kg/year), Thailand (485 kg/year), and the United States (323 kg/year). We show that continental China, Indonesia, and Malaysia have the highest imports of iAs (292, 174, and 123 kg/year, respectively). Bangladesh ranks highest in EHR followed by Vietnam and Cambodia (150, 141, and 111 per 100,000, respectively). Countries that depend exclusively on imported rice are importing a substantial amount of risk, as, e.g., Kiribati and Solomon Islands (57 and 53 per 100,000, respectively). We discuss the potential policy options for reducing population dietary health risks by well-balanced apportioning of rice sources. This study targets policy design solutions based on health gains, rather than on safe levels of the risk factor alone.

Environmental implications of economic transformation in China's Pearl River Delta region: Dynamics at four nested geographical scales over 1987-2017

Environmental pollution in the Pearl River Delta (PRD) region is largely driven by socioeconomic forces outside the region as vast majority of manufacturing products produced in the region are destined to national and international markets. Given the remarkable economic transformation of the PRD in the past decades, this study investigates the impacts of local, provincial, national, and global socio-economic drivers on PRD's pollution dynamics under the background of significant economic restructuring and upgrading from 1987 to 2017. The results indicate that changes in pollution pattern were deeply shaped by the economic transformation. The share of PRD's emissions driven by international exports expanded significantly before 2007 as a result of the fast growth of international exports. The transformation of economic growth to domestic consumption driven model since the 2007-2008 global financial crisis had resulted in an increasing contribution share to the PRD's environmental pollution from local demand and trade with Rest of China (RoC). Similarly, as final demand structure evolving towards the high value-added manufacturing and services, the share of emissions driven by low value-added manufacturing (LVM) demand had decreased by an enlarged margin, while that driven by high value-added manufacturing (HVM) demand and services demand had moved in the opposite direction. The structural decomposition analysis shows that reduction in emission intensity remains the most effective way in pollution alleviation. The contribution of changes in production input structure also shifted from a strong impetus force before 2007 to a mitigating force afterwards due to significant technological progresses in the industrial sectors since the global financial crisis. With the marginal cost of reducing emission intensity becoming prohibitively expensive, the optimization of production structure and consumption pattern is likely to play more important role in future emission mitigation.

The employment effect of Chinese industrial enterprises embedded in environmental cost-adjusted global value chains

The employment effect of enterprises embedded in global value chains (GVCs) has important theoretical value, but existing research has ignored the impact of environmental costs on employment under the division of labor system within the value chain. By constructing a GVC-embedded index considering environmental costs, this study investigates the impact of Chinese industrial enterprises' embedding into GVCs on employment at both the theoretical and empirical levels. It is found that when the environmental cost is considered, the improvement of GVC embeddedness has a significant inhibiting effect on employment, especially for female laborers, lower-skilled laborers, state-owned enterprises, private enterprises, and enterprises in the eastern region of China. The research also shows that when considering environmental costs, the labor cost increase effect enhances the negative effect of increased GVC embeddedness on employment, while the innovation promotion effect and the foreign direct investment effect serve to mitigate the negative effect. The results provide a reference for developing countries seeking to effectively protect people's livelihood and employment while achieving a leap in the division of labor along the green value chain.

Inequality in historical transboundary anthropogenic PM2.5 health impacts

Atmospheric transport of fine particulate matter (PM_2.5), the leading environmental risk factor for public health, is estimated to exert substantial transboundary effects at present. During the past several decades, human-produced pollutant emissions have undergone drastic and regionally distinctive changes, yet it remains unclear about the resulting global transboundary health impacts. Here we show that between 1950 and 2014, global anthropogenic PM_2.5 has led to 185.7 million premature deaths cumulatively, including about 14% from transboundary pollution. Among four country groups at different affluence levels, on a basis of per capita contribution to transboundary mortality, a richer region tends to exert severer cumulative health externality, with the poorest bearing the worst net externality after contrasting import and export of pollution mortality. The temporal changes in transboundary mortality and cross-regional inequality are substantial. Effort to reduce PM_2.5-related transboundary mortality should seek international collaborative strategies that account for historical responsibility and inequality.

