Transboundary Pollution Research Articles

The dynamic relation between fertilization, precipitation and the diffusion of agricultural non-point pollution in Hainan Island

With the increasing demand for crops, the excessive application of fertilizers has gradually become a significant factor affecting water quality. Therefore, studying the relationship between agricultural fertilizer runoff and water quality is crucial for the sustainable development of agricultural production. The present study sets up a new dynamic model of nitrogen fertilizer loss, introducing variables such as precipitation, fertilization application during dry and rainy seasons, and their lagged and interaction terms. The paper analyzed the issue of fertilizer runoff under the complex interactions of various factors, including spatial and temporal scales and climatic conditions, and explored the relationship between agricultural activities and water quality changes in the context of sustainable development. Due to Hainan Island’s independent river system, which is free from transboundary pollution, and its low level of industrial pollution, it provides an excellent sample for assessing the impact of agricultural non-point source pollution on water quality. Based on watershed monitoring data from Hainan Island, this study draws the following conclusions: 1. Precipitation exhibits a pronounced seasonal influence on total nitrogen concentration. 2. Nitrogen fertilizer enters into water bodies through precipitation, resulting in a lag effect on total nitrogen concentration. 3. The influence of grain and tropical crops on nitrogen loss is less significant, while cash crops will trigger the nitrogen overloading of rivers in scenarios where they account for a high proportion of the planting structure of the sown area.

Seasonal anomaly of particulate matter concentration in an equatorial climate: Evaluating the transboundary impact from neighboring provinces on Padang City, Indonesia.

This study investigated the anomalous seasonal variations in particulate matter (PM) concentrations-specifically PM2.5 and PM10-in Padang City, Indonesia, situated within the Equatorial climate zone. A one-year dataset of half-hourly PM measurements from January to December 2023, collected by the Air Quality Monitoring System (AQMS) managed by the Environmental Agency of West Sumatra (DLH), was utilized. Maps of hotspots and air mass backward trajectories were used to identify possible transboundary emissions affecting Padang City. Despite the region experiencing nearly continuous rainfall, significant elevations in PM levels were observed during the typically drier months of August to October. Specifically, PM2.5 levels peaked at 36.57µg/m3 and PM10 at 39.58µg/m3 in October, significantly higher than in other months and indicating a substantial deviation from the typical expectations for equatorial climates. These results suggest that the high PM concentrations are not solely due to local urban emissions or normal seasonal variations but are also significantly influenced by transboundary smoke from peatland fires and agricultural burning in neighboring provinces such as Bengkulu, Riau, Jambi, and South Sumatra. Backward trajectory analysis further confirmed the substantial impact of regional activities on degradation of air quality in Padang City. The study underscores the need for integrated air quality management that includes both local and transboundary pollution sources. Enhanced monitoring, public engagement, and inter-regional collaboration are emphasized as crucial strategies for mitigating the adverse effects of PM pollution in equatorial regions like Padang City.

Strategic dynamics of local governments in regional collaborative governance: An evolutionary game theory analysis of haze pollution response in the Fen-Wei Plain, China

Regional collaborative governance has become a key strategy for environmental protection, especially in reducing transboundary pollution transfer. This study, set against the backdrop of environmental governance in China's Fen-Wei Plain, employs evolutionary game theory to deeply analyze the strategic choices of local governments in managing haze pollution. We developed a model incorporating 14 key variables to systematically explore the emission reduction strategies of local governments under various policy environments. Through numerical simulations, we not only validate the effectiveness of the model but also focuses on how incentives and punishments from the central government influence the stability of local governments adopting a “strict enforcement” strategy. We find that appropriate incentives from the central government can significantly enhance the tendency of local governments to choose a “strict enforcement” strategy for emission reduction. Under certain conditions, whether adopting “strict enforcement” or “superficial enforcement,” both can lead to an Evolutionarily Stable Strategy (ESS). Moreover, the intensity of rewards and penalties from the central government and the benefits of collaborative governance by local governments are key factors determining the stability of strategies. Our findings underscore the importance of establishing performance-oriented incentive mechanisms, refining reward and punishment measures, and focusing on sustainable and adaptable governance strategies. The strategic recommendations provided by this study offer important guidance for balancing incentives and punishments, thereby stimulating local government enthusiasm for governance, which supports high-quality environmental protection and sustainable development goals.

