Perspectives and challenges in the future use of plant nutrients in tilled and mixed agricultural systems

Producing an adequate quantity of healthy food without polluting the environment is a serious challenge for future agriculture around the world. The Food 21 research program in Sweden has researched all aspects--economic, environmental, and social--of sustainable farming systems. This paper presents some of the research from that and other relevant international research programs that have focused on better nutrient-use efficiency, especially for nitrogen and phosphorus. It shows that a range of sustainable solutions to nutrient-use efficiency exists, some of which are complex but some very simple. Government policies, including subsidies; research and technology; and public acceptance of farming practices all combine to create these solutions. Participatory approaches to knowledge transfer are needed, in which scientists, policy makers, farmers, advisers, and consumers exchange information and together build sustainable farming systems.     

Contaminants of food

A scheme has been developed to rank 70 industrial organic chemicals in order of their priority for further study as potential contaminants of food. Numerical scales were developed for the following seven key criteria concerning environmental issues, food and toxicity:

-Production volume

-Pattern of usage

-Possible fate in the environment

-Likelihood of chemical entering the food chain

-Mechanism of entry into the food chain

-Persistence and accumulation in the food chain

-Toxicity.

Each chemical was assigned a score for the above criteria, which were combined to give an overall ranking for the chemicals. This scheme has been endorsed by the MAFF Steering Group on Chemical Aspects of Food Surveillance. It will be used in the assessment of relative priorities for further non-statutory surveillance for these contaminants in the UK food supply.     

Dietary exposure to dioxin-like compounds in three age groups: results from the Flemish environment and health study

Lipophilic contaminants are present in the environment and bioaccumulate in the food chain. Therefore, their intake via animal fat of various sources was assessed for three age groups of the Flemish population, participating in a large biomonitoring program of the Flemish government. In total, 1636 adolescents (14-15 years), 1186 mothers (18-44 years), and 1586 adults (50-65 years) participated in the study and completed a semi quantitative food frequency questionnaire. Individual consumption data were combined, via a so-called simple distribution approach, with recent data on polychlorinated dibenzo-p-dioxins/furans and dioxin-like polychlorinated biphenyls, measured via the chemical-activated luciferase gene expression (CALUX) bio-assay in food items available on the Flemish market. The median (95th percentile) estimated intakes of dioxin-like contaminants were 2.24 (4.61), 2.09 (4.26), and 1.74 (3.53) pg CALUX-TEQ kg(-1) bw d(-1) for, respectively adolescents, mothers and adults. These data are in the same range as those found in other European studies. The CALUX-TEQ results of respectively 59.8%, 53.7% and 36.2% of the adolescent, mother and adult population exceed the tolerable weekly intake (TWI) of 14 pg WHO-TEQ kg(-1) bw w(-1), as derived by the Scientific Committee on Food [Scientific Committee on Food, 2001. Opinion of the Scientific Committee on Food on the Risk Assessment of Dioxins and Dioxin-like PCBs in Food, CS/CNTM/DIOXIN/20 final Brussels, Belgium]. The main contributors of dioxin-like substances are fish and seafood (25-43% of the total intake), added fats (22-25% of the total intake) and dairy products (17-20% of the total intake).     

A generic model of human lifetime exposure to persistent organic contaminants: development and application to PCB-101

We have developed a model which successfully reconstructs the lifetime polychlorinated biphenyl (PCB)-101 burden of the UK population for individuals born between 1920 and 1980. It not only follows burdens and clearance of persistent organic contaminants throughout a human lifetime--taking changes in age and body composition into account--but also, importantly, incorporates changing environmental concentrations of the compound of interest. Predicted results agree well with available measured lipid concentrations in human tissues. Its unique construction takes into account both changing environmental concentrations of PCBs in principal food groups and changing dietary habits during the time period. Because environmental burdens of persistent organic contaminants have changed over the last 60 years, residues in food will also have mirrored this change. Critically in this respect, the year in which an individual was born determines the shape and magnitude of their exposure profile for a given compound. Observed trends with age represent an historical legacy of exposure and are not simply a function of equal yearly cumulative inputs. We can demonstrate that the release profile of PCB-101 controls levels in the food supply and ultimately the burden of individuals throughout their life. This effect is expected to be similar for other PCB congeners and persistent organic compounds such as polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs). Models of this type have important applications as predictive tools to estimate the likely impact of source-reduction strategies on human tissue concentrations.     