Effects of land use, climate, and imperviousness on urban stormwater quality: A meta-analysis

Many natural and anthropogenic factors cause degradation of urban stormwater quality, resulting in negative consequences to receiving waters. In order to improve water quality models at a variety of scales, accurate estimates of pollutant (nutrients, total suspended solids, and heavy metal) concentrations are needed using potential explanatory variables. To this end, a meta-analysis was performed on aggregated stormwater quality data from the published literature from 360 urban catchments worldwide to understand how urban land use and land cover (LULC), climate (i.e., Kӧppen-Geiger zone), and imperviousness (1) affect runoff quality, and (2) whether they are able to predict stormwater pollutant concentrations. Runoff pollutant concentrations were more influenced by LULC and climate than imperviousness. Differences in LULC significantly affected the generation of metals and some nitrogen species. Road, city center, and commercial LULCs generally produced the most elevated pollutant concentrations. Changes in climate zones resulted in significant differences in concentrations of nutrients and metals. Continental and arid climate zones produced runoff with the highest pollutant concentrations. Rainfall patterns seemed to have a more important role in affecting runoff quality than seasonal temperature. Differences in imperviousness only significantly affected chromium and nickel concentrations, although increased imperviousness led to slightly (not significantly) elevated concentrations of nutrients, suspended solids, and other heavy metals. Multiple linear regression models were created to predict the quality of urban runoff. Predictive equations were significant (p < 0.05) for 67% of the pollutants analyzed (ammonia, total Kjeldahl nitrogen, total nitrogen, total phosphorus, cadmium, nickel, lead, and zinc) suggesting that LULC, climate, and imperviousness are useful predictors of stormwater quality when local field monitoring or modeling is not practical. This study provides useful relationships to better inform urban stormwater quality models and regulations such as total maximum daily loads.

Regional trade agreement burdens global carbon emissions mitigation

Regional trade agreements (RTAs) have been widely adopted to facilitate international trade and cross-border investment and promote economic development. However, ex ante measurements of the environmental effects of RTAs to date have not been well conducted. Here, we estimate the CO₂ emissions burdens of the Regional Comprehensive Economic Partnership (RCEP) after evaluating its economic effects. We find that trade among RCEP member countries will increase significantly and economic output will expand with the reduction of regional tariffs. However, the results show that complete tariff elimination among RCEP members would increase the yearly global CO₂ emissions from fuel combustion by about 3.1%, doubling the annual average growth rate of global CO₂ emissions in the last decade. The emissions in some developing members will surge. In the longer run, the burdens can be lessened to some extent by the technological spillover effects of deeper trade liberalization. We stress that technological advancement and more effective climate policies are urgently required to avoid undermining international efforts to reduce global emissions.

The Regional Comprehensive Economic Partnership (RCEP) will come into force in January 2022. Here the authors quantify ex ante economic and environmental effects following RCEP tariff reductions.

Regional interaction of lung cancer incidence influenced by PM2.5 in China

PM_2.5 is the key pollutant threatening human health and can even cause lung cancer. Pollution is the most serious problem in China with its fast industrialisation, urbanisation and high population density. This pollutant is conveyed through the atmosphere, trade and the embodied emission flow amongst regions. Scientific evaluation of the responsibility for regional lung cancer by considering both internal and external influences seems to be meaningful in addressing regional inequity. This study develops a relatively convenient and practical method to evaluate the regional inequity reflected by lung cancer associated with PM_2.5 pollution in China. Results show that PM_2.5 emissions and concentrations have similar distribution patterns: high values were predominant in the east and south where has high population density, while the west had low values. The cancer incidence rate showed high values mainly in eastern and central China. At a provincial scale, the lung cancer incidence rate was significantly correlated with PM_2.5 concentration levels, and a high correlation was also found between PM_2.5 concentration and emissions, indicating that emission reduction is the key to lung cancer prevention. Due to domestic trade, some developed regions more pulled lung cancer in less developed regions, and some less developed regions also have an obvious influence on external regions. Spatially, provinces in northern and central China are always more influenced by external regions. Lung cancer inequity analysis shows that coastline regions are more advantaged, while the reverse applies to inland China. The central government needs to further strengthen regional coordinated development measures, such as economic compensation for medical care and adjustments to industry structure. It should optimise spatial allocation and comprehensively consider regional inequity and character.