POLLUTION AND ITS ECOLOGICAL CONSEQUENCES: STRATEGIES FOR MITIGATING ENVIRONMENTAL DAMAGE

Pollution, a pervasive environmental issue, poses significant threats to ecosystems, biodiversity, and human health. This article provides a comprehensive overview of the various types of pollution, including air, water, soil, and chemical pollutants, and their detrimental effects on ecological systems. The study examines the pathways through which pollutants enter and accumulate in the environment, leading to disruptions in ecological balance, loss of biodiversity, and degradation of natural habitats. The article also explores the intricate connections between pollution and climate change, emphasizing how pollutants such as greenhouse gases exacerbate global warming and contribute to long-term ecological damage. In response to these challenges, the article outlines a range of strategies for mitigating environmental damage caused by pollution. These strategies include advancements in pollution control technologies, such as catalytic converters and air purification systems, as well as policy interventions aimed at reducing emissions and promoting sustainable practices. The role of ecological restoration techniques, such as bioremediation and reforestation, in reversing pollution-induced damage is also discussed. Furthermore, the article highlights the importance of international cooperation and regulatory frameworks in addressing transboundary pollution issues and ensuring the effective implementation of mitigation strategies. By integrating scientific research with practical solutions, this article provides a valuable resource for environmental scientists, policymakers, and conservationists seeking to understand and mitigate the ecological consequences of pollution. The study underscores the urgency of adopting comprehensive and coordinated approaches to pollution management to protect and restore the health of our planet's ecosystems.

TROPOMI unravels transboundary transport pathways of atmospheric carbon monoxide in Tibetan Plateau

Numerous studies have reported in situ monitoring and source analysis in the Tibetan Plateau (TP), a region crucial for climate systems. However, a gap remains in understanding the comprehensive distribution of atmospheric pollutants in the TP and their transboundary pollution transport. Here, we analyzed the high-resolution satellite TROPOMI observations from 2018 to 2023 in Tibet and its surrounding areas. Our result reveals that, contrary to the results from in situ surface CO monitoring, Tibet exhibits a distinct seasonality in atmospheric carbon monoxide total column average mixing ratio (XCO), with higher levels in summer and lower levels in winter. This distinctive seasonal pattern may be related to the TP's ‘air pump’ effect and the Asia summer monsoon. Before 2022, the annual growth rate of XCO in Tibet was 1.63 %·year−1; however, it declined by 6.88 % in 2022. Source analysis and satellite observations suggest that CO from South Asia may enter Tibet either by crossing the Himalayas or through the Yarlung Zangbo Grand Canyon. We discovered that spring outbreaks of open biomass burning (OBB) in South and Southeast Asia led to an 11.57–27.98 % increase in XCO over Tibet. Favorable wind pattern and unique topography of the canyon promote the high concentrations CO transport to Tibet. Our greater concern is whether the TP will experience more severe transboundary pollution in the future.

Participatory mapping of transboundary pollution: the case of Imperial Beach, California

Participatory mapping of transboundary pollution: the case of Imperial Beach, California

Border Carbon Adjustments and Leakage in the Presence of Public Pollution Abatement Activities

This paper sheds light on the unidentified effects of unilateral environmental and trade actions within an international trade framework with two large open economies, transboundary pollution, and Public Pollution Abatement (PPA) activities. When private and public abatement coexists in the exporting country, stricter environmental policy by the importing one magnifies the carbon leakage effect. Pareto efficiency dictates that Border Carbon Adjustment (BCA) should account not only for the difference in carbon taxes between the two countries, but also for the policy’s unintended consequences on PPA. More importantly, we argue that a conditional reduction of BCA, subject to stricter environmental policy by the country that exports the polluting good, decreases global pollution and increases countries’ welfare. Such reform strategy generates strong incentives for countries with laxer environmental policy to adopt a stricter one.