Home transport and wastage: environmentally relevant household activities in the life cycle of food

In environmental systems analysis of food production systems, the consumer phase (home transport, cooking, storing, and wastage) is an important contributor to the total life-cycle environmental impact. However, households are the least investigated part of the food chain. Information gathering about households involves difficulties; the number of households is large, and food-related activities are embedded in other household activities. In cooperation between researchers from environmental systems analysis and consumer research, Swedish households were surveyed by questionnaire, diary, and interviews. Data on home transport of food and wastage were collected. The average weekly driving distance was 28 to 63 km per household, depending on how trips made in conjunction with other errands are allocated. The wastage of prepared food ranged between 0 and 34% for different food categories, and wastage from storing between 0 and 164% (more food was discarded, e.g. by cleaning out a cupboard, than consumed). In both cases dairy products scored highest.     

Exposure of ruminants to persistent organic pollutants and potential of decontamination

Human activities are emitting persistent organic pollutants (POPs) to the environment. These compounds have raised concerns about the risk of transfer through the food chain via animal products. They are characterized by a strong persistence in environmental matrices and a lipophilicity which may lead to their accumulation in fat tissues. In EU Regulations (no. 1881/2006, 1259/2011), maximum acceptable levels for polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/Fs), and dioxin-like or nondioxin-like polychlorinated biphenyls (PCBs) in food of animal origin have been set. Transfer rates from contaminated fodder to milk have been established: for PCBs, the rate of transfer varies from 5 to 90 % and for PCDD/Fs from 1 to 40 %. The differential transfer of the compounds towards milk is related to the hydrophobicity of the pollutants and to their metabolic susceptibility. According to numerous authors, soil is the major reservoir for POPs, and its involuntary ingestion by farm animals reared outdoors may be the main cause of animal product contamination (meat, milk, or eggs). Recent studies seem to indicate that soil is a real risk matrix in terms of transfer of pollutants to the food chain. A POP crisis management is extremely difficult, since it impacts many farmers located in the contaminated area. The question arising is to know if livestock contaminated by POPs may be decontaminated and further used for their initial purpose. Recent data demonstrate that the decontamination process appear feasible and depends on initial level of contamination or the physiological status of the animals.     

Comparison of levels of polychlorinated biphenyls in edible oils and oil-based products--possible link to environmental factors

Food consumption has been widely reported to be the main source of human exposure to PCBs. A total of 47 samples of food products on sale in supermarkets in the United Kingdom were thus analyzed for PCBs to determine residual levels in oil and oil-based products. The objective was to compare the measured levels of total PCBs (Sigma PCBs) in food products to those reported in various environmental compartments. Combined extraction and online clean up was achieved using Accelerated Solvent Extraction (ASE) to recover target analytes for analysis by GC-MSD (gas chromatography mass spectrometry). Sigma PCBs (ng/g) in each product were in the ranges of 4.73-44.38 edible oil; 1.40-6.18 mayonnaise; 1.21-6.25 salad cream; 1.28-5.64 seafood sauce, and 0.97-15.08 exotic dressing. The level of human exposure to PCBs in all products was < 1 microg/kg body weight/day when considering a 70 kg male or 57 kg female, possibly reflecting the reported decline of PCBs in the environment.     

