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The aim of this paper is to explore consumers’ intention of recycling obsolete mobile phone through formal channels in China. Taking Jiangsu Province as an example, the survey results revealed that although nearly half of consumers prefer to save their obsoleted mobile phones at residence, those who are willing to participate in recycling prefer formal recycling channels instead of informal ones. To explore the determinants of formal recycling intention from the perspective of consumers’ psychological characteristics, an integrative model based on the theory of planned behavior was established, in which the effect of consumers’ privacy concern was thoroughly explored. The results indicated that recycling attitude, subjective norm, perceived behavioral control, and moral norm are all positively influential factors. Inconsistent with prior studies, consumers’ privacy concern is found to have a direct positive rather than a negative effect on formal recycling intention. It also has a negative moderating effect on the relationship between subjective norm and formal recycling intention. Therefore, to promote consumers’ formal recycling behavior of obsolete mobile phones, a series of measures are proposed to influence these psychological factors in the model. First, a positive social atmosphere for participation in formal recycling should be vigorously created. Then, further efforts are required to increase the publicity and availability of formal recycling channels. Furthermore, joint efforts should be made for privacy information protection during formal recycling processes, including establishing certification standards for secure data erasure, further routinizing recycling processes and establishing a credible image to obtain consumers’ trust by formal recycling enterprises, etc.

Currently, atmospheric emission inventory that includes multi-type pollutants and sources is still limited at the city level. This study developed a high-resolution emission inventory of eight pollutants based on detailed investigated data for Wuxi city in 2015. Results show that the total emissions of sulfur dioxide (SO2), nitrogen oxides (NOx), total suspended particulates (TSP), particulate matter with an aerodynamic diameter of 10 μm or less (PM10), particulate matter with an aerodynamic diameter of 2.5 μm or less (PM2.5), carbon monoxide (CO), ammonia (NH3), and volatile organic compounds (VOCs) were 36.9 kt, 95.2 kt, 287.3 kt, 127.8 kt, 46.0 kt, 626.4 kt, 10.9 kt, and 104.9 kt, respectively. Power plants were the major contributors of SO2 and NOx, accounting for 34.6% and 36.3% of the total emissions, respectively. Road dust was the dominant source of particulate matter, contributing 63.1%, 57.8% and 38.2% to the total TSP, PM10 and PM2.5 emissions, respectively. Around 67.0% of CO emissions were from iron and steel plants, while 50.1% of NH3 emissions were from livestock and poultry sectors. VOCs emissions largely came from oil refinery and chemical industry, with a share of 41.3%. High NH3 emissions were found in the southwest and northeast of Wuxi where high-intensity agriculture was located, while other pollutants were mainly concentrated on the eastern Wuxi where heavy industries, crowded traffic and highly dense population were located. Most pollutants from the industrial source exhibited the lowest value in February due to the Chinese Spring Festival with the exception of CO and NH3. This study helps to formulate the targeted air pollution control measures for Wuxi city by providing detailed information regarding the spatial-temporal distribution of multi-type air pollutants.

The phosphorus footprint (PF) is a novel concept to analyze human burdens on phosphorus resources. However, research on PF approach is still limited, and current several PF studies include incomplete phosphorus sources and have limited quantitative interpretation about the drivers of PF changes, which can help understand future trends of PF. This study develops a more comprehensive PF model by considering crop, livestock and aquatic food, and non-food goods, which covers the mainly phosphorus containing products consumed by human. The model is applied to quantify China's PF from 1961 to 2014, and the results of the model are also used to analyze the factors driving the PF changes and explored China's PF scenarios for 2050 using an econometric analysis model (STIRPAT). The result shows that China's PF increased over 11-fold, from 0.9 to 10.6 Tg between 1961 and 2014. The PF of livestock food dominated China's PF, accounting for 57% of the total in 1961 and 45% in 2014. The key factors driving the increase in China's PF are the increase in population and urbanization rate, with contributions of 38% and 33%, respectively. We showed that in the baseline scenario, China's PF would increase by 70% during 2014–2050 and cause the depletion of China's phosphate reserves in 2045. However, in the best case scenario, China's PF would decrease by 15% in 2050 compared with that in 2014, and it would have 50% of current phosphate reserve remaining by 2050. Several mitigation measures are then proposed by considering China's realities from both production and consumption perspective, which can provide valuable policy insights to other rapid developing countries to mitigate the P footprint.