A long-term Doppler wind LiDAR study of heavy pollution episodes in western Yangtze River Delta region, China

Previous studies are primarily based on surface air pollution for a single event, leaving research on the temporal characteristics of aerosols and wind fields in the atmospheric boundary layer (ABL) and their associations unclear due to a lack of long-term vertical profile data. This study was the first to conduct long-term Doppler wind LiDAR measurements from Sep. 2019 to Aug. 2022 in Hefei in western Yangtze River Delta (YRD) region, China. The spatiotemporal characteristics of retrieved aerosol backscatter coefficient (β) and wind profiles were analyzed from the perspective of long-term statistics and typical heavy pollution episodes (HPEs). The seasonal profile of β showed a peak in the near-surface layer meanwhile the overall β profile (<0.5 km) was the highest in winter but lowest in summer. Combined with ground-based meteorological and air quality observations, 12 HPEs were identified and classified into dust-related events and fog-haze episodes. The results showed a consistency between hourly variations in PM10 (particulate matter smaller than 10 μm) concentration and β retrieved at 300 m during a high PM10 concentration (>150 μg/m3) period. Different roles of horizontal wind at different altitudes and its associated time delay effect on surface PM10 pollution were evaluated based on correlation coefficients (Ф) and air pollution diffusion conditions. Significant positive Ф values were noticed below 0.5 km during the entire dust-related EP4 and EP6, indicating that the higher wind speeds could exacerbate PM10 pollution. In contrast, large negative Ф values meant the removal of PM10 pollutants by strong winds below 0.8 km during 24 h after peak in EP3. Combining with backward trajectory analysis and meteorological condition, notable transboundary pollution with positive contributions from upper winds (>1.5 km) was discovered in dust-related EP1, EP4, EP7, EP9, and EP10. Time delay effect (1-h/2-h lag) of upper winds (>0.8 km) on surface PM10 pollution was explored in EP5, EP6, EP7, EP8, and EP9. In spring dust-related HPEs, surface PM10 pollution was mostly contributed by long-range transport of aerosol particles at higher altitudes (>1.5 km) from the northwest direction, driven by the Mongolian cyclone and the cold front system. Transboundary aerosols originated from the northern part of Anhui province and the YRD region in the middle altitudes (∼0.5 km) was the main contributor to fog-haze HPEs. The findings demonstrated the ability of the real-time Doppler wind LiDAR system to monitor transboundary air pollution and provided a scientific reference for policy makers.

Epistemic Communities, Between Science and Power in International Domains: A Systematic Literature Review

Epistemic communities were emphasized in constructivism discourse as powerful emerging non-state actors that can drive policies in international domains. The rise of scientific consortiums in policymaking has driven policy directions by using scientific standards. Other realms in international relations also recognize the roles of scientific communities other than creating standards to fix global challenges, such as to serve states’ interests and cooperation tools. This study aims to investigate which realm of epistemic communities are more prevalent. The tools and conditions for influential epistemic communities were also not sufficiently investigated. By using a systematic literature review (SLR) that is overlooked in international relations studies, this paper organized previous databases that use primary data on epistemic communities. The result of this paper shows epistemic communities are the most prevalent in creating scientific standards to address global challenges. Some tools that used were knowledge transfers, training, research collaborations, and networking funding. However, other studies also found that scientific consortiums may be used to legitimize the status quo. In sensitive issues like transboundary pollution, more distrust was found. This study eventually draws some limitations and agenda for future studies.

The Establishment of a Regional Court in Southeast Asia to Combat Environmental Issues

Abstract Regional arrangements for dispute resolution are sanctioned under Article 52 of the United Nations Charter. Following therefrom, the regions of Europe, America and Africa have set up regional courts for the resolution of all kinds of disputes between respective Member States, including for human rights issues. In the Southeast Asian region, despite the setting up of the Association of Southeast Asian Nations (ASEAN) on 8 August 1967, there has yet to be any concrete form of a binding dispute resolution mechanism. In recent times, environmental issues have been given due recognition by their elevation onto the human rights platform in many international conventions, and also crafted into the constitutions of many countries around the world. Against this background, this article explores the viability of establishing a regional court for Southeast Asia. The research finds that the establishment of a regional court in Southeast Asia is necessary, not only to tackle transboundary pollution issues between Member States, but also as a forum of last resort by individuals or groups within Member States which have yet to recognise environmental rights as human rights.