Comparison of levels of polychlorinated biphenyls in edible oils and oil-based products—possible link to environmental factors

Food consumption has been widely reported to be the main source of human exposure to PCBs. A total of 47 samples of food products on sale in supermarkets in the United Kingdom were thus analyzed for PCBs to determine residual levels in oil and oil-based products. The objective was to compare the measured levels of total PCBs (ΣPCBs) in food products to those reported in various environmental compartments. Combined extraction and online clean up was achieved using Accelerated Solvent Extraction? (ASE) to recover target analytes for analysis by GC-MSD (gas chromatography mass spectrometry). Σ PCBs (ng/g) in each product were in the ranges of 4.73–44.38 edible oil; 1.40–6.18 mayonnaise; 1.21–6.25 salad cream; 1.28–5.64 seafood sauce, and 0.97–15.08 exotic dressing. The level of human exposure to PCBs in all products was < 1 μg/kg body weight/day when considering a 70 kg male or 57 kg female, possibly reflecting the reported decline of PCBs in the environment.     

An integrated approach to model the biomagnification of organic pollutants in aquatic food webs of the Yangtze Three Gorges Reservoir ecosystem using adapted pollution scenarios

The impounding of the Three Gorges Reservoir (TGR) at the Yangtze River caused large flooding of urban, industrial, and agricultural areas, and profound land use changes took place. Consequently, substantial amounts of organic and inorganic pollutants were released into the reservoir. Additionally, contaminants and nutrients are entering the reservoir by drift, drainage, and runoff from adjacent agricultural areas as well as from sewage of industry, aquacultures, and households. The main aim of the presented research project is a deeper understanding of the processes that determines the bioaccumulation and biomagnification of organic pollutants, i.e., mainly pesticides, in aquatic food webs under the newly developing conditions of the TGR. The project is part of the Yangtze-Hydro environmental program, financed by the German Ministry of Education and Science. In order to test combinations of environmental factors like nutrients and pollution, we use an integrated modeling approach to study the potential accumulation and biomagnification. We describe the integrative modeling approach and the consecutive adaption of the AQUATOX model, used as modeling framework for ecological risk assessment. As a starting point, pre-calibrated simulations were adapted to Yangtze-specific conditions (regionalization). Two exemplary food webs were developed by a thorough review of the pertinent literature. The first typical for the flowing conditions of the original Yangtze River and the Daning River near the city of Wushan, and the second for the stagnant reservoir characteristics of the aforementioned region that is marked by an intermediate between lake and large river communities of aquatic organisms. In close cooperation with German and Chinese partners of the Yangtze-Hydro Research Association, other site-specific parameters were estimated. The MINIBAT project contributed to the calibration of physicochemical and bathymetric parameters, and the TRANSMIC project delivered hydrodynamic models for water volume and flow velocity conditions. The research questions were firstly focused on the definition of scenarios that could depict representative situations regarding food webs, pollution, and flow conditions in the TGR. The food webs and the abiotic site conditions in the main study area near the city of Wushan that determine the environmental preconditions for the organisms were defined. In our conceptual approach, we used the pesticide propanil as a model substance.     

Results of the monitoring program of pesticide residues in organic food of plant origin in Lombardy (Italy)

Organic agriculture, with its restrictions on the use of synthetic chemical inputs, seems to offer a low-residue alternative to conventional methods. In Europe, the Council Regulation n. 2092/91/EEC regulates the production and trade of organic products and foodstuffs; national and regional legislation in Italy gives specific guidance on the surveillance of organic agriculture. However, monitoring of specific chemical residues in organic foodstuffs is part of the regular controls on food, aiming to safeguard consumer's health. Monitoring programs are coordinated at the national level by the Ministry of Health and at local level by Regional authorities. In Lombardy, in accordance with the provisions of the General Directorate of Health of the Region and under the supervision of the 15 Local Health Units, a monitoring program of pesticide residues in food of plant origin is undertaken every year. The International Centre for Pesticides and Health Risk Prevention (ICPS), on behalf of the General Directorate of Health of the Region of Lombardy, has been collecting and elaborating the data resulting from the analysis of food samples, carried out by the local laboratories. During the period 2002–2005, a total of 3508 samples food of plant origin were analyzed for pesticide residues, among which were 266 samples of organic farming products. Commodities were classified into groups (citrus fruits, legumes, vegetables, potatoes, processed products, cereals, and fruit other than citrus) and the outcomes of the analyses were reported by year, origin of the sample and presence/absence of pesticide residues. Results showed that the vast majority of organic farming products were in conformity with the relevant legislation and did not contain detectable pesticide residues. A limited amount of samples had residues at concentration below the Maximum Residue Limit (MRL). Only in one sample the residue level was above the MRL, however it did not pose a concern for public health, as demonstrated by the outcomes of dietary risk assessment. Organic fruits and vegetables can be expected to contain fewer agrochemical residues than conventionally grown alternatives. There is a widespread belief that organic agriculture products are safer and healthier than conventional foods. It is difficult to come to conclusions, but what should be made clear to the consumer is that “organic” does not automatically equal “safe”. In the absence of adequate comparative data, additional studies in this area of research are required.     