Global Trends and Drivers in Consumption- and Income-Based Emissions of Polycyclic Aromatic Hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) are a class of the most hazardous substances. As unavoidable byproducts of petrogenic and pyrogenic processes, their emissions are dominantly linked to various economic sectors. In international trade, not only final consumption but also primary input can transfer the emissions among regions. Therefore, a long-term impact assessment of the international trade on PAH global emissions based on the final consumption and primary input could significantly benefit worldwide PAH mitigation strategies. This study investigated the changes in consumption- and income-based PAH emissions and interregional flows of worldwide regions, using the latest available data from 1999 to 2014. Results show that in 2014, 16.8 and 10.1% of global PAH emissions were transferred by consumption and primary input through international trade. Meanwhile, the production-, consumption-, and income-based emissions in most regions were decreasing. Furthermore, from the consumption-based perspective, sub-Saharan Africa surpassed China and became the largest net exporter of consumption-based emissions. From the income-based perspective, the net income-based outflows of India and the rest of Asia increased significantly, indicating the income-based emission leakage in emerging markets. From the socioeconomic perspective, emission intensity dominated the global decline in PAH emissions. As the two main factors driving the increase in emissions, the primary input structure (41%) had a larger effect than the final demand level (28%) from 1999 to 2014. Therefore, global cooperation, through the mitigation strategies of reducing emission factors and improving international trade patterns, is posited as an efficient strategy to reduce PAH pollution and related health risks.

Consumption-based PM2.5-related premature mortality in the Beijing-Tianjin-Hebei region

The Beijing-Tianjin-Hebei (BTH) region, which has a resource-dependent economy dominated by clusters of heavy industries, has long borne the highest PM_2.5 pollution levels in China, prompting serious concerns about the region's disease burden. Pollution-intensive industries in the BTH region not only meet local consumer demands but also those of other places via the supply chain. In the present study, we combined a multi-region input-output model with adjoint source sensitivity modeling technique at a high resolution (0.25° × 0.3125°) to apportion PM_2.5-related mortality risks in the BTH to consuming areas and sectors. The model predicted that exposure to ambient PM_2.5 caused 0.12 million premature deaths (95% confidence interval: 0.08-0.15) in the BTH region in 2013. The adjoint source sensitivity results showed that only 46% of the total premature deaths were attributable to local consumption. The top contributors of local consumption were rural households and the agricultural sector in Hebei, and service sector in Beijing. Consumption of other domestic regions and international export accounted for 25% of the total premature deaths in the BTH, mainly to support consumption of manufacturing and construction products of these outer regions. Atmospheric transport of pollutants, mainly from the surrounding areas, accounted for the remaining 29% of total deaths in BTH. Our findings underline the consumption-based driven force of BTH's pollution and associated health impacts, which may facilitate the joint control actions among the BTH region and its surrounding areas from a comprehensive perspective.

Mitigation potential of global ammonia emissions and related health impacts in the trade network

Ammonia (NH3) emissions, mainly from agricultural sources, generate substantial health damage due to the adverse effects on air quality. NH3 emission reduction strategies are still far from being effective. In particular, a growing trade network in this era of globalization offers untapped emission mitigation potential that has been overlooked. Here we show that about one-fourth of global agricultural NH3 emissions in 2012 are trade-related. Globally they induce 61 thousand PM2.5-related premature mortalities, with 25 thousand deaths associated with crop cultivation and 36 thousand deaths with livestock production. The trade-related health damage network is regionally integrated and can be characterized by three trading communities. Thus, effective cooperation within trade-dependent communities will achieve considerable NH3 emission reductions allowed by technological advancements and trade structure adjustments. Identification of regional communities from network analysis offers a new perspective on addressing NH3 emissions and is also applicable to agricultural greenhouse gas emissions mitigation.