Combined short-term and long-term emission controls improve air quality sustainably in China

The effectiveness of national policies for air pollution control has been demonstrated, but the relative effectiveness of short-term emission reduction measures in comparison with national policies has not. Here we show that short-term abatement measures during important international events substantially reduced PM2.5 concentrations, but air quality rebounded to pre-event levels after the measures ceased. Long-term adherence to strict emission reduction policies led to successful decreases of 54% in PM2.5 concentrations in Beijing, and 23% in atmospheric nitrogen deposition in China from 2012 to 2020. Incentivized by “blue skies” type campaigns, economic development and reactive nitrogen pollution are quickly decoupled, showing that a combination of inspiring but aggressive short-term measures and effective but durable long-term policies delivers sustainable air quality improvement. However, increased ammonia concentrations, transboundary pollutant flows, and the complexity to achieving reduction targets under climate change scenarios, underscore the need for the synergistic control of multiple pollutants and inter-regional action.

Transboundary pollution control under evolving social norms: a mean-field approach

Transboundary pollution control under evolving social norms: a mean-field approach

TRANSBOUNDARY POLLUTION OF THE ENVIRONMENT AS A SUBJECT OF TEACHING IN UNIVERSITITES

The paper presents the results of the research on teaching transboundary environmental pollution issues within the economics of nature use framework in Ukraine’s universities. The methods of in-depth analysis of the data source, structural, semantic and comparative analysis, and qualitative content analysis were applied for studying the syllabuses of the related curricula. According to the research results, the syllabuses mainly focus on urgent issues of environmental pollution in Ukraine and its regions, and sometimes they concern environmental challenges for enterprises. Transboundary pollution of the environment is considered indirectly in the context of global environmental issues and international cooperation. The relevant issues are presented much more comprehensively in the environmental safety curricula. The approach seems reasonable. However, it substantially restricts the consideration of the environmental economics as an integral field of knowledge. Another observation is that teachers mostly ignore such an important component of the environment as biodiversity when elaborating the syllabuses and curricula.

Analysis of the dynamic mechanism of trans-boundary pollution collaborative control in the Yangtze River Economic Belt

Climate change mitigation requires simultaneous reduction of carbon emissions and air pollution. This study examines the synergy between pollution reduction and carbon reduction, identifying key variables and strategies to achieve this goal. Using a Geographical Detector model and a Coupling Degree of Coordination model, 108 cities in the Yangtze River Economic Belt (YREB) are investigated. Results show that while controlling PM2.5 has been more successful than managing carbon emissions in the YREB, synergy between pollution reduction and carbon emissions increased by an average of 7.2% from 2006 to 2019. Spatial analysis reveals higher synergy in upstream areas, indicating significant spatial diversity. The impact of pollution and emission reduction synergies is influenced by societal and environmental variables, including industry structure, technological innovation, energy structure, human capital quality, and economic basis. Synergy is amplified when natural limits align with high-quality development drivers such as technical innovation and the digital economy. Recommendations include enhancing city-to-city contact, improving energy and industrial structures, and fostering technological innovation to address regional variations in synergy levels.

A case study of surface ozone source contributions in the Seoul metropolitan area using the adjoint of CMAQ

