Economic risks hidden in local water pollution and global markets: A retrospective analysis (1995-2010) and future perspectives on sustainable development goal 6.

Pollution from untreated wastewater discharges depletes clean water supply for humans and the environment. It poses adverse economic impacts by determining agricultural yields, manufacturing productivity, and ecosystem functionality. Current studies mainly focus on quantity-related water scarcity assessment. It is unknown how low water quality amplifies local water stress and induces cascading economic risks globally. In this study, we estimated both quality and quantity-related water scarcity index (WSI), local economic water scarcity risk (WSR), and cascading virtual WSR evident in global trade markets across 40 major economies from 1995 to 2010. We find developing countries, e.g., India and China, witnessed fast growth in both quantity and quality-related WSI. Major developed economies, e.g., the US and Germany, experienced a modest increase in water stress but alleviated quality-related risks. Local economic risk (WSR) grew from $116B to $380B, with quality-related risks rising from 20 % to 30 %. Virtual economic WSR in global supply chains increased from $39B to $160B, with quality-related risks increasing from 19 % to 27 %. China became the top exporter of economic WSR, ranked above the US, France, and Japan, and the second-largest position as an importer, trailing only the US. We finally conducted scenario modeling by 2030, assuming different progresses on SDG 6 targets. The findings suggest that only the most ambitious progress in both water quality enhancement and efficiency improvement helps to alleviate ∼20 % economic WSR globally. Our findings underscore the necessity for strategies that integrate management of untreated wastewater flows, improved water use efficiency, and diversification of supply chain networks to enhance global economic resilience to water challenges in the future.

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.

Economic Growth Facilitates Household Fuel Use Transition to Reduce PM2.5-Related Deaths in China.

Exposure to ambient and indoor particle matter (PM2.5) leads to millions of premature deaths in China. In recent years, indoor air pollution and premature deaths associated with polluting fuel cooking demonstrate an abrupt decline. However, the driving forces behind the mortality change are still unclear due to the uncertainty in household fuel use prediction. Here, we propose an integrated approach to estimate the fuel use fractions and PM2.5-related deaths from outdoor and indoor sources during 2000-2020 across China. Our model estimated 1.67 and 1.21 million premature deaths attributable to PM2.5 exposure in 2000 and 2020, respectively. We find that the residential energy transition is associated with a substantial reduction in premature deaths from indoor sources, with 100,000 (95% CI: 76,000-122,000) for urban and 265,000 (228,000-300,000) for rural populations during 2000-2020. Economic growth is the dominant driver of fuel use transition and avoids 21% related deaths (357,000, 315,000-402,000) from polluting fuel cooking since 2000, which offsets the adverse impact of ambient emissions contributed by economic growth. Our findings give an insight into the coupled impact of socioeconomic factors in reshaping health burden in exposure pathways.

Source Contributions to PM2.5-Related Mortality and Costs: Evidence for Emission Allocation and Compensation Strategies in China.

The emissions from various pollution sources were not proportional to their contributions to ambient PM2.5 concentrations and associated health burdens. That means even with the same total abatement targets, different abatement allocation strategies across emission sources can have distinct health benefits. Insufficient knowledge of various sources' contributions to health burdens in China, the country suffering substantial PM2.5-related deaths, hindered the government from seeking optimized abatement allocation strategies. In this context, we separated the contributions of 155 emission sources (31 provinces × 5 sectors) to PM2.5-related mortality across China in 2017 by coupling the Comprehensive Air Quality Model with Extensions (CAMx), Weather Research and Forecasting model (WRF), and health impact assessment model. We further identified the priority-control emission sources and quantified interprovincial ecological compensation volumes to alleviate inequality induced by emission allocation strategies. Results showed that PM2.5 pollution caused 899,443 excess deaths and around 127 billion USD costs in 2017. Approximately half of the deaths and costs were attributable to emissions from sources outside the boundary of the regions where the deaths occurred. Twenty-five out of 155 emission sources that contributed to the top 60% mortality burdens and had high marginal abatement efficiencies in China shall be the priority-control emission sources. A 1 µg/m3 decrease of PM2.5 concentration in regions where these key emission sources occur shall be compensated by 76-153 million USD in their receptor regions. Our study sheds light on the sources' contributions to mortality burdens and costs and provides scientific evidence for optimizing the emission allocation and compensation strategies in China. It also has wide implications for other countries suffering similar problems.