Biotransport of mercury and human methylmercury exposure through crabs in China - A life cycle-based analysis

Exposure to methylmercury (MeHg) has various toxic effects on humans. The evaluation of human MeHg exposure has previously focused on fish consumption. However, in this study, we found that MeHg levels in domestic crabs in China were also relatively high (range: 50-1400 ng/g, dry weight). The high MeHg levels in crabs and their high consumption do not match the risk assessment of MeHg, indicating an underestimated exposure risk, especially in MeHg-sensitive groups such as pregnant women. The annual crab MeHg content output in China was estimated to be 30 ± 27 kg. A total of 6.8% of the country's land area contributes 71% of the MeHg output. However, 66% of the output is redistributed to non-crab-producing regions via interregional food trade, posing risks to the population on a national scale. The daily intake of MeHg from crabs could easily exceed the reference dose (0.1 µg/kg of body weight per day) suggested by the United States Environmental Protection Agency with consideration of coexposure from fish, rice, and other food sources. We suggest that future MeHg exposure analysis includes crab MeHg as a coexposure pathway to estimate the dietary MeHg limit accurately and emphasize the influence of interregional food trade on MeHg exposure.

Assessing the effects of labor market dynamics on CO2 emissions in global value chains

International production fragmentation has led to substantial changes in labor market, such as job creation/job loss, changing labor market structure and labor productivity. Such changes are perceived to affect CO₂ emissions of those economies that participate in different parts of global value chains. This paper develops an accounting framework relating CO₂ emissions to labor market shaped by global value chains. It analyses the influential factors driving CO₂ emissions, and documents several pervasive empirical patterns. This is based on the recent environmental accounts developed by the European Commission and the World Input-Output Database over 2000-2014. The results show that the growth of CO₂ emissions is primarily reduced by intensity effect, followed by labor market structural change due to participation in value chains, while it is driven by labor productivity effect and job creation. In particular, the foreign job creation effect is mostly emission-increasing, even in those economies with shrinking domestic employment. These results highlight the role of labor market and global value chains in climate policymaking.

Industrial polycyclic aromatic hydrocarbons (PAHs) emissions embodied in domestic trade in China in 2012

Atmospheric Polycyclic Aromatic Hydrocarbons (PAHs) emissions cause non-negligible damage to human health and well-being. Effective regional cooperation is urgently required to mitigate PAHs emissions to maintain satisfactory air quality. This study quantified and tracked China's PAHs emissions flows embodied in interprovincial trade. A production-based emissions inventory of 16 U.S. EPA priority PAHs based on commercial energy consumption in China in 2012 was compiled using the emissions factor approach. Then, a multiregional input-output model was constructed to reveal consumption-based emissions and to track the PAHs emissions embodied in the trade of 27 major sectors across 30 regions in China. Key structural paths were also identified using structural path analysis (SPA). In 2012, the total industrial energy-derived PAHs emissions were estimated to be 47.7 tons of BaP-toxic equivalents (8032.7 tons of mass). Shandong, Hebei, and Hubei accounted for more than 24.0% of the production-side PAHs emissions in the whole country. Approximately 30.8% of China's PAHs emissions were embodied in goods consumed outside of the province in which they were produced. PAHs flow tended to start in the western regions and ended in the eastern regions along the coast. The results of the SPA showed that critical paths, such as from the Metallurgy sector to the Construction sector, embodied a large amount of emissions and had the potential to affect the performance of the entire system. By paying attention to the consumption-based accounting as well as the production-based accounting of emissions and by focusing on vital transfer paths, policymakers can devise effective and targeted environmental protection and sustainable development policies in China.