ABSTRACT To quantitatively investigate the transboundary behaviors and source attributions of ozone (O3) and its precursor species over East Asia, we utilize the adjoint technique in the CMAQ modeling system (the CMAQ adjoint). Our focus is on the Seoul Metropolitan Area (SMA) in South Korea, which is the receptor region of this study. We examine the contributions of both local and transported emissions to an O3 exceedance episode observed on June 3, 2019, estimating up to four days in advance. By using the CMAQ adjoint, we can determine the sensitivity of O3 remaining in the SMA to changes in O3 precursor emissions (emissions-based sensitivity) and concentrations (concentrations-based sensitivity) along the long-range transport pathways and emission source regions overseas. These include Beijing-Tianjin-Hebei (BTH), Shandong, Yangtze River Delta (YRD), and Central China. CMAQ adjoint-derived source attributions suggest that overseas precursor emissions and O3 contributed significantly to the O3 exceedance event in SMA. The emissions-based sensitivities revealed that precursor emissions originating from Shandong, YRD, Central China, and BTH contributed 11.42 ppb, 4.28 ppb, 1.24 ppb, 0.9 ppb, respectively, to the O3 exceedance episode observed in the SMA. Meanwhile, Korean emissions contributed 31.1 ppb. Concentrations-based sensitivities indicated that 19.3 ppb of contributions originated in regions beyond eastern China and directly affected the O3 level in the SMA in the form of background O3. In addition to capturing the transboundary movements of air parcels between the source and receptor regions, we performed HYSPLIT backward trajectory analyses. The results align with the trajectories of O3 and its precursors that we obtained from the adjoint method. This study represents a unique effort in employing the adjoint technique to examine the impacts of regional O3 on South Korea, utilizing a combination of emissions-based and concentrations-based sensitivities. Implications: This research brings to light the critical role of both local and regional precursor emissions in contributing to an ozone (O3) exceedance event in the Seoul Metropolitan Area (SMA), South Korea. Utilizing the CMAQ adjoint technique, a novel approach in the context of South Korea’s O3 investigations, we were able to delineate the quantitative contributions of different regions, both within South Korea and from overseas areas such as Beijing, Shandong, Shanghai, and Central China. Importantly, the results underscore the substantial influence of transboundary pollutant transport, emphasizing the need for international collaboration in addressing air quality issues. As metropolitan areas around the globe grapple with similar challenges, the methodology and insights from this study offer a potent tool and framework for regions seeking to understand and mitigate the impacts of O3 on human health and the environment. By integrating different sensitivity types, coupled with HYSPLIT backward trajectory analyses, this research equips policymakers with comprehensive data to design targeted interventions, emphasizing the significance of collaborative efforts in tackling regional air pollution challenges. However, it’s important to note the limitation of this study, which is a case study conducted over a short time period. This constraint may impact the generalizability of the findings and suggests a need for further research to validate and expand upon these results.

Leveraging physics-based and explainable machine learning approaches to quantify the relative contributions of rain and air pollutants to wet deposition

A quantitative understanding of the roles of rainfall and pollutant concentrations in wet deposition is important because they critically influence terrestrial and aquatic ecosystems. However, their relative contributions to wet deposition, which vary across regions, have not yet been identified. We propose two methods that quantitatively separate the contributions of rain and pollutant concentrations to wet deposition: one is based on simplified equations describing the wet scavenging of pollutants and the other is based on random forest models employing SHapley Additive exPlanations. Three-dimensional long-term air quality simulations from 2003 to 2019 are used as inputs for both the physics-based and machine learning models. Remarkably, the results drawn from the explainable machine learning model are consistent with those from the physics-based approach: overall, rain is a more important limiting factor than pollutant concentrations and the relative contribution of rain is larger than that of pollutants by up to a factor of 3–4 in polluted regions. In polluted regions, pollutant concentrations can remain relatively high even in the presence of precipitation owing to continuous and intense emissions; therefore, wet deposition is limited by rainfall. The contribution of rainfall is larger by 1.5–2.5 than that of pollutant concentrations in regions even with low emissions and this considerably large role of rain suggests that regional or transboundary pollutant transport plays a key role in modulating wet deposition. However, in very remote regions, once the rainfall amount exceeds a certain value, rainfall no longer contributes to increasing wet deposition because atmospheric pollutants are readily removed by rain. So, the contributions of the two factors are comparable in pristine regions. Our results can serve as a basis for explaining interannual variations in wet deposition and for future projections of wet deposition under emission control plans and climate change scenarios across regions.

Mitigating boundary pollution: Evidence from China's environmental protection inspection centers

The efficacy of a vertical environmental protection system in managing transboundary pollution has not been extensively explored. Through a quasi-natural experiment facilitated by China's six environmental protection inspection centers (EPICs), this study assesses their impact on boundary pollution intensity and compares it with their effect on non-boundary pollution intensity. The findings demonstrate that the institution of EPICs significantly mitigates the intensity of boundary pollution, with a more pronounced reduction effect compared to non-boundary areas. Analysis of mechanisms reveals that both boundary and non-boundary enterprises achieve a reduction in pollution intensity through the enlargement of production capacities, enhancement of investments in pollution control, and a decrease in total pollution emissions. Given that boundary enterprises exhibit a greater magnitude in reducing total pollution emissions, the resultant effect on pollution intensity reduction is more significant among these entities. Furthermore, heterogeneity analysis indicates that the impact of EPICs on reducing pollution intensity is more substantial among samples with minimal political connections, elevated political incentives, and within heavily polluting industries, with boundary enterprises experiencing a more pronounced influence. This article unveils that strengthening coordination between central and local authorities, alongside fostering corporate actual investment in environmental protection, serves as pivotal mechanisms, offering innovative strategies for global environmental governance and advancing both the practice and theory of sustainable development.