As the largest producer of coal chemical products in the world, China faces tremendous pressure to reduce its carbon emission. An accurate quantification of the carbon dioxide (CO2) emission of coal chemical industry in China is therefore necessary. However, due to the variety of coal chemical products and limitations of CO2 emission factors, the total CO2 emission of coal chemical industry has yet to be determined. In this study, local CO2 emission factors of coal chemical products in China are published based on first hand data from twenty-three coal chemical enterprises and the total CO2 emission of China's coal chemical industry is extrapolated. The provincial-level spatial distribution of the CO2 emission of coal chemical industry is presented to assist the government in identifying key emission reduction areas. Additionally, scenario analysis of CO2 emission for China’s modern coal chemical industry in 2020 is conducted to determine whether the development of the modern coal chemical industry will have a significant impact on future CO2 emission, as well as the effect of carbon capture, utilization and storage technologies on the reduction in carbon emission. The estimate shows that the total CO2 emission of the coal chemical industry in 2015 was 607 million tonnes (Mt), accounting for approximately 5.71% of China’s total CO2 emission. The figure is higher than the total annual CO2 emission of a country such as Canada (555 Mt) or Brazil (486 Mt). Quantifying the emission of the coal chemical industry is therefore critical to understand the global carbon budget. The spatial distribution shows that Shandong, Inner Mongolia and Shanxi release one-third of the coal chemical industry’s total CO2 emission. Considering the development of the modern coal chemical industry, its CO2 emission is predicted to be as high as 416.52 million tonnes in 2020. However, the CO2 emission could be reduced by 317.98 million tonnes when carbon capture, utilization and storage are applied to process and energy systems simultaneously. This paper quantifies the CO2 emission of the coal chemical industry in China for the first time, identifies key chemical products and the provinces in which they are produced, explores the carbon reduction potential by scenario analysis, and provides specific data to support the assessment of effective CO2 reduction policy.

Estimations of greenhouse gas (GHG) emissions from municipal wastewater treatment plants (MWTPs) remain significant uncertainties in China owing to a lack of reliable emission factors (EFs). This study developed a framework to obtain multi-level (technology, province, and nation) GHG EFs of MWTPs using a database containing 3107 MWTPs in China and published site-specific monitoring data. Results show that GHG EFs of different technologies range widely from 180.0 to 615.7 g CO

A better understanding of the waste of end-of-life batteries from electric vehicles (EVs) is a basis for their sustainable management. This study aims to estimate the waste of end-of-life EV batteries during 2006–2040 in China and to analyze the opportunities and challenges of subsequent utilization, based on a developed numerical model, real market data, and elaborately developed scenarios. The result shows that end-of-life batteries would increase from 0.1 to 7.8 thousand tons during 2012–2018, and then to 1500–3300 thousand tons in 2040. Of the waste streams, around 50% are estimated to be metal materials, representing great opportunities for battery recycling for material recovery. Economically, battery recycling for energy storage is estimated to create more economic benefits compared with that for material recovery solely (147.8 versus 76.9 billion US dollars). However, the supply of end-of-life batteries can hardly meet the demand for renewable energy storage in the near future, and a spatial mismatch of the supply and demand of energy storage capacity exists between the eastern and western regions in China. Accordingly, this study highlights national coordination for the rational layout of the collection, disassembly, and remanufacture facilities for the second use of end-of-life EV batteries in China.

Intensified human activities have generated a large amount of phosphorus-containing waste (P waste). Unrecycled P waste is lost to the environment and causes eutrophication, while the increasing phosphate consumption risks the depletion of phosphorus resources. The management of P waste is critical to solving these problems. In this study, we quantified the historic trends of P waste generation and recycling in China. From 1900 to 2015, the annual generation of P waste increased from 1 Mt P to 12 Mt P. Crop farming was the largest P waste source in most years, while P waste from phosphate mining and phosphorus chemical production increased the fastest. The total recycled P waste increased 5-fold, but phosphorus loss increased 26-fold. In 2015, 28% of the P waste was lost on cultivated land, and 21% was lost on nonarable land. The largest phosphorus contributor to inland water changed from crop farming to aquaculture. The full recycling of P waste would have reduced phosphate consumption by more than one-third in 2015. The results of a scenario analysis showed that a healthier diet would greatly increase the generation and loss of P waste, but balanced fertilization could reduce the generation of P waste by 17% and promoting waste recycling could reduce the phosphorus loss by 35%.

Recycling lithium-ion batteries from electric vehicles is considered an important way to tackle the future supply risks of virgin materials, but the actual environmental impact of traction battery recycling is controversial. This study conducted a process-based life cycle assessment to quantify the environmental impacts of hydrometallurgical recycling of two common lithium-ion traction batteries (lithium nickel manganese cobalt oxide and lithium iron phosphate battery) and reusing materials in their manufacturing in China. The results show that recycling can cause net environmental benefits of the two traction battery types for the considered impact categories, but the net benefits for direct recycling technology are higher because of fewer requirements of chemicals and energy. Reusing recovered materials in battery manufacturing would reduce the impacts in comparison to no recycling, but the reduction potential of greenhouse gas emission and energy demand is not significant. Sensitivity analysis shows that recycling benefits are highly dependent on recovering efficiency and electricity used for manufacturing and recycling. Comprehensive management strategies are necessary to improve the end-of-life traction battery management, such as using carbon-free energy sources, designing batteries with less metal, and developing recycling technology using fewer chemicals. This study contributes by offering transparent life cycle inventory for hydrometallurgical recycling lithium-ion traction batteries and providing scientific knowledge to improve their sustainable management.

China is now boasting a huge number of end-of-life vehicles (ELVs) with a low recovery rate, resulting in a waste of resources and severe environmental pollution. Predicting the generation of ELVs in future helps to enhance recycling efficiency by providing a basis for the planning of recycling industry. However, previous research did not provide a detailed, mid-term forecast. Based on a stocks-driven model and the bottom-up extrapolation of in-use stocks, this study characterizes the generation of end-of-life household vehicles (HVs) in China by addressing the detailed spatial-temporal patterns and resource potentials during 2019–2050. The results show that the annual end-of-life HVs in China will continuously increase during 2019–2050, resulting an accumulated 1.48 billion units, among which urban areas will account for 86%, and internal combustion engine vehicles (ICEVs) will take up 80%. Regarding the spatial patterns, eastern region will possess the largest proportion, and wide variations are found among all provinces due to the difference in population size and economic development level, which have important implications for further planning of end-of-life HVs recycling industry. Before 2050, accumulated quantity of all types of metals in end-of-life HVs will approach domestic mine production (in 2019), or even approach the current global mine production, indicating they have a great potential as an indispensable source for domestic resource supply.

Pig husbandry has been developing rapidly during the past few decades, which has greatly increased the amounts of pig slurry as well as environmental impacts. How to appropriately treat the pig slurry has turned to a great challenge for sustainable pig husbandry, and this issue is especially critical to China, the biggest producer and consumer of pigs. This study tried to explore the effective ways of treating pig slurry, which could mitigate environmental impacts and increase resource utilization. The main method used in this study was life cycle assessment, which could evaluate the environmental impacts of four ways of treating pig slurry. Each kind of treatment technology consisted of three main processes - in-house handling, outdoor treatment and end disposal. This study used the CML2001 method to evaluate environmental impacts. Data sources for this study came from field investigations at pig farms, suppliers of relevant technologies, literature and the ecoinvent database. The results indicated that global warming potential (GWP), eutrophication potential (EP), and acidification potential (AP) were the three main impact categories. Meanwhile, all scenarios showed negative environmental impacts in ozone layer depletion potential (ODP), freshwater aquatic ecotoxicity potential (FAETP), abiotic depletion potential (ADP, element & fossil) and human toxicity potential (HTP) impact categories. It was also found that Deep-pit system and field application (DP-FA) scenario performed best in ADP (element & fossil). In-house separation and field application (S-FA) scenario had the lowest GWP and the second lowest EP, while having negative impacts in ODP, FAETP, HTP and ADP (element & fossil). Therefore, this study suggests using DP-FA scenario from the perspective of sustaining long-term resources and popularizing the S-FA scenario in the term of mitigating environmental impacts.

Human has greatly disturbed nitrogen (N) cycles through the food production and consumption (FPC) activities, which caused serious environmental consequences. A few studies address the pathways of N cycles to clarify the interrelationships between human activities and the altered N cycles, especially in terms of the spatial aspects of N flows, which are also influenced by natural factors. Here, we developed an integrated model to quantify the spatiotemporal patterns of N flows within the FPC and applied it to the Chaohu Watershed from 1949 to 2012. We found that total N inputs into the FPC increased by 6-fold during 1949-2012, while N inputs from chemical fertilizer had the largest increase, with an annual growth rate of 8.6%. N generation in manure doubled, but the recycling rate decreased by 50% in the study period. The total N losses increased from 17 to 130Gg-N/yr between 1949 and 2012. Annually, ~7% of total N losses was discharged into surface water annually, which peaked at 9.5Gg-N/yr during 1998-2003, two times as that in the early 1980s when algae blooms first occurred in Chaohu lake. Spatially, around one-fifth of the catchment area was responsible for all of N losses to surface water. These intensive areas located in the eastern and southern-central regions, which were identified as the critical areas for priority N mitigation. This study provided a method to depict spatiotemporal patterns of regional N flows for identifying the critical sources and areas of N pollution for precision watershed management.

Rapid increase in accumulation of phosphorus (P) relative to nitrogen (N) has been observed in human-impacted regions, but the reasons are largely unknown. We developed an Integrated Nutrient Flow Analysis (INFA) model in order to assess the changes in nutrient flows of the Chaohu Lake basin from 1978 to 2015. Results show that the increase in total N input is slower than that of P (3.5-fold versus 4.2-fold) during 1978–2015, while total N loss increases much faster than that of P (3.1-fold versus 2.3-fold). We found a decline trend in the N:P ratio of nutrient input and accumulation since the mid-1990s. The decline in N:P ratio of nutrient loss to waterbodies in the basin is correlated (p

The phosphorus (P) cycle is an important Earth system process. While natural P mobilization is slow, humans have been altering P cycle by intensifying P releases from lithosphere to ecosystems. Here, we examined magnitudes of which humans have altered the P cycles by integrating the estimates from recent literatures, and furthermore illustrated the consequences. Based on our synthesis, human alterations have tripled the global P mobilization in land-water continuum and increased P accumulation in soil with 6.9 ± 3.3 Tg-P yr–1. Around 30% of atmospheric P transfer is caused by human activities, which plays a significant role than previously thought. Pathways involving with human alterations include phosphate extraction, fertilizers application, wastes generation, and P losses from cropland. This study highlights the importance of sustainable P supply as a control on future food security because of regional P scarcity, food demand increase and continuously P intensive food production. Besides, accelerated P...

The aim of this study is to establish an energy use efficiency and GHG emissions (EUE-GHG) model to promote ecological agriculture, not only examining these indicators on crop production in Anhui Province from 1990 to 2014, but also comparing them among 16 provincial cities in 2014. The results reveal that energy use efficiency decreased significantly from 3.75 to 1.87 during 1990–2005, and then increased to 2.08 in 2014, while the GHG emissions increased rapidly from 2919.51 CO 2 -eq in 1990–8993.46 CO 2 -eq in 2014. These two important indicators were mainly determined by the great energy consumption from the use of agricultural machines and the use of chemical fertilizers. Regard to spatial perspective, the central and northern cities, including Fuyang, Bengbu, Suzhou, Huaibei, and Hefei, had the smaller EUEs and the higher GHG emissions than those in the southern cities, due to their large consumption of agricultural resources and the economic reasons. Several mitigation policies are then proposed by considering the local realities so that valuable policy insights can be shared by the stakeholders in other Chinese regions.

Cement is a critical material for urbanization, but its energy-intensive production creates serious potential environmental impacts. As further air pollutant mitigation become more expensive and difficult, ‘co-control’ measure by new energy-efficient technologies is proposed to bring co-benefits. In this study we conducted a cost-effectiveness analysis to evaluate available new technologies in Chinese cement industry. The analysis verified the findings of recent studies that many technologies have huge co-control potential, but we also found the heterogeneity and conflict in different parameters of certain technologies that has not declared by existing studies. The finding indicates the necessity to design the technology promotion roadmap. We obtained a technology promotion roadmap by establishing a multi-objective optimization model and it proves to be the best solution for achieving energy saving, PM2.5, SO2 and CO2 abatement compared to single-objective optimization models. Furthermore, pollutant emissions and energy consumption of the cement industry under four control scenarios are projected for 2010–2030. Under integrated measure scenario combining technology promotion and product structure adjustment, energy consumption will drop back to 2006–2007 level by 2030. The major air pollutant emissions will be ∼44% lower than business-as-usual scenario and the CO2 emission will be reduced by ∼15%. The annual monetary benefit of technology promotion is estimated to be 396.5 billion RMB Yuan in 2030. The findings verify the co-control strategy and update our understanding of new technologies implementation. The technology promotion roadmap and scenario analysis results are supportable for future policy-making of cement industry.

As the world’s largest consumer of textiles, China is now facing a rapid increase of textile waste. Understanding consumers’ clothing disposal behaviors is instructive to encourage more environmental-friendly recycling practices. Take Nanjing city as an example, a questionnaire was developed and conducted to assess consumers’ behaviors with respect to their disposal of obsolete clothing. The results show that the average lifespan of obsolete clothing among Nanjing citizens is 3.75 years, differing by gender, age and income. Clothing is obsoleted mostly due to worn-out conditions, resulting in a longer lifespan than countries like UK. Despite of several alternatives for recycling, most prevailing options consumers choose are throwing away and keeping at residence, which indicates there is much room for improving disposal behaviors. Although online clothing-recycling platform (OCRP) has now emerged as a new channel for disposing of unwanted clothing, less than 10% of respondents deem the OCRP as one of their major channels to handle old clothing. However, further analysis based on an integration of Technology Acceptance Model (TAM) and Theory of Planned Behavior (TPB) indicates that most of consumers have the intention to adopt OCRP. Perceived usefulness (PU) has a significantly positive relationship with consumers’ platform adopting intentions. Meanwhile, subjective norm (SN), perceived ease of use (PEOU), and perceived behavioral control (PBC) also play roles in explaining the variance of behavioral intentions towards adopting OCRP successively. According to the results, implications for improving consumers’ clothing recycling performances are discussed.

Low nitrogen use efficiency (NUE) and phosphorus use efficiency (PUE) of crop farming has been causing serious environmental consequences. Here, we established a NUECF (nutrient use efficiency of crop farming) model with substance flow analysis (SFA) method to examine NUE and PUE of cultivating nine main crops in Chaohu Watershed in 2015. We collected data mainly from questionnaires, interview, literature, and governmental statistical yearbooks. We found that the total NUE and the total PUE were low, bellowing 12.3% and 5.2%, respectively. The nutrient inputs especially large-scale livestock manure, domestic livestock manure, and chemical fertilizers far exceeded the crop products. Different crops also showed the various patterns of nutrient use efficiencies. Rice consumed the largest nutrient inputs (807 kg N ha−1 and 367 kg P ha−1) and contributed the lowest nutrient use efficiencies (NUE: 5.8%, PUE: 2.7%). This was mainly resulted from its large fertilizer application intensity and the largest cultivated area. Rapeseed, vegetable, and wheat also contributed the great nutrient inputs and low nutrient use efficiencies, due to the similar reasons. Concerning the various patterns of fertilizer-application and cultivated areas of these crops, we analyzed six scenarios focusing on rice, wheat, rapeseed, and vegetable for 2030 and 2050 to explore an efficient nutrient management. We selected the four key factors including application intensity of chemical fertilizer, application rate of domestic livestock manure, application rate of large-scale livestock manure, and cultivated area to design the scenarios. The scenario results showed that though current policy of controlling chemical fertilizer application is a good start to manage nutrient, we have to enhance an integrated nutrient management, including reducing chemical fertilizers on specific crops, enlarging livestock manure, and controlling cultivated areas of specific crops. With the integrated nutrient management, we can expect the nutrient inputs to reduced by 26% and hence improve the nutrient use efficiencies efficiently from 2015 to 2050. The study managed the nutrients from examining nutrient use efficiencies among different crops, and could provide an effective way to mitigate the environmental problems from crop farming.

Forecasting the trend of scrapped household automobiles (HAs) at the city level will help to improve the automobile recycling system, and further promote the implementation of the national circular economy strategy. Based on a stocks-driven model, we project the generation of HAs scrap in urban and rural areas of Nanjing city in 2019–2050, under different scenarios of population development and automobile ownership growth. The results show Nanjing will display a notable net addition demand for HAs, with the in-use stocks increasing from 1.83 million units in 2018 to 3.68–6.11 million units in around 2038, then declining slightly till 2050. Because of wide gap in population size and difference in ownership rate, urban residents will occupy nearly 90% of the total amount for the incoming 3 decades. During the studied period, the total amount of HAs scrap in Nanjing will grow continuously to around 2042, reflecting a peak of scrap within the following two decades; then it will show a slight slide till 2050. The cumulative amount of HAs scrap will reach approximately 12.5–18.7 million, roughly 1.4–2 times of the estimated HAs for the whole nation in 2018. Again, scrapped HAs will be dominated by urban area. Compared with prediction results for the whole nation, Nanjing is shown to hold higher level of HAs in-use stocks and scrap as expected. The study then discusses the scenario uncertainty from the perspective of potential evolve of HAs lifetime distribution and the development of new-energy automobiles. The recycling potentials of scrapped HAs are finally estimated.

The use of social media platforms (e.g. Twitter and Facebook) to raise public awareness towards wildlife conservation is an emerging discussion. However, little is currently known about the propagation pattern of wildlife-related information on social media. In this study, a quantitative model was developed based on 230 independent cetacean stranding incidents (2008–2018) across mainland China from a popular Chinese social media platform (Sina Weibo). This model enabled analysis of the post formation process, identification of the key factors influencing the popularity of the posts and wildlife-related incidents, and allowed investigation of public opinions. The results showed that central media users can increase the overall possibility of elevating incident popularity by ∼75 times, an attractive species or incident by ∼5 times, and a negative social ethics incident by ∼3 times. Traditional media users and celebrity influencers performed key roles in affecting the level of re-posting. Online audiences of highly popular posts predominantly encompassed both users from relatively developed regions and female users. It was observed that posts which became popular within ∼12 h retained their influence for ∼3 d. Post popularity was closely related to comment counts rather than forwarding in the first day of posting and the whole status retention time. Public opinion generally expressed a supportive attitude towards wildlife conservation, but lacked in-depth thinking, and individual responsibility was expressed through revival incidents. In order to raise public awareness towards biodiversity conservation, social media–based wildlife information dissemination should balance the content of attractive and non-charismatic species or incidents and include more positive emotions. Posts via traditional users (especially central media users) and opinion leaders (celebrities) can attract a highly educated audience and females, and thus evoke increased comment numbers during the first day of posting. This will help to popularise conservation knowledge and legislation with continuous efforts.

Life-cycle assessment (LCA) emphasizes obtaining primary data from an on-site process to reduce uncertainties. However, data of the upstream process from secondary sources also yield significant uncertainties, which have not been drawn enough attention. This study aims to explore the importance of primary data of the upstream process in LCAs. Here, we choose lithium, a key component of lithium-ion (Li-ion) battery, as a case to present a cradle-to-gate LCA for its production by rock-based technology (LRT). Then, we compare the environmental impacts of lithium by LRT with that by brine-based technology (LBT) and the Li-ion battery using lithium by the two methods. The result shows that the impacts of rock-based lithium production are dominated by the leaching process, which has the highest levels of impacts for 8 of 10 environmental categories. Besides, all 10 impact categories of lithium produced by LRT are much larger than that by LBT, with differences up to 60.4 -fold. We also find that the Li-ion battery pack by rock-based lithium offers a 17-32% increase in acidification and global warming potential relative to that by brine-based lithium. Our results contribute by providing the first mass-produced life-cycle inventory of rock-based lithium and showing the importance of primary data of the upstream process in LCAs.

The flavon luteolin has various health-promoting activities including cardiovascular protection, anti-inflammatory activity and anticancer activity. A serum concentration of about 100 nM luteolin is reached by dietary habit. However, little is known about the function of luteolin over its physiological concentration range. In this study, we investigated whether a physiological concentration of luteolin could activate nuclear factor-erythroid-2-related factor 2 (Nrf2)-mediated expression of phase II drug-metabolizing enzymes in human hepatoma HepG2 cells. Interestingly, less than 1 nM of luteolin could induce phase II drug-metabolizing enzymes, such as GSTs, HO-1, and NQO1. Both 1 and 100 nM luteolin increased expression and activity of ALDH2, which metabolized toxic acetaldehyde into nontoxic acetic acid. Luteolin increased nuclear accumulation of Nrf2 and enhanced the ARE-binding complex through increasing the stability of the Nrf2 protein. Luteolin increased phosphorylation of Nrf2 at Ser40, and MEK inhibitors (U0126 and PD98059) canceled luteolin-induced phosphorylation of Nrf2. Furthermore, luteolin increased modified Keap1. In conclusion, a physiological concentration of luteolin induces the expression of phase II drug-metabolizing enzymes by enhancement of Nrf2 nuclear accumulation through MEK1/2-ERK1/2-mediated phosphorylation of Nrf2, increasing Nrf2 stability and inducing a conformational change of Keap1.

Identifying the key nodes of the phosphorus flows in animal raising system is fundamental to improve P utilization efficiency and reduce the P contamination. This study established a phosphorus flow analysis model for livestock and poultry raising, depicted P flows for major livestock and poultry under two raising modes, and further analyzed their spatial and temporal distributions. We find that around 15% of P input was transferred into the products, and in P output around 40% lost into the environment in 2015. The P flows have been increasing since 2000, and the main contributor is pigs followed by beef cattle. It should be noticed that P loss from livestock and poultry raising is huge with extensive prospect of recycling in some central provinces of China, and western region where ecological environment is fragile, has a higher P loss rate which need to change the dietary preference and adjust raising structure. As for diets, pork and eggs are better choices than milk or other kinds of meat in terms of reducing the P load, when producing per unit protein or energy. This study contributes to the understanding of P management in husbandry industry, the quantification of environmental loads of animal-based food and the identification of the potential of reducing P loss to realize sustainable utilization of P.

Phosphorus (P) is an essential nutrient for living systems with emerging sustainability challenges related to supply uncertainty and aquatic eutrophication. However, its long-term temporal dynamics and subsequent effects on freshwater ecosystems are still unclear. Here, we quantify the P pathways across China over the past four centuries with a life cycle process-balanced model and evaluate the concomitant potential for eutrophication with a spatial resolution of 5 arc-minutes in 2012. We find that P cycling in China has been artificially intensified during this period to sustain the increasing population and its demand for animal protein-based diets, with continuous accumulations in inland waters and lands. In the past decade, China's international trade of P involves net exports of P chemicals and net imports of downstream crops, specifically soybeans from the United States, Brazil, and Argentina. The contribution of crop products to per capita food P demand, namely, the P directly consumed by humans, declined from over 98% before the 1950s to 76% in 2012, even though there was little change in per capita food P demand. Anthropogenic P losses to freshwater and their eutrophication potential clustered in wealthy coastal regions with dense populations. We estimate that Chinese P reserve depletion could be postponed for over 20 y by more efficient life cycle P management. Our results highlight the importance of closing the P cycle to achieve the cobenefits of P resource conservation and eutrophication mitigation in the world's most rapidly developing economy.