The effect of indirect household energy consumption on PM 2.5 emission in China: An analysis based on CLA method

PM 2.5 emissions caused by household activities are considered to be important drivers of haze formation, and indirect activities closely related to industrial structure account for a large proportion of them. This article quantifies the indirect effects on energy usage and PM 2.5 emissions of urban and rural residents' lifestyles in China during 2005-2015 according to the application of consumer lifestyle analysis. The results show that during this period, the degree of indirect impact on energy consumption of residents' living was 2.44-2.71 times as of direct impact, and there are large regional differences between those two impacts. PM 2.5 emissions from energy consumption per unit of households in North, Northeast and Northwest China are higher than that in other regions, while energy consumption in South China is relatively environmentally friendly. Residential, clothing and transportation are the most energy-intensive and PM 2.5-intensive activities among all indirect energy consumption activities. This is the first time that the CLA method has been used to analyze and calculate PM2.5 emissions caused by household energy consumption in a wide area of China through data collection over a longer period. The calculation results are more accurate than previous studies using other methods. Also, it provides factual evidence for key policies of energy saving and environmental protection, as well as pointing out the main sectors of household energy consumption that caused high PM 2.5 emissions for specific regions. The above contributions can provide a theoretical basis and accurate reference data for governments to more purposefully guide the transformation of energy-intensive industries represented by residence and other industries and improve technology to reduce their emissions.

Impacts of Environmental Policies on Global Green Trade

The objective of this study was to investigate the impact of environmental policies on bilateral green exports among developed and developing countries. The empirical analysis was based on the fixed-effects gravity model estimation with the PPML (Poisson pseudo-maximum likelihood) for bilateral green trade of world countries for 1990–2019. This study focused on two proxy environmental policy indicators: environment-related tax and energy intensity. The major findings were that, first, promotion of environment-related tax increases green exports among HIC (high-income countries) and, second, an increase in the green trade of a country depends on the energy intensity level of its trading partner countries in order to stabilize domestic demand and production. This result is shown to be significant and consistent within the trade between the same income groups. Thus, supporting the green growth strategy, empirical results suggest that LMY (low- and middle-income) countries have to promote environmental policies and green production processes to be competitive in the global market.

Real economic benefits and environmental costs accounting of China-US trade

A critical reason for China-United States trade friction is that China has a huge trade balance, especially the trade balance of goods. However, this huge trade balance is based on the results of official statistics and does not reflect the real economic benefits and environmental costs embodied in China-US trade, where both refer to trade in value-added and embodied CO₂ emission costs, respectively. This paper calculates the trade in value-added and carbon emission transfer between China and the United States based on the World Input-Output Database. Results demonstrate that: (1) Gross trade statistics seriously overestimate China's benefits in China-US trade. The China-US trade surplus, based on gross trade statistics, is 20% higher than when based on trade in value-added accounting. (2) In China-US bilateral trade, China mainly adopts the trade model of importing intermediate products and exporting final products，whereas the United States mainly adopts the trade model of importing final products and exporting intermediate products. China's exports to the United States contain many of value-added in Korea, Taiwan, and Japan. (3) From 2000 through 2014, China maintained a large surplus of CO₂ emissions exports to the United States, and China paid a huge environmental cost in its trade with the United States. (4) In China-US trade, China's environmental costs per unit value-added is 3.02 times that of the United States.