The impact of trans-provincial watershed eco-compensation policy on carbon emissions: Evidence from China

To manage transboundary pollution, China has promoted trans-provincial watershed eco-compensation (WEC), which is a market-oriented policy that adjusts ecological and economic interests between upstream and downstream areas and promotes regional green and low-carbon transformation. Hence, a reasonable evaluation of the carbon emission reduction effect of WEC is of great value for achieving green transformation. Using data from Chinese counties between 2003 and 2020, we consider 11 trans-provincial WEC agreements and evaluate their influence on carbon emissions. We find that trans-provincial WEC policies reduce water pollution emissions and significantly lower carbon emission levels. Mechanism tests show that the policy reduces carbon emissions by limiting polluting industrial development and stimulating low-carbon technological innovations. Moreover, this policy improves regional low-carbon economic development, and there are significant heterogeneity effects of the WEC in different regions and compensation modes. This research provides new insights for transitional countries to design green transformation policies.

Numerical evaluation of mercury concentration by using a distributional multimedia model in the Lake Biwa-Yodo River Basin, Japan

A distributional multimedia model was developed and applied to the Lake Biwa-Yodo River Basin in Japan to reproduce the mercury level in different environmental media. This model was developed based on a Level III steady-state fugacity model, and the space was divided into four environmental media (atmosphere, water, soil, and sediment). The mass transfer of Hg in this model consists of emission, deposition, sedimentation inside one medium, and advection between different media. The dissolution rate and ion exchange equilibrium have also been considered. We estimated Hg emissions in the Lake Biwa-Yodo River Basin from 1957 to 2009 based on the Pollutant Release and Transfer Registry (PRTR) system and the domestic usage of Hg in Japan. The distribution of emission was based on land data, including industrial land area, industrial location, and proportion of the population. The calculated and observed Hg concentrations were compared to evaluate the model. At both large scale and small scale, results showed that the distributional model could predict Hg concentrations in all environmental media. Sediment and soil media showed the accumulation of Hg by showing the higher concentrations than that of other media. In terms of geographical distribution, the urban area and downstream of the river showed high Hg concentrations owing to high Hg emissions. The Hg concentration in the atmosphere was affected by the transboundary pollution. Thus, the distributional multimedia model could reliably calculate the environmental Hg concentration and be utilized in environmental monitoring and management.

Chemical composition and origins of PM2.5 in Chiang Mai (Thailand) by integrated source apportionment and potential source areas

Upper Southeast Asian region lacks source apportionment studies of air pollution, particularly PM2.5, despite its persistence. This study aims to quantify PM2.5 source contributions and identify their potential source areas in urban Chiang Mai (Thailand) as a representative of the region, using the positive matrix factorization (PMF) receptor model and the potential source contribution function (PSCF). A total of 51 samples were collected and analyzed for water-soluble ions, organic carbon, elemental carbon, carbohydrates, carboxylates, and metals. An average PM2.5 concentration of 116 ± 35 and 35 ± 6 μg m−3 was found during smoke-haze (SH) and non-smoke-haze (NSH) periods, respectively. The average PMF-resolved contributions to PM2.5 in the SH period were the following: biomass burning (59.3 μg m−3) > secondary sulfate (26.2 μg m−3) > dust (16.1 μg m−3) > traffic (14.6 μg m−3). In contrast, those in the NSH period were the following: traffic (27.2 μg m−3) > dust (5.9 μg m-3) > biomass burning (2.5 μg m−3). The PSCF revealed that biomass burning has the main potential source area along the Thai-Myanmar border, while the secondary sulfate largely originated in Indian continent. Local pollution from traffic and dust contributed consistently but was minor in comparison. The source composition exhibited major seasonal change because of the lack of biomass burning and transboundary pollution in the wet season, where exhaust and non-exhaust traffic emissions became the main contributors. These findings offer insights into how regional PM2.5 affects the local pollution in the urban atmosphere.