Cost Volume Pyramid Based Depth Inference for Multi-View Stereo.

We propose a cost volume-based neural network for depth inference from multi-view images. We demonstrate that building a cost volume pyramid in a coarse-to-fine manner instead of constructing a cost volume at a fixed resolution leads to a compact, lightweight network and allows us inferring high resolution depth maps to achieve better reconstruction results. To this end, we first build a cost volume based on uniform sampling of fronto-parallel planes across the entire depth range at the coarsest resolution of an image. Then, given current depth estimate, we construct new cost volumes iteratively to perform depth map refinement. We show that working on cost volume pyramid can lead to a more compact, yet efficient network structure compared with existing works. We further show that the (residual) depth sampling can be fully determined by analytical geometric derivation, which serves as a principle for building compact cost volume pyramid. To demonstrate the effectiveness of our proposed framework, we extend our cost volume pyramid structure to handle the unsupervised depth inference scenario. Experimental results on benchmark datasets show that our model can perform 6x faster with similar performance as state-of-the-art methods for supervised scenario and demonstrates superior performance on unsupervised scenario. Code is available at https://github.com/JiayuYANG/CVP-MVSNet.

Near-real-time monitoring of global CO2 emissions reveals the effects of the COVID-19 pandemic.

The COVID-19 pandemic is impacting human activities, and in turn energy use and carbon dioxide (CO2) emissions. Here we present daily estimates of country-level CO2 emissions for different sectors based on near-real-time activity data. The key result is an abrupt 8.8% decrease in global CO2 emissions (-1551 Mt CO2) in the first half of 2020 compared to the same period in 2019. The magnitude of this decrease is larger than during previous economic downturns or World War II. The timing of emissions decreases corresponds to lockdown measures in each country. By July 1st, the pandemic's effects on global emissions diminished as lockdown restrictions relaxed and some economic activities restarted, especially in China and several European countries, but substantial differences persist between countries, with continuing emission declines in the U.S. where coronavirus cases are still increasing substantially.

Revealing Environmental Inequality Hidden in China's Inter-regional Trade.

Trade among regions or countries not only allows the exchange of goods and services but also leads to the transfer of pollution. The unequal exchange of goods and services and associated value added and pollution may be subject to environmental inequality in China given that Chinese provinces are in different development stages. By using the latest multiregional input-output tables and the sectoral air pollutant emission inventory in 2012, we traced emissions and value added along China's domestic supply chains. Here, we show that 62%-76% of the consumption-based air-pollutant emissions of richer regions (Beijing-Tianjin, East Coast and South Coast) were outsourced to other regions; however, approximately 70% of the value added triggered by these region's final consumption was retained within the region. Some provinces in western China, such as Guizhou, Ningxia, and Yunnan, not only incurred net pollution inflows but also suffered a negative balance of value added when trading with rich provinces. Addressing such inequalities could provide not only a basis for determining each province's responsibility for pollution control but also a model for other emerging economies.

Public health impacts of city policies to reduce climate change: findings from the URGENCHE EU-China project.