The implication of the air quality pattern in South Korea after the COVID-19 outbreak

By using multiple satellite measurements, the changes of the aerosol optical depth (AOD) and nitrogen dioxide (NO₂) over South Korea were investigated from January to March 2020 to evaluate the COVID-19 effect on the regional air quality. The NO₂ decrease in South Korea was found but not significant, which indicates the effects of spontaneous social distancing under the maintenance of ordinary life. The AODs in 2020 were normally high in January, but they became lower starting from February. Since the atmosphere over Eastern Asia was unusually stagnant in January and February 2020, the AOD decrease in February 2020 clearly reveals the positive effect of the COVID-19. Considering the insignificant NO₂ decrease in South Korea and the relatively long lifetime of aerosols, the AOD decrease in South Korea may be more attributed to the improvement of the air quality in neighboring countries. In March, regional atmosphere became well mixed and ventilated over South Korea, contributing to large enhancement of air quality. While the social activity was reduced after the COVID-19 outbreak, the regional meteorology should be also examined significantly to avoid the biased evaluation of the social impact on the change of the regional air quality.

Global and National Environmental Impacts of the US-China Trade War

The recent "US-China trade war" has aroused concern over trade-related environmental impacts. This study built a multiregional computable general equilibrium model to simulate environmental impacts of the "US-China trade war" under different scenarios of tariff and nontariff barriers and the battlefield spreading ranges. The present study found that although the trade war will cause a global economic downturn, which will seemingly reduce environmental pressure globally, global carbon emissions are expected to increase rather than decline. On the one hand, the CO₂ emission increase caused by land-use changes in Brazil and Argentina will far exceed the emission reduction because of decreased global production. On the other hand, some countries/economies especially those developing countries such as Vietnam, Russia, and India will face emission increases driven by scale effects. Countries such as Korea, the UK, and France will enjoy a reduction in emissions driven by structural effects. China and the US will face a reduction in production and CO₂ emissions, but their CO₂ emission intensities will rise. The results remind us that as global production and supply chains are formed, it is important to closely monitor trade-related environmental impacts. Efforts should be made to balance the interests of trade and the environment.

Role of export industries on ozone pollution and its precursors in China

This study seeks to estimate how global supply chain relocates emissions of tropospheric ozone precursors and its impacts in shaping ozone formation. Here we show that goods produced in China for foreign markets lead to an increase of domestic non-methane volatile organic compounds (NMVOCs) emissions by 3.5 million tons in 2013; about 13% of the national total or, equivalent to half of emissions from European Union. Production for export increases concentration of NMVOCs (including some carcinogenic species) and peak ozone levels by 20-30% and 6-15% respectively, in the coastal areas. It contributes to an estimated 16,889 (3,839-30,663, 95% CI) premature deaths annually combining the effects of NMVOCs and ozone, but could be reduced by nearly 40% by closing the technology gap between China and EU. Export demand also alters the emission ratios between NMVOCs and nitrogen oxides and hence the ozone chemistry in the east and south coast.

Linkage analysis of economic consumption, pollutant emissions and concentrations based on a city-level multi-regional input-output (MRIO) model and atmospheric transport

China is experiencing serious atmospheric pollution, which also exhibits significant spatial heterogeneity. The Chinese government has implemented targeted pollution control measures at the city level, emphasizing coordination among cities to prevent and control air pollution in key regions such as Beijing-Tianjin-Hebei (BTH) urban agglomeration. This study combined an inter-city multi-regional input-output (MRIO) model with an air quality dispersion model consisting of a weather research and forecasting (WRF) model and the CALPUFF model (WRF/CALPUFF) to study the inter-city economic consumption, pollutant emission and concentration among 13 cities in BTH urban agglomeration. NO_x is chosen as an example. The combined effects of economic linkage and atmospheric transport show that NO_x concentrations in cities in the BTH urban agglomeration are attributable to three consumption sources: a local contribution from the target city's own local economic consumption (average, 25%), and non-local consumption contributions, including other cities in the BTH urban agglomeration (average, 36%) and regions outside of BTH (average, 39%). Compared with the contributions to NO_x concentrations calculated using only the MRIO model or atmospheric transport stimulation model, the results of this paper quantify that the consumption outside of a city could provide a greater impact on the city's air quality due to the combined effects of economic linkage and atmospheric transport. To avoid negative impacts of emission reduction targets on economic consumption, governmental regional pollution control policies should consider the combined effects of economic linkage and atmospheric transport.