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Sample records for lichen-caribou-wolf food chain

  1. Transfer of {sup 210}Po and {sup 210}Pb through the lichen-caribou-wolf food chain of northern Canada

    SciTech Connect

    Thomas, P.A.; Sheard, J.W.; Swanson, S.

    1994-06-01

    Natural background activity and food chain transfer of the uranium decay products, {sup 210}Po and {sup 210}Pb, were examined in the lichen-caribou-wolf food chain at two locations in the Northwest Territories of Canada. {sup 210}Po and {sup 210}Pb activities in lichens differed with species and location. Both {sup 210}Po and {sup 210}Pb were markedly higher in caribou bone than in wolf bone. {sup 210}Po activities in liver, kidney, and muscle were similar in both species. Caribou fetuses had lower activities of {sup 210}Po but higher activities of {sup 210}Pb than maternal muscle and placenta, suggesting greater placental transport of {sup 210}Pb than {sup 210}Po. Concentration ratios (CR = Bq kg{sup {minus}1} in consumer/Bq kg{sup {minus}1} in its food source) and f{sub f} values (f{sub f} in d kg{sup {minus}1} = Bq kg{sup {minus}1} in muscle/Bq d{sup {minus}1} ingested) showed that wolves retain more {sup 210}Po and less {sup 210}Pb from their diet than do caribou. {sup 210}Po CRs averaged 0.38 for caribou/lichens, 0.26 for caribou/rumen contents, and 0.40 for wolves/caribou. {sup 210}Pb CRs averaged 0.36 for caribou/lichens, 0.57 for caribou/rumen contents, and 0.13 for wolves/caribou. 43 refs., 4 figs., 5 tabs.

  2. Uranium series radionuclides, polonium-210 and lead-210, in the lichen-caribou-wolf food chain of the Northwest Territories

    SciTech Connect

    Thomas, P.A.; Sheard, J.W.; Swanson, S.

    1994-12-31

    This report examines baseline concentrations and transfer of the uranium decay products polonium-210 and lead-210 in the lichen-caribou-wolf food chain at two locations in the Northwest Territories, Baker Lake and Snowdrift. At each location, concentrations of the two radionuclides were determined in the lichen species Cetraria nivalis and Cladina mitis, and several tissues from caribou and wolves. Baseline concentrations and transfer coefficients within the food chain were compared between the two locations. Lichen samples were also collected from Kasba Lake, a third hunting ground used by northern Saskatchewan hunters. The lichen species chosen were common forage for caribou. Both the predominant lichen species at each location and rumen contents were used to estimate the winter diet of caribou in the calculation of transfer coefficients. The results are relevant to environmental monitoring in areas of potential future uranium mining development and the transfer coefficients determined in the study may be used to estimate radionuclide concentrations and radiation doses in future environmental assessments.

  3. Food Chain Security and Vulnerability

    NASA Astrophysics Data System (ADS)

    Brunet, Sébastien; Delvenne, Pierre; Claisse, Frédéric

    In our contemporary societies, the food chain could be defined as a macro-technical system, which depends on a wide variety of actors and risks analysis methods. In this contribution, risks related to the food chain are defined in terms of "modern risks" (Beck 1992). The whole national economic sector of food production/distribution is vulnerable to a local accident, which can affect the functioning of food chain, the export programs and even the political system. Such a complex socio-technical environment is undoubtedly vulnerable to intentional act such as terrorism.

  4. Developing sustainable food supply chains.

    PubMed

    Smith, B Gail

    2008-02-27

    This paper reviews the opportunities available for food businesses to encourage consumers to eat healthier and more nutritious diets, to invest in more sustainable manufacturing and distribution systems and to develop procurement systems based on more sustainable forms of agriculture. The important factors in developing more sustainable supply chains are identified as the type of supply chain involved and the individual business attitude to extending responsibility for product quality into social and environmental performance within their own supply chains. Interpersonal trust and working to standards are both important to build more sustainable local and many conserved food supply chains, but inadequate to transform mainstream agriculture and raw material supplies to the manufactured and commodity food markets. Cooperation among food manufacturers, retailers, NGOs, governmental and farmers' organizations is vital in order to raise standards for some supply chains and to enable farmers to adopt more sustainable agricultural practices. PMID:17766237

  5. Towards biotracing in food chains.

    PubMed

    Hoorfar, Jeffrey; Wagner, Martin; Jordan, Kieran; Bouquin, Solveig Lind; Skiby, Jeffrey

    2011-03-01

    Biotracing is tracing (backward)/tracking (forward) biological contamination in the food/feed chain. Advances in detection technologies, improvements in molecular marker identification, clearer understanding of pathogenicity markers, improved modelling methodologies and, more importantly, the integration of these disciplines will lead to better capability in full-chain tracing and tracking biological contaminations (biotracing). The advantages of improved biotraceability are faster intervention, limited recalls and more targeted remedial action. The project is not dealing with risk assessments but developing tools that can be used in "second-generation" risk assessments involving quantitative microbiology. This concept is the core activity of BIOTRACER, which is an Integrated Project (2007-2011) funded by the EU 6th Framework Programme. The research in biotracing is organised into five Research Areas, and 21 cross-disciplinary work packages that cover tracing and tracking of contamination in feed, meat and dairy chains, in addition to accidental and deliberate contamination of bottled water. The BIOTRACER Consortium consists of 46 partners, including Europe's largest food/feed industries, several SMEs, and relevant International Cooperation (INCO) countries. The Consortium includes experts in predictive microbiology, database developers, software companies, risk assessors, risk managers, system biologists, food and molecular microbiologists, legislative officers, standardization and validation members and food retailers. The outcomes will ensure a more reliable and rapid response to a microbial contamination event. PMID:20627434

  6. Validation of a terrestrial food chain model

    SciTech Connect

    Travis, C.C.; Blaylock, B.P. )

    1992-04-01

    An increasingly important topic in risk assessment is the estimation of human exposure to environmental pollutants through pathways other than inhalation. The Environmental Protection Agency (EPA) has recently developed a computerized methodology (EPA, 1990) to estimate indirect exposure to toxic pollutants from Municipal Waste Combuster emissions. This methodology estimates health risks from exposure to toxic pollutants from the terrestrial food chain (TFC), soil ingestion, drinking water ingestion, fish ingestion, and dermal absorption via soil and water. Of these, one of the most difficult to estimate is exposure through the food chain. This paper estimates the accuracy of the EPA methodology for estimating food chain contamination. To our knowledge, no data exist on measured concentrations of pollutants in food grown around Municipal Waste Incinerators, and few field-scale studies have been performed on the uptake of pollutants in the food chain. Therefore, to evaluate the EPA methodology, we compare actual measurements of background contaminant levels in food with estimates made using EPA's computerized methodology. Background levels of contaminants in air, water, and soil were used as input to the EPA food chain model to predict background levels of contaminants in food. These predicted values were then compared with the measured background contaminant levels. Comparisons were performed for dioxin, pentachlorophenol, polychlorinated biphenyls, benzene, benzo(a)pyrene, mercury, and lead.

  7. Dioxin in the agricultural food chain

    SciTech Connect

    Stevens, J.B.; Gerbec, E.N.

    1988-09-01

    Polychlorinated dibenzo-p-dioxin's (PCDD) behavior in the agricultural food chain was modeled in this study. The source of PCDD was a municipal solid waste (MSW) incinerator. Of the farm livestock investigated only the beef cow and the milk cow were shown to contribute significant amounts of PCDD to humans. Milk was the single highest dietary source of PCDD. Comparison of the calculated human dose of PCDD from the agricultural food chain with an estimate human PCDD dose from inhalation of contaminated air revealed that the agricultural food chain could be responsible for a vast majority of the dose to an individual impacted by these facilities. Thus, these data suggest that operating MSW facilities in agricultural areas may result in enhanced PCDD exposure to individuals via the agricultural food chain. The data also suggest that milk and beef may be good sentinels to evaluate environmental impacts of these facilities.

  8. Food Chain Security in Romania

    NASA Astrophysics Data System (ADS)

    Galatchi, Liviu-Daniel; Mihalache, Diana-Lacramioara

    During the last years, Romania, as a member country of the European Union, has achieved much progress in the transposition of the Community in the field of foodstuffs. According to the commitments assumed through the position documents during the negotiation process and in order to approach in a unitary way in the field of food safety, the legislative approaches were initiated to promote and adopt a legislative document which may lead to the establishment and organization of a structure corresponding to the European model. In this case, a questionnaire was considered suitable to get a brief and objective data about the food safety, in Romania and other European countries. The questionnaire has been translated and adapted to facilitate the work of the participants, assuring that none of the questions is altered. Most of the results were obtained from the processing sector. The questionnaire was a suitable and useful method for achieving knowledge concerning food safety. It showed that the last years brought an important evolution regarding food industry and its safety around Europe, but still there are many actions that need to be taken.

  9. Quantifying food waste in Hawaii's food supply chain.

    PubMed

    Loke, Matthew K; Leung, PingSun

    2015-12-01

    Food waste highlights a considerable loss of resources invested in the food supply chain. While it receives a lot of attention in the global context, the assessment of food waste is deficient at the sub-national level, owing primarily to an absence of quality data. This article serves to explore that gap and aims to quantify the edible weight, economic value, and calorie equivalent of food waste in Hawaii. The estimates are based on available food supply data for Hawaii and the US Department of Agriculture's (USDA's) loss-adjusted food availability data for defined food groups at three stages of the food supply chain. At its highest aggregated level, we estimate Hawaii's food waste generation at 237,122 t or 26% of available food supply in 2010. This is equivalent to food waste of 161.5 kg per person, per annum. Additionally, this food waste is valued at US$1.025 billion annually or the equivalent of 502.6 billion calories. It is further evident that the occurrence of food waste by all three measures is highest at the consumer stage, followed by the distribution and retail stage, and is lowest at the post-harvest and packing stage. The findings suggest that any meaningful intervention to reduce food waste in Hawaii should target the consumer, and distribution and retail stages of the food supply chain. Interventions at the consumer stage should focus on the two protein groups, as well as fresh fruits and fresh vegetables. PMID:26446198

  10. 40 CFR 264.276 - Food-chain crops.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 27 2012-07-01 2012-07-01 false Food-chain crops. 264.276 Section 264... Treatment § 264.276 Food-chain crops. The Regional Administrator may allow the growth of food-chain crops in... Regional Administrator will specify in the facility permit the specific food-chain crops which may be...

  11. 40 CFR 264.276 - Food-chain crops.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Food-chain crops. 264.276 Section 264... Treatment § 264.276 Food-chain crops. The Regional Administrator may allow the growth of food-chain crops in... Regional Administrator will specify in the facility permit the specific food-chain crops which may be...

  12. 40 CFR 264.276 - Food-chain crops.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 26 2011-07-01 2011-07-01 false Food-chain crops. 264.276 Section 264... Treatment § 264.276 Food-chain crops. The Regional Administrator may allow the growth of food-chain crops in... Regional Administrator will specify in the facility permit the specific food-chain crops which may be...

  13. 40 CFR 264.276 - Food-chain crops.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 27 2013-07-01 2013-07-01 false Food-chain crops. 264.276 Section 264... Treatment § 264.276 Food-chain crops. The Regional Administrator may allow the growth of food-chain crops in... Regional Administrator will specify in the facility permit the specific food-chain crops which may be...

  14. 40 CFR 264.276 - Food-chain crops.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 26 2014-07-01 2014-07-01 false Food-chain crops. 264.276 Section 264... Treatment § 264.276 Food-chain crops. The Regional Administrator may allow the growth of food-chain crops in... Regional Administrator will specify in the facility permit the specific food-chain crops which may be...

  15. A New Model for Food Chain

    NASA Astrophysics Data System (ADS)

    Liu, Chung-Chu; Liu, Xia-Shi

    2002-01-01

    An experiment for a new model of food chain was studied. In this special circulating system we succeeded in integrating animal, fish and plant production into a new model of food chain. The advantages of the new model are as follows: A. The new model of food chain was under special water circulating system. Hence water consumption was minimized and it would be possible to be use the model in the area where water shortage. B. Output of this model was ten times more than that of output in the conventional production system, for example the products obtained from new model in an area of 66m3 exceeded same amount of products obtained from conventional production system in an area of 660m3. It may be possible to raise the output up to 20-fold if better management is made. In that case, such high output and high water use efficiency may be a hopeful base for the study to set up a new biosphere on Moon and Mars. C. Growth of the plant in this model will mainly depend on its own circulation without add fertilizer and pesticide except for supplementary certain food to feed the animal and fish product, Hence, the products from this model will be no pollution food. In our primary experiment shows that rice, celery, water convolvulus, water spinach and tomato growing well in this model. D. By use of water circulating system there will be no pollution to ecosystem. E. Based on this new model of food chain, it is possible to start the experiment on setting up the artificial biosphere No.. Key words: Food chain, Water circulating system, Artificial biosphere

  16. Food-chain competition influences gene's size

    NASA Astrophysics Data System (ADS)

    Dembska, Marta; Dudek, Mirosław R.; Stauffer, Dietrich

    2006-11-01

    We have analyzed an effect of the Bak-Sneppen predator-prey food-chain self-organization on nucleotide content of evolving species. In our model, genomes of the species under consideration have been represented by their nucleotide genomic fraction and we have applied two-parameter Kimura model of substitutions to include the changes of the fraction in time. The initial nucleotide fraction and substitution rates were decided with the help of random number generator. Deviation of the genomic nucleotide fraction from its equilibrium value was playing the role of the fitness parameter, B, in Bak-Sneppen model. Our finding is, that the higher is the value of the threshold fitness, during the evolution course, the more frequent are large fluctuations in number of species with strongly differentiated nucleotide content; and it is more often the case that the oldest species, which survive the food-chain competition, might have specific nucleotide fraction making possible generating long genes.

  17. 40 CFR 265.276 - Food chain crops.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Food chain crops. 265.276 Section 265... FACILITIES Land Treatment § 265.276 Food chain crops. (a) An owner or operator of a hazardous waste land treatment facility on which food chain crops are being grown, or have been grown and will be grown in...

  18. 40 CFR 265.276 - Food chain crops.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 27 2012-07-01 2012-07-01 false Food chain crops. 265.276 Section 265... FACILITIES Land Treatment § 265.276 Food chain crops. (a) An owner or operator of a hazardous waste land treatment facility on which food chain crops are being grown, or have been grown and will be grown in...

  19. 40 CFR 265.276 - Food chain crops.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 26 2014-07-01 2014-07-01 false Food chain crops. 265.276 Section 265... FACILITIES Land Treatment § 265.276 Food chain crops. (a) An owner or operator of a hazardous waste land treatment facility on which food chain crops are being grown, or have been grown and will be grown in...

  20. 40 CFR 265.276 - Food chain crops.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 27 2013-07-01 2013-07-01 false Food chain crops. 265.276 Section 265... FACILITIES Land Treatment § 265.276 Food chain crops. (a) An owner or operator of a hazardous waste land treatment facility on which food chain crops are being grown, or have been grown and will be grown in...

  1. 40 CFR 265.276 - Food chain crops.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 26 2011-07-01 2011-07-01 false Food chain crops. 265.276 Section 265... FACILITIES Land Treatment § 265.276 Food chain crops. (a) An owner or operator of a hazardous waste land treatment facility on which food chain crops are being grown, or have been grown and will be grown in...

  2. All about Food Chains. Animal Life for Children. [Videotape].

    ERIC Educational Resources Information Center

    2000

    Whether animals are herbivores, carnivores, or omnivores, each one is part of an eternal food chain that carries on from one generation to the next. In this videotape, students learn more about terms like "predator,""pre-consumer" and "producer," as well as the cycles of food chains and food webs and how they support all of Earth's creatures. This…

  3. Myco-Heterophytes and Parasitic Plants in Food Chains.

    ERIC Educational Resources Information Center

    Hershey, David R.

    1999-01-01

    Advocates including plants at several trophic levels when studying food chains. Presents background information on parasitic plants, myco-heterophytes (saprophytes), and carnivorous plants. Contains 20 references. (WRM)

  4. The Ocean Book: Food Chains...Come and Eat!

    ERIC Educational Resources Information Center

    Science Activities, 1989

    1989-01-01

    Six paper and pencil activities on marine ecology are presented with answers. Included are a food pyramid, a maze, a find-a-word puzzle, a sea food chain, a crossword puzzle, and a predator-prey puzzle. (CW)

  5. Effect of parity on productivity and sustainability of Lotka-Volterra food chains: bounded orbits in food chains.

    PubMed

    Massarelli, Nicole; Hoffman, Kathleen; Previte, Joseph P

    2014-12-01

    Hairston, Slobodkin, and Smith conjectured that top down forces act on food chains, which opposed the previously accepted theory that bottom up forces exclusively dictate the dynamics of populations. We model food chains using the Lotka-Volterra predation model and derive sustainability constants which determine which species will persist or go extinct. Further, we show that the productivity of a sustainable food chain with even trophic levels is predator regulated, or top down, while a sustainable food chain with odd trophic levels is resource limited, which is bottom up, which is consistent with current ecological theory. PMID:24362648

  6. PRODUCTION OF NON-FOOD-CHAIN CROPS WITH SEWAGE SLUDGE

    EPA Science Inventory

    Feasibility and market potential were determined for non-food-chain crops cultivated using sewage sludge. Non-food-chain crops that are currently being sold on the open market or that have a good potential for marketability were selected. From a list of 20 crops, 3 were selected ...

  7. Food Chain Defense in the United States

    NASA Astrophysics Data System (ADS)

    Jackson, Leeanne

    Protecting the United States food and agricultural critical infrastructure and key resources is an important responsibility shared by Federal, State, local, tribal, and territorial governments and private industry partners. Interference with the food or agricultural infrastructure could have a devastating impact on the Nation's public health and economy. Adequate protection and resiliency of infrastructure in the Food and Agriculture Sector requires a number of integrated processes and procedures undertaken by all sector partners. A number of tools, guidance documents, educational materials, and regulations are available to aid in protecting the United States Food and Agriculture Sector.

  8. Increasing Capacity Exploitation in Food Supply Chains Using Grid Concepts

    NASA Astrophysics Data System (ADS)

    Volk, Eugen; Müller, Marcus; Jacob, Ansger; Racz, Peter; Waldburger, Martin

    Food supply chains today are characterized by fixed trade relations with long term contracts established between heterogeneous supply chain companies. Production and logistics capacities of these companies are often utilized in an economically inefficient manner only. In addition, increased consumer awareness in food safety issues renders supply chain management even more challenging, since integrated tracking and tracing along the whole food supply chain is needed. Facing these issues of supply chain management complexity and completely documented product quality, this paper proposes a full lifecycle solution for dynamic capacity markets based on concepts used in the field of Grid [1], like management of Virtual Organization (VO) combined with Service Level Agreement (SLA). The solution enables the cost-efficient utilization of real world capacities (e.g., production capacities or logistics facilities) by using a simple, browser-based portal. Users are able to enter into product-specific negotiations with buyers and suppliers of a food supply chain, and to obtain real-time access to product information including SLA evaluation reports. Thus, business opportunities in wider market access, process innovation, and trustworthy food products are offered for participating supply chain companies.

  9. Food Chain to Food Web: A Natural Progression?

    ERIC Educational Resources Information Center

    Webb, Paul; Boltt, Gill

    1990-01-01

    Investigated is the ability of high school pupils and university students to answer questions based on relationships within food webs using sound ecological principles. Research methods used and the results of this study are discussed. (CW)

  10. Food safety through the meat supply chain.

    PubMed

    Attenborough, M; Matthews, K R

    2000-01-01

    Food poisoning in humans can be caused by many different bacterial genera. While the incidence of food poisoning in England, Wales and Scotland from Salmonella has reached a plateau, there has been an increase in the incidence from Campylobacter. The incidence from Escherichia coli O157:H7 rose to 1997 but declined slightly in 1998 (data from the Public Health Laboratory Service and the Scottish Centre for Infection and Environmental Health). This organism has a high virulence in humans and a very low infective dose. Infection can produce a wide range of responses, including death. The low infective dose presents a major threat. The organism is relatively heat-sensitive and the cooking of food products to achieve a centre core temperature of 70 degrees C for 2 min is sufficient to destroy it. It is relatively acid-tolerant and will survive for several weeks at pH 4.2. Several foodstuffs, as well as water, have been implicated in world-wide outbreaks. The E. coli O157:H7 food-borne outbreak in Lanarkshire in 1996 led to 21 fatalities. The Pennington Group report, issued in April 1997, reported on the circumstances leading to this outbreak, the implications for food safety and the lessons to be learnt. Four areas covered within the Pennington Group report specific to meat hygiene are reviewed in this paper. On-farm practices must ensure the presentation of clean animals for slaughter. There is a requirement for the development and introduction of risk assessment techniques based upon Hazard Analysis of Critical Control Points in abattoirs, and the Meat and Livestock Commission (MLC) is producing a manual for use by the abattoir sector. The Pennington report stated that there was a need for research into the potential use of end-process treatments such as steam pasteurization. The MLC is involved in evaluating such a system. Meat production premises and butchers' shops in England are introducing HACCP through an MLC scheme funded by the Department of Health. At the

  11. Chaos in a three-species food chain

    SciTech Connect

    Hastings, A.; Powell, T. )

    1991-06-01

    A continuous time model of a food chain incorporating nonlinear functional (and numerical) responses exhibits chaotic dynamics in long-term behavior when biologically reasonable parameter values are chosen. The appearance of chaos in this model suggests the chaotic dynamics may be common in natural food webs. One approach to the study of an ecological community begins with an important object: its food web. Theoretical studies of food webs must contend with the question of how to couple the large number of interacting species.

  12. Practical Use Of It In Traceability In Food Value Chains

    NASA Astrophysics Data System (ADS)

    Ratcliff, Jon; Boddington, Michael

    Traceability is today considered an essential requirement for the food value chain due to the need to provide consumers with accurate information in the event of food safety recalls, to provide assurance with regard the source and production systems for food products and in certain countries to comply with government legislation. Within an individual business traceability can be quite simple to implement, however, in a global trading market, traceability of the entire supply chain, including logistics is extremely complex. For this reason IT solutions such as TraceTracker have been developed which not only provide electronic solutions for complete traceability but also allow products to be tracked at any point in the supply chain.

  13. State of research: environmental pathways and food chain transfer.

    PubMed Central

    Vaughan, B E

    1984-01-01

    Data on the chemistry of biologically active components of petroleum, synthetic fuel oils, certain metal elements and pesticides provide valuable generic information needed for predicting the long-term fate of buried waste constituents and their likelihood of entering food chains. Components of such complex mixtures partition between solid and solution phases, influencing their mobility, volatility and susceptibility to microbial transformation. Estimating health hazards from indirect exposures to organic chemicals involves an ecosystem's approach to understanding the unique behavior of complex mixtures. Metabolism by microbial organisms fundamentally alters these complex mixtures as they move through food chains. Pathway modeling of organic chemicals must consider the nature and magnitude of food chain transfers to predict biological risk where metabolites may become more toxic than the parent compound. To obtain predictions, major areas are identified where data acquisition is essential to extend our radiological modeling experience to the field of organic chemical contamination. PMID:6428875

  14. Food-chain contamination evaluations in ecological risk assessments

    SciTech Connect

    Linder, G.

    1994-12-31

    Food-chain models have become increasingly important within the ecological risk assessment process. This is the case particularly when acute effects are not readily apparent, or the contaminants of concern are not readily detoxified, have a high likelihood for partitioning into lipids, or have specific target organs or tissues that may increase their significance in evaluating their potential adverse effects. An overview of food-chain models -- conceptual, theoretical, and empirical -- will be considered through a series of papers that will focus on their application within the ecological risk assessment process. Whether a food-chain evaluation is being developed to address relatively simple questions related to chronic effects of toxicants on target populations, or whether a more complex food-web model is being developed to address questions related to multiple-trophic level transfers of toxicants, the elements within the food chain contamination evaluation can be generalized to address the mechanisms of toxicant accumulation in individual organisms. This can then be incorporated into more elaborate models that consider these organismal-level processes within the context of a species life-history or community-level responses that may be associated with long-term exposures.