BACKGROUND: Climate change is a global threat to health and wellbeing. Here we provide findings of an international research project investigating the health and wellbeing impacts of policies to reduce greenhouse gas emissions in urban environments. METHODS: Five European and two Chinese city authorities and partner academic organisations formed the project consortium. The methodology involved modelling the impact of adopted urban climate-change mitigation transport, buildings and energy policy scenarios, usually for the year 2020 and comparing them with business as usual (BAU) scenarios (where policies had not been adopted). Carbon dioxide emissions, health impacting exposures (air pollution, noise and physical activity), health (cardiovascular, respiratory, cancer and leukaemia) and wellbeing (including noise related wellbeing, overall wellbeing, economic wellbeing and inequalities) were modelled. The scenarios were developed from corresponding known levels in 2010 and pre-existing exposure response functions. Additionally there were literature reviews, three longitudinal observational studies and two cross sectional surveys. RESULTS: There are four key findings. Firstly introduction of electric cars may confer some small health benefits but it would be unwise for a city to invest in electric vehicles unless their power generation fuel mix generates fewer emissions than petrol and diesel. Second, adopting policies to reduce private car use may have benefits for carbon dioxide reduction and positive health impacts through reduced noise and increased physical activity. Third, the benefits of carbon dioxide reduction from increasing housing efficiency are likely to be minor and co-benefits for health and wellbeing are dependent on good air exchange. Fourthly, although heating dwellings by in-home biomass burning may reduce carbon dioxide emissions, consequences for health and wellbeing were negative with the technology in use in the cities studied. CONCLUSIONS: The climate-change reduction policies reduced CO2 emissions (the most common greenhouse gas) from cities but impact on global emissions of CO2 would be more limited due to some displacement of emissions. The health and wellbeing impacts varied and were often limited reflecting existing relatively high quality of life and environmental standards in most of the participating cities; the greatest potential for future health benefit occurs in less developed or developing countries.

Abundance and distribution of Macrolide-Lincosamide-Streptogramin resistance genes in an anaerobic-aerobic system treating spiramycin production wastewater.

The behaviors of the Macrolide-Lincosamide-Streptogramin (MLS) resistance genes were investigated in an anaerobic-aerobic pilot-scale system treating spiramycin (SPM) production wastewater. After screening fifteen typical MLS resistance genes with different mechanisms using conventional PCR, eight detected genes were determined by quantitative PCR, together with three mobile elements. Aerobic sludge in the pilot system exhibited a total relative abundance of MLS resistance genes (per 16S rRNA gene) 2.5 logs higher than those in control samples collected from sewage and inosine wastewater treatment systems (P < 0.05), implying the presence of SPM could induce the production of MLS resistance genes. However, the total relative gene abundance in anaerobic sludge (4.3 × 10(-1)) was lower than that in aerobic sludge (3.7 × 10(0)) despite of the higher SPM level in anaerobic reactor, showing the advantage of anaerobic treatment in reducing the production of MLS resistance genes. The rRNA methylase genes (erm(B), erm(F), erm(X)) were the most abundant in the aerobic sludge (5.3 × 10(-1)-1.7 × 10(0)), followed by esterase gene ere(A) (1.3 × 10(-1)) and phosphorylase gene mph(B) (5.7 × 10(-2)). In anaerobic sludge, erm(B), erm(F), ere(A), and msr(D) were the major ones (1.2 × 10(-2)-3.2 × 10(-1)). These MLS resistance genes (except for msr(D)) were positively correlated with Class 1 integron (r(2) = 0.74-0.93, P < 0.05), implying the significance of horizontal transfer in their proliferation.

A Multiple Indicators Multiple Cause (MIMIC) model of respiratory health and household factors in Chinese children: the seven Northeastern cities (SNEC) study.

In China, with the rapid economic development and improvement of living standards over the past few decades, the household living environment has shifted dramatically. The aim of the present study is to assess the impact of home environment factors on respiratory symptoms and asthma in Chinese children. Investigators analyzed data collected in the 25 districts from the seven Northeastern cities to examine health effects on respiratory symptoms and asthma in 31,049 children aged 2-14 years. Factor analysis was used to reduce 33 children's lifestyle and household variables to six new 'factor' variables. The multiple indicators multiple causes approach was used to examine the relationship between indoor air pollution and respiratory health status, controlling for covariates. Factor analyses generated six factor variables of potential household risk factors from an original list of 33 variables. The respiratory symptoms and asthma were significantly associated with the recent home renovation factor (estimate = 0.076, p < 0.001), pet ownership factor (estimate = 0.095, p < 0.001), environmental tobacco smoke (ETS) exposure factor (estimate = 0.181, p < 0.001) and PVC-flooring factor (estimate = 0.031, p = 0.007). Home ventilation factor was not related to any respiratory condition (estimate = 0.028, p = 0.074). Independent respiratory health effects existed for multiple household environmental factors recent home renovation, pet ownership, ETS, and PVC-flooring.

Microbial community functional structure in response to antibiotics in pharmaceutical wastewater treatment systems.

It is widely demonstrated that antibiotics in the environment affect microbial community structure. However, direct evidence regarding the impacts of antibiotics on microbial functional structures in wastewater treatment systems is limited. Herein, a high-throughput functional gene array (GeoChip 3.0) in combination with quantitative PCR and clone libraries were used to evaluate the microbial functional structures in two biological wastewater treatment systems, which treat antibiotic production wastewater mainly containing oxytetracycline. Despite the bacteriostatic effects of antibiotics, the GeoChip detected almost all key functional gene categories, including carbon cycling, nitrogen cycling, etc., suggesting that these microbial communities were functionally diverse. Totally 749 carbon-degrading genes belonging to 40 groups (24 from bacteria and 16 from fungi) were detected. The abundance of several fungal carbon-degrading genes (e.g., glyoxal oxidase (glx), lignin peroxidase or ligninase (lip), manganese peroxidase (mnp), endochitinase, exoglucanase_genes) was significantly correlated with antibiotic concentrations (Mantel test; P < 0.05), showing that the fungal functional genes have been enhanced by the presence of antibiotics. However, from the fact that the majority of carbon-degrading genes were derived from bacteria and diverse antibiotic resistance genes were detected in bacteria, it was assumed that many bacteria could survive in the environment by acquiring antibiotic resistance and may have maintained the position as a main player in nutrient removal. Variance partitioning analysis showed that antibiotics could explain 24.4% of variations in microbial functional structure of the treatment systems. This study provides insights into the impacts of antibiotics on microbial functional structure of a unique system receiving antibiotic production wastewater, and reveals the potential importance of the cooperation between fungi and bacteria with antibiotic resistance in maintaining the stability and performance of the systems.

Antibiotic resistance characteristics of environmental bacteria from an oxytetracycline production wastewater treatment plant and the receiving river.

We characterized the bacterial populations in surface water receiving effluent from an oxytetracycline (OTC) production plant. Additional sampling sites included the receiving river water 5 km upstream and 20 km downstream from the discharge point. High levels of OTC were found in the wastewater (WW), and the antibiotic was still detectable in river water downstream (RWD), with undetectable levels in river water upstream (RWU). A total of 341 bacterial strains were isolated using nonselective media, with the majority being identified as Gammaproteobacteria. The MICs were determined for 10 antibiotics representing seven different classes of antibiotics, and the corresponding values were significantly higher for the WW and RWD isolates than for the RWU isolates. Almost all bacteria (97%) from the WW and RWD samples demonstrated multidrug-resistant (MDR) phenotypes, while in RWU samples, these were less frequent (28%). The WW and RWD isolates were analyzed for the presence of 23 tetracycline (tet) resistance genes. The majority of isolates (94.2% and 95.4% in WW and RWD, respectively) harbored the corresponding genes, with tet(A) being the most common (67.0%), followed by tet(W), tet(C), tet(J), tet(L), tet(D), tet(Y), and tet(K) (in the range between 21.0% and 40.6%). Class I integrons were detected in the majority of WW and RWD isolates (97.4% and 86.2%, respectively) but were not associated with the tet genes. We hypothesize that the strong selective pressure imposed by a high concentration of OTC contributes to the wide dissemination of tetracycline resistance genes and other antibiotic resistance genes, possibly through mobile genetic elements.