Results of the monitoring program of pesticide residues in organic food of plant origin in Lombardy (Italy)

Organic agriculture, with its restrictions on the use of synthetic chemical inputs, seems to offer a low-residue alternative to conventional methods. In Europe, the Council Regulation n. 2092/91/EEC regulates the production and trade of organic products and foodstuffs; national and regional legislation in Italy gives specific guidance on the surveillance of organic agriculture. However, monitoring of specific chemical residues in organic foodstuffs is part of the regular controls on food, aiming to safeguard consumer's health. Monitoring programs are coordinated at the national level by the Ministry of Health and at local level by Regional authorities. In Lombardy, in accordance with the provisions of the General Directorate of Health of the Region and under the supervision of the 15 Local Health Units, a monitoring program of pesticide residues in food of plant origin is undertaken every year. The International Centre for Pesticides and Health Risk Prevention (ICPS), on behalf of the General Directorate of Health of the Region of Lombardy, has been collecting and elaborating the data resulting from the analysis of food samples, carried out by the local laboratories. During the period 2002-2005, a total of 3508 samples food of plant origin were analyzed for pesticide residues, among which were 266 samples of organic farming products. Commodities were classified into groups (citrus fruits, legumes, vegetables, potatoes, processed products, cereals, and fruit other than citrus) and the outcomes of the analyses were reported by year, origin of the sample and presence/absence of pesticide residues. Results showed that the vast majority of organic farming products were in conformity with the relevant legislation and did not contain detectable pesticide residues. A limited amount of samples had residues at concentration below the Maximum Residue Limit (MRL). Only in one sample the residue level was above the MRL, however it did not pose a concern for public health, as demonstrated by the outcomes of dietary risk assessment. Organic fruits and vegetables can be expected to contain fewer agrochemical residues than conventionally grown alternatives. There is a widespread belief that organic agriculture products are safer and healthier than conventional foods. It is difficult to come to conclusions, but what should be made clear to the consumer is that "organic" does not automatically equal "safe". In the absence of adequate comparative data, additional studies in this area of research are required.     

中国有机食品的研究与发展前景

介绍了有机食品的基本概念和有机食品所应具备的条件，并比较了有机食品与绿色食品的区别与联系；在对国内外有机食品的发展概况和中国发展有机食品的有利条件的全面论述和分析的基础上，阐明了中国有机食品的发展不仅有着良好的国内外市场，而且有着广阔的前景。     

Organic and inorganic mercury in the food chain of some lakes and reservoirs in Finland

Contents of organic and inorganic mercury in food chain specimens, as well as sedimentation in two natural Finnish lakes and three impounded reservoirs, were studied. The proportion of organic mercury of total mercury varied in individual specimens from 32.7 to 100 %. Sedimentation (settleable solid) with very high contents of organic matter had ratios of organic to total mercury ranging from 2.4 to 87.3 %. These variations were similar in each of five water ecosystems studied. Benthic invertebrates had higher ratios of organic to total mercury than reported earlier. Total mercury concentrations in fish, zoobenthos and zooplankton of young impounded reservoirs were significantly higher than those of natural lakes. To explain this it is suggested that humic materials transfer mercury to the water and thence into the food chain.     

有机固体废物堆肥化处理的微生物学机理研究

由于符合持续发展的理念 ,利用微生物技术处理有机固体废物越来越受到人们的重视 ,其核心问题则是木质纤维素的生物降解。随着园林废物等高木质纤维素含量的城市生活垃圾的不断增加 ,以及对农业固体废物和食品工业废物再利用的需要 ,这一领域的研究取得了很大的进展。在研究中 ,针对好氧堆肥和厌氧发酵 2项主要的微生物处理技术 ,对其优势微生物菌群、不同降解底物和微生物降解动力学方面的最新研究进展进行了回顾和总结 ,并对环境微生物制剂的应用以及有机固体废物的微生物处理技术的发展做了合理的展望。     

Intellectual capital,financial resources,and green supply chain management as predictors of financial and environmental performance

This research examines the influence of intellectual capital on financial and environmental performance with a mediating role of green supply chain management and a moderating role of financial resources. Structural model estimation was conducted on the data set of 324 Pakistani manufacturing SMEs and showed that intellectual capital significantly encourages green supply chain management as well as significantly contributes to financial and environmental performance. Green supply chain management partially mediates the relationship between intellectual capital and performance both the financial and environmental. Financial resources significantly strengthen the relationship between intellectual capital and green supply chain management. In light of the results, we suggest that firms should encourage intellectuality among their managers and employees to adopt green practices that can improve their financial and environmental performance. In addition, it is also suggested for managers and CEOs to effectively manage financial resources that are necessary for green practices.

     

Adaptation to environmental stress in Daphnia magna simultaneously exposed to a xenobiotic

In standardized ecotoxicological testing chemicals are investigated under optimal conditions for the test organisms despite the fact that environmental factors such as predation pressure and food availability are important parameters regulating natural populations. Food limitation and predator presence can induce shifts in life-history traits in various Daphnia species, especially trade-offs in reproductive biomass allocation. These adaptive responses are thought to ensure survival of the population in a highly variable environment. A xenobiotic dispersant (used in textile dyeing processes) also shifted the biomass allocation of Daphnia magna. To assess whether the dispersant could hinder D. magna adaptation to varying environmental conditions, we conducted experiments with food level and presence of Chaoborus larvae as environmental factors and simultaneous exposure to the dispersant. At low food level and in presence of the predator, D. magna produced fewer but larger sized neonates, regardless of dispersant exposure. The dispersant shifted biomass allocation towards more but smaller sized offspring in all experiments. However, the adaptive response to the environmental factors and the dispersant effect cancelled each other out in that they induced independently from each other opposite shifts in biomass allocation. In summary, the dispersant exposure resulted not in an inhibition of the adaptive response but in a reduction of the value of the response. Our study with this model substance demonstrates that xenobiotics can affect the adaptation of organisms to environmental stress which can result in effects likely to be overlooked in standardized testing.     

Development and implementation of eco-genomic tools for aquatic ecosystem biomonitoring: the SYNAQUA French-Swiss program

The effectiveness of environmental protection measures is based on the early identification and diagnosis of anthropogenic pressures. Similarly, restoration actions require precise monitoring of changes in the ecological quality of ecosystems, in order to highlight their effectiveness. Monitoring the ecological quality relies on bioindicators, which are organisms revealing the pressures exerted on the environment through the composition of their communities. Their implementation, based on the morphological identification of species, is expensive because it requires time and experts in taxonomy. Recent genomic tools should provide access to reliable and high-throughput environmental monitoring by directly inferring the composition of bioindicators’ communities from their DNA (metabarcoding). The French-Swiss program SYNAQUA (INTERREG France-Switzerland 2017–2019) proposes to use and validate the tools of environmental genomic for biomonitoring and aims ultimately at their implementation in the regulatory bio-surveillance. SYNAQUA will test the metabarcoding approach focusing on two bioindicators, diatoms, and aquatic oligochaetes, which are used in freshwater biomonitoring in France and Switzerland. To go towards the renewal of current biomonitoring practices, SYNAQUA will (1) bring together different actors: scientists, environmental managers, consulting firms, and biotechnological companies, (2) apply this approach on a large scale to demonstrate its relevance, (3) propose robust and reliable tools, and (4) raise public awareness and train the various actors likely to use these new tools. Biomonitoring approaches based on such environmental genomic tools should address the European need for reliable, higher-throughput monitoring to improve the protection of aquatic environments under multiple pressures, guide their restoration, and follow their evolution.     

Life Cycle Analyses and Resource Assessments

Prof. Ulgiati stresses that we should always use an ecosystem view when transforming energy from one form to another. Sustainable growth and development of both environmental and human-dominated systems require optimum use of available resources for maximum power output. We have to adapt to the laws of nature because nature has to take care of all the waste products we produce. The presentation addresses a much needed shift away from linear production and consumption pattern, toward reorganization of economies and lifestyle that takes complexity—of resources, of the environment and of the economy—into proper account. The best way to reach maximum yield from the different kinds of biomass is to use biorefineries. Biorefinery is defined as the sustainable processing of biomass into a spectrum of marketable products like heat, power, fuels, chemicals, food, feed, and materials. However, biomass from agricultural land must be used for the production of food and not fuel. Prof. Voss focuses on the sustainability of energy supply chains and energy systems. Life cycle analyses (LCA) provides the conceptual framework for a comprehensive comparative evaluation of energy supply options with regard to their resource requirements as well as the health and environmental impact. Full scope LCA considers not only the emissions from plant operation, construction, and decommissioning but also the environmental burdens and resource requirements associated with the entire lifetime of all relevant upstream and downstream processes within the energy chain. This article describes the results of LCA analyses for state-of-the-art heating and electricity systems as well as of advanced future systems. Total costs are used as a measure for the overall resource consumption.     

Occurrence and source analysis of typical veterinary antibiotics in manure, soil, vegetables and groundwater from organic vegetable bases, northern China

The residue of antibiotics is becoming an intractable environmental problem in many organic vegetable bases. However, their residual levels and distribution are still obscure. This work systematically analyzed the occurrence and migration of typical veterinary antibiotics in organic vegetable bases, northern China. The results showed that there was no obvious geographical difference in antibiotic distribution between soil and manure. A simple migration model can be easy and quick to predict the accumulation of antibiotics in soil. Antibiotics were mainly taken up through water transport and passive absorption in vegetables. The distribution of antibiotics in a plant was in the sequence leaf > stem > root, and performed biological accumulation. The residues of antibiotics in all samples in winter were significantly higher than those in summer. Overall, this work can lay the foundation for understanding ecological risk of antibiotics and their potential adverse effects on human health by food chain.     

Brominated flame retardants and related chlorinated persistent organic pollutants in fish from river Elbe and its main tributary Vltava

Brominated flame retardants (BFRs) are widely used industrial chemicals, residues of which can be nowadays found in all environmental compartments. The widespread presence of BFRs in various environmental compartments and food chain is a consequence of both their broad application area and physico-chemical properties, such as resistance to degradation and high lipophilicity. Alike in the case of other halogenated persistent organic pollutants (POPs), fish can be used as a bioindicator of aquatic environment pollution. In presented study, conducted in the year 2005, altogether 80 samples representing the most abundant fresh water fish species, viz. chub (Leuciscus cephalus), bream (Abramis brama), and perch (Perca fluviatilis) collected in 11 sampling sites located at Elbe and Vltava (Moldau) rivers were examined for levels of major BFRs. Without any exception, BFRs were detected in all fish samples. BDE 47 was the dominating congener in all fish species. This fact was not surprising, since it used to be the main component in various kinds of technical mixtures. With regard to relatively high levels of BDE 47 in fish tissue, as compared to other BFRs, and considering strong correlation with the total PBDEs content, simplified laboratory examination and, consequently, increased samples throughput can be obtained when only this congener is monitored. The potential of comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GCxGC-TOFMS), to provide more comprehensive information on the bioaccumulating chemicals occurring in fish samples, has been demonstrated in this study.