  15. Food chain analysis at a mining waste-contaminated wetland

    SciTech Connect

    Pascoe, G.A.; Blanchet, R.J.; Linder, G.

    1994-12-31

    A food chain analysis was performed in support of a baseline ecological risk assessment oat the Milltown Reservoir Sediments Superfund site in Montana. The site consists of over 450 acres of primarily palustrine wetland contaminated with metals from mining-wastes transported from upstream sources. The food chain analysis focused on several species of terrestrial and aquatic animals indigenous to montane wetlands of the northern Rocky Mountains. Samples of small mammal tissues, grasses, forbs, invertebrates, soils, sediment, aquatic plants, and fish were collected and analyzed for As, Cd, Cu, Pb, and Zn. A linear multimedia food-chain model was constructed to estimate daily intakes of the metals for each receptor, with assumed values for aquatic and terrestrial food items from the site, ingestion of local surface water, incidental ingestion of soils or sediments, and estimated bioavailability of soil metals. Evaluation of health risks was performed by the quotient method, where exposures expressed as daily intakes were compared to literature toxicity values. Results from the food chain analysis suggested that the health of primary consumers and higher trophic organisms (including mice, voles, muskrats, beaver, various waterfowl species, osprey, bald eagles, and deer) is not at risk due to the presence of elevated metals in sediments or upland soils at the site.

  16. Comparison of aquatic food chains using nitrogen isotopes.

    PubMed Central

    Cabana, G; Rasmussen, J B

    1996-01-01

    Recent studies have shown the utility of delta(15)N to model trophic structure and contaminant bioaccumulation in aquatic food webs. However, cross-system comparisons in delta(15)N can be complicated by differences in delta(15)N at the base of the food chain. Such baseline variation in delta(15)N is difficult to resolve using plankton because of the large temporal variability in the delta(15)N of small organisms that have fast nitrogen turnover. Comparisons using large primary consumers, which have stable tissue isotopic signatures because of their slower nitrogen turnover, show that delta(15)N increases markedly with the human population density in the lake watershed. This shift in delta(15)N likely reflects the high delta(15)N of human sewage. Correcting for this baseline variation in delta(15)N, we report that, contrary to expectations based on previous food-web analysis, the food chains leading up to fish varied by about only one trophic level among the 40 lakes studied. Our results also suggest that the delta(15)N signatures of nitrogen at the base of the food chain will provide a useful tool in the assessment of anthropogenic nutrient inputs. Images Fig. 4 PMID:8855268

  17. Rationale for evaluating a closed food chain for space habitats

    NASA Technical Reports Server (NTRS)

    Modell, M.; Spurlock, J. M.

    1980-01-01

    Closed food cycles for long duration space flight and space habitation are examined. Wash water for a crew of six is economically recyclable after a week, while a total closed loop water system is effective only if the stay exceeds six months' length. The stoichiometry of net plant growth is calculated and it is shown that the return of urine, feces, and inedible plant parts to the food chain, along with the addition of photosynthesis, closes the food chain loop. Scenarios are presented to explore the technical feasibility of achieving a closed loop system. An optimal choice of plants is followed by processing, waste conversion, equipment specifications, and control requirements, and finally, cost-effectiveness.

  18. Reducing ethylene levels along the food supply chain: a key to reducing food waste?

    PubMed

    Blanke, Michael M

    2014-09-01

    Excessive waste along the food supply chain of 71 (UK, Netherlands) to 82 (Germany) kg per head per year sparked widespread criticism of the agricultural food business and provides a great challenge and task for all its players and stakeholders. Origins of this food waste include private households, restaurants and canteens, as well as supermarkets, and indicate that 59-65% of this food waste can be avoided. Since ∼50% of the food waste is fruit and vegetables, monitoring and control of their natural ripening gas - ethylene - is suggested here as one possible key to reducing food waste. Ethylene accelerates ripening of climacteric fruits, and accumulation of ethylene in the supply chain can lead to fruit decay and waste. While ethylene was determined using a stationary gas chromatograph with gas cylinders, the new generation of portable sensor-based instruments now enables continuous in situ determination of ethylene along the food chain, a prerequisite to managing and maintaining the quality and ripeness of fruits and identifying hot spots of ethylene accumulation along the supply chain. Ethylene levels were measured in a first trial, along the supply chain of apple fruit from harvest to the consumer, and ranged from 10 ppb in the CA fruit store with an ethylene scrubber, 70 ppb in the fruit bin, to 500 ppb on the sorting belt in the grading facility, to ppm levels in perforated plastic bags of apples. This paper also takes into account exogenous ethylene originating from sources other than the fruit itself. Countermeasures are discussed, such as the potential of breeding for low-ethylene fruit, applications of ethylene inhibitors (e.g. 1-MCP) and absorber strips (e.g. 'It's Fresh', Ryan'), packages (e.g. 'Peakfresh'), both at the wholesale and retail level, vents and cooling for the supply chain, sale of class II produce ('Wunderlinge'), collection (rather than waste) of produce on the 'sell by' date ('Die Tafel') and whole crop purchase (WCP) to aid reducing

  19. Research on the marine food chain. Final technical report

    SciTech Connect

    Eppley, R.W.

    1985-01-01

    This final report includes summaries of the Food Chain Research Group's extensive basic research in Southern California Bight waters and on planktonic organisms which are important components of the bight's pelagic food web. Additionally, the report conveys much of the information resulting from biological, chemical and physical oceanographic research by others active in the study of the pelagic realm of the Bight, especially that conducted during the last several decades. Hence, the book is intended to be a comprehensive description and analysis of the pelagic food web form and function in the Bight and of interactions between food web components and the environmental parameters affecting these. It is presented in a style intended to be informative to the layman as well as the scientist interested in the important coastal resources represented by the Southern California Bight.

  20. Microsporidia – Emergent Pathogens in the Global Food Chain

    PubMed Central

    Stentiford, G.D.; Becnel, J.J.; Weiss, L.M.; Keeling, P.J.; Didier, E.S.; Williams, B.A.P.; Bjornson, S.; Kent, M.L.; Freeman, M.A.; Brown, M.J.F.; Troemel, E.R.; Roesel, K.; Sokolova, Y.; Snowden, K.F.; Solter, L.

    2016-01-01

    Intensification of food production has the potential to drive increased disease prevalence in food plants and animals. Microsporidia are diversely distributed, opportunistic, and density-dependent parasites infecting hosts from almost all known animal taxa. They are frequent in highly managed aquatic and terrestrial hosts, many of which are vulnerable to epizootics, and all of which are crucial for the stability of the animal–human food chain. Mass rearing and changes in global climate may exacerbate disease and more efficient transmission of parasites in stressed or immune-deficient hosts. Further, human microsporidiosis appears to be adventitious and primarily associated with an increasing community of immune-deficient individuals. Taken together, strong evidence exists for an increasing prevalence of microsporidiosis in animals and humans, and for sharing of pathogens across hosts and biomes. PMID:26796229

  1. Microsporidia - Emergent Pathogens in the Global Food Chain.

    PubMed

    Stentiford, G D; Becnel, J J; Weiss, L M; Keeling, P J; Didier, E S; Williams, B A P; Bjornson, S; Kent, M L; Freeman, M A; Brown, M J F; Troemel, E R; Roesel, K; Sokolova, Y; Snowden, K F; Solter, L

    2016-04-01

    Intensification of food production has the potential to drive increased disease prevalence in food plants and animals. Microsporidia are diversely distributed, opportunistic, and density-dependent parasites infecting hosts from almost all known animal taxa. They are frequent in highly managed aquatic and terrestrial hosts, many of which are vulnerable to epizootics, and all of which are crucial for the stability of the animal-human food chain. Mass rearing and changes in global climate may exacerbate disease and more efficient transmission of parasites in stressed or immune-deficient hosts. Further, human microsporidiosis appears to be adventitious and primarily associated with an increasing community of immune-deficient individuals. Taken together, strong evidence exists for an increasing prevalence of microsporidiosis in animals and humans, and for sharing of pathogens across hosts and biomes. PMID:26796229

  2. Food waste within food supply chains: quantification and potential for change to 2050

    PubMed Central

    Parfitt, Julian; Barthel, Mark; Macnaughton, Sarah

    2010-01-01

    Food waste in the global food supply chain is reviewed in relation to the prospects for feeding a population of nine billion by 2050. Different definitions of food waste with respect to the complexities of food supply chains (FSCs)are discussed. An international literature review found a dearth of data on food waste and estimates varied widely; those for post-harvest losses of grain in developing countries might be overestimated. As much of the post-harvest loss data for developing countries was collected over 30 years ago, current global losses cannot be quantified. A significant gap exists in the understanding of the food waste implications of the rapid development of ‘BRIC’ economies. The limited data suggest that losses are much higher at the immediate post-harvest stages in developing countries and higher for perishable foods across industrialized and developing economies alike. For affluent economies, post-consumer food waste accounts for the greatest overall losses. To supplement the fragmentary picture and to gain a forward view, interviews were conducted with international FSC experts. The analyses highlighted the scale of the problem, the scope for improved system efficiencies and the challenges of affecting behavioural change to reduce post-consumer waste in affluent populations. PMID:20713403

  3. Traceability in the food animal industry and supermarket chains.

    PubMed

    Pettitt, R G

    2001-08-01

    Since the 1950s, consumers in the United Kingdom (UK) have learned to expect cheap, but safe food. A number of incidents in the 1980s and 1990s caused public alarm and loss of confidence in the role of producers and the Government in the food supply. This review examines the impact of recent food scares in the UK, where scrutiny of the food industry has led to the introduction of new controls at all stages of production. Animal feed manufacture, livestock production, slaughter and the use or disposal of animal by-products are now controlled in ways unimagined prior to the identification of bovine spongiform encephalopathy (BSE) in the late 1980s. Traceability has become an important issue for consumers and, by proxy, for the multiple retailers that service consumer needs. Retailers have increasingly managed the food chain to ensure high standards that can be proven by audit. The retailers have also found that a commercial advantage can be gained from certain aspects of source verification. In order to maximise sales in a depressed market, producer groups have themselves developed a multiplicity of assurance schemes. PMID:11548528

  4. Cadmium flux and genotoxicity in an experimental marine food chain

    NASA Astrophysics Data System (ADS)

    Lin, Guangheng; Qin, Song; Tseng, C. K.

    1991-12-01

    Cadmium flux through a lab food chain ( Phaeodactylum tricornutum Bohlin- Penaeus orientalis Kishinouye- Hexagrammos otakii Jordan et Starks) and its genotoxicity were investigated. The results are as follows: 1. High doses of cadmium (>0.003 mol/L) induced flocculation and quick precipitation of Phaeodactylum tricornutum; lower doses of cadmium could be adsorbed on and absorbed by P. tricornutum without delaying its growth. Cadmium concentrations in algae increased with dosage, and cadmium ions removed from the medium were in proportion to dosage. In vivo chelation and organizable combination of absorbed cadmium ions by metabolites of P. tricornutum can be considered as bio-detoxification.

  5. Analysis of ratio-dependent food chain model

    NASA Astrophysics Data System (ADS)

    Ko, Wonlyul; Ahn, Inkyung

    2007-11-01

    In this paper, a food chain model with ratio-dependent functional response is studied under homogeneous Neumann boundary conditions. The large time behavior of all non-negative equilibria in the time-dependent system is investigated, i.e., conditions for the stability at equilibria are found. Moreover, non-constant positive steady-states are studied in terms of diffusion effects, namely, Turing patterns arising from diffusion-driven instability (Turing instability) are demonstrated. The employed methods are comparison principle for parabolic problems and Leray-Schauder Theorem.

  6. Accumulation of cadmium in a freshwater food chain experimental model.

    PubMed

    Ferard, J F; Jouany, J M; Truhaut, R; Vasseur, P

    1983-02-01

    The study of food chain contamination in nature or in the laboratory requires precise definitions of some terms. A simplified model of a freshwater food chain has been elaborated to try to point out hazards related to the presence of cadmium in the aquatic environment. Three different species belonging to various trophic levels, but to the same aquatic systems were used. The required biological and analytical criteria are described. The time course of the experiment was 34 days starting with a 10-day contamination of the first trophic level (algae). The algae were then separated, washed with fresh medium, and given to the second trophic level (daphnids) to eat for 20 days. The third trophic level (fish) was then introduced for 4 days as a scavenger. The methodology was designed to determine the accumulation of cadmium by daphnids and then fish from the algal source. The results show a high direct bioaccumulation of cadmium in algae. The indirect bioaccumulation of daphnids was of the same order of magnitude, but for fish it was smaller. Nevertheless the cadmium transfer from daphnids to fish was obvious. PMID:6851925

  7. Identifying Innovative Interventions to Promote Healthy Eating Using Consumption-Oriented Food Supply Chain Analysis

    PubMed Central

    Hawkes, Corinna

    2009-01-01

    The mapping and analysis of supply chains is a technique increasingly used to address problems in the food system. Yet such supply chain management has not yet been applied as a means of encouraging healthier diets. Moreover, most policies recommended to promote healthy eating focus on the consumer end of the chain. This article proposes a consumption-oriented food supply chain analysis to identify the changes needed in the food supply chain to create a healthier food environment, measured in terms of food availability, prices, and marketing. Along with established forms of supply chain analysis, the method is informed by a historical overview of how food supply chains have changed over time. The method posits that the actors and actions in the chain are affected by organizational, financial, technological, and policy incentives and disincentives, which can in turn be levered for change. It presents a preliminary example of the supply of Coca-Cola beverages into school vending machines and identifies further potential applications. These include fruit and vegetable supply chains, local food chains, supply chains for health-promoting versions of food products, and identifying financial incentives in supply chains for healthier eating. PMID:23144674

  8. Identifying Innovative Interventions to Promote Healthy Eating Using Consumption-Oriented Food Supply Chain Analysis.

    PubMed

    Hawkes, Corinna

    2009-07-01

    The mapping and analysis of supply chains is a technique increasingly used to address problems in the food system. Yet such supply chain management has not yet been applied as a means of encouraging healthier diets. Moreover, most policies recommended to promote healthy eating focus on the consumer end of the chain. This article proposes a consumption-oriented food supply chain analysis to identify the changes needed in the food supply chain to create a healthier food environment, measured in terms of food availability, prices, and marketing. Along with established forms of supply chain analysis, the method is informed by a historical overview of how food supply chains have changed over time. The method posits that the actors and actions in the chain are affected by organizational, financial, technological, and policy incentives and disincentives, which can in turn be levered for change. It presents a preliminary example of the supply of Coca-Cola beverages into school vending machines and identifies further potential applications. These include fruit and vegetable supply chains, local food chains, supply chains for health-promoting versions of food products, and identifying financial incentives in supply chains for healthier eating. PMID:23144674

  9. An overview of food chain impacts from municipal waste combustion

    SciTech Connect

    Hattemer-Frey, H.A.; Travis, C.C.

    1989-01-01

    Human exposure to pollutants emitted from a municipal waste combustor (MWC) can occur via inhalation, ingestion of contaminated food items, infant consumption of mother's milk, and dermal absorption. Of particular concern, however, are potential exposures from ingesting contaminated food items. The food chain has been shown to be the primary source of human exposure to a large class of organics, including DDT, dioxin, pentachlorophenol, benzo(a)pyrene, and most pesticides. Various measurement and predictive techniques can be used to evaluate the movement and transfer of chemicals within and between environmental media as well as the concentration of organics to which humans are exposed. Since organic chemicals tend to accumulate in the media in which they are most soluble, a few basic physicochemical properties can be used to predict the behavior and fate of chemicals released into the environment. Multimedia transport models estimate the concentration of a pollutant in various environmental media and then use those concentrations to predict the amount of pollutant to which humans are exposed. This paper quantifies the extent of human exposure to 2, 3, 7, 8-tetrachlorinated dibenzo-p-dioxin (TCDD, commonly referred to as dioxin) and cadmium emitted from an arbitrary MWC in the US. It also provides an innovative perspective on human exposure to facility-emitted pollutants using a probabilistic risk assessment (PRA) approach. 103 refs., 5 figs., 16 tabs.

  10. AGE DEPENDENT MODEL OF PCB IN A LAKE MICHIGAN FOOD CHAIN

    EPA Science Inventory

    An age-dependent food chain model that considers species bioenergetics and toxicant exposure through water and food was developed. It was successfully applied to PCB contamination in the Lake Michigan lake trout food chain represented by phytoplankton, Mysis, alewife, and lake tr...

  11. Does moving up a food chain increase aggregation in parasites?

    PubMed

    Lester, R J G; McVinish, R

    2016-05-01

    General laws in ecological parasitology are scarce. Here, we evaluate data on numbers of fish parasites published by over 200 authors to determine whether acquiring parasites via prey is associated with an increase in parasite aggregation. Parasite species were grouped taxonomically to produce 20 or more data points per group as far as possible. Most parasites that remained at one trophic level were less aggregated than those that had passed up a food chain. We use a stochastic model to show that high parasite aggregation in predators can be solely the result of the accumulation of parasites in their prey. The model is further developed to show that a change in the predators feeding behaviour with age may further increase parasite aggregation. PMID:27170651

  12. Stability analysis of three species food chain with competition

    NASA Astrophysics Data System (ADS)

    Abadi, Savitri, D.

    2015-03-01

    We study a food chain system that consists of 1 prey and 2 predators populations. The prey population grows logistically while the predators apply different Holling functional responses. The first predator preys on the prey following Holling type II functional response and the second predator preys on both the prey and the first predator following Holling type II and III functional responses, respectively. The study starts with the stability analysis of critical points of the systems. Then, by using normal form and centre manifold method the information about other nontrivial solutions due to bifurcation including possible limit cycles appearance is obtained. The results are confirmed by numerical simulation using MatCont and biological interpretation of the results are also presented.

  13. The changing role of veterinary expertise in the food chain.

    PubMed

    Enticott, Gareth; Donaldson, Andrew; Lowe, Philip; Power, Megan; Proctor, Amy; Wilkinson, Katy

    2011-07-12

    This paper analyses how the changing governance of animal health has impacted upon veterinary expertise and its role in providing public health benefits. It argues that the social sciences can play an important role in understanding the nature of these changes, but also that their ideas and methods are, in part, responsible for them. The paper begins by examining how veterinary expertise came to be crucial to the regulation of the food chain in the twentieth century. The relationship between the veterinary profession and the state proved mutually beneficial, allowing the state to address the problems of animal health, and the veterinary profession to become identified as central to public health and food supply. However, this relationship has been gradually eroded by the application of neoliberal management techniques to the governance of animal health. This paper traces the impact of these techniques that have caused widespread unease within and beyond the veterinary profession about the consequences for its role in maintaining the public good of animal health. In conclusion, this paper suggests that the development of the social sciences in relation to animal health could contribute more helpfully to further changes in veterinary expertise. PMID:21624916

  14. The changing role of veterinary expertise in the food chain

    PubMed Central

    Enticott, Gareth; Donaldson, Andrew; Lowe, Philip; Power, Megan; Proctor, Amy; Wilkinson, Katy

    2011-01-01

    This paper analyses how the changing governance of animal health has impacted upon veterinary expertise and its role in providing public health benefits. It argues that the social sciences can play an important role in understanding the nature of these changes, but also that their ideas and methods are, in part, responsible for them. The paper begins by examining how veterinary expertise came to be crucial to the regulation of the food chain in the twentieth century. The relationship between the veterinary profession and the state proved mutually beneficial, allowing the state to address the problems of animal health, and the veterinary profession to become identified as central to public health and food supply. However, this relationship has been gradually eroded by the application of neoliberal management techniques to the governance of animal health. This paper traces the impact of these techniques that have caused widespread unease within and beyond the veterinary profession about the consequences for its role in maintaining the public good of animal health. In conclusion, this paper suggests that the development of the social sciences in relation to animal health could contribute more helpfully to further changes in veterinary expertise. PMID:21624916

  15. COMIDA: a radionuclide food chain model for acute fallout deposition.

    PubMed

    Abbott, M L; Rood, A S

    1994-01-01

    A dynamic food chain model and computer code, named "COMIDA," has been developed to estimate radionuclide concentrations in agricultural food products following an acute fallout event. COMIDA estimates yearly harvest concentrations for five human crop types (Bq kg-1 crop per Bq m-2 deposited) and integrated concentrations for four animal products (Bq d kg-1 animal product per Bq m-2) for a unit deposition that occurs on any user-specified day of the year. COMIDA is structurally very similar to the PATHWAY model and includes the same seasonal transport processes and discrete events for soil and vegetation compartments. Animal product assimilation is modeled using simpler equilibrium models. Differential transport and ingrowth of up to three radioactive progeny are also evaluated. Benchmark results between COMIDA and PATHWAY for monthly fallout events show very similar seasonal agreement for integrated concentrations in milk and beef. Benchmark results between COMIDA and four international steady-state models show good agreement for deposition events that occur during the middle of the growing season. COMIDA will be implemented in the new Department of Energy version of the MELCOR Accident Consequence Code System for evaluation of accidental releases from nuclear power plants. PMID:8253573

  16. Asymptotic stability of tri-trophic food chains sharing a common resource.

    PubMed

    Vrkoč, Ivo; Křivan, Vlastimil

    2015-12-01

    One of the key results of the food web theory states that the interior equilibrium of a tri-trophic food chain described by the Lotka-Volterra type dynamics is globally asymptotically stable whenever it exists. This article extends this result to food webs consisting of several food chains sharing a common resource. A Lyapunov function for such food webs is constructed and asymptotic stability of the interior equilibrium is proved. Numerical simulations show that as the number of food chains increases, the real part of the leading eigenvalue, while still negative, approaches zero. Thus the resilience of such food webs decreases with the number of food chains in the web. PMID:26498384

  17. A Food Chain Algorithm for Capacitated Vehicle Routing Problem with Recycling in Reverse Logistics

    NASA Astrophysics Data System (ADS)

    Song, Qiang; Gao, Xuexia; Santos, Emmanuel T.

    2015-12-01

    This paper introduces the capacitated vehicle routing problem with recycling in reverse logistics, and designs a food chain algorithm for it. Some illustrative examples are selected to conduct simulation and comparison. Numerical results show that the performance of the food chain algorithm is better than the genetic algorithm, particle swarm optimization as well as quantum evolutionary algorithm.

  18. A false positive food chain error associated with a generic predator gut content ELISA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conventional prey-specific gut content ELISA and PCR assays are useful for identifying predators of insect pests in nature. However, these assays are prone to yielding certain types of food chain errors. For instance, it is possible that prey remains can pass through the food chain as the result of ...

  19. Arsenic Contamination in Food-chain: Transfer of Arsenic into Food Materials through Groundwater Irrigation

    PubMed Central

    Joardar, J.C.; Parvin, S.; Correll, Ray; Naidu, Ravi

    2006-01-01

    Arsenic contamination in groundwater in Bangladesh has become an additional concern vis-à-vis its use for irrigation purposes. Even if arsenic-safe drinking-water is assured, the question of irrigating soils with arsenic-laden groundwater will continue for years to come. Immediate attention should be given to assess the possibility of accumulating arsenic in soils through irrigation-water and its subsequent entry into the food-chain through various food crops and fodders. With this possibility in mind, arsenic content of 2,500 water, soil and vegetable samples from arsenic-affected and arsenic-unaffected areas were analyzed during 1999–2004. Other sources of foods and fodders were also analyzed. Irrigating a rice field with groundwater containing 0.55 mg/L of arsenic with a water requirement of 1,000 mm results in an estimated addition of 5.5 kg of arsenic per ha per annum. Concentration of arsenic as high as 80 mg per kg of soil was found in an area receiving arsenic-contaminated irrigation. A comparison of results from affected and unaffected areas revealed that some commonly-grown vegetables, which would usually be suitable as good sources of nourishment, accumulate substantially-elevated amounts of arsenic. For example, more than 150 mg/kg of arsenic has been found to be accumulated in arum (kochu) vegetable. Implications of arsenic ingested in vegetables and other food materials are discussed in the paper. PMID:17366772

  20. Costs of food waste along the value chain: evidence from South Africa.

    PubMed

    Nahman, Anton; de Lange, Willem

    2013-11-01

    In a previous paper (Nahman et al., 2012), the authors estimated the costs of household food waste in South Africa, based on the market value of the wasted food (edible portion only), as well as the costs of disposal to landfill. In this paper, we extend the analysis by assessing the costs of edible food waste throughout the entire food value chain, from agricultural production through to consumption at the household level. First, food waste at each stage of the value chain was quantified in physical units (tonnes) for various food commodity groups. Then, weighted average representative prices (per tonne) were estimated for each commodity group at each stage of the value chain. Finally, prices were multiplied by quantities, and the resulting values were aggregated across the value chain for all commodity groups. In this way, the total cost of food waste across the food value chain in South Africa was estimated at R61.5 billion per annum (approximately US$7.7 billion); equivalent to 2.1% of South Africa's annual gross domestic product. The bulk of this cost arises from the processing and distribution stages of the fruit and vegetable value chain, as well as the agricultural production and distribution stages of the meat value chain. These results therefore provide an indication of where interventions aimed at reducing food waste should be targeted. PMID:23910243

  1. Chaotic Red Queen coevolution in three-species food chains

    PubMed Central

    Dercole, Fabio; Ferriere, Regis; Rinaldi, Sergio

    2010-01-01

    Coevolution between two antagonistic species follows the so-called ‘Red Queen dynamics’ when reciprocal selection results in an endless series of adaptation by one species and counteradaptation by the other. Red Queen dynamics are ‘genetically driven’ when selective sweeps involving new beneficial mutations result in perpetual oscillations of the coevolving traits on the slow evolutionary time scale. Mathematical models have shown that a prey and a predator can coevolve along a genetically driven Red Queen cycle. We found that embedding the prey–predator interaction into a three-species food chain that includes a coevolving superpredator often turns the genetically driven Red Queen cycle into chaos. A key condition is that the prey evolves fast enough. Red Queen chaos implies that the direction and strength of selection are intrinsically unpredictable beyond a short evolutionary time, with greatest evolutionary unpredictability in the superpredator. We hypothesize that genetically driven Red Queen chaos could explain why many natural populations are poised at the edge of ecological chaos. Over space, genetically driven chaos is expected to cause the evolutionary divergence of local populations, even under homogenizing environmental fluctuations, and thus to promote genetic diversity among ecological communities over long evolutionary time. PMID:20356888

  2. Hydrocarbons and surfactants: Ecotoxicology in a marine pelagic food chain

    SciTech Connect

    Skadsheim, A.; Hoivangli, V.; Labes-Carrier, C.

    1996-12-31

    Accidental spills and production lead to discharges of petroleum hydrocarbons and surface active agents to the sea. The Norwegian government has set guidelines adopted from the OSPAR commission for assessment and studies of the environmental load from these discharges. The free water masses are poorly studied compared to the benthic processes in this context and we question how oil and surfactants might bioaccumulate in a simplified marine pelagic food chain comprised of algae, crustaceans and fish. When test methods and species recommended for initial water based acute toxicity studies are to be implemented in more comprehensive studies like assessment of bioaccumulation various problems arose. An improvement of the OSPAR method for the production of Water Accommodated Fractions (WAFs) of oil is presented. Emphasis is on control of oil concentration and distribution in water, and on applicability for studies where larger volumes of WAF are required than for the demand in acute toxicity tests. Acute toxicity assessments of one oil, Blended Arabian Light topped at 150{degrees}C, and two non-ionic dispersants, hexaetoxyparanonylphenol and a sophorolipid, were conducted on OSPAR recommended species. The toxicity responses were in line with observations made by others. At a given concentration the oil particle size during WAF preparation might influence subsequent expression of toxic effects. The same applied for the presence of emulsified oil particles in the WAR where the organisms were exposed. Reasons for selecting other test organisms than those officially recommended for continued studies on bioaccumulation are presented and discussed.

  3. Bioaccumulation of hydrophobic chemicals in an agricultural food chain

    SciTech Connect

    McLachlan, M.S.

    1995-12-31

    The concentrations of PCDD/Fs, PCBs and hexachlorobenzene were measured in an air-plant/soil-cow-human food chain in southern Germany. The data were interpreted using the fugacity modeling concept. The fugacities in air, soil and plants were found to be similar for many of the compounds, suggesting near equilibrium partitioning, while the fugacities increased somewhat from feed to cows` milk, indicating that moderate biomagnification takes place in the cow. However, a decrease in fugacity of several orders of magnitude from air to plants to cows` milk was observed for more involatile, hydrophobic compounds. This phenomenon, termed biodilution, could be attributed to two processes. Firstly, the air/plant partitioning of involatile compounds does not approach equilibrium due to the kinetically limiting air side resistance. Secondly, very hydrophobic compounds are more poorly absorbed in the digestive tract of the cow. Metabolism in cows also resulted in biodilution of certain congeners. The fugacities in human milk were 20 to 50 times higher than in cows` milk, indicating strong biomagnification.

  4. Food after Fukushima--Japan's regulatory response to the radioactive contamination of its food chain.

    PubMed

    Berends, Gijs; Kobayashi, Megumi

    2012-01-01

    The nuclear accident in Fukushima triggered a process of regulatory action, inspections, and market restrictions that has deeply affected the Japanese food market. When higher than permissible levels of radioactivity entered the food chain, the Japanese Government had to take strong measures to protect consumers. At the same time, it had to explore ways to avoid disproportionate penalties on the producers from the affected region. This article examines Japan's regulatory response to the nuclear accident and the legal instruments the government accordingly employed. Our analysis follows four regulatory steps that were taken by the government to safeguard the food chain: the establishment of maximum permissible levels for radioactive levels in food; the adoption of guidelines on how to monitor these levels; the restriction of the distribution and consumption of excessively contaminated food and, finally, where and when possible, the lifting of these restrictions. This article discusses how the Food and Drug Administration has come to adopt informal guidance (agency advice that influences regulated entities but does not carry the force and effect of law) as its primary method of policymaking, as opposed to more formalized procedures like notice-and-comment rulemaking or case-specific adjudication. Using major developments in administrative law and modifications to FDA's regulatory regime as milestones, the article traces how and why FDA's use of informal guidance to fulfill its statutory mandate has changed over the past century. Along the way, the article identifies important doctrinal questions that persist today, namely (1) whether informal advisory opinions bind FDA and (2) the degree of judicial deference guidance documents should receive under the Supreme Court's decisions in Chevron and Mead. The article attempts to resolve these doctrinal ambiguities. It then undertakes a normative analysis of FDA's increasing reliance on informal guidance, and conclude that

  5. Evolutionary consequences of food chain length in kelp forest communities.

    PubMed Central

    Steinberg, P D; Estes, J A; Winter, F C

    1995-01-01

    Kelp forests are strongly influenced by macroinvertebrate grazing on fleshy macroalgae. In the North Pacific Ocean, sea otter predation on macroinvertebrates substantially reduces the intensity of herbivory on macroalgae. Temperate Australasia, in contrast, has no known predator of comparable influence. These ecological and biogeographic patterns led us to predict that (i) the intensity of herbivory should be greater in temperate Australasia than in the North Pacific Ocean; thus (ii) Australasian seaweeds have been under stronger selection to evolve chemical defenses and (iii) Australasian herbivores have been more strongly selected to tolerate these compounds. We tested these predictions first by measuring rates of algal tissue loss to herbivory at several locations in Australasian and North Pacific kelp forests. There were significant differences in grazing rates among sea otter-dominated locations in the North Pacific (0-2% day-1), Australasia (5-7% day-1), and a North Pacific location lacking sea otters (80% day-1). The expectations that chronically high rates of herbivory in Australasia have selected for high concentrations of defensive secondary metabolites (phlorotannins) in brown algae and increased tolerance of these defenses in the herbivores also were supported. Phlorotannin concentrations in kelps and fucoids from Australasia were, on average, 5-6 times higher than those in a comparable suite of North Pacific algae, confirming earlier findings. Furthermore, feeding rates of Australasian herbivores were largely unaffected by phlorotannins, regardless of the compounds' regional source. North Pacific herbivores, in contrast, were consistently deterred by phlorotannins from both Australasia and the North Pacific. These findings suggest that top-level consumers, acting through food chains of various lengths, can strongly influence the ecology and evolution of plantherbivore interactions. Images Fig. 1 Fig. 2 Fig. 3 PMID:11607573

  6. Analysis of the sensitivity of a model of terrestrial food chains

    SciTech Connect

    Ganushik, V.; Mitro, A.; Musatova, O.; Sabova, T.

    1985-10-01

    This paper estimates, by means of a sensitivity analysis, the importance of the individual parameters of the model for terrestrial food chains. This method creates the basis for the calculation of the numerical values of the buildup factors of radionuclides in the chain deposited from the atmosphere-the content in food products. The ORB-11 model describes the transportation of radioactive substances through food chains. Several principal food products are considered: wheat, fruits, cucumbers, cabbage, potato, milk, and meat. The coefficient of sensitivity (CS) was computed for each input parameter, radionuclide, contamination route, and given change of input parameter by formula. The data obtained can be used for a stochastic approach to the mnDeling of the transportation of radioactive substances through the food chains, and to the planning of radioecological investigations.

  7. Application of a food chain model to polychlorinated biphenyl contamination of the lobster and winter flounder food chains in New Bedford Harbor

    SciTech Connect

    Connolly, J.P. Manhattan Coll., Riverdale, NY )

    1991-04-01

    As part of a Remedial Investigation/Feasibility Study for the New Bedford Harbor Superfund site a model of polychlorinated biphenyls (PCBs) in the lobster and winter flounder food chains was developed. This model successfully reproduces tri-, tetra-, penta-, and hexachlorobiphenyl concentrations observed at all levels of the food chain and across the 2 order of magnitude concentration gradient in the system. The model indicated that PCB concentrations in the flounder and, to a lesser extent, in the lobster are derived from the sediment. Dietary uptake exceeds uptake across the gill for all four homologues and becomes the dominant route at the higher chlorinated homologues. The assimilation efficiency of ingested PCB apparently declines from relatively high values for tri-chlorobiphenyl to relatively low values for hexachlorobiphenyl. Differences in observed lobster and flounder PCB concentrations appear to be due to differences in the importance of the benthic component of the food chains of these animals and differences in whole body lipid content.

  8. Purchasing Behavior and Calorie Information at Fast-Food Chains in New York City, 2007

    PubMed Central

    Bassett, Mary T.; Dumanovsky, Tamara; Huang, Christina; Silver, Lynn D.; Young, Candace; Nonas, Cathy; Matte, Thomas D.; Chideya, Sekai; Frieden, Thomas R.

    2008-01-01

    We surveyed 7318 customers from 275 randomly selected restaurants of 11 fast food chains. Participants purchased a mean of 827 calories, with 34% purchasing 1000 calories or more. Unlike other chains, Subway posted calorie information at point of purchase and its patrons more often reported seeing calorie infomation than patrons of other chains (32% vs 4%; P<.001); Subway patrons who saw calorie information purchased 52 fewer calories than did other Subway patrons (P<.01). Fast-food chains should display calorie information prominently at point of purchase, where it can be seen and used to inform purchases. PMID:18556597

  9. Purchasing behavior and calorie information at fast-food chains in New York City, 2007.

    PubMed

    Bassett, Mary T; Dumanovsky, Tamara; Huang, Christina; Silver, Lynn D; Young, Candace; Nonas, Cathy; Matte, Thomas D; Chideya, Sekai; Frieden, Thomas R

    2008-08-01

    We surveyed 7318 customers from 275 randomly selected restaurants of 11 fast food chains. Participants purchased a mean of 827 calories, with 34% purchasing 1000 calories or more. Unlike other chains, Subway posted calorie information at point of purchase and its patrons more often reported seeing calorie information than patrons of other chains (32% vs 4%; P<.001); Subway patrons who saw calorie information purchased 52 fewer calories than did other Subway patrons (P<.01). Fast-food chains should display calorie information prominently at point of purchase, where it can be seen and used to inform purchases. PMID:18556597

  10. Lost food, wasted resources: global food supply chain losses and their impacts on freshwater, cropland, and fertiliser use.

    PubMed

    Kummu, M; de Moel, H; Porkka, M; Siebert, S; Varis, O; Ward, P J

    2012-11-01

    Reducing food losses and waste is considered to be one of the most promising measures to improve food security in the coming decades. Food losses also affect our use of resources, such as freshwater, cropland, and fertilisers. In this paper we estimate the global food supply losses due to lost and wasted food crops, and the resources used to produce them. We also quantify the potential food supply and resource savings that could be made by reducing food losses and waste. We used publically available global databases to conduct the study at the country level. We found that around one quarter of the produced food supply (614 kcal/cap/day) is lost within the food supply chain (FSC). The production of these lost and wasted food crops accounts for 24% of total freshwater resources used in food crop production (27 m(3)/cap/yr), 23% of total global cropland area (31 × 10(-3)ha/cap/yr), and 23% of total global fertiliser use (4.3 kg/cap/yr). The per capita use of resources for food losses is largest in North Africa & West-Central Asia (freshwater and cropland) and North America & Oceania (fertilisers). The smallest per capita use of resources for food losses is found in Sub-Saharan Africa (freshwater and fertilisers) and in Industrialised Asia (cropland). Relative to total food production, the smallest food supply and resource losses occur in South & Southeast Asia. If the lowest loss and waste percentages achieved in any region in each step of the FSC could be reached globally, food supply losses could be halved. By doing this, there would be enough food for approximately one billion extra people. Reducing the food losses and waste would thus be an important step towards increased food security, and would also increase the efficiency of resource use in food production. PMID:23032564

  11. 40 CFR 257.3-5 - Application to land used for the production of food-chain crops (interim final).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... production of food-chain crops (interim final). 257.3-5 Section 257.3-5 Protection of Environment... Application to land used for the production of food-chain crops (interim final). (a) Cadmium. A facility or... for the production of food-chain crops shall not exist or occur, unless in compliance with...

  12. US-Based Food and Agricultural Value Chains and Their Relevance to Healthy Diets

    PubMed Central

    Gereffi, Gary; Lee, Joonkoo; Christian, Michelle

    2009-01-01

    This article examines the structure and health implications of two industries, chicken and tomatoes, that play prominent roles in US food and agricultural competitiveness. Both industries have become more concentrated over time, with powerful “lead firms” driving geographical, technological, and marketing changes. Overall, a processed food revolution has taken place in agricultural products that transforms the types of food and dietary options available to consumers. The nature of contemporary food and agricultural value chains affects the strategies and policies that can be effectively employed to address major health goals such as improved nutrition, food safety, and food security. PMID:23144675

  13. Antimicrobial Resistance in the Food Chain: A Review

    PubMed Central

    Verraes, Claire; Van Boxstael, Sigrid; Van Meervenne, Eva; Van Coillie, Els; Butaye, Patrick; Catry, Boudewijn; de Schaetzen, Marie-Athénaïs; Van Huffel, Xavier; Imberechts, Hein; Dierick, Katelijne; Daube, George; Saegerman, Claude; De Block, Jan; Dewulf, Jeroen; Herman, Lieve

    2013-01-01

    Antimicrobial resistant zoonotic pathogens present on food constitute a direct risk to public health. Antimicrobial resistance genes in commensal or pathogenic strains form an indirect risk to public health, as they increase the gene pool from which pathogenic bacteria can pick up resistance traits. Food can be contaminated with antimicrobial resistant bacteria and/or antimicrobial resistance genes in several ways. A first way is the presence of antibiotic resistant bacteria on food selected by the use of antibiotics during agricultural production. A second route is the possible presence of resistance genes in bacteria that are intentionally added during the processing of food (starter cultures, probiotics, bioconserving microorganisms and bacteriophages). A last way is through cross-contamination with antimicrobial resistant bacteria during food processing. Raw food products can be consumed without having undergone prior processing or preservation and therefore hold a substantial risk for transfer of antimicrobial resistance to humans, as the eventually present resistant bacteria are not killed. As a consequence, transfer of antimicrobial resistance genes between bacteria after ingestion by humans may occur. Under minimal processing or preservation treatment conditions, sublethally damaged or stressed cells can be maintained in the food, inducing antimicrobial resistance build-up and enhancing the risk of resistance transfer. Food processes that kill bacteria in food products, decrease the risk of transmission of antimicrobial resistance. PMID:23812024

  14. Some thoughts on using a landscape framework to address cumulative impacts on wetland food chain support

    NASA Astrophysics Data System (ADS)

    Klopatek, Jeffrey M.

    1988-09-01

    Problems of using food chain support as a functional attribute of a wetland are discussed. It is suggested that primary production may not be the metric that best evaluates food chain support. Environmental constructs of the wetland and resultant habitat variables appear to yield more information on life-support functions. A landscape-oriented approach is derived to separate hierarchically the wet-lands into ecological regions and landscape elements. This classification scheme allows for predetermination of environmental constraints and the possible natural limits of wetland food chain support. It is proposed that models derived from spatial location theory be used to determine the movement of animals from wetland patches experiencing impacts on food chain support. Patch size, distance between patches, habitat diversity, and environmental constraints are incorporated in these models.

  15. SOME THOUGHTS ON USING A LANDSCAPE FRAMEWORK TO ADDRESS CUMULATIVE IMPACTS ON WETLAND FOOD CHAIN SUPPORT

    EPA Science Inventory

    A landscape-level approach is derived to hierarchically separate the nation's wetlands into ecological regions. his classification scheme allows for the predetermination of the environmental constraints and possible natural limits of the wetlands food chain support. iscussion fol...

  16. RFID Application Strategy in Agri-Food Supply Chain Based on Safety and Benefit Analysis

    NASA Astrophysics Data System (ADS)

    Zhang, Min; Li, Peichong

    Agri-food supply chain management (SCM), a management method to optimize internal costs and productivities, has evolved as an application of e-business technologies. These days, RFID has been widely used in many fields. In this paper, we analyze the characteristics of agri-food supply chain. Then the disadvantages of RFID are discussed. After that, we study the application strategies of RFID based on benefit and safety degree.

  17. Microsporidia – Emergent Pathogens in the Global Food Chain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Intensi'cation of food production has the potential to drive increased disease prevalence in food plants and animals. Microsporidia are diversely distributed, opportunistic, and density-dependent parasites infecting hosts from almost all known animal taxa. They are frequent in highly managed aqua...

  18. Effects of nutrient recycling and food-chain length on resilience

    SciTech Connect

    DeAngelis, D.L.; Bartell, S.M. ); Brenkert, A.L. )

    1989-11-01

    The attempt to explain the observed structure of ecological food webs has been one of the recent key issues of theoretical ecology. Unquestionably, many factors are involved in determining food-web structure. The dissipation of available energy from one trophic level to the next has been emphasized by Yodzis as the major factor limiting the length of food chains. However, Pimm and Lawton and Pimm have argued that a decrease in relative stability with increasing food-chain length may also be a factor. By relative stability (more commonly, resilience), we mean the rate at which a stable ecological system returns to a steady state following a perturbation. Resilience can be defined more precisely as the inverse of the return time T{sub R}, the time it takes a systems to return a specified fraction of the way toward a steady state following a perturbation. Besides its possible significance to food-web structure, ecosystem resilience is a factor of practical importance, since it is a measure of the rate at which the ecosystem can recover from disturbances. Our purpose is to investigate resilience in food-chain and food-web models as nutrient input and the trophic structure are varied and to offer explanations of the observed model behaviors. In this paper we present the basic results by first using a simple abstract food-chain model at steady state and then showing that these results hold for a more complex food-web simulation model without a constant steady state solution.

  19. Productivity, Disturbance and Ecosystem Size Have No Influence on Food Chain Length in Seasonally Connected Rivers

    PubMed Central

    Warfe, Danielle M.; Jardine, Timothy D.; Pettit, Neil E.; Hamilton, Stephen K.; Pusey, Bradley J.; Bunn, Stuart E.; Davies, Peter M.; Douglas, Michael M.

    2013-01-01

    The food web is one of the oldest and most central organising concepts in ecology and for decades, food chain length has been hypothesised to be controlled by productivity, disturbance, and/or ecosystem size; each of which may be mediated by the functional trophic role of the top predator. We characterised aquatic food webs using carbon and nitrogen stable isotopes from 66 river and floodplain sites across the wet-dry tropics of northern Australia to determine the relative importance of productivity (indicated by nutrient concentrations), disturbance (indicated by hydrological isolation) and ecosystem size, and how they may be affected by food web architecture. We show that variation in food chain length was unrelated to these classic environmental determinants, and unrelated to the trophic role of the top predator. This finding is a striking exception to the literature and is the first published example of food chain length being unaffected by any of these determinants. We suggest the distinctive seasonal hydrology of northern Australia allows the movement of fish predators, linking isolated food webs and potentially creating a regional food web that overrides local effects of productivity, disturbance and ecosystem size. This finding supports ecological theory suggesting that mobile consumers promote more stable food webs. It also illustrates how food webs, and energy transfer, may function in the absence of the human modifications to landscape hydrological connectivity that are ubiquitous in more populated regions. PMID:23776641

  20. Bioaccumulation in food chains--a rational approach

    SciTech Connect

    Moriarty, F.; Walker, C.H.

    1987-04-01

    How much and how quickly pollutants move along food webs is an important part of predicting ecological effects. Animal size and comparative metabolism are two important aspects that have been mostly ignored.

  1. Making traceability work across the entire food supply chain.

    PubMed

    Bhatt, Tejas; Buckley, Greg; McEntire, Jennifer C; Lothian, Paul; Sterling, Brian; Hickey, Caitlin

    2013-12-01

    The Institute of Food Technologists held Traceability Research Summits on July 14, August 22, and November 1, 2011, to address how to meet the growing requirement for agriculture and food traceability. Each meeting had a group of about 50 individuals who came from food companies, trade associations, local, state, and federal governments, 3rd-party traceability solution providers, not-for-profit corporations, consultants, and consumer groups. They discussed and deliberated the objectives of traceability and the means to develop product tracing in the food system. A total of 70 people participated in the 3 summits. These individuals were invited to participate in a small workgroup responsible for considering the details related to product tracing and presenting draft concepts to the larger group on November 1, 2011, in Chicago. During this meeting, the larger assembly further refined the concepts and came to an agreement on the basic principles and overall design of the desired approach to traceability. PMID:24138197

  2. Supply chain management for small business--how to avoid being part of the food chain.

    PubMed

    Knechtges, J P; Watts, C A

    2000-08-01

    A supply chain is a series of customer and supplier relationships that extend throughout and beyond the company. It is an interwoven set of links that together form a chain supplying our customers in a seamless and integrated fashion delivering a high level of customer satisfaction. Supply chain management (SCM) integrates all activities so they are focused on customer satisfaction (both internally and externally). One of the things this article will attempt to accomplish is to provide a clear understanding of SCM's positive impact on customer service as well as on improving profitability, cash flow, product cycle times, and communication. Whether we go forward in the supply chain to the final end-user or backward in the supply chain to our supplier's suppliers, SCM will significantly improve our ability to serve our customers. PMID:11183383

  3. Food Chains & Webs. A Multimedia CD-ROM. [CD-ROM].

    ERIC Educational Resources Information Center

    2001

    This CD-ROM is designed for classroom and individual use to teach and learn about food chains and food webs. Integrated animations, custom graphics, three-dimensional representations, photographs, and sound are featured for use in user-controlled activities. Interactive lessons are available to reinforce the subject material. Pre- and post-testing…

  4. The phosphorus footprint of China's food chain: implications for food security, natural resource management, and environmental quality.

    PubMed

    Wang, F; Sims, J T; Ma, L; Ma, W; Dou, Z; Zhang, F

    2011-01-01

    Efficient use of phosphorus (P) for producing food, preventing water pollution, and managing a dwindling rock P reserve are major challenges for China. We analyzed P stocks and flows in the Chinese food chain to identify where P use efficiency can be improved, where P leaks to the environment, and the research, technologies, and policies needed to improve P use. We found a high degree of inefficiency; of 6652 Gg P entering the food chain, only 1102 Gg P (18%) exit as food for humans. The greatest inefficiencies were a large build-up of soil P (3670 Gg P yr; 52% of P inputs) and high P losses to the environment from animal production (1582 Gg P yr; 60% of excreted P). Improving P use in China must focus on national-scale nutrient management strategies, better animal nutrition, and adoption of technologies and policies to reduce P discharges from the animal sector and recycle P as manures in agriculture. PMID:21712576

  5. Moving up the information food chain: Deploying softbots on the World Wide Web

    SciTech Connect

    Etzioni, O.

    1996-12-31

    I view the World Wide Web as an information food chain. The maze of pages and hyperlinks that comprise the Web are at the very bottom of the chain. The WebCrawlers and Alta Vistas of the world are information herbivores; they graze on Web pages and regurgitate them as searchable indices. Today, most Web users feed near the bottom of the information food chain, but the time is ripe to move up. Since 1991, we have been building information carnivores, which intelligently hunt and feast on herbivores in Unix, on the Internet, and on the Web.

  6. Bioaccumulation of organic and inorganic selenium in a laboratory food chain

    SciTech Connect

    Besser, J.M.; Canfield, T.J.; La Point, T.W. )

    1993-01-01

    Aquatic organisms accumulated selenium (Se) from inorganic and organic Se species via aqueous and food-chain exposure routes. The authors measured aqueous and food-chain Se bioaccumulation from selenate, selenite, and seleno-L-methionine in a laboratory food chain of algae (Chlamydomonas reinhardtii), daphnids (Daphnia magna), and fish (bluegill, Lepomis macrochirus). Selenium concentrations were monitored radiometrically with [sup 75]Se-labeled compounds. All three organisms concentrated Se more strongly from aqueous selenomethionine than from either inorganic Se species. Bioconcentration factors estimated from 1 [mu]g Se/L Se-methionine exposures were approximately 16,000 for algae, 200,000 for daphnids, and 5,000 for bluegills. Algae and daphnids concentrated Se more strongly from selenite than selenate whereas bluegills concentrated Se about equally from both inorganic species. Bioaccumulation of foodborne Se by daphnids and bluegills was similar in food chains dosed with different Se species. Daphnids and bluegills did not accumulate Se concentrations greater than those in their diet, except at very low dietary Se concentrations. Food-chain concentration factors (CFs) for daphnids decreased from near 1.0 to 0.5 with increases in algal Se concentrations, whereas CFs estimated from bluegill exposures averaged 0.5 over a range of foodborne Se concentrations. In exposures based on selenite, bluegills accumulated greater Se concentrations from food than from water.

  7. Food chain transfer of selenium in lentic and lotic habitats of a western Canadian watershed

    SciTech Connect

    Orr, P.L.; Guiguer, K.R.; Russel, C.K.

    2006-02-15

    Selenium (Se) is an essential micronutrient, exhibiting a narrow margin between nutritionally optimal and potentially toxic concentrations. Egg-laying vertebrates at the top of aquatic food chains are most at risk in environments with elevated aqueous Se concentrations. The Elk River watershed in British Columbia, Canada receives effluents containing Se from five coal mine operations. This study tested three hypotheses that might account for higher Se concentrations in fish from lentic compared to lotic habitats in the watershed: (1) enhanced uptake by aquatic primary producers, (2) longer food chain length, or (3) greater food web accumulation through sediment-detrital pathways. Stable isotope and Se concentration data demonstrated that Se concentrations in aquatic primary producers and food chain lengths were comparable in lentic and lotic habitats. Enhanced formation of organoselenium and subsequent uptake and cycling via sediment detrital pathways likely account for higher fish tissue Se concentrations in lentic than in lotic areas.

  8. [Protection of the Croatian population from accidental radioactive contamination of the food chain].

    PubMed

    Lokobauer, N; Franić, Z; Bauman, A

    1993-03-01

    The paper indicates the importance of investigating radionuclide translocation in the human food chain, and the contribution of selected food components in total exposure of the population after accidental radioactive contamination. Data on radioactive contamination and risk assessment of the Croatian population after the Chernobyl nuclear accident are given and possibilities of decontamination of food chain components are discussed. Literature data on radionuclide removal from the human food chain are compared to the results of own investigations. Emphasis is placed on biologically most important radionuclides, 131I, 90Sr, 137Cs, and the most effective means of protection are sought. The preventive measures following a nuclear accident should be based on the cost-benefit principle i.e. the damage from applying radiation protection measures should not exceed the benefit from possible dose reduction. PMID:8347101

  9. Effectiveness of the food recovery at the retailing stage under shelf life uncertainty: An application to Italian food chains

    SciTech Connect

    Muriana, Cinzia

    2015-07-15

    Highlights: • The food recovery is seen as suitable way to manage food near to its expiry date. • The variability of the products shelf life must be taken into account. • The paper addresses the mathematic modeling of the profit related to food recovery. • The optimal time to withdraw the products is determinant for food recovery. - Abstract: Food losses represent a significant issue affecting food supply chains. The possibility of recovering such products can be seen as an effective way to reduce such a phenomenon, improve supply chain performances and ameliorate the conditions of undernourished people. The topic has been already investigated by a previous paper enforcing the hypothesis of deterministic and constant Shelf Life (SL) of products. However, such a model cannot be properly extended to products affected by uncertainties of the SL as it does not take into account the deterioration costs and loss of profits due to the overcoming of the SL within the cycle time. Thus the present paper presents an extension of the previous one under stochastic conditions of the food quality. Differently from the previous publication, this work represents a general model applicable to all supply chains, especially to those managing fresh products characterized by uncertain SL such as fruits and vegetables. The deterioration costs and loss of profits are included in the model and the optimal time at which to withdraw the products from the shelves as well as the quantities to be shipped at each alternative destination have been determined. A comparison of the proposed model with that reported in the previous publication has been carried out in order to underline the impact of the SL variability on the optimality conditions. The results show that the food recovery strategy in the presence of uncertainty of the food quality is rewarding, even if the optimal profit is lower than that of the deterministic case.

  10. HAZARDOUS WASTE IDENTIFICATION RULE (HWIR) AQUATIC FOOD CHAINS MODULE

    EPA Science Inventory

    The Aquatic Food Web (AqFW) module calculates chemical concentrations in aquatic organisms that are consumed by human and ecological receptors (e.g., fish filet; aquatic macrophytes). These concentrations are used as input to the human and ecological exposure modules to determine...

  11. Effectiveness of the food recovery at the retailing stage under shelf life uncertainty: An application to Italian food chains.

    PubMed

    Muriana, Cinzia

    2015-07-01

    Food losses represent a significant issue affecting food supply chains. The possibility of recovering such products can be seen as an effective way to reduce such a phenomenon, improve supply chain performances and ameliorate the conditions of undernourished people. The topic has been already investigated by a previous paper enforcing the hypothesis of deterministic and constant Shelf Life (SL) of products. However, such a model cannot be properly extended to products affected by uncertainties of the SL as it does not take into account the deterioration costs and loss of profits due to the overcoming of the SL within the cycle time. Thus the present paper presents an extension of the previous one under stochastic conditions of the food quality. Differently from the previous publication, this work represents a general model applicable to all supply chains, especially to those managing fresh products characterized by uncertain SL such as fruits and vegetables. The deterioration costs and loss of profits are included in the model and the optimal time at which to withdraw the products from the shelves as well as the quantities to be shipped at each alternative destination have been determined. A comparison of the proposed model with that reported in the previous publication has been carried out in order to underline the impact of the SL variability on the optimality conditions. The results show that the food recovery strategy in the presence of uncertainty of the food quality is rewarding, even if the optimal profit is lower than that of the deterministic case. PMID:25863767

  12. The food chain as a source of human exposure from municipal waste combustion: An uncertainty analysis

    SciTech Connect

    Belcher, G.D.; Travis, C.C.; Bruins, R.J.F.; Environmental Protection Agency, Cincinnati, OH . Office of Environmental Criteria and Assessment)

    1989-01-01

    The current installed incineration capacity of municipal waste combustors (MWCs) in the United States has reached approximately 50 thousand tons per day and is projected to triple over the next decade. As the use of MWCs as a waste management alternative has increased, public concern over possible environmental and human health effects has also increased. Of particular concern are health risks associated with potential exposures through the food chain. The food chain is the primary pathway of human exposure for a large class of organics, such as dioxin, PCBs, DDT, and other pesticides. Because many pollutants emitted by MWCs are lipophilic, extremely persistent compounds, they tend to sorb strong to air particles, soil, and sediment and to bioaccumulate in living organisms. As a result, the food chain can be a major pathway of exposure to pollutants emitted by MWCs. It is the purpose of this paper to assess the magnitude of human exposure through the food chain for two pollutants released by MWCs: cadmium and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), commonly referred to as dioxin. These pollutants were chosen as representative of two chemical classes: metals and organics. Cadmium is a metal which presumably will enter the food chain primarily through vegetative root uptake, while dioxin is an extremely lipophilic compound which will bioconcentrate in beef and milk. 57 refs., 7 figs., 14 tabs.

  13. Stable nitrogen isotope ratios and accumulation of various HOCs in northern Baltic aquatic food chains

    SciTech Connect

    Broman, D.; Axelman, J.; Bergqvist, P.A.; Naef, C.; Rolff, C.; Zebuehr, Y.

    1995-12-31

    Ratios of naturally occurring stable isotopes of nitrogen ({delta}{sup 15}N) can be used to numerically classify trophic levels of organisms in food chains. By combining analyses results of various HOCs (e.g. PCDD/Fs, PCBs, DDTs, HCHs and some other pesticides) the biomagnification of these substances can be quantitatively estimated. In this paper different pelagic and benthic northern Baltic food chains were studied. The {delta}{sup 15}N-data gave food chain descriptions qualitatively consistent with previous conceptions of trophic arrangements in the food chains. The different HOCs concentrations were plotted versus the {delta}{sup 15}N-values for the different trophic levels and an exponential model of the form e{sup (A+B*{delta}N)} was fitted to the data. The estimates of the constant B in the model allows for an estimation of a biomagnification power (B) of different singular, or groups of, contaminants. A B-value around zero indicates that a substance is flowing through the food chain without being magnified, whereas a value > 0 indicates that a substance is biomagnified. Negative B-values indicate that a substance is not taken up or is metabolized. The A-term of the expression is only a scaling factor depending on the background level of the contaminant.

  14. Improving food safety within the dairy chain: an application of conjoint analysis.

    PubMed

    Valeeva, N I; Meuwissen, M P M; Lansink, A G J M Oude; Huirne, R B M

    2005-04-01

    This study determined the relative importance of attributes of food safety improvement in the production chain of fluid pasteurized milk. The chain was divided into 4 blocks: "feed" (compound feed production and its transport), "farm" (dairy farm), "dairy processing" (transport and processing of raw milk, delivery of pasteurized milk), and "consumer" (retailer/catering establishment and pasteurized milk consumption). The concept of food safety improvement focused on 2 main groups of hazards: chemical (antibiotics and dioxin) and microbiological (Salmonella, Escherichia coli, Mycobacterium paratuberculosis, and Staphylococcus aureus). Adaptive conjoint analysis was used to investigate food safety experts' perceptions of the attributes' importance. Preference data from individual experts (n = 24) on 101 attributes along the chain were collected in a computer-interactive mode. Experts perceived the attributes from the "feed" and "farm" blocks as being more vital for controlling the chemical hazards; whereas the attributes from the "farm" and "dairy processing" were considered more vital for controlling the microbiological hazards. For the chemical hazards, "identification of treated cows" and "quality assurance system of compound feed manufacturers" were considered the most important attributes. For the microbiological hazards, these were "manure supply source" and "action in salmonellosis and M. paratuberculosis cases". The rather high importance of attributes relating to quality assurance and traceability systems of the chain participants indicates that participants look for food safety assurance from the preceding participants. This information has substantial decision-making implications for private businesses along the chain and for the government regarding the food safety improvement of fluid pasteurized milk. PMID:15778330

  15. Use of calorie information at fast-food and chain restaurants among US Adults, 2009

    PubMed Central

    Wethington, Holly; Maynard, Leah M.; Haltiwanger, Christine; Blanck, Heidi M.

    2015-01-01

    Background The aim of this study was to examine reading and use of calorie information at fast-food/chain restaurants. Methods A cross-sectional analysis was conducted on a sample of 4363 US adults using the 2009 HealthStyles survey. The outcome variable was reading calorie information when available while ordering at fast-food/chain restaurants. Among those who go to fast-food/chain restaurants, we conducted multivariable logistic regression to examine associations between sociodemographic variables and reading calorie information when available. Among those who report reading calorie information when available, we assessed the proportion using calorie information. Results Among those who reported eating at fast-food/chain restaurants, 36.4% reported reading calorie information when available. Reading calorie information was not related to race/ethnicity, income or education. Compared with men, women had higher odds [adjusted odds ratio (OR) =1.8; 95% confidence interval (CI) =1.5–2.1] of reading calorie information when available while those who frequented fast-food/chain restaurants ≥3 times/week (aOR =0.6; 95% CI =0.4–0.8) had lower odds compared with those going <4 times/month. Of those who reported reading calorie information when available, 95.4% reported using calorie information at least sometimes. Conclusions Almost all who read calorie information when available use the information at least sometimes. Research is needed on how calorie information is being used. PMID:24263224

  16. Longer Food Chains in Pelagic Ecosystems: Trophic Energetics of Animal Body Size and Metabolic Efficiency.

    PubMed

    McGarvey, Richard; Dowling, Natalie; Cohen, Joel E

    2016-07-01

    Factors constraining the structure of food webs can be investigated by comparing classes of ecosystems. We find that pelagic ecosystems, those based on one-celled primary producers, have longer food chains than terrestrial ecosystems. Yet pelagic ecosystems have lower primary productivity, contrary to the hypothesis that greater energy flows permit higher trophic levels. We hypothesize that longer food chain length in pelagic ecosystems, compared with terrestrial ecosystems, is associated with smaller pelagic animal body size permitting more rapid trophic energy transfer. Assuming negative allometric dependence of biomass production rate on body mass at each trophic level, the lowest three pelagic animal trophic levels are estimated to add biomass more rapidly than their terrestrial counterparts by factors of 12, 4.8, and 2.6. Pelagic animals consequently transport primary production to a fifth trophic level 50-190 times more rapidly than animals in terrestrial webs. This difference overcomes the approximately fivefold slower pelagic basal productivity, energetically explaining longer pelagic food chains. In addition, ectotherms, dominant at lower pelagic animal trophic levels, have high metabolic efficiency, also favoring higher rates of trophic energy transfer in pelagic ecosystems. These two animal trophic flow mechanisms imply longer pelagic food chains, reestablishing an important role for energetics in food web structure. PMID:27322123

  17. Food Chain Defense and Its Potential Implications on Traditional Foods: The Portuguese Case

    NASA Astrophysics Data System (ADS)

    Veiga, Alexandra; Empis, José

    Traditional foods are presented as important components of local diets characterised by unique dispersed production, hence providing specific scenarios of compliance with Food Safety and Food Defense practices. The evolution of attitudes towards Food Safety and Food Defense during the last years, with the concomitant and resulting legislative changes, has affected traditional foods. Their present and future consequences for the production and consumption of these important cultural, societal and economical components of local diets are discussed, and the Portuguese case is presented in more detail.

  18. Evaluation of the safety assurance level for Salmonella spp. throughout the food production chain in Switzerland.

    PubMed

    Sauli, I; Danuser, J; Wenk, C; Stärk, K D C

    2003-07-01

    In Switzerland. the safeguarding of food is the responsibility of industry, organizations, and governmental authorities. The dispersion of the tasks and the diversity of implemented safety measures among involved stakeholders do not allow a general overview of the national safety assurance level provided. A comprehensive evaluation of the level of safety assurance provided for foodborne pathogens such as Salmonella spp. is therefore lacking, and the prevalence of Salmonella spp. at various points in the food production chain is not known. The objectives of this study were to (i) collect data on safety measures implemented throughout the food production chain in Switzerland regarding Salmonella spp.; (ii) evaluate the safety assurance level for Salmonella spp. at each step of the production chain for chicken meat, pork, beef, and milk and dairy products (bovine origin); and (iii) gather data on the prevalence of the pathogen at each step. Data on implemented safety assurance measures for Salmonella spp. were gathered from the various stakeholders in the food production chain. The data were analyzed by a semiquantitative method that considered the quality and relevance of the implemented safety measures for Salmonella spp. The safety assurance level for Salmonella spp. was evaluated from "no safety assurance" to "very good safety assurance." Available results of testing for Salmonella spp. from 1998 to 2000 were used for calculating the prevalence of the pathogen throughout the food production chain. The results showed a varying safety assurance level for Salmonella spp. throughout the food production chain. Strengths (e.g., feed production for chickens) and weaknesses (e.g., pork production) were observed. These results serve as a basis for a rational optimization of the system. PMID:12870745

  19. Changes in sodium levels in chain restaurant foods in Canada (2010−2013): a longitudinal study

    PubMed Central

    Scourboutakos, Mary J.

    2014-01-01

    Background Several restaurant chains have committed to reducing sodium levels in their foods; however, how much sodium levels have changed over the past few years is unknown. The objective was to measure changes in sodium in restaurant foods from 2010 to 2013. Methods Data for the serving size, calorie and sodium level of 3878 foods were collected from the websites of 61 Canadian restaurant chains in 2010 and 2013. A longitudinal study of changes in sodium levels in foods available from the restaurants in 2010 and 2013 (n = 2198) was conducted. Levels in newly reported and discontinued foods were also investigated. Results Sodium levels (mg/serving) decreased in 30.1% of foods, increased in 16.3% and were unchanged in 53.6%. The average change in foods with a decrease in sodium was –220 (standard deviation [SD] ± 303) mg/serving (a decline of 19% [SD ± 17%]), whereas the average change in foods with an increase in sodium was 251 (SD ± 349) mg/serving (a 44% [SD ± 104%] increase). The prevalence and magnitude of change varied depending on the restaurant and food category. Overall, there was a small, yet significant, decrease in sodium per serving (–25 [SD ± 268] mg, p < 0.001); however, the percentage of foods exceeding the daily sodium adequate intake (1500 mg) and tolerable upper intake level (2300 mg) remained unchanged. Interpretation The observed increases and decreases in sodium show that industry efforts to voluntarily decrease sodium levels in Canadian restaurant foods have produced inconsistent results. Although the lower levels in some foods show that sodium reduction is possible, the simultaneous increase in other foods demonstrates the need for targets and timelines for sodium reduction in restaurants. PMID:25553327

  20. Accumulation of potentially toxic elements in plants and element transfer to human food chain

    SciTech Connect

    Dudka, S.; Miller, W.P.

    1995-12-31

    This paper summarizes the biological pathways of cadmium, mercury, and lead into the human food chain; major sources of bioaccumulation; and exposure limits. For occupationally non-exposed persons and non-smokers, food is the main source of cadmium. About one-third of the total Cd burden originates from animal products and two-thirds from plant products. Consumption of fish and other aquatic animals is the main source of Hg intake by humans. The Provisional Tolerable Weekly Intake (PTWI) of Hg is achieved through occupational exposure or by consumption of large amounts of contaminated fish. About half of human Pb intake comes from food, of which more than half originates from plants. Drinking water and ingestion of Pb-rich soil and dust make up the other half of the Pb burden in humans. Cases of cadmium and methylmercury poisoning have been reported in Japan. No acute hazard from lead in the food chain has been determined so far.

  1. Potential contaminants in the food chain: identification, prevention and issue management.

    PubMed

    Scanlan, Francis P

    2007-01-01

    Contaminants are a vast subject area of food safety and quality. They are generally divided into chemical, microbiological and physical classes and are present in our food chain from raw materials to finished products. They are the subject of international and national legislation that has widened to cover more and more contaminant classes and food categories. In addition, consumers have become increasingly aware of and alarmed by their risks, whether rightly or not. What is the food industry doing to ensure the safety and quality of the products we feed our children? This is a valid question which this article attempts to address from an industrial viewpoint. Chemical food safety is considered a complex field where the risk perception of consumers is often the highest. The effects of chronic or acute exposure to chemical carcinogens may cause disease conditions long after exposure that can be permanently debilitating or even fatal. It is also a moving target, as knowledge about the toxicity and occurrence data of new chemical contaminants continues to be generated. Their identification, prevention and management are challenges to the food industry as a whole. A reminder of the known chemical hazards in the food chain will be presented with an emphasis on the use of early warning to identify potential new contaminants. Early warning is also a means of prevention, anticipating food safety concerns before they become issues to manage. Current best management practices including Hazard Analysis and Critical Control Points relating to the supply chain of baby foods and infant formulae will be developed. Finally, key lessons from a case study on recent contamination issues in baby food products will be presented. PMID:17664897

  2. Branched Chain Fatty Acid (BCFA) Content of Foods and Estimated Intake in the United States

    PubMed Central

    Bae, SangEun; Lawrence, Peter; Wang, Dong Hao

    2015-01-01

    Branched chain fatty acids (BCFA) are bioactive food components that constitute about 2% of fatty acids in cow’s milk fat. Little systematic information on the BCFA content of other foods is available to estimate dietary intakes. We report BCFA distribution and content of fresh and processed foods representing the major foods of Americans and estimate BCFA intake. BCFA are primarily components of dairy and ruminant foods, and were absent from chicken, pork, and salmon. Dairy and beef delivered most of the 500 mg per day mean intake; in comparison, intake of the widely studied long chain polyunsaturates eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is estimated to average 100 mg per day. Common adjustments in diet can double BCFA daily intake. The fermented foods sauerkraut and miso had appreciable fractions of BCFA but overall are low fat foods providing very small amounts in the diet, and other fermented foods did not contain BCFA as might have been expected from microbial exposure. These data support the quantitative importance of BCFA delivered primarily from dairy and beef and highlight the need for research into their health effects. PMID:24830474

  3. Modelling food chain structure and contaminant bioaccumulation using stable nitrogen isotopes

    NASA Astrophysics Data System (ADS)

    Cabana, Gilbert; Rasmussen, Joseph B.

    1994-11-01

    THE nitrogen pools of animals are enriched in 15N relative to their food1, with the top predators having the highest concentrations of this stable isotope2. The use of δ15N to indicate trophic position depends on the degree to which it reflects variation in the underly-ing food-web structure, rather than variable fractionation along the food chain. Here we compare adult lake trout, a top pelagic predator, from a series of lakes, and find that δ15N values vary from 7.5 to 17.5%o, a surprisingly wide range for one species. The length of the food chain can explain this variation, supporting the idea that δ15N is a food-web descriptor. Food-chain length was measured by the presence or absence of two intermediate trophic levels, pelagic forage fish and the macrozooplankter, Mysis relicta, each of which when present contributes about three δ15N units to the trout signature. We find that δ15N can be used as a continuous, integrative measure of trophic position, which is supported by its correlation to mercury levels in lake trout.

  4. Copper transfer and influence on a marine food chain

    SciTech Connect

    Edding, M.; Tala, F.

    1996-12-31

    Copper is an essential element, required for normal growth by all plants and animals; and a regular constituent in the environment (Lewis and Cave 1982; Lewis 1994). This heavy metal is an essential micronutrient that at higher concentrations can be deleterious to algae and other aquatic biota (Chang and Sibley 1993). Copper toxicity to algae depends upon the individual species, their physiological and environmental conditions, and the chemical forms of metal in the medium (Sunda and Gullard 1976). When copper is accumulated by phytoplankton it can be transferred and may produce toxic effects on zooplankton (Wikfors and Ukeles 1982). Different species of microalgae present different capacities of resistance to copper. Cyanophyceae pre-cultured in a Cu-enriched medium (635 {mu}gCu{center_dot}L{sup {minus}1}) showed an EC{sub 50} that could reach 318 {mu}gCu{center_dot}L{sup {minus}1} for Plectonema radiosum and 339 {mu}gCu{center_dot}L{sup {minus}1} in Phormidium sp. (Takamura et al. 1990). Scenedesmus, Selenastrum and Chlorella were reported able to accumulate copper and other metal ions with an efficiency of 67-98% (Brady et al. 1994). Also, Dunaliella resisted concentrations form 0.38 mgCu{center_dot}L{sup {minus}1} (D. minuta) up to 50.8 mgCu{center_dot}L{sup {minus}1} (D. acidophila), depending on the pH of the medium (Grimmler et al. 1991). One the microalgae are copper-enriched, the copper that is part of the cell can be transferred to the surrounding water and to its predator producing uncertain effects. This study observed the effect of copper on the growth of Dunaliella tertiolecta and Isochrysis galbana that are currently used as food for hatchery-grown scallop larvae (Argopecten purpuratus). We observed the path of copper form the water column into the microalgal cell and the effect of copper-enriched food on the scallop larvae. 16 refs., 3 figs., 2 tabs.

  5. Management traceability information system for the food supply chain

    NASA Astrophysics Data System (ADS)

    Bendriss, S.; Benabdelhafid, A.; Boukachour, J.

    2008-06-01

    For a long time, the traceability was applied only for management reasons, but with the advent of new communication and information technologies more and more used in the logistic medium, the notion of the traceability became new extensive to meet the new market needs in term of information by ensuring accessibility the data characteristic or been dependent on the product throughout its life cycle. On the basis of this postulate, we tried to raise some questions of research, beginning by the presentation of the progress achieved, assumptions and objective relating to the traceability, in the second time we mentioned principal work by showing how evolved the scientific question especially the information systems integrating the traceability were developed very little in the literature. Based on what was developed in the first part, we present our generic modeling approach of communicating product "smart object", able to take into account the various essential elements for its traceability: the product in its various states, various operations carried out on the product, resources used, its localization, and interactions between the product and its environment carried out on the basis of whole of service. In order to validate our generic modeling, a case of study representing an application in a context of food industry is presented.

  6. Polyunsaturated fatty acids in the food chain in Europe.

    PubMed

    Sanders, T A

    2000-01-01

    Intakes of partially hydrogenated fish oil and animal fats have declined and those of palm, soybean, sunflower, and rapeseed oils have increased in northern Europe in the past 30 y. Soybean and rapeseed oils are currently the most plentiful liquid vegetable oils and both have desirable ratios of n-6 to n-3 fatty acids. However, soybean and rapeseed oils are commonly partially hydrogenated for use in commercial frying to decrease susceptibility to oxidative degradation. This process leads to selective losses of alpha-linolenic acid (18:3n-3). Intake of linoleic acid (18:2n-6) has risen in many northern European countries. In the United Kingdom, intakes have increased from approximately 10 g/d in the late 1970s to approximately 15 g/d in the 1990s. The intake of alpha-linolenic acid is estimated to be approximately 1-2 g/d but varies with the type of culinary oil used. There are few reliable estimates of the intake of long-chain n-3 fatty acids, but those are generally approximately 0.1-0.5 g/d. The increased use of intensive, cereal-based livestock production systems has resulted in a lower proportion of n-3 fatty acids in meat compared with traditional extensive production systems. Overall, there has been a shift in the balance between n-6 and n-3 fatty acids over the past 30 y. This shift is reflected in the declining concentrations of docosahexaenoic acid and rising concentrations of linoleic acid in breast milk. PMID:10617968

  7. Northern Marshall Islands radiological survey: terrestrial food chain and total doses

    SciTech Connect

    Robison, W.L.; Mount, M.E.; Phillips, W.A.; Conrado, C.A.; Stuart, M.L.; Stoker, C.E.

    1982-09-30

    A radiological survey was conducted from September through November of 1978 to assess the concentrations of persistent manmade radionuclides in the terrestrial and marine environments of 11 atolls and 2 islands in the Northern Marshall Islands. The survey consisted mainly of an aerial radiological reconnaissance to map the external gamma-ray exposure rates over the islands of each atoll. The logistical support for the entire survey was designed to accommodate this operation. As a secondary phase of the survey, shore parties collected appropriate terrestrial and marine samples to assess the radiological dose from pertinent food chains to those individuals residing on the atolls, who may in the future reside on some of the presently uninhabited atolls, or who collect food from these atolls. Over 5000 terrestrial and marine samples were collected for radionuclide analysis from 76 different islands. Soils, vegetation, indigenous animals, and cistern water and groundwater were collected from the islands. Reef and pelagic fish, clams, lagoon water, and sediments were obtained from the lagoons. The concentration data for /sup 90/Sr, /sup 137/Cs, /sup 238/Pu, /sup 239/ /sup 240/Pu, and /sup 241/Am in terrestrial food crops, fowl, and animals collected at the atolls or islands are summarized. An assessment of the total dose from the major exposure pathways including external gamma, terrestrial food chain including food products and drinking water, marine food chain, and inhalation is provided. Radiological doses at each atoll or island are calculated from the average radionuclide concentrations in the terrestrial foods, marine foods, etc. assuming the average daily intake for each food item.

  8. The direct application of the polymerase chain reaction to DNA extracted from foods.

    PubMed

    Dickinson, J H; Kroll, R G; Grant, K A

    1995-04-01

    Two methods for the successful extraction of DNA from foods are described. The rapid lysis method uses a proteinase K buffer system to lyse cells and solubilize food samples. DNA is then precipitated using isopropanol. The second method achieves cell lysis using toluene and mutanolysin, and solubilization using guanidium thiocyanate. Following protein removal with organic solvents DNA is precipitated with isopropanol. Both methods enabled the polymerase chain reaction to be applied directly to DNA extracted from samples of cheese, coleslaw and raw chicken and allowed the direct rapid, sensitive and specific detection of Yersinia enterocolitica, Aerococcus viridans and Listeria monocytogenes in these foods. PMID:7766115

  9. Ecological risk characterization based on exposure to contaminants through the Rocky Mountain Arsenal aquatic food chains

    SciTech Connect

    Toll, J.E.; Cothern, K.A.; Pavlou, S.; Tate, D.J.; Armstrong, J.P.

    1994-12-31

    This paper describes ecological risk characterization methods and results for characterizing potential risk from exposure to bioaccumulative contaminants of concern (aldrin, dieldrin, endrin, DDT, DDE, and mercury) through the lake food chains at Rocky Mountain Arsenal (RMA). Aquatic risks were estimated for the bald eagle, great blue heron, shorebird, and water bird using a prey-tissue-concentration-based food web model. Methods for estimating missing tissue concentration data were developed on a case-by-case basis and will be described. A sediment-based food web model was also considered and the reasons for its rejection will be described. Generalizable insights from the aquatic ecological risk characterization will be discussed.

  10. Trends and advances in food analysis by real-time polymerase chain reaction.

    PubMed

    Salihah, Nur Thaqifah; Hossain, Mohammad Mosharraf; Lubis, Hamadah; Ahmed, Minhaz Uddin

    2016-05-01

    Analyses to ensure food safety and quality are more relevant now because of rapid changes in the quantity, diversity and mobility of food. Food-contamination must be determined to maintain health and up-hold laws, as well as for ethical and cultural concerns. Real-time polymerase chain reaction (RT-PCR), a rapid and inexpensive quantitative method to detect the presence of targeted DNA-segments in samples, helps in determining both accidental and intentional adulterations of foods by biological contaminants. This review presents recent developments in theory, techniques, and applications of RT-PCR in food analyses, RT-PCR addresses the limitations of traditional food analyses in terms of sensitivity, range of analytes, multiplexing ability, cost, time, and point-of-care applications. A range of targets, including species of plants or animals which are used as food ingredients, food-borne bacteria or viruses, genetically modified organisms, and allergens, even in highly processed foods can be identified by RT-PCR, even at very low concentrations. Microfluidic RT-PCR eliminates the separate sample-processing step to create opportunities for point-of-care analyses. We also cover the challenges related to using RT-PCR for food analyses, such as the need to further improve sample handling. PMID:27407185

  11. The Priority position paper: Protecting Europe's food chain from prions.

    PubMed

    Requena, Jesús R; Kristensson, Krister; Korth, Carsten; Zurzolo, Chiara; Simmons, Marion; Aguilar-Calvo, Patricia; Aguzzi, Adriano; Andreoletti, Olivier; Benestad, Sylvie L; Böhm, Reinhard; Brown, Karen; Calgua, Byron; Del Río, José Antonio; Espinosa, Juan Carlos; Girones, Rosina; Godsave, Sue; Hoelzle, Ludwig E; Knittler, Michael R; Kuhn, Franziska; Legname, Giuseppe; Laeven, Paul; Mabbott, Neil; Mitrova, Eva; Müller-Schiffmann, Andreas; Nuvolone, Mario; Peters, Peter J; Raeber, Alex; Roth, Klaus; Schmitz, Matthias; Schroeder, Björn; Sonati, Tiziana; Stitz, Lothar; Taraboulos, Albert; Torres, Juan María; Yan, Zheng-Xin; Zerr, Inga

    2016-05-01

    Bovine spongiform encephalopathy (BSE) created a global European crisis in the 1980s and 90s, with very serious health and economic implications. Classical BSE now appears to be under control, to a great extent as a result of a global research effort that identified the sources of prions in meat and bone meal (MBM) and developed new animal-testing tools that guided policy. Priority ( www.prionpriority.eu ) was a European Union (EU) Framework Program 7 (FP7)-funded project through which 21 European research institutions and small and medium enterprises (SMEs) joined efforts between 2009 and 2014, to conduct coordinated basic and applied research on prions and prion diseases. At the end of the project, the Priority consortium drafted a position paper ( www.prionpriority.eu/Priority position paper) with its main conclusions. In the present opinion paper, we summarize these conclusions. With respect to the issue of re-introducing ruminant protein into the feed-chain, our opinion is that sustaining an absolute ban on feeding ruminant protein to ruminants is essential. In particular, the spread and impact of non-classical forms of scrapie and BSE in ruminants is not fully understood and the risks cannot be estimated. Atypical prion agents will probably continue to represent the dominant form of prion diseases in the near future in Europe. Atypical L-type BSE has clear zoonotic potential, as demonstrated in experimental models. Similarly, there are now data indicating that the atypical scrapie agent can cross various species barriers. More epidemiological data from large cohorts are necessary to reach any conclusion on the impact of its transmissibility on public health. Re-evaluations of safety precautions may become necessary depending on the outcome of these studies. Intensified searching for molecular determinants of the species barrier is recommended, since this barrier is key for important policy areas and risk assessment. Understanding the structural basis for

  12. The Priority position paper: Protecting Europe's food chain from prions

    PubMed Central

    Kristensson, Krister; Korth, Carsten; Zurzolo, Chiara; Simmons, Marion; Aguilar-Calvo, Patricia; Aguzzi, Adriano; Andreoletti, Olivier; Benestad, Sylvie L.; Böhm, Reinhard; Brown, Karen; Calgua, Byron; del Río, José Antonio; Espinosa, Juan Carlos; Girones, Rosina; Godsave, Sue; Hoelzle, Ludwig E.; Knittler, Michael R.; Kuhn, Franziska; Legname, Giuseppe; Laeven, Paul; Mitrova, Eva; Müller-Schiffmann, Andreas; Nuvolone, Mario; Peters, Peter J.; Raeber, Alex; Roth, Klaus; Schmitz, Matthias; Schroeder, Björn; Sonati, Tiziana; Stitz, Lothar; Taraboulos, Albert; Torres, Juan María; Yan, Zheng-Xin; Zerr, Inga

    2016-01-01

    ABSTRACT Bovine spongiform encephalopathy (BSE) created a global European crisis in the 1980s and 90s, with very serious health and economic implications. Classical BSE now appears to be under control, to a great extent as a result of a global research effort that identified the sources of prions in meat and bone meal (MBM) and developed new animal-testing tools that guided policy. Priority (www.prionpriority.eu) was a European Union (EU) Framework Program 7 (FP7)-funded project through which 21 European research institutions and small and medium enterprises (SMEs) joined efforts between 2009 and 2014, to conduct coordinated basic and applied research on prions and prion diseases. At the end of the project, the Priority consortium drafted a position paper (www.prionpriority.eu/Priority position paper) with its main conclusions. In the present opinion paper, we summarize these conclusions. With respect to the issue of re-introducing ruminant protein into the feed-chain, our opinion is that sustaining an absolute ban on feeding ruminant protein to ruminants is essential. In particular, the spread and impact of non-classical forms of scrapie and BSE in ruminants is not fully understood and the risks cannot be estimated. Atypical prion agents will probably continue to represent the dominant form of prion diseases in the near future in Europe. Atypical L-type BSE has clear zoonotic potential, as demonstrated in experimental models. Similarly, there are now data indicating that the atypical scrapie agent can cross various species barriers. More epidemiological data from large cohorts are necessary to reach any conclusion on the impact of its transmissibility on public health. Re-evaluations of safety precautions may become necessary depending on the outcome of these studies. Intensified searching for molecular determinants of the species barrier is recommended, since this barrier is key for important policy areas and risk assessment. Understanding the structural basis

  13. Mobilising the Commodity Chain Concept in the Politics of Food and Farming

    ERIC Educational Resources Information Center

    Jackson, Peter; Ward, Neil; Russell, Polly

    2006-01-01

    Focusing on the concept of "commodity chains" within the food industry, this paper analyses the term's widespread and variable usage in both academic and policy-orientated work. Despite recent criticisms, the concept has retained its popular appeal alongside competing metaphors such as networks, circuits and assemblages. Examining the concept in…

  14. Preconceptions and Relations Used by Children in the Construction of Food Chains.

    ERIC Educational Resources Information Center

    Gallegos, Leticia; And Others

    1994-01-01

    Examines the predator-prey relations and the preconceptions held by children (n=506) on the construction of food chains. Results show that the classification of herbivores and carnivores is based on children's preconceptions of size and ferocity and sheds light on the difficulties students have at higher education levels in the resolution of food…

  15. Seeking Emotional Involvement in Science Education: Food-Chains and Webs.

    ERIC Educational Resources Information Center

    Alsop, Steve

    2001-01-01

    Documents a study of emotion in two grade 8 science classrooms. Describes a lesson on food-chains and webs designed with a conceptual and an emotional agenda. Discusses issues of emotion, sensation and relevance in science teaching. (Author/MM)

  16. Food Chains. Animal Life in Action[TM]. Schlessinger Science Library. [Videotape].

    ERIC Educational Resources Information Center

    2000

    This 23-minute videotape for grades 5-8, presents the myriad of animal life that exists on the planet. Students can view and perform experiments and investigations that help explain animal traits and habits. The food chain provides a clear example of how life continues year after year. Students learn how the cycle of energy starts with the sun,…

  17. MODELLING KEPONE IN THE STRIPED BASS FOOD CHAIN OF THE JAMES RIVER ESTUARY

    EPA Science Inventory

    A mathematical model that computes the accumulation of Kepone in the striped bass food chain of the James River estuary was developed. The purpose of the model was to help understand the relationship of Kepone levels in important fish species to sediment and water column Kepone c...

  18. Ecological vulnerability in wildlife: application of a species-ranking method to food chains and habitats.

    PubMed

    De Lange, Hendrika J; Lahr, Joost; Van der Pol, Joost J C; Faber, Jack H

    2010-12-01

    Nature development in The Netherlands is often planned on contaminated soils or sediments. This contamination may present a risk for wildlife species desired at those nature development sites and must be assessed by specific risk assessment methods. In a previous study, we developed a method to predict ecological vulnerability in wildlife species by using autecological data and expert judgment; in the current study, this method is further extended to assess ecological vulnerability of food chains and terrestrial and aquatic habitats typical for The Netherlands. The method is applied to six chemicals: Cd, Cu, Zn, dichlorodiphenyltrichloroethane, chlorpyrifos, and ivermectin. The results indicate that species in different food chains differ in vulnerability, with earthworm-based food chains the most vulnerable. Within and between food chains, vulnerability varied with habitat, particularly at low trophic levels. The concept of habitat vulnerability was applied to a case study of four different habitat types in floodplains contaminated with cadmium and zinc along the river Dommel, The Netherlands. The alder floodplain forest habitat contained the most vulnerable species. The differences among habitats were significant for Cd. We further conclude that the method has good potential for application in mapping of habitat vulnerability. PMID:20973107

  19. A Specific Qualitative Detection Method for Peanut (Arachis Hypogagea) in Foods Using Polymerase Chain Reaction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A qualitative method for detection of peanuts in foods using polymerase chain reaction was developed. A universal primer pair CP 03-5 /CP 03-3 was designed to confirm the validity of the DNAs for PCR. The plant-specific amplified fragments were detected from 13 kinds of plants using the universal pr...

  20. A Specific Qualitative Detection Method for Peanut (Arachis Hypogaea) in Foods Using Polymerase Chain Reaction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We developed a qualitative detection method for peanuts in foods using polymerase chain reaction (PCR). We designed a universal primer pair CP 03-5’/ CP 03-3’ to confirm the validity of the DNAs for PCR. The plant specific amplified fragments were detected from 13 kinds of plants using the universal...

  1. The Reinforcing Effects of Houselight Illumination during Chained Schedules of Food Presentation

    ERIC Educational Resources Information Center

    Allen, Ron; Kupfer, Jeff; Malagodi, E. F.

    2008-01-01

    Pigeons' keypecking was maintained under two- and three-component chained schedules of food presentation. The component schedules were all fixed-interval schedules of either 1- or 2-min duration. Across conditions the presence of houselight illumination within each component schedule was manipulated. For each pigeon, first-component response rates…

  2. Ecohydrological streamflow distributions and hydraulic food chain models

    NASA Astrophysics Data System (ADS)

    Ceola, S.; Botter, G.; Bertuzzo, E.; Mari, L.; Rodriguez-Iturbe, I.; Rinaldo, A.

    2010-12-01

    storage and discharge from observed p(Q) are also drawn. A quantitative analysis of the possible implications of hydrological fluctuations on river ecosystems, from a food-web perspective based on mass balance equations for detritus, vegetation, grazers and predators, is finally presented.

  3. The role of discharge variation in scaling of drainage area and food chain length in rivers

    USGS Publications Warehouse

    Sabo, John L.; Finlay, Jacques C.; Kennedy, Theodore A.; Post, David M.

    2010-01-01

    Food chain length (FCL) is a fundamental component of food web structure. Studies in a variety of ecosystems suggest that FCL is determined by energy supply, environmental stability, and/or ecosystem size, but the nature of the relationship between environmental stability and FCL, and the mechanism linking ecosystem size to FCL, remain unclear. Here we show that FCL increases with drainage area and decreases with hydrologic variability and intermittency across 36 North American rivers. Our analysis further suggests that hydrologic variability is the mechanism underlying the correlation between ecosystem size and FCL in rivers. Ecosystem size lengthens river food chains by integrating and attenuating discharge variation through stream networks, thereby enhancing environmental stability in larger river systems.

  4. Microbial source tracking: a tool for identifying sources of microbial contamination in the food chain.

    PubMed

    Fu, Ling-Lin; Li, Jian-Rong

    2014-01-01

    The ability to trace fecal indicators and food-borne pathogens to the point of origin has major ramifications for food industry, food regulatory agencies, and public health. Such information would enable food producers and processors to better understand sources of contamination and thereby take corrective actions to prevent transmission. Microbial source tracking (MST), which currently is largely focused on determining sources of fecal contamination in waterways, is also providing the scientific community tools for tracking both fecal bacteria and food-borne pathogens contamination in the food chain. Approaches to MST are commonly classified as library-dependent methods (LDMs) or library-independent methods (LIMs). These tools will have widespread applications, including the use for regulatory compliance, pollution remediation, and risk assessment. These tools will reduce the incidence of illness associated with food and water. Our aim in this review is to highlight the use of molecular MST methods in application to understanding the source and transmission of food-borne pathogens. Moreover, the future directions of MST research are also discussed. PMID:24345044

  5. Probabilistic accident consequence uncertainty analysis: Food chain uncertainty assessment. Volume 2: Appendices

    SciTech Connect

    Brown, J.; Goossens, L.H.J.; Kraan, B.C.P.

    1997-06-01

    This volume is the second of a two-volume document that summarizes a joint project by the US Nuclear Regulatory and the Commission of European Communities to assess uncertainties in the MACCS and COSYMA probabilistic accident consequence codes. These codes were developed primarily for estimating the risks presented by nuclear reactors based on postulated frequencies and magnitudes of potential accidents. This two-volume report, which examines mechanisms and uncertainties of transfer through the food chain, is the first in a series of five such reports. A panel of sixteen experts was formed to compile credible and traceable uncertainty distributions for food chain transfer that affect calculations of offsite radiological consequences. Seven of the experts reported on transfer into the food chain through soil and plants, nine reported on transfer via food products from animals, and two reported on both. The expert judgment elicitation procedure and its outcomes are described in these volumes. This volume contains seven appendices. Appendix A presents a brief discussion of the MAACS and COSYMA model codes. Appendix B is the structure document and elicitation questionnaire for the expert panel on soils and plants. Appendix C presents the rationales and responses of each of the members of the soils and plants expert panel. Appendix D is the structure document and elicitation questionnaire for the expert panel on animal transfer. The rationales and responses of each of the experts on animal transfer are given in Appendix E. Brief biographies of the food chain expert panel members are provided in Appendix F. Aggregated results of expert responses are presented in graph format in Appendix G.

  6. 78 FR 36711 - Food and Drug Administration Safety and Innovation Act Title VII-Drug Supply Chain; Standards for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-19

    ... HUMAN SERVICES Food and Drug Administration 21 CFR Chapter I Food and Drug Administration Safety and Innovation Act Title VII--Drug Supply Chain; Standards for Admission of Imported Drugs, Registration of...: Food and Drug Administration, HHS. ACTION: Notification of public meeting; request for...

  7. Bioaccumulation and food chain transfer of corrosion products from radioactive stainless steel

    SciTech Connect

    Young, J.S.

    1986-07-01

    Two sets of experiments were conducted to determine if corrosion products from radioactive Type 347 stainless steel could be biologically transferred from sediment through a marine food chain, and whether corrosion products dissolved in seawater could be bioaccumulated and then eliminated. Corrosion products containing /sup 60/Co and /sup 63/Ni from the radioactive stainless steel were introduced into marine sediments. Infaunal polychaete worms exposed to these sediments bioaccumulated the radionuclides. The feeding of these worms to shrimp and fish resulted in a trophic transfer of the radioactive products across a one-step food chain. The magnitude of the transfers are described in terms of transfer factors. Dissolved corrosion products as measured by the radionuclides were also bioaccumulated by shrimp and fish concentrating more than fish. Concentration factors were calculated.

  8. Biological proliferation of cesium-137 through the detrital food chain in a forest ecosystem in Japan

    PubMed Central

    Murakami, Masashi; Ohte, Nobuhito; Suzuki, Takahiro; Ishii, Nobuyoshi; Igarashi, Yoshiaki; Tanoi, Keitaro

    2014-01-01

    Radionuclides, including 137Cs, were released from the disabled Fukushima Daiichi Nuclear Power Plant and had been deposited broadly over forested areas of north-eastern Honshu Island, Japan. In the forest, 137Cs was highly concentrated on leaf litters deposited in autumn 2010, before the accident. Monitoring of the distribution of 137Cs among functional groups clearly showed the role of the detrital food chain as the primary channel of 137Cs transfer to consumer organisms. Although many studies have reported the bioaccumulation (or dilution) of radioactive materials through trophic interactions, the present results highlight the importance of examining multiple possible pathways (e.g., grazing vs. detrital chains) in the proliferation of 137Cs through food webs. These results provide important insight into the future distribution and transfer of 137Cs within forest ecosystems. PMID:24398571

  9. Biological proliferation of cesium-137 through the detrital food chain in a forest ecosystem in Japan.

    PubMed

    Murakami, Masashi; Ohte, Nobuhito; Suzuki, Takahiro; Ishii, Nobuyoshi; Igarashi, Yoshiaki; Tanoi, Keitaro

    2014-01-01

    Radionuclides, including (137)Cs, were released from the disabled Fukushima Daiichi Nuclear Power Plant and had been deposited broadly over forested areas of north-eastern Honshu Island, Japan. In the forest, (137)Cs was highly concentrated on leaf litters deposited in autumn 2010, before the accident. Monitoring of the distribution of (137)Cs among functional groups clearly showed the role of the detrital food chain as the primary channel of (137)Cs transfer to consumer organisms. Although many studies have reported the bioaccumulation (or dilution) of radioactive materials through trophic interactions, the present results highlight the importance of examining multiple possible pathways (e.g., grazing vs. detrital chains) in the proliferation of (137)Cs through food webs. These results provide important insight into the future distribution and transfer of (137)Cs within forest ecosystems. PMID:24398571

  10. Risk evaluation for sludge-borne elements to wildlife food chains

    SciTech Connect

    Woodyard, D.K.

    1986-01-01

    Studies were conducted to evaluate the human and wildlife food chain risks from exposure to potentially toxic metals associated with recycling sludges to forest lands. The fate of 5 selected metals, Cd, Cr, Cu, Ni, and Zn, were determined in both field and laboratory food chains exposed to sludge-borne metals. Knowledge gained on the fate of the selected metals and existing knowledge of their toxicological properties were used to complete a risk assessment. Some metals, primarily Cd and Cr, did accumulate in wildlife forages during the first year after application but returned to background concentrations by the second growing season. Maximum metal concentrations were magnitudes less than doses suspected to elicit chronic toxicities in wildlife. Tissues collected from herbivorous and omnivorous small mammals showed no evidence of metal accumulation. Laboratory experiments support this observation. The soil macroinvertebrate-vertebrate insectivore food chain did appear as a potential pathway for metals to accumulate, as woodcock (Philohela minor) fed sludge-contaminated earthworms concentrated Cd in kidney and liver tissues. However, muscle tissues collected from the woodcock did not contain significant concentrations of the selected metals.

  11. Dynamic modeling system for the transfer of radioactivity in terrestrial food chains

    SciTech Connect

    Simmonds, J.R.; Linsley, G.S.

    1981-11-01

    A dynamic modeling system is described for the transfer of radionuclides in terrestrial food chains. The main features of the system are its ability to predict the time dependence of the major transfer processes and its flexibility and applicability to a range of contamination scenarios. The modeling system is regarded as a basic framework on which more realistic models can be based, given the availability of reliable environmental transfer data. An example of such a development is included for /sup 90/Sr in the pasture-cow-milk pathway. The model predicts annual average concentrations of /sup 90/Sr in milk caused by fallout in the United Kingdom to within 15% of measured values for over most of the 20-y period for which data exist. It makes possible the evaluation of the time dependence of the contributions of various transfer processes. Following acute releases to the atmosphere or releases in any other contamination scenario where direct deposition is absent, certain pathways often not considered in food-chain models, such as the external contamination of plants caused by resuspension processes or the ingestion of contaminants together with soil by grazing animals, are shown to be potentially important in the transfer of activity to man. The main application of dynamic food-chain models is the prediction of the consequences of accidental releases to the terrestrial environment. The predictions can be used in planning countermeasures and in assessing the health, economic, and social impacts of accidental release.

  12. Topological invariants in the study of a chaotic food chain system

    NASA Astrophysics Data System (ADS)

    Duarte, Jorge; Januário, Cristina; Martins, Nuno

    2008-06-01

    The study of ecological systems has generated deep interest in exploring the complexity of chaotic food chains. The role of chaos in ecosystems is not entirely understood. One approach to have a better comprehension of ecological chaos is by analyzing it in mathematical models of basic food chains. In this article it is considered a classical chaotic food chain model from the literature. We use the theory of symbolic dynamics to study the topological entropy and the parameter space ordering of kneading sequences associated with one-dimensional maps that reproduce significant aspects of the model dynamics. The topological entropy allows us to distinguish different chaotic states in some realistic system parameter region. Another numerical invariant is introduced in order to characterize isentropic dynamics. Studying a set of maps with the same topological entropy, we exhibit numerical results about the relation between the second topological invariant and each of the control parameters in consideration. This work provides an illustration of how our understanding of ecological models can be enhanced by the theory of symbolic dynamics.

  13. Food chain dynamics and potential ecological risks of mercury at the Carson River site

    SciTech Connect

    Peterson, S.C.

    1995-12-31

    The USEPA is conducting a remedial investigation of mercury contamination in the Carson River watershed, located near Carson City in central west Nevada. As a component of this investigation, water, sediment, and tissue samples were collected for mercury speciation and other analyses. Tissues analyses from the seven site-investigation areas and four background areas include: whole-body and fillet analyses of five species of fish, composite and individual analyses of three species of benthic macroinvertebrates, blood, feather and liver analyses of two bird species, composite analyses of zooplankton, and whole-body analyses of lizards. The data are used to develop site-specific estimates of mercury bioaccumulation in aquatic food chains of riverine/riparian, open-water, and mudflat habitats at the Carson River site. Because the behavior and food chain dynamics of mercury in semi-arid ecosystems of the southwestern US is poorly understood, these data can be compared and contrasted with bioaccumulation estimates derived from well-studied ecosystems such as northern temperate lakes. Potential ecological risks of mercury exposure through the food chain and through ingestion of and contact with contaminated media are evaluated for important wildlife receptors occurring at the Carson River site.

  14. The food chain as a source of human exposure to organic chemicals

    SciTech Connect

    Hattemer-Frey, H.A.; Travis, C.C.

    1989-01-01

    Although human exposure to environmentally released pollutants can occur via several pathways including, inhalation, ingestion of contaminated food items, infant consumption of mother's milk, and dermal absorption, of particular concern are potential exposures from ingesting contaminated food items, since the food chain has been shown to be a primary source of human exposure to a large class of organics, including DDT, TCDD, pentachlorophenol, benzo(a)pyrene, and most pesticides. For risk assessment purposes, an important objective in evaluating the environmental behavior and fate of various pollutants is predicting the major pathways and extent of human exposure. Many chemicals cycle in the environment with cross-media transfers occurring between air, water, soil, and biota. As a result of this cycling behavior and a chemical's presence in various environmental media, human exposure often results from multiple sources. We found that 50--80% of all chemicals released into the environment result in human exposure through multiple media. The purpose of this presentation is to provide a perspective on the food chain as a source of human exposure to organic chemicals chronically released into the environment. 121 refs., 3 figs., 9 tabs.

  15. Portable gliadin-immunochip for contamination control on the food production chain.

    PubMed

    Chiriacò, Maria Serena; de Feo, Francesco; Primiceri, Elisabetta; Monteduro, Anna Grazia; de Benedetto, Giuseppe Egidio; Pennetta, Antonio; Rinaldi, Ross; Maruccio, Giuseppe

    2015-09-01

    Celiac disease (CD) is one of the most common digestive disorders caused by an abnormal immune reaction to gluten. So far there are no available therapies, the only solution is a strict gluten-free diet, which however could be very challenging as gluten can be hidden in many food products. Furthermore an additional problem is related to cross-contamination of nominal gluten-free foods with gluten-based ones during manufacturing. Here we propose a lab on chip platform as a powerful tool to help food manufacturers to evaluate the real amount of gluten in their products by an accurate in-situ control of the production chain and maybe to specify the real gluten content in packages labeling. Our portable gliadin-immunochips, based on an electrochemical impedance spectroscopy transduction method, were first calibrated and then validated for both liquid and solid food matrixes by analyzing different beers and flours. The high specificity of our assay was also demonstrated by performing control experiments on rice and potatoes flours containing prolamin-like proteins. We achieved limit of quantification of 0.5 ppm for gliadin that is 20 times lower than the worldwide limit established for gluten-free food while the method of analysis is faster and cheaper than currently employed ELISA-based methods. Moreover our results on food samples were validated through a mass spectrometry standard analysis. PMID:26003692

  16. Opportunity for high value-added chemicals from food supply chain wastes.

    PubMed

    Matharu, Avtar S; de Melo, Eduardo M; Houghton, Joseph A

    2016-09-01

    With approximately 1.3 billion tonnes of food wasted per annum, food supply chain wastes (FSCWs) may be viewed as the contemporary Periodic Table of biobased feedstock chemicals (platform molecules) and functional materials. Herein, the global drivers and case for food waste valorisation within the context of global sustainability, sustainable development goals and the bioeconomy are discussed. The emerging potential of high value added chemicals from certain tropical FSCW is considered as these are grown in three major geographical areas: Brazil, India and China, and likely to increase in volume. FSCW in the context of biorefineries is discussed and two case studies are reported, namely: waste potato, and; orange peel waste. Interestingly, both waste feedstocks, like many others, produce proteins and with the global demand for vegetable proteins on the rise then proteins from FSCW may become a dominant area. PMID:26996261

  17. Interaction of nanoparticles with edible plants and their possible implications in the food chain

    PubMed Central

    Rico, Cyren M.; Majumdar, Sanghamitra; Duarte-Gardea, Maria; Peralta-Videa, Jose R.; Gardea-Torresdey, Jorge L.

    2011-01-01

    The uptake, bioaccumulation, biotransformation, and risks of nanomaterials (NMs) for the food crops are still not well understood. Very few NMs and plant species have been studied, mainly at the very early growth stages of the plants. Most of the studies, except one with multiwalled carbon nanotubes performed on the model plant Arabidopsis thaliana and another with ZnO nanoparticles (NPs) on ryegrass, reported the effect of NMs on seed germination or 15 day old seedlings. Very few references describe the biotransformation of NMs in food crops and the possible transmission of the NMs to the next generation of plants exposed to NMs is unknown. The possible biomagnification of NPs in the food chain is also unknown. PMID:21405020

  18. FoodChain-Lab: A Trace-Back and Trace-Forward Tool Developed and Applied during Food-Borne Disease Outbreak Investigations in Germany and Europe

    PubMed Central

    Filter, Matthias; Falenski, Alexander; Appel, Bernd; Käsbohrer, Annemarie

    2016-01-01

    FoodChain-Lab is modular open-source software for trace-back and trace-forward analysis in food-borne disease outbreak investigations. Development of FoodChain-Lab has been driven by a need for appropriate software in several food-related outbreaks in Germany since 2011. The software allows integrated data management, data linkage, enrichment and visualization as well as interactive supply chain analyses. Identification of possible outbreak sources or vehicles is facilitated by calculation of tracing scores for food-handling stations (companies or persons) and food products under investigation. The software also supports consideration of station-specific cross-contamination, analysis of geographical relationships, and topological clustering of the tracing network structure. FoodChain-Lab has been applied successfully in previous outbreak investigations, for example during the 2011 EHEC outbreak and the 2013/14 European hepatitis A outbreak. The software is most useful in complex, multi-area outbreak investigations where epidemiological evidence may be insufficient to discriminate between multiple implicated food products. The automated analysis and visualization components would be of greater value if trading information on food ingredients and compound products was more easily available. PMID:26985673

  19. FoodChain-Lab: A Trace-Back and Trace-Forward Tool Developed and Applied during Food-Borne Disease Outbreak Investigations in Germany and Europe.

    PubMed

    Weiser, Armin A; Thöns, Christian; Filter, Matthias; Falenski, Alexander; Appel, Bernd; Käsbohrer, Annemarie

    2016-01-01

    FoodChain-Lab is modular open-source software for trace-back and trace-forward analysis in food-borne disease outbreak investigations. Development of FoodChain-Lab has been driven by a need for appropriate software in several food-related outbreaks in Germany since 2011. The software allows integrated data management, data linkage, enrichment and visualization as well as interactive supply chain analyses. Identification of possible outbreak sources or vehicles is facilitated by calculation of tracing scores for food-handling stations (companies or persons) and food products under investigation. The software also supports consideration of station-specific cross-contamination, analysis of geographical relationships, and topological clustering of the tracing network structure. FoodChain-Lab has been applied successfully in previous outbreak investigations, for example during the 2011 EHEC outbreak and the 2013/14 European hepatitis A outbreak. The software is most useful in complex, multi-area outbreak investigations where epidemiological evidence may be insufficient to discriminate between multiple implicated food products. The automated analysis and visualization components would be of greater value if trading information on food ingredients and compound products was more easily available. PMID:26985673

  20. The salt content of products from popular fast-food chains in Costa Rica.

    PubMed

    Heredia-Blonval, Katrina; Blanco-Metzler, Adriana; Montero-Campos, Marielos; Dunford, Elizabeth K

    2014-12-01

    Salt is a major determinant of population blood pressure levels. Salt intake in Costa Rica is above levels required for good health. With an increasing number of Costa Ricans visiting fast food restaurants, it is likely that fast-food is contributing to daily salt intake. Salt content data from seven popular fast food chains in Costa Rica were collected in January 2013. Products were classified into 10 categories. Mean salt content was compared between chains and categories. Statistical analysis was performed using Welch ANOVA and Tukey-Kramer HSD tests. Significant differences were found between companies; Subway products had lowest mean salt content (0.97 g/100 g; p < 0.05) while Popeye's and KFC had the highest (1.57 g/100 g; p < 0.05). Significant variations in mean salt content were observed between categories. Salads had a mean salt content of 0.45 g/100 g while sauces had 2.16 g/100 g (p < 0.05). Wide variation in salt content was also seen within food categories. Salt content in sandwiches ranged from 0.5 to 2.1 g/100 g. The high levels and wide variation in salt content of fast food products in Costa Rica suggest that salt reduction is likely to be technically feasible in many cases. With an increasing number of consumers purchasing fast foods, even small improvements in salt levels could produce important health gains. PMID:25171851

  1. ORGANIC CONTAMINANT DISTRIBUTION IN SEDIMENTS, POLYCHAETES (NEREIS VIRENS) AND THE AMERICAN LOBSTER, HOMARUS AMERICANUS IN A LABORATORY FOOD CHAIN EXPERIMENT

    EPA Science Inventory

    A laboratory experiment was conducted to investigate the transfer of organic contaminants from an environmentally contaminated marine sediment through a simple marine food chain. The infaunal polychaete, Nereis virens, was exposed to contaminated sediment collected from the Passa...

  2. Impact of medium and long chain triglycerides consumption on appetite and food intake in overweight men

    PubMed Central

    St-Onge, Marie-Pierre; Mayrsohn, Brian; O’Keeffe, Majella; Kissileff, Harry R.; Choudhury, Arindam Roy; Laferrère, Blandine

    2014-01-01

    Background Medium chain triglycerides (MCT) enhance thermogenesis and may reduce food intake relative to long chain triglycerides (LCT). The goal of this study was to establish the effects of MCT on appetite and food intake and determine whether differences were due to differences in hormone concentrations. Methods Two randomized, crossover studies were conducted in which overweight men consumed 20 g of MCT or corn oil (LCT) at breakfast. Blood samples were obtained over 3 h. In Study 1 (n=10), an ad lib lunch was served after 3 h. In Study 2 (n=7), a pre-load containing 10 g of test oil was given at 3 h and lunch was served 1 h later. Linear mixed model analyses were performed to determine the effects of MCT and LCT oil on change in hormones and metabolites from fasting, adjusting for body weight. Correlations were computed between differences in hormones just before the test meals and differences in intakes after the two oils for Study 1 only. Results Food intake at the lunch test meal after the MCT pre-load (Study 2) was (mean ± SEM) 532 ± 389 kcal vs. 804 ± 486 kcal after LCT (P < 0.05). MCT consumption resulted in a lower rise in triglycerides (P = 0.014) and glucose (P = 0.066) and a higher rise in peptide YY (P = 0.017) and leptin (P = 0.036) compared to LCT (combined data). Correlations between differences in hormone levels (GLP-1, PYY) and differences in food intake were in the opposite direction to expectations. Conclusions MCT consumption reduced food intake acutely but this does not seem to be mediated by changes in GLP-1, PYY, and insulin. PMID:25074387

  3. Use of calorie information at fast food and chain restaurants among US youth aged 9–18 years, 2010

    PubMed Central

    Wethington, H.; Maynard, L.M.; Blanck, H.M.

    2015-01-01

    Background To examine whether youth use calorie information when it is available at fast food/chain restaurants and what factors are associated with using this information to make their food selection. Methods A cross-sectional analysis was conducted on a sample of 721 youth (9–18 years) using the 2010 YouthStyles and HealthStyles surveys. The outcome measure was reported use of calorie information at fast food/chain restaurants. Multivariable logistic regression was used to examine the associations between sociodemographic variables and the use of calorie information at fast food/chain restaurants. Results Of those who visited fast food/chain restaurants, 42.4% reported using calorie information at least sometimes. Girls were more likely than boys (adjusted odds ratio (aOR) = 1.8, 95% confidence interval (CI) = 1.2–2.5) and youth who were obese were more likely than those at a healthy weight (aOR = 1.7, 95% CI = 1.04–2.9) to use calorie information, and youth eating at a fast food/chain restaurant twice a week or more versus once a week or less were half as likely to report using calorie information (aOR = 0.5, 95% CI = 0.4–0.8). Conclusion Public health education efforts can benefit from research to determine how to increase usage among youth so that their food choices are appropriate for their caloric needs. PMID:23697388

  4. Soil-to-Plant Concentration Ratios for Assessing Food Chain Pathways in Biosphere Models

    SciTech Connect

    Napier, Bruce A.; Fellows, Robert J.; Krupka, Kenneth M.

    2007-10-01

    This report describes work performed for the U.S. Nuclear Regulatory Commission’s project Assessment of Food Chain Pathway Parameters in Biosphere Models, which was established to assess and evaluate a number of key parameters used in the food-chain models used in performance assessments of radioactive waste disposal facilities. Section 2 of this report summarizes characteristics of samples of soils and groundwater from three geographical regions of the United States, the Southeast, Northwest, and Southwest, and analyses performed to characterize their physical and chemical properties. Because the uptake and behavior of radionuclides in plant roots, plant leaves, and animal products depends on the chemistry of the water and soil coming in contact with plants and animals, water and soil samples collected from these regions of the United States were used in experiments at Pacific Northwest National Laboratory to determine radionuclide soil-to-plant concentration ratios. Crops and forage used in the experiments were grown in the soils, and long-lived radionuclides introduced into the groundwater provide the contaminated water used to water the grown plants. The radionuclides evaluated include 99Tc, 238Pu, and 241Am. Plant varieties include alfalfa, corn, onion, and potato. The radionuclide uptake results from this research study show how regional variations in water quality and soil chemistry affect radionuclide uptake. Section 3 summarizes the procedures and results of the uptake experiments, and relates the soil-to-plant uptake factors derived. In Section 4, the results found in this study are compared with similar values found in the biosphere modeling literature; the study’s results are generally in line with current literature, but soil- and plant-specific differences are noticeable. This food-chain pathway data may be used by the NRC staff to assess dose to persons in the reference biosphere (e.g., persons who live and work in an area potentially affected by

  5. Uranium in the Near-shore Aquatic Food Chain: Studies on Periphyton and Asian Clams

    SciTech Connect

    Bunn, Amoret L.; Miley, Terri B.; Eslinger, Paul W.; Brandt, Charles A.; Napier, Bruce A.

    2007-12-31

    The benthic aquatic organisms in the near-shore environment of the Columbia River are the first biological receptors that can be exposed to groundwater contaminants coming from the U.S. Department of Energy's Hanford Site. The primary contaminant of concern in the former nuclear fuels processing area at the Site, known as the 300 Area, is uranium. Currently, there are no national clean up criteria for uranium and ecological receptors. This report summarizes efforts to characterize biological uptake of uranium in the food chain of the benthic aquatic organisms and provide information to be used in future assessments of uranium and the ecosystem.

  6. Persistence and global stability in a delayed Leslie-Gower type three species food chain

    NASA Astrophysics Data System (ADS)

    Nindjin, A. F.; Aziz-Alaoui, M. A.

    2008-04-01

    Our investigation concerns the three-dimensional delayed continuous time dynamical system which models a predator-prey food chain. This model is based on the Holling-type II and a Leslie-Gower modified functional response. This model can be considered as a first step towards a tritrophic model (of Leslie-Gower and Holling-Tanner type) with inverse trophic relation and time delay. That is when a certain species that is usually eaten can consume immature predators. It is proved that the system is uniformly persistent under some appropriate conditions. By constructing a proper Lyapunov function, we obtain a sufficient condition for global stability of the positive equilibrium.

  7. Stability and bifurcation analysis on a three-species food chain system with two delays

    NASA Astrophysics Data System (ADS)

    Cui, Guo-Hu; Yan, Xiang-Ping

    2011-09-01

    The present paper deals with a three-species Lotka-Volterra food chain system with two discrete delays. By linearizing the system at the positive equilibrium and analyzing the associated characteristic equation, the asymptotic stability of the positive equilibrium and existence of local Hopf bifurcations are investigated. Furthermore, by using the normal form theory and the center manifold reduction, explicit formulae are derived to determine the direction of bifurcations and the stability of bifurcating periodic solutions. Finally, to verify our theoretical predictions, some numerical simulations are also included at the end of this paper.

  8. Comparative effect of water and food-chain mediated cadmium exposure in rats.

    PubMed

    Asagba, Samuel Ogheneovo

    2010-12-01

    This study sets out to compare the absorption and toxicity of Cadmium (Cd) administered via the food-chain and inorganic Cd administered in drinking water after 1 and 3 months exposure using rats as animal model. The food-chain was mimicked by exposing rats to diet containing Cd pre-exposed fish. The uptake of Cd by the rats after both mode of exposure was calculated by summing up the Cd burden in the liver and kidneys and was expressed in terms of % intake. The toxicity of Cd was assessed by monitoring biochemical indices of liver function in the plasma and liver. Regardless of the mode of exposure of the rats, the Cd load in the liver and kidney was significantly (P < 0.05) higher than the respective controls with the kidney having a significantly higher load than the liver after both periods of exposure. However irrespective of the mode of exposure, more Cd was accumulated in the liver and kidney of the 3 months exposed rats relative to those exposed for 1 month. The uptake of Cd by rats exposed to Cd via the food-chain for 1 and 3 months was significantly (P < 0.05) lower when compared to the corresponding water mediated Cd exposed rats, except for the liver after 3 months of exposure. The liver L-ALT activity of rats administered inorganic Cd in drinking water for 1 and 3 months was significantly (P < 0.05) lower as compared to controls. Parallel analysis of the plasma showed no significant (P > 0.05) difference in L-ALT activity between both groups after the same periods of exposure. The L-AST activity in the plasma of rats similarly exposed to Cd for 1 and 3 months was significantly (P < 0.05) higher as compared to controls with a corresponding reduction in the liver. Conversely no significant (P > 0.05) change was observed in plasma and liver L-ALT and L-AST activities after food-chain mediated exposure to Cd for 1 and 3 months in relation to their respective controls. These findings indicate that Cd incorporated in fish is more easily bioavailable, but

  9. Transfer of Metals in Food Chain: An Example with Copper and Lettuce

    NASA Astrophysics Data System (ADS)

    Vincevica-Gaile, Zane; Klavins, Maris

    2012-12-01

    Present study investigated the possible transfer of metals in the food chain (from soil to edible plants). The experiment was done with lettuce Lactuca sativa grown in different types of soil contaminated with copper (Cu2+) in various concentrations, with or without addition of humic substances. The highest content of copper was detected in lettuce samples grown in soils with lower levels of organic matter, thus indicating the importance of soil organics in metal transfer routes and accumulation rates in plants. It was found that copper accumulation in lettuce grown in contaminated soils can be significantly reduced by the addition of humic substances.

  10. Arsenic as a food chain contaminant: mechanisms of plant uptake and metabolism and mitigation strategies.

    PubMed

    Zhao, Fang-Jie; McGrath, Steve P; Meharg, Andrew A

    2010-01-01

    Arsenic (As) is an environmental and food chain contaminant. Excessive accumulation of As, particularly inorganic arsenic (As(i)), in rice (Oryza sativa) poses a potential health risk to populations with high rice consumption. Rice is efficient at As accumulation owing to flooded paddy cultivation that leads to arsenite mobilization, and the inadvertent yet efficient uptake of arsenite through the silicon transport pathway. Iron, phosphorus, sulfur, and silicon interact strongly with As during its route from soil to plants. Plants take up arsenate through the phosphate transporters, and arsenite and undissociated methylated As species through the nodulin 26-like intrinsic (NIP) aquaporin channels. Arsenate is readily reduced to arsenite in planta, which is detoxified by complexation with thiol-rich peptides such as phytochelatins and/or vacuolar sequestration. A range of mitigation methods, from agronomic measures and plant breeding to genetic modification, may be employed to reduce As uptake by food crops. PMID:20192735

  11. Transgenic and cloned animals in the food chain--are we prepared to tackle it?

    PubMed

    Jagadeesan, Premanandh; Bin Salem, Samara

    2015-11-01

    Transgenic and cloned animal production for various purposes has been increasing rapidly in recent times. While the actual impact of these animals in the food chain is unknown, the significance of tracking and monitoring measures to curb accidental and or deliberate release has been discussed. Religious perspectives from different faiths and traditions have been presented. Although the concept of substantial equivalence satisfies the technical and nutritional requirements of these products when assessed against comparators, public opinion and religious concerns should also be considered by the regulators while developing policy regulations. In conclusion, measures to prevent real or perceived risks of transgenic and cloned animals in food production require global coordinated action. It is worthwhile to consider establishing effective tracking systems and analytical procedures as this will be a valuable tool if a global consensus is not reached on policy regulation. PMID:25857482

  12. The role of top predator interference on the dynamics of a food chain model

    NASA Astrophysics Data System (ADS)

    Upadhyay, Ranjit Kumar; Naji, Raid Kamel; Raw, Sharada Nandn; Dubey, Balram

    2013-03-01

    In this paper, the effects of top predator interference on the dynamics of a food chain model involving an intermediate and a top predator are considered. It is assumed that the interaction between the prey and intermediate predator follows the Volterra scheme, while that between the top predator and its favorite food depends on Beddington-DeAngelis type of functional response. The boundedness of the system, existence of an attracting set, local and global stability of non-negative equilibrium points are established. Number of the bifurcation and Lyapunov exponent bifurcation diagrams is established. It is observed that, the model has different types of attracting sets including chaos. Moreover, increasing the top predator interference stabilizes the system, while increasing the normalization of the residual reduction in the top predator population destabilizes the system.

  13. Veterinary Public Health Approach to Managing Pathogenic Verocytotoxigenic Escherichia coli in the Agri-Food Chain.

    PubMed

    Duffy, Geraldine; McCabe, Evonne

    2014-10-01

    Verocytoxigenic Escherichia coli (VTEC) comprises many diverse serogroups, but seven serogroups, O157, O26, O103, O145, O111, O21, and O45, have been most commonly linked to severe human infections, though illness has also been reported from a range of other VTEC serogroups. This poses challenges in assessing the risk to humans from the diverse range of VTEC strains that may be recovered from animals, the environment, or food. For routine assessment of risk posed by VTEC recovered from the agri-food chain, the concept of seropathotype can be used to rank the human risk potential from a particular VTEC serogroup on the basis of both serotype (top seven serogroups) and the presence of particular virulence genes (vt in combination with eae, or aaiC plus aggR). But for other VTEC serogroups or virulence gene combinations, it is not currently possible to fully assess the risk posed. VTEC is shed in animal feces and can persist in the farm environment for extended periods ranging from several weeks to many months, posing an ongoing reservoir of contamination for grazing animals, water courses, and fresh produce and for people using farmland for recreational purposes. Appropriate handling and treatment of stored animal waste (slurries and manures) will reduce risk from VTEC in the farm environment. Foods of animal origin such as milk and dairy products and meat may be contaminated with VTEC during production and processing, and the pathogen may survive or grow during processing operations, highlighting the need for well-designed and validated Hazard Analysis Critical Control Point management systems. This article focuses on a veterinary public health approach to managing VTEC, highlighting the various routes in the agri-food chain for transmission of human pathogenic VTEC and general approaches to managing the risk. PMID:26104349

  14. Presence of Candy and Snack Food at Checkout in Chain Stores: Results of a Pilot Study.

    PubMed

    Basch, Corey H; Kernan, William D; Menafro, Anthony

    2016-10-01

    Community health professionals must use multiple strategies to address the rising rates of childhood obesity in the United States. One such strategy is to address the underlying causes of childhood obesity, including lack of exercise and the consumption of calorically-dense snack foods. This study examines the presence of candy and snack food in the checkout lines of all retail chain stores in a selected community to determine the presence of these products, the ways in which these products are promoted, and the type of physical environment through which customers navigate during the checkout process. The findings confirm that candy, soft drinks, snacks, and ice cream were present in a large majority of these retail stores. Further, this pilot study found that many of these stores "corral" customers through the check-out line in such a way that it is necessary to pass these snack foods directly. Three themes for discussion emerged from the review of the data collected, including product marketing, product packaging, and product placement. Implications for childhood health are presented in the context of these marketing strategies. The results and subsequent discussion provide important insight into the ways in which the presence of candy and snack food at checkout lines might contribute to childhood obesity rates. PMID:27101366

  15. Detection and traceability of genetically modified organisms in the food production chain.

    PubMed

    Miraglia, M; Berdal, K G; Brera, C; Corbisier, P; Holst-Jensen, A; Kok, E J; Marvin, H J P; Schimmel, H; Rentsch, J; van Rie, J P P F; Zagon, J

    2004-07-01

    Both labelling and traceability of genetically modified organisms are current issues that are considered in trade and regulation. Currently, labelling of genetically modified foods containing detectable transgenic material is required by EU legislation. A proposed package of legislation would extend this labelling to foods without any traces of transgenics. These new legislations would also impose labelling and a traceability system based on documentation throughout the food and feed manufacture system. The regulatory issues of risk analysis and labelling are currently harmonised by Codex Alimentarius. The implementation and maintenance of the regulations necessitates sampling protocols and analytical methodologies that allow for accurate determination of the content of genetically modified organisms within a food and feed sample. Current methodologies for the analysis of genetically modified organisms are focused on either one of two targets, the transgenic DNA inserted- or the novel protein(s) expressed- in a genetically modified product. For most DNA-based detection methods, the polymerase chain reaction is employed. Items that need consideration in the use of DNA-based detection methods include the specificity, sensitivity, matrix effects, internal reference DNA, availability of external reference materials, hemizygosity versus homozygosity, extrachromosomal DNA, and international harmonisation. For most protein-based methods, enzyme-linked immunosorbent assays with antibodies binding the novel protein are employed. Consideration should be given to the selection of the antigen bound by the antibody, accuracy, validation, and matrix effects. Currently, validation of detection methods for analysis of genetically modified organisms is taking place. In addition, new methodologies are developed, including the use of microarrays, mass spectrometry, and surface plasmon resonance. Challenges for GMO detection include the detection of transgenic material in materials

  16. Transfer of selenium from prey to predators in a simulated terrestrial food chain.

    PubMed

    Hopkins, William A; Staub, Brandon P; Baionno, Jennifer A; Jackson, Brian P; Talent, Larry G

    2005-04-01

    Little is known about the accumulation and effects of selenium in reptiles. We developed a simplified laboratory food chain where we fed commercial feed laden with seleno-D,L-methionine (30 microg/g dry mass) to crickets (Acheta domestica) for 5-7 d. Se-enriched crickets (approximately 15 microg/g Se [dry mass]) were fed to juvenile male and female lizards (Sceloporus occidentalis) for 98 d while conspecifics were fed uncontaminated crickets. Lizards fed contaminated prey accumulated Se concentrations ranging from 9.3 (in female carcass) to 14.1 (in female gonad) microg/g compared to <1.5 microg/g in tissues of controls. Female gonad concentrations approached the highest of thresholds for reproductive toxicity in oviparous vertebrates. However, we observed no consistent effect of dietary treatment on sublethal parameters or survival. Our simplified food chain proved to be an ecologically relevant method of exposing lizards to Se, and forms the foundation for future studies on maternal transfer and teratogenicity of Se. PMID:15620590

  17. Complex dynamics in the Leslie-Gower type of the food chain system with multiple delays

    NASA Astrophysics Data System (ADS)

    Guo, Lei; Song, Zi-Gen; Xu, Jian

    2014-08-01

    In this paper, we present a Leslie-Gower type of food chain system composed of three species, which are resource, consumer, and predator, respectively. The digestion time delays corresponding to consumer-eat-resource and predator-eat-consumer are introduced for more realistic consideration. It is called the resource digestion delay (RDD) and consumer digestion delay (CDD) for simplicity. Analyzing the corresponding characteristic equation, the stabilities of the boundary and interior equilibrium points are studied. The food chain system exhibits the species coexistence for the small values of digestion delays. Large RDD/CDD may destabilize the species coexistence and induce the system dynamic into recurrent bloom or system collapse. Further, the present of multiple delays can control species population into the stable coexistence. To investigate the effect of time delays on the recurrent bloom of species population, the Hopf bifurcation and periodic solution are investigated in detail in terms of the central manifold reduction and normal form method. Finally, numerical simulations are performed to display some complex dynamics, which include multiple periodic solution and chaos motion for the different values of system parameters. The system dynamic behavior evolves into the chaos motion by employing the period-doubling bifurcation.

  18. Food-chain and dose model, CALDOS, for assessing Canada's Nuclear Fuel Waste Management concept.

    PubMed

    Zach, R; Sheppard, S C

    1991-05-01

    The food-chain and dose model, CALculation of DOSe (CALDOS), was developed for assessing Canada's concept for nuclear fuel waste disposal in a vault deep in crystalline rock of the Canadian Shield. The model is very general and based on the Shield as a whole. The critical group is totally self-sufficient and represented by ICRP (1975) Reference Man for dose prediction. CALDOS assumes steady-state conditions and deals with variation and uncertainty through Monte Carlo simulation techniques. Ingrowth of some radioactive daughters is considered during food-chain transfer. A limit is set on root uptake to avoid unrealistic plant concentrations. Integrated ingestion and inhalation rates of man are calculated in a unique way, based on energy needs. Soil ingestion by man and external exposure from building material are unique pathways considered. Tritium, 129I, and 222Rn are treated through special models, and 14C and 129I involve unique geosphere dose limits. All transfer coefficients are lognormally distributed, and the plant/soil concentration ratio is correlated with the soil partition coefficient. Animals' ingestion rates are normally distributed and correlated with each other. Comprehensive sets of internal and external dose conversion factors were calculated for CALDOS. Sample calculations show that dose distributions tend to be strongly right-skewed. Many features of CALDOS are relevant for environmental assessment in general. PMID:2019495

  19. Food-chain and dose model, CALDOS, for assessing Canada's Nuclear Fuel Waste Management concept

    SciTech Connect

    Zach, R.; Sheppard, S.C. )

    1991-05-01

    The food-chain and dose model, CALculation of DOSe (CALDOS), was developed for assessing Canada's concept for nuclear fuel waste disposal in a vault deep in crystalline rock of the Canadian Shield. The model is very general and based on the Shield as a whole. The critical group is totally self-sufficient and represented by ICRP (1975) Reference Man for dose prediction. CALDOS assumes steady-state conditions and deals with variation and uncertainty through Monte Carlo simulation techniques. Ingrowth of some radioactive daughters is considered during food-chain transfer. A limit is set on root uptake to avoid unrealistic plant concentrations. Integrated ingestion and inhalation rates of man are calculated in a unique way, based on energy needs. Soil ingestion by man and external exposure from building material are unique pathways considered. Tritium, {sup 129}I, and {sup 222}Rn are treated through special models, and {sup 14}C and {sup 129}I involve unique geosphere dose limits. All transfer coefficients are lognormally distributed, and the plant/soil concentration ratio is correlated with the soil partition coefficient. Animals' ingestion rates are normally distributed and correlated with each other. Comprehensive sets of internal and external dose conversion factors were calculated for CALDOS. Sample calculations show that dose distributions tend to be strongly right-skewed. Many features of CALDOS are relevant for environmental assessment in general.

  20. Influence of dispersants on trophic transfer of petroleum hydrocarbons in a marine food chain

    SciTech Connect

    Wolfe, M.; Tjeerdema, R.; Sowby, M.

    1995-12-31

    When crude oil is accidentally released into the ocean, it threatens many levels of marine life. Intervention, in the form of chemical dispersing agents, alters the normal behavior of petroleum hydrocarbons (PH) by increasing their functional water solubility and the extent of their exposure to sub-surface organisms. Dispersing agents may modify bioavailability as a result of altered interactions between dispersed PH droplets and organismal cell membranes.The objective of this research was to determine the impact of dispersing agents on PH bioavailability and trophic transfer in primary levels of a marine food chain. Uptake, bioaccumulation, depuration, and metabolic transformation of a model PH, {sup 14}C-naphthalene, were measured and compared for Prudhoe Bay Crude Oil (PBCO) dispersed with Corexit 9527 and undispersed preparations of the water-accommodated fractions (WAF) of PBCO at two salinities and temperatures. The model food chain consisted of Isochrysis galbana and Brachionus plicatilis. Direct aqueous exposure was compared with combined aqueous and dietary exposure. Fractionation and identification of metabolites was done by HPLC co-chromatography with analytical standards, and quantitation was done by liquid scintillation counting. GC-FID characterization of WAF and dispersed oil (DO) preparations shows higher concentrations of petroleum hydrocarbons and a greater number of individual constituents in the dispersed oil preparations.

  1. Feed the crop not the soil: rethinking phosphorus management in the food chain.

    PubMed

    Withers, Paul J A; Sylvester-Bradley, Roger; Jones, Davey L; Healey, John R; Talboys, Peter J

    2014-06-17

    Society relies heavily on inorganic phosphorus (P) compounds throughout its food chain. This dependency is not only very inefficient and increasingly costly but is depleting finite global reserves of rock phosphate. It has also left a legacy of P accumulation in soils, sediments and wastes that is leaking into our surface waters and contributing to widespread eutrophication. We argue for a new, more precise but more challenging paradigm in P fertilizer management that seeks to develop more sustainable food chains that maintain P availability to crops and livestock but with reduced amounts of imported mineral P and improved soil function. This new strategy requires greater public awareness of the environmental consequences of dietary choice, better understanding of soil-plant-animal P dynamics, increased recovery of both used P and unutilized legacy soil P, and new innovative technologies to improve fertilizer P recovery. In combination, they are expected to deliver significant economic, environmental, and resource-protection gains, and contribute to future global P stewardship. PMID:24840064

  2. Assessment of Food Chain Pathway Parameters in Biosphere Models: Annual Progress Report for Fiscal Year 2004

    SciTech Connect

    Napier, Bruce A.; Krupka, Kenneth M.; Fellows, Robert J.; Cataldo, Dominic A.; Valenta, Michelle M.; Gilmore, Tyler J.

    2004-12-02

    This Annual Progress Report describes the work performed and summarizes some of the key observations to date on the U.S. Nuclear Regulatory Commission’s project Assessment of Food Chain Pathway Parameters in Biosphere Models, which was established to assess and evaluate a number of key parameters used in the food-chain models used in performance assessments of radioactive waste disposal facilities. Section 2 of this report describes activities undertaken to collect samples of soils from three regions of the United States, the Southeast, Northwest, and Southwest, and perform analyses to characterize their physical and chemical properties. Section 3 summarizes information gathered regarding agricultural practices and common and unusual crops grown in each of these three areas. Section 4 describes progress in studying radionuclide uptake in several representative crops from the three soil types in controlled laboratory conditions. Section 5 describes a range of international coordination activities undertaken by Project staff in order to support the underlying data needs of the Project. Section 6 provides a very brief summary of the status of the GENII Version 2 computer program, which is a “client” of the types of data being generated by the Project, and for which the Project will be providing training to the US NRC staff in the coming Fiscal Year. Several appendices provide additional supporting information.

  3. Experimental food-chain studies to evaluate cadmium accumulation in amphibians

    SciTech Connect

    Boliman, M.; Gillett, C.; Wilborn, D.; Ott, S.; Linder, G.

    1994-12-31

    In order to more adequately address the uncertainty within the ecological risk assessment process, the authors completed a series of laboratory exposures with representative terrestrial (small herbivorous mammal) and wetland (amphibian) vertebrates for evaluating an validating relatively simple, linear food-chain models used in evaluating cadmium exposures in soils. Here, the authors summarize the work on food-chain contamination evaluations using laboratory feeding trials with amphibians. In these studies, frogs (Xenopuslaevis) were exposed to different metal-contaminated earthworm diets for 28 days. Earthworms (Eisenia foetida) used in these trials had been exposed to site-soils contaminated with cadmium, and following 28-day exposures to cadmium-contaminated worms, the frogs were killed and tissues were analyzed for total cadmium. No mortality or exposure related body weight changes were apparent in these feeding studies, but earthworm cadmium concentrations of 700 ppm were associated with elevated cadmium concentrations in livers of exposed frogs. In addition, female frogs had increased cadmium concentrations (relative to pair-fed controls) in their eggs.

  4. Meta-food-chains as a many-layer epidemic process on networks.

    PubMed

    Barter, Edmund; Gross, Thilo

    2016-02-01

    Notable recent works have focused on the multilayer properties of coevolving diseases. We point out that very similar systems play an important role in population ecology. Specifically we study a meta-food-web model that was recently proposed by Pillai et al. [Theor. Ecol. 3, 223 (2009)]. This model describes a network of species connected by feeding interactions, which spread over a network of spatial patches. Focusing on the essential case, where the network of feeding interactions is a chain, we develop an analytical approach for the computation of the degree distributions of colonized spatial patches for the different species in the chain. This framework allows us to address ecologically relevant questions. Considering configuration model ensembles of spatial networks, we find that there is an upper bound for the fraction of patches that a given species can occupy, which depends only on the networks mean degree. For a given mean degree there is then an optimal degree distribution that comes closest to the upper bound. Notably scale-free degree distributions perform worse than more homogeneous degree distributions if the mean degree is sufficiently high. Because species experience the underlying network differently the optimal degree distribution for one particular species is generally not the optimal distribution for the other species in the same food web. These results are of interest for conservation ecology, where, for instance, the task of selecting areas of old-growth forest to preserve in an agricultural landscape, amounts to the design of a patch network. PMID:26986348

  5. Bioaccumulation and food-chain analysis for evaluating ecological risks in terrestrial and wetland habitats: Availability-transfer factors (ATFs) in soil {r_arrow} soil macroinvertebrate {r_arrow} amphibian food chains

    SciTech Connect

    Linder, G.; Bollman, M.; Callahan, C.; Gillette, C.; Nebeker, A.; Wilborn, D.

    1998-12-31

    As part of the ecological risk assessment process for terrestrial and wetland habitats, the evaluation of bioaccumulative chemicals of concern (BCCs) is frequently pursued through food-chain analysis with a subsequent comparison of daily doses to benchmark toxicity reference values, when available. Food-chain analysis has frequently been applied to the analysis of exposure to BCCs identified as chemicals of potential ecological concern (COPECs) in the ecological risk assessment process. Here, designed studies focused on wetland food-chains such as hydric soil {r_arrow} soil macroinvertebrate {r_arrow} amphibian and terrestrial food-chains such as soil {r_arrow} plant {r_arrow} small mammal illustrate an approach for the derivation and validation of trophic transfer factors for metals considered as COPECs such as cadmium, chromium, copper, lead, and zinc. The results clearly indicate that the transfer of chemicals between trophic levels is critical in the bioaccumulation process in wetland and terrestrial food-chains and is influenced by numerous interacting abiotic and biotic factors, including physicochemical properties of soil, and the role, if any, that the metal has in the receptor as a required trace element.

  6. Bioaccumulative and conchological assessment of heavy metal transfer in a soil-plant-snail food chain

    PubMed Central

    2012-01-01

    Background Copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb) can pose serious threats to environmental health because they tend to bioaccumulate in terrestrial ecosystems. We investigated under field conditions the transfer of these heavy metals in a soil-plant-snail food chain in Banat area, Romania. The main goal of this paper was to assess the Roman snail (Helix pomatia) usefulness in environmental monitoring as bioindicator of heavy metal accumulation. Eight sampling sites, selected by different history of heavy metal (HM) exposure, were chosen to be sampled for soil, nettle leaves, and newly matured snails. This study also aimed to identify the putative effects of HM accumulation in the environment on phenotypic variability in selected shell features, which included shell height (SH), relative shell height (RSH), and whorl number (WN). Results Significantly higher amounts of HMs were accumulated in snail hepatopancreas and not in foot. Cu, Zn, and Cd have biomagnified in the snail body, particularly in the hepatopancreas. In contrast, Pb decreased when going up into the food chain. Zn, Cd, and Pb correlated highly with each other at all levels of the investigated food chain. Zn and Pb exhibited an effective soil–plant transfer, whereas in the snail body only foot Cu concentration was correlated with that in soil. There were significant differences among sampling sites for WN, SH, and RSH when compared with reference snails. WN was strongly correlated with Cd and Pb concentrations in nettle leaves but not with Cu and Zn. SH was independent of HM concentrations in soil, snail hepatopancreas, and foot. However, SH correlated negatively with nettle leaves concentrations for each HM except Cu. In contrast, RSH correlated significantly only with Pb concentration in hepatopancreas. Conclusions The snail hepatopancreas accumulates high amounts of HMs, and therefore, this organ can function as a reliable biomarker for tracking HM bioavailability in soil. Long

  7. Arsenic and Cadmium in Food-chain in Bangladesh—An Exploratory Study

    PubMed Central

    Khan, Shafiqul Islam; Yunus, Mohammad; Rahman, Mahfuzar; Hore, Samar Kumar; Vahter, Marie; Wahed, M.A.

    2010-01-01

    Arsenic contamination of tubewell water is a major public-health problem in Bangladesh. In the recent years, the use of shallow and deep tubewell water for irrigation and the use of excess amount of cheap fertilizers and pesticides containing cadmium pose a serious threat of contamination of arsenic and cadmium in food. In an exploratory study, arsenic and cadmium were measured in foods from Matlab, a rural area in Bangladesh, that is extensively affected by arsenic and the economy is agriculture-based. Raw and cooked food samples were collected from village homes (households, n=13) and analyzed to quantify concentrations of arsenic and cadmium using atomic absorption spectrophotometry. Washing rice with water before cooking reduced the concentration of arsenic in raw rice by 13–15%. Rice, when cooked with excess water discarded, showed a significant decrease in arsenic concentration compared to that cooked without discarding the water (p<0.001). In contrast, concentration of cadmium did not decrease in cooked rice after discarding water. Cooked rice with discarded water had significantly lower concentration of arsenic compared to raw rice (p=0.002). Raw rice had higher concentration of arsenic compared to raw vegetables (p<0.001); however, no such difference was found for cadmium. Compared to raw vegetables (e.g. arum), concentration of arsenic increased significantly (p=0.024) when cooked with arsenic-contaminated water. Thus, the practice of discarding excess water while cooking rice reduces the concentration of arsenic but not of cadmium in cooked rice. However, water generally not discarded when cooking vegetables to avoid loss of micronutrients consequently retains arsenic. The results suggest that arsenic and cadmium have entered the food-chain of Bangladesh, and the cooking practices influence the concentration of arsenic but not of cadmium in cooked food. PMID:21261203

  8. Trophic transfer of naturally produced brominated aromatic compounds in a Baltic Sea food chain.

    PubMed

    Dahlgren, Elin; Lindqvist, Dennis; Dahlgren, Henrik; Asplund, Lillemor; Lehtilä, Kari

    2016-02-01

    Brominated aromatic compounds (BACs) are widely distributed in the marine environment. Some of these compounds are highly toxic, such as certain hydroxylated polybrominated diphenyl ethers (OH-PBDEs). In addition to anthropogenic emissions through use of BACs as e.g. flame retardants, BACs are natural products formed by marine organisms such as algae, sponges, and cyanobacteria. Little is known of the transfer of BACs from natural producers and further up in the trophic food chain. In this study it was observed that total sum of methoxylated polybrominated diphenyl ethers (MeO-PBDEs) and OH-PBDEs increased in concentration from the filamentous red alga Ceramium tenuicorne, via Gammarus sp. and three-spined stickleback (Gasterosteus aculeatus) to perch (Perca fluviatilis). The MeO-PBDEs, which were expected to bioaccumulate, increased in concentration accordingly up to perch, where the levels suddenly dropped dramatically. The opposite pattern was observed for OH-PBDEs, where the concentration exhibited a general trend of decline up the food web, but increased in perch, indicating metabolic demethylation of MeO-PBDEs. Debromination was also indicated to occur when progressing through the food chain resulting in high levels of tetra-brominated MeO-PBDE and OH-PBDE congeners in fish, while some penta- and hexa-brominated congeners were observed to be the dominant products in the alga. As it has been shown that OH-PBDEs are potent disruptors of oxidative phosphorylation and that mixtures of different congener may act synergistically in terms of this toxic mode of action, the high levels of OH-PBDEs detected in perch in this study warrants further investigation into potential effects of these compounds on Baltic wildlife, and monitoring of their levels. PMID:26517387

  9. An extended patch-dynamic framework for food chains in fragmented landscapes.

    PubMed

    Liao, Jinbao; Chen, Jiehong; Ying, Zhixia; Hiebeler, David E; Nijs, Ivan

    2016-01-01

    Habitat destruction, a key determinant of species loss, can be characterized by two components, patch loss and patch fragmentation, where the former refers to the reduction in patch availability, and the latter to the division of the remaining patches. Classical metacommunity models have recently explored how food web dynamics respond to patch loss, but the effects of patch fragmentation have largely been overlooked. Here we develop an extended patch-dynamic model that tracks the patch occupancy of the various trophic links subject to colonization-extinction-predation dynamics by incorporating species dispersal with patch connectivity. We found that, in a simple food chain, species at higher trophic level become extinct sooner with increasing patch loss and fragmentation due to the constraint in resource availability, confirming the trophic rank hypothesis. Yet, effects of fragmentation on species occupancy are largely determined by patch loss, with maximal fragmentation effects occurring at intermediate patch loss. Compared to the spatially explicit simulations that we also performed, the current model with pair approximation generates similar community patterns especially in spatially clustered landscapes. Overall, our extended framework can be applied to model more complex food webs in fragmented landscapes, broadening the scope of existing metacommunity theory. PMID:27608823

  10. Biomagnification of cadmium selenide quantum dots in a simple experimental microbial food chain

    NASA Astrophysics Data System (ADS)

    Werlin, R.; Priester, J. H.; Mielke, R. E.; Krämer, S.; Jackson, S.; Stoimenov, P. K.; Stucky, G. D.; Cherr, G. N.; Orias, E.; Holden, P. A.

    2011-01-01

    Previous studies have shown that engineered nanomaterials can be transferred from prey to predator, but the ecological impacts of this are mostly unknown. In particular, it is not known if these materials can be biomagnified-a process in which higher concentrations of materials accumulate in organisms higher up in the food chain. Here, we show that bare CdSe quantum dots that have accumulated in Pseudomonas aeruginosa bacteria can be transferred to and biomagnified in the Tetrahymena thermophila protozoa that prey on the bacteria. Cadmium concentrations in the protozoa predator were approximately five times higher than their bacterial prey. Quantum-dot-treated bacteria were differentially toxic to the protozoa, in that they inhibited their own digestion in the protozoan food vacuoles. Because the protozoa did not lyse, largely intact quantum dots remain available to higher trophic levels. The observed biomagnification from bacterial prey is significant because bacteria are at the base of environmental food webs. Our findings illustrate the potential for biomagnification as an ecological impact of nanomaterials.

  11. Specific detection of banana residue in processed foods using polymerase chain reaction.

    PubMed

    Sakai, Yumiko; Ishihata, Kimie; Nakano, Shigeru; Yamada, Toshihiro; Yano, Takeo; Uchida, Kouji; Nakao, Yoshiki; Urisu, Atsuo; Adachi, Reiko; Teshima, Reiko; Akiyama, Hiroshi

    2010-07-28

    Specific polymerase chain reaction (PCR) methods were developed for the detection of banana residue in processed foods. For high banana specificity, the primer set BAN-F/BAN-R was designed on the basis of the large subunit of ribulose-1,5-bisphosphate carboxylase (rbcL) genes of chloroplasts and used to obtain amplified products specific to banana by both conventional and real-time PCR. To confirm the specificity of these methods, genomic DNA samples from 31 other species were examined; no amplification products were detected. Subsequently, eight kinds of processed foods containing banana were investigated using these methods to confirm the presence of banana DNA. Conventional PCR had a detection limit of 1 ppm (w/w) banana DNA spiked in 50 ng of salmon testis DNA, whereas SYBR Green I real-time semiquantitative PCR had a detection limit as low as 10 ppm banana DNA. Thus, both methods show high sensitivity and may be applicable as specific tools for the detection of trace amounts of banana in commercial food products. PMID:20604506

  12. An extended patch-dynamic framework for food chains in fragmented landscapes

    PubMed Central

    Liao, Jinbao; Chen, Jiehong; Ying, Zhixia; Hiebeler, David E.; Nijs, Ivan

    2016-01-01

    Habitat destruction, a key determinant of species loss, can be characterized by two components, patch loss and patch fragmentation, where the former refers to the reduction in patch availability, and the latter to the division of the remaining patches. Classical metacommunity models have recently explored how food web dynamics respond to patch loss, but the effects of patch fragmentation have largely been overlooked. Here we develop an extended patch-dynamic model that tracks the patch occupancy of the various trophic links subject to colonization-extinction-predation dynamics by incorporating species dispersal with patch connectivity. We found that, in a simple food chain, species at higher trophic level become extinct sooner with increasing patch loss and fragmentation due to the constraint in resource availability, confirming the trophic rank hypothesis. Yet, effects of fragmentation on species occupancy are largely determined by patch loss, with maximal fragmentation effects occurring at intermediate patch loss. Compared to the spatially explicit simulations that we also performed, the current model with pair approximation generates similar community patterns especially in spatially clustered landscapes. Overall, our extended framework can be applied to model more complex food webs in fragmented landscapes, broadening the scope of existing metacommunity theory. PMID:27608823

  13. Radionuclides in the terrestrial ecosystem near a Canadian uranium mill -- Part 2: Small mammal food chains and bioavailability

    SciTech Connect

    Thomas, P.A.

    2000-06-01

    Food chain transfer through the soil-vegetation-small mammal food chain was measured by concentration ratios (CRs) for uranium, {sup 226}Ra, {sup 210}Pb, and {sup 210}Po at three sites near the Key Lake uranium mill in northern Saskatchewan. Plant/soil CRs, animal carcass/GI tract CRs, and animal/soil CRs were depressed at sites impacted by mill and tailings dusts relative to a nearby control site. Thus, radionuclides associated with large particulates in tailings and/or ore dusts may be less bioavailable to terrestrial plants and animals than natural sources of radioactive dust. These results show that reliance on default food chain transfer parameters, obtained from uncontaminated terrestrial ecosystems, may overpredict impacts at uranium mine and mill sites. Given the omnivorous diet of small mammals and birds, animal/soil CRs are recommended as the most cost-effective and robust means of predicting animal concentrations from environmental monitoring data at uranium mill facilities.

  14. Possible ecosystem impacts of applying maximum sustainable yield policy in food chain models.

    PubMed

    Ghosh, Bapan; Kar, T K

    2013-07-21

    This paper describes the possible impacts of maximum sustainable yield (MSY) and maximum sustainable total yield (MSTY) policy in ecosystems. In general it is observed that exploitation at MSY (of single species) or MSTY (of multispecies) level may cause the extinction of several species. In particular, for traditional prey-predator system, fishing under combined harvesting effort at MSTY (if it exists) level may be a sustainable policy, but if MSTY does not exist then it is due to the extinction of the predator species only. In generalist prey-predator system, harvesting of any one of the species at MSY level is always a sustainable policy, but harvesting of both the species at MSTY level may or may not be a sustainable policy. In addition, we have also investigated the MSY and MSTY policy in a traditional tri-trophic and four trophic food chain models. PMID:23542048

  15. Dynamical behavior of fractional-order Hastings-Powell food chain model and its discretization

    NASA Astrophysics Data System (ADS)

    Matouk, A. E.; Elsadany, A. A.; Ahmed, E.; Agiza, H. N.

    2015-10-01

    In this work, the dynamical behavior of fractional-order Hastings-Powell food chain model is investigated and a new discretization method of the fractional-order system is introduced. A sufficient condition for existence and uniqueness of the solution of the proposed system is obtained. Local stability of the equilibrium points of the fractional-order system is studied. Furthermore, the necessary and sufficient conditions of stability of the discretized system are also studied. It is shown that the system's fractional parameter has effect on the stability of the discretized system which shows rich variety of dynamical behaviors such as Hopf bifurcation, an attractor crisis and chaotic attractors. Numerical simulations show the tea-cup chaotic attractor of the fractional-order system and the richer dynamical behavior of the corresponding discretized system.

  16. Analysis of a stochastic tri-trophic food-chain model with harvesting.

    PubMed

    Liu, Meng; Bai, Chuanzhi

    2016-09-01

    We consider a tri-trophic stochastic food-chain model with harvesting. We first establish critical values between persistence in mean and extinction for each species. The results show that persistence and extinction of a species only depends on the demographic impacts of environmental stochasticity on the species and species at lower tropic levels; however, the mean abundance of a species depends on the impacts of environmental stochasticity at all trophic levels. Then we consider stability in distribution of the model. Finally, we provide a necessary and sufficient condition for existence of optimal harvesting strategy and give the optimal harvesting effort and maximum of sustainable yield. The results show that the optimal harvesting strategy is closely related to the stochastic noises in the model. PMID:26846770

  17. Uptake and transfer of14C-simetryne through the laboratory freshwater food chain

    NASA Astrophysics Data System (ADS)

    Xu, Ying; Lay, J. P.; Zhang, Yongyuan

    1989-03-01

    This paper deals with the bioconcentration of14C-simetryne from water by aquatic test organisms: green algae— Monoraphidium minutum, rotifers— Brachionus rubens, daphnids— Daphnia magna, and fish— Brachydanio rerio. The chemical was bioconcentrated rapidly in all test species during the first 48 hours of experiment. The BCF values (bioconcentration factor) from all uptake studies show that simetryne has higher accumulation in algae than in rotifers, daphnids and zebra fish. The logarithm of the n-octanol/water partition coefficient of simetryne measured as 2.06±0.05 was correlated with the BCFs in the organisms as based on the lipid contents. 14C-simetryne uptake via the food-chain amounted to only 22% to 42% of the bioconcentration from water. Clearance of14C-derived residues from fish was rapid with a half-life of 2.1 days.

  18. Estimated dose to man from uranium milling via the terrestrial food-chain pathway

    SciTech Connect

    Rayno, D.R.

    1982-01-01

    One of the major pathways of radiological exposure to man from uranium milling operations is through the terrestrial food chain. Studies by various investigators have shown the extent of uptake and distribution of U-238, U-234, Th-230, Ra-226, Pb-210, and Po-210 in plants and animals. These long-lived natural radioisotopes, all nuclides of the uranium decay series, are found in concentrated amounts in uranium mill tailings. Data from these investigations are used to estimate the dose to man from consumption of beef and milk contaminated by the tailings. This dose estimate from this technologically enhanced source is compared with that from average normal dietary intake of these radionuclides from natural sources.

  19. Stability and Bifurcation Analysis of a Three-Species Food Chain Model with Delay

    NASA Astrophysics Data System (ADS)

    Pal, Nikhil; Samanta, Sudip; Biswas, Santanu; Alquran, Marwan; Al-Khaled, Kamel; Chattopadhyay, Joydev

    In the present paper, we study the effect of gestation delay on a tri-trophic food chain model with Holling type-II functional response. The essential mathematical features of the proposed model are analyzed with the help of equilibrium analysis, stability analysis, and bifurcation theory. Considering time-delay as the bifurcation parameter, the Hopf-bifurcation analysis is carried out around the coexisting equilibrium. The direction of Hopf-bifurcation and the stability of the bifurcating periodic solutions are determined by applying the normal form theory and center manifold theorem. We observe that if the magnitude of the delay is increased, the system loses stability and shows limit cycle oscillations through Hopf-bifurcation. The system also shows the chaotic dynamics via period-doubling bifurcation for further enhancement of time-delay. Our analytical findings are illustrated through numerical simulations.

  20. Mathematical Model of Three Species Food Chain Interaction with Mixed Functional Response

    NASA Astrophysics Data System (ADS)

    Ws, Mada Sanjaya; Mohd, Ismail Bin; Mamat, Mustafa; Salleh, Zabidin

    In this paper, we study mathematical model of ecology with a tritrophic food chain composed of a classical Lotka-Volterra functional response for prey and predator, and a Holling type-III functional response for predator and super predator. There are two equilibrium points of the system. In the parameter space, there are passages from instability to stability, which are called Hopf bifurcation points. For the first equilibrium point, it is possible to find bifurcation points analytically and to prove that the system has periodic solutions around these points. Furthermore the dynamical behaviors of this model are investigated. Models for biologically reasonable parameter values, exhibits stable, unstable periodic and limit cycles. The dynamical behavior is found to be very sensitive to parameter values as well as the parameters of the practical life. Computer simulations are carried out to explain the analytical findings.

  1. Local stability of a five dimensional food chain model in the ocean

    NASA Astrophysics Data System (ADS)

    Kusumawinahyu, W. M.; Hidayatulloh, M. R.

    2014-02-01

    This paper discuss a food chain model on a microbiology ecosystem in the ocean, where predation process occurs. Four population growth rates are discussed, namely bacteria, phytoplankton, zooplankton, and protozoa growth rate. When the growth of nutrient density is also considered, the model is governed by a five dimensional dynamical system. The system considered in this paper is a modification of a model proposed by Hadley and Forbes [1], by taking Holling Type I as the functional response. For sake of simplicity, the model needs to be scaled. Dynamical behavior, such as existence condition of equilibrium points and their local stability are addressed. There are eight equilibrium points, where two of them exist under certain conditions. Three equilibrium points are unstable, while two points stable under certain conditions and the other three points are stable if the Ruth-Hurwitz criteria are satisfied. Numerical simulations are carried out to illustrate analytical findings.

  2. Correlated Biogeographic Variation of Magnesium across Trophic Levels in a Terrestrial Food Chain

    PubMed Central

    Sun, Xiao; Kay, Adam D.; Kang, Hongzhang; Small, Gaston E.; Liu, Guofang; Zhou, Xuan; Yin, Shan; Liu, Chunjiang

    2013-01-01

    Using samples from eastern China (c. 25 – 41° N and 99 – 123° E) and from a common garden experiment, we investigate how Mg concentration varies with climate across multiple trophic levels. In soils, plant tissue (Oriental oak leaves and acorns), and a specialist acorn predator (the weevil Curculio davidi), Mg concentration increased significantly with different slopes from south to north, and generally decreased with both mean annual temperature (MAT) and precipitation (MAP). In addition, soil, leaf, acorn and weevil Mg showed different strengths of association and sensitivity with climatic factors, suggesting that distinct mechanisms may drive patterns of Mg variation at different trophic levels. Our findings provide a first step toward determining whether anticipated changes in temperature and precipitation due to climate change will have important consequences for the bioavailability and distribution of Mg in food chain. PMID:24223807

  3. Stable nitrogen isotope ratios and accumulation of PCDD/F and PCB in Baltic aquatic food chains

    SciTech Connect

    Broman, D.; Naef, C.; Rolff, C.; Zebuehr, Y.

    1994-12-31

    Ratios of naturally occurring stable isotopes of nitrogen ({delta}{sup 15}N) can be used to numerically classify trophic levels of organisms in food chains. By combining analyses results of PCDD/Fs and non-ortho PCBs the biomagnification of these substances can be quantitatively estimated. The two Baltic food chains studied were one pelagic (phytoplankton -- settling particulate matter (SPM) -- zooplankton -- mysids -- herring -- cod) and one littoral (phytoplankton -- SPM -- blue mussel -- eider duck). The {delta}{sup 15}N-data gave food chain descriptions qualitatively consistent with previous conceptions of trophic arrangements in the food chains. Phytoplankton showed the lowest average {delta}{sup 15}N-value and the juvenile eider duck and the cod showed the highest average {delta}{sup 15}N-values for the littoral and pelagic food chains, respectively. The PCDD/Fs and PCBs concentrations were plotted versus the {delta}{sup 15}N-values for the different trophic levels and an exponential model of the form e{sup (A + B*{delta}N)} was fitted to the data. The estimates of the constant B in the model allows for an estimation of a biomagnification power (B) of different singular, or groups of, contaminants. A B-value around zero indicates that a substance is flowing through the food chain without being magnified, whereas a value > 0 indicates that a substance is biomagnified. Negative B-values indicate that a substance is not taken up or is metabolized. The A-term of the expression is only a scaling factor depending on the background level of the contaminant.

  4. Particle-size dependent accumulation and trophic transfer of cerium oxide through a terrestrial food chain.

    PubMed

    Hawthorne, Joseph; De la Torre Roche, Roberto; Xing, Baoshan; Newman, Lee A; Ma, Xingmao; Majumdar, Sanghamitra; Gardea-Torresdey, Jorge; White, Jason C

    2014-11-18

    The accumulation and trophic transfer of nanoparticle (NP) or bulk CeO2 through a terrestrial food chain was evaluated. Zucchini (Cucurbita pepo L.) was planted in soil with 0 or 1228 μg/g bulk or NP CeO2. After 28 d, zucchini tissue Ce content was determined by ICP-MS. Leaf tissue from each treatment was used to feed crickets (Acheta domesticus). After 14 d, crickets were analyzed for Ce content or were fed to wolf spiders (family Lycosidae). NP CeO2 significantly suppressed flower mass relative to control and bulk treatments. The Ce content of zucchini was significantly greater when exposure was in the NP form. The flowers, leaves, stems, and roots of zucchini exposed to bulk CeO2 contained 93.3, 707, 331, and 119,000 ng/g, respectively; NP-exposed plants contained 153, 1510, 479, and 567 000 ng/g, respectively. Crickets fed NP CeO2-exposed zucchini leaves contained significantly more Ce (33.6 ng/g) than did control or bulk-exposed insects (15.0-15.2 ng/g). Feces from control, bulk, and NP-exposed crickets contained Ce at 248, 393, and 1010 ng/g, respectively. Spiders that consumed crickets from control or bulk treatments contained nonquantifiable Ce; NP-exposed spiders contained Ce at 5.49 ng/g. These findings show that NP CeO2 accumulates in zucchini at greater levels than equivalent bulk materials and that this greater NP intake results in trophic transfer and possible food chain contamination. PMID:25340623

  5. Meta-food-chains as a many-layer epidemic process on networks

    NASA Astrophysics Data System (ADS)

    Barter, Edmund; Gross, Thilo

    2016-02-01

    Notable recent works have focused on the multilayer properties of coevolving diseases. We point out that very similar systems play an important role in population ecology. Specifically we study a meta-food-web model that was recently proposed by Pillai et al. [Theor. Ecol. 3, 223 (2009), 10.1007/s12080-009-0065-1]. This model describes a network of species connected by feeding interactions, which spread over a network of spatial patches. Focusing on the essential case, where the network of feeding interactions is a chain, we develop an analytical approach for the computation of the degree distributions of colonized spatial patches for the different species in the chain. This framework allows us to address ecologically relevant questions. Considering configuration model ensembles of spatial networks, we find that there is an upper bound for the fraction of patches that a given species can occupy, which depends only on the networks mean degree. For a given mean degree there is then an optimal degree distribution that comes closest to the upper bound. Notably scale-free degree distributions perform worse than more homogeneous degree distributions if the mean degree is sufficiently high. Because species experience the underlying network differently the optimal degree distribution for one particular species is generally not the optimal distribution for the other species in the same food web. These results are of interest for conservation ecology, where, for instance, the task of selecting areas of old-growth forest to preserve in an agricultural landscape, amounts to the design of a patch network.

  6. Influence of dispersants on petroleum bioavailability in a marine food chain

    SciTech Connect

    Wolfe, M.; Tjeerdema, R.; Sowby, M.

    1995-12-31

    When crude oil is accidentally released into the ocean it threatens many levels of marine life. Intervention, in the form of chemical dispersing agents, may alter the normal behavior of petroleum hydrocarbons (PH) by increasing their functional water solubility and the extent of their exposure to sub-surface marine organisms. Further, the dispersing agent may modify bioavailability as a result of altered interactions between dispersed PH droplets and organismal cell membranes, To date, little information exists on the sub-lethal effects of dispersants and factors modifying their role in the bioavailability and disposition of PH in marine food chains. The objective of the current research was to determine the impact of dispersing agents on PH bioavailability to primary levels of a marine food chain. Uptake, bioaccumulation, deputation, and metabolic transformation of a model PH, {sup 14}C-naphthalene, were measured and compared for dispersed Prudhoe Bay Crude Oil (PBCO) vs. undispersed preparations of the water-accommodated fractions (WAF) of PBCO at two salinities (22 and 34 ppt) employing Isochrysis galbana, a primary producer, and Brachionus plicatilis, a primary consumer. Fractionation and identification of metabolites was done by HPLC co-chromatography with analytical standards, and quantitation was done by liquid scintillation counting. GC-FID characterization of WAF and dispersed oil preparations shows higher concentrations of petroleum hydrocarbons and a greater number of individual constituents in the dispersed oil preparations. However, short term (eight hour) and long term (two week) static exposure studies indicate the uptake of{sup 14}C-naphthalene from WAF preparations is inhibited by up to 50% from dispersed oil preparations. Results of comparative static and flow-through chamber exposure studies will be presented.

  7. Assessment of the effects of cage fish-farming on damselfish-associated food chains using stable-isotope analyses.

    PubMed

    Jan, Rong-Quen; Kao, Shuh-Ji; Dai, Chang-Feng; Ho, Cheng-Tze

    2014-09-15

    To assess the effect of cage fish-farming on the coral reef ecosystem off Xiaoliuchiu Island, southern Taiwan, geographical differences in the food chain of each of two damselfishes, Pomacentrus vaiuli and Chromis margaritifer, were examined using a stable-isotope approach. For each damselfish, individuals were found to consume similar foods at all sites. However, specimens collected at sites near the cage farm (as the experimental sites) exhibited lower δ(13)C and higher δ(15)N signatures compared to those from reference sites. Similar trends also occurred in the zooplankton and detritus, two major food sources for both damselfishes. This finding indicates that particulate organic matter released by the farm may have entered the coral reef ecosystem through the pelagic food chain. Artificial reef emplacement is recommended to provide extra habitats under cage farms to support additional pelagic-feeding fish populations, thereby reducing environmental impacts of cage farming on coral reefs. PMID:25103907

  8. Consumer acceptability of interventions to reduce Campylobacter in the poultry food chain

    PubMed Central

    MacRitchie, L.A.; Hunter, C.J.; Strachan, N.J.C.

    2014-01-01

    Reducing human Campylobacter cases has become a priority for the UK Government. However the public's views on acceptability of interventions to reduce Campylobacter in poultry production are poorly understood in the UK and in other countries around the world. The objective of the study was to investigate how increasing awareness and knowledge changes consumer acceptability of interventions that reduce human campylobacteriosis in the poultry food chain. This approach is readily applicable to other risks and associated interventions. It involved a survey of the views of consumers in the Grampian region in North East Scotland. This found that better hygiene practices on farm, freezing chicken meat and vaccination of chickens were acceptable to the majority of participants (95%, 53% & 52% respectively) whilst irradiation and chemical wash of chicken meat were acceptable to <50%. Increasing consumer awