Stable nitrogen isotopic composition (δ¹⁵N) of aquatic biota increases with anthropogenic N inputs such as sewage and livestock waste downstream. Increase in δ¹⁵N of riparian spiders downstream may reflect the anthropogenic pollution exposure through predation on aquatic insects. A two-source mixing model based on stable carbon isotopic composition showed the greatest dependence on aquatic insects (84%) by horizontal web-building spiders, followed by intermediate (48%) and low (31%) dependence by cursorial and vertical web-building spiders, respectively. The spider body size was negatively correlated with the dietary proportion of aquatic insects and spider δ¹⁵N. The aquatic subsidies transported anthropogenic N to smaller riparian spiders downstream. This transport of anthropogenic N was regulated by spider’s guild designation and body size.

Based on the panel data of 63 counties of Zhejiang Province from 2003 to 2017, this paper studied the total-factor substitution efficiency of chemical fertilizer input and its spatial-temporal evolution by using the Super-efficiency DEA(Data Envelopment Analysis) model, locational Gini coefficient and Theil index. And the driving factors of the total-factor substitution efficiency of chemical fertilizer input were analyzed by constructing the Panel Tobit model. The results showed that: the comprehensive efficiency of total-factor substitution for chemical fertilizer input in Zhejiang Province is low, and technical efficiency is the main drive for promoting comprehensive efficiency; Gini coefficient is below the warning line of 0.4, and the difference of substitution efficiency, relatively small, mainly comes from the contribution within the region, and the difference ratio of contribution by the Southwestern Zhejiang is rapidly increasing. In detail, financial investment in agriculture serve as the greatest the driving force, and government chemical fertilizer input subsidies have a significantly negative effect. Therefore, we should improve the subsidy policy system, increase government investment in agricultural infrastructure, adjust the structure of agroindustry and improve the income of rural residents under the premise of reducing the fertilizer input intensity.

Temuco is a mid-size city representative of severe wood smoke pollution in southern Chile; however, little is known about the indoor air quality in this region. A field measurement campaign at 63 households in the Temuco urban area was conducted in winter 2014 and is reported here. In this study, indoor and outdoor (24-hr) PM2.5 and its elemental composition were measured and compared. Infiltration parameters and outdoor/indoor contributions to indoor PM2.5 were also determined. A statistical evaluation of how various air quality interventions and household features influence indoor PM2.5 was also performed.This study determined median indoor and outdoor PM2.5 concentrations of 44.4 and 41.8 μg/m3, respectively. An average infiltration factor (0.62 ± 0.06) was estimated using sulfur as a tracer species. Using a simple mass balance approach, median indoor and outdoor contributions to indoor PM2.5 concentrations were then estimated as 12.5 and 26.5 μg/m3, respectively; therefore, 68% of indoor PM2.5 comes from outdoor infiltration. This high percentage is due to high outdoor pollution and relatively high household air exchange rates (median: 1.06 h−1).This study found that S, Br and Rb were dominated by outdoor contributions, while Si, Ca, Ti, Fe and As originated from indoor sources. Using continuous indoor and outdoor PM2.5 measurements, a median indoor source strength of 75 μg PM2.5/min was estimated for the diurnal period, similar to literature results. For the evening period, the median estimate rose to 135 μg PM2.5/min, reflecting a more intense wood burning associated to cooking and space heating at night.Statistical test results (at the 90% confidence level) support the ongoing woodstove replacement program (reducing emissions) and household weatherization subsidies (reducing heating demand) for improving indoor air quality in southern Chile, and suggest that a cookstove improvement program might be helpful as well.

Neonicotinoid insecticides like thiacloprid enter agricultural surface waters, where they may affect predator–prey-interactions, which are of central importance for ecosystems as well as the functions these systems provide. The effects of field relevant thiacloprid concentrations on the leaf consumption of Gammarus fossarum (Amphipoda) were assessed over 96 h (n = 13–17) in conjunction with its predation on Baetis rhodani (Ephemeroptera) nymphs. The predation by Gammarus increased significantly at 0.50–1.00 μg/L. Simultaneously, its leaf consumption decreased with increasing thiacloprid concentration. As a consequence of the increased predation at 1.00 μg/L, gammarids' dry weight rose significantly by 15% compared to the control. At 4.00 μg/L, the reduced leaf consumption was not compensated by an increase in predation causing a significantly reduced dry weight of Gammarus (∼20%). These results may finally suggest that thiacloprid adversely affects trophic interactions, potentially translating into alterations in ecosystem functions, like leaf litter breakdown and aquatic-terrestrial subsidies.

The role of a yellow-legged gull (Larus michahellis) small colony in conveying trace elements (As, Cd, Cr, Cu, Ni, Pb, THg, V, Zn) was assessed in a Mediterranean nature reserve (Marinello ponds) at various spatial and temporal scales. Trace element concentrations in guano were high and seasonally variable. In contrast, contamination in the ponds was not influenced by season but showed strong spatial variability among ponds, according to the different guano input. Biogenic enrichment factor B confirmed the role of gulls in the release of trace elements through guano subsidies. In addition, comparing trace element pond concentrations to the US NOAA’s SQGs, As, Cu and Ni showed contamination levels associated with possible negative biological effects. Thus, this study reflects the need to take seabirds into account as key factors influencing ecological processes and contamination levels even in remote areas, especially around the Mediterranean, where these birds are abundant but overlooked.

To understand dispersal and assimilation of aquaculture waste subsidies in a naturally low-productivity environment, we applied a novel, rapid transmethylation technique to analyse sediment and biota fatty acid composition. This technique was initially validated at Atlantic salmon farms in Macquarie Harbour, Australia, where sediments were collected at farm and control locations. Subsequently, sediment, benthic polychaete and zooplankton were sampled at sites 0, 50, 250, 500 and 1000m distant from multiple cages. Results demonstrated an acute deposition zone up to 50m from cages and a diffuse zone extending 500m from cages. Changes in sediment concentration of linoleic acid, oleic acid and total fatty acids were effective tracers of farm deposition. Bacterial biomarkers indicated that aquaculture waste stimulates bacterial productivity in sediments, with elevated biomarker concentrations also detected in benthic polychaetes. Overall, fatty acid analysis was a sensitive technique to characterize the benthic footprint of aquaculture influence.

The extensive waste produced in construction and demolition activities affects the ecological environment, impeding green development in countries worldwide, including China. China has paid increasing attention to managing construction and demolition waste (CDW). However, most of the existing research only qualitatively studies the factors affecting the recycling of CDW and does not reveal the critical factors. Therefore, based on stakeholder theory and the grey-DEMATEL method, this paper aims to identify and quantitatively analyze the critical factors in CDW recycling from the perspective of China. This paper drew the following conclusions: (1) Stakeholders in China’s CDW recycling mainly include the government, CDW production units, and CDW recycling units. (2) Public policy, government subsidies, media promotion, human resources, cost, environmental awareness, technological innovation, and supply chain management are the eight dimensions with 13 factors that constitute CDW recycling in China. (3) For the total relations between factors affecting the recycling of CDW in China, the most influential factor is specific legislation and regulations. The factor with the highest degree of prominence is environmental awareness. The factor with the largest net cause value is the rationality of disposal and landfill charges. The factor with the largest net effect value is experienced construction workers. (4) The critical factors in China’s CDW recycling include specific legislation and regulations, mandatory degree of normative standards, environmental awareness, the supply of raw materials for CDW recycling units, and the sale of remanufactured products. Finally, this paper identifies the following management implications: (1) the government should prioritize the task of improving specific legislation and regulations, with a focus on a mandatory degree of normative standards. (2) CDW production units should put the task of improving environmental awareness high on their agenda, with a focus on the supply of raw materials for recycling units. (3) CDW recycling units should prioritize the issue of the sale of remanufactured products. This paper also provides a theoretical basis for revealing the critical factors of CDW recycling in other countries or regions.

The disposal of food waste has attracted worldwide attention. Each year, the amount of wasted food accounts for an estimated one third of annual food production globally. This large amount of food waste has caused serious land, water, and air pollution. In the past, most research on food waste was focused solely on food waste disposal processing. Only a few studies analysed the flow of materials in food waste treatment processes. Therefore, this paper focused on the process of food waste anaerobic treatment in Beijing and investigated the treatment. According to a life cycle theory, the food waste treatment process is divided into three processes: “collection and transportation, disposal, and resource utilization.” This paper analysed the input and output of food waste treatment in different processes and evaluated the economic and environmental costs and benefits of food waste treatment. The study found that 200 t of food waste anaerobic treatment can obtain benefits 66,888 Chinese yuan, generate electricity energy 43,350 kW⋅h, and reduce carbon dioxide emissions 16,087 kg. Generally, the economic and environmental benefits of the food waste anaerobic treatment project are considerable. However, the economic benefits are mainly from government subsidies. There are many impurities in food waste, which indicates some problems in food waste treatment. Thus, the proposals to strengthen waste classification, optimize the layout of garbage collection and transportation, and accelerate the development of waste treatment plants have been put forward.

Theoretically, agriculture can be the victim and the cause of climate change. Using annual data for the period of 1970–2014, this study examines the interaction between agriculture technology factors and the environment in terms of carbon emissions in Jordan. The results provide evidence for unidirectional causality running from machinery, subsidies, and other transfers, rural access to an improved water source and fertilizers to carbon emissions. The results also reveal the existence of bidirectional causality between the real income and carbon emissions. The variance error decompositions highlight the importance of subsidies and machinery in explaining carbon emissions. They also show that fertilizers, the crop and livestock production, the land under cereal production, the water access, the agricultural value added, and the real income have an increasing effect on carbon emissions over the forecast period. These results are important so that policy-makers can build up strategies and take in considerations the indicators in order to reduce carbon emissions in Jordan.