Understanding historical patterns of phosphorus (P) cycling is critical for sustainable P management and eutrophication mitigation in watersheds. This study built a bottom-up model using the substance flow analysis approach to quantify P cycling in the Chaohu watershed during 1978-2012. We found that P flows have been intensified, with a 5-fold increase of annual P inputs to sustain the expanding intensive agriculture. Annually, most P inputs (75%) were stored within the watershed, which caused accelerating buildup of legacy P in cultivated land (from 4.9 Gg to 6.5 × 10(2) Gg), uncultivated land (from 2.1 Gg to 1.3 × 10(2) Gg) and surface water (from 3.7 Gg to 2.6 × 10(2) Gg) during 1978-2012. The main legacy P sources include fertilizer application for cultivated land, phosphogypsum abandonment for uncultivated land, respectively. The animal husbandry contributed about 63-66% of total P inputs to surface water. The contribution of animal food-P increased greatly during 1978-2012, from 7% to 24% and from 1% to 8% for urban and rural residents, respectively. This work demonstrates principle for the buildup of legacy P at the watershed-scale, and advances the knowledge of sustainable P management, such as improving agricultural technologies to reduce fertilizer application.

Drugs, xenobiotics including environmental pollutants, and certain food components modulate expression of drug-metabolizing enzymes. An aryl hydrocarbon receptor (AhR) possesses possible expression of phase I and phase II enzymes directly by binding of its ligands such as 2,3,7,8-tetrachlorodibenzo- p -dioxin (TCDD) and indirectly by regulating expression of nuclear factor-erythroid-2-related factor 2 (Nrf2). Previous our result demonstrated that luteolin, a natural flavonoid existing in vegetables and herbs, competed the binding of TCDD to AhR. In the present study, we investigated the effect of luteolin on the expression of drug-metabolizing enzymes through the AhR and Nrf2 pathways. Luteolin inhibited TCDD-induced protein expression of phase I enzyme cytochrome P450 1A1 (CYP1A1), phase II enzymes NAD(P)H:quinone oxidoreductase-1 (NQO1) and glutathione- S -transferase P1 (GSTP1) in HepG2, Hepa1c1c7 and RL-34 cells in a dose-dependent manner. Luteolin suppressed TCDD- and tert -butylhydroquinone-induced Nrf2 protein by decreasing its stability in HepG2 cells. In tert -butylhydroquinone treated cells, luteolin dose-dependently inhibited NQO1, GSTP1 and aldo–keto reductases (AKRs). Of these, protein expression of CYP1A1 and GSTP1 was mainly dominated by the AhR pathway, while that of NQO1 and AKRs was by the Nrf2 pathway. In conclusion, luteolin inhibits expression of phase I and phase II drug-metabolizing enzymes by modulating the AhR and Nrf2 pathways.

Black soybean seed coat is a rich source of polyphenols that have been reported to have various physiological functions. The present study investigated the potential protective effects of polyphenolic extracts from black soybean seed coat on DNA damage in human hepatoma HepG2 cells and ICR mice. The results from micronucleus (MN) assay revealed that black soybean seed coat extract (BE) at concentrations up to 25μg/mL was non-genotoxic. It is noteworthy that BE (at 4.85μg/mL) and its main components, procyanidins (PCs) and cyanidin 3-glucoside (C3G), at 10μM significantly reduced the genotoxic effect induced by benzo[a]pyrene [B(a)P]. To obtain insights into the underlying mechanism, we investigated BE and its main components on drug-metabolizing enzyme expression. The results of this study demonstrate that BE and its main components, PCs and C3G, down-regulated B(a)P-induced cytochrome P4501A1 (CYP1A1) expression by inhibiting the transformation of aryl hydrocarbon receptor. Moreover, they increased expression of detoxifying defense enzymes, glutathione S-transferases (GSTs) via increasing the binding of nuclear factor-erythroid-2-related factor 2 to antioxidant response elements. Collectively, we found that PCs and C3G, which are the main active compounds of BE, down-regulated CYP1A1 and up-regulated GST expression to protect B(a)P-induced DNA damage in HepG2 cells and ICR mice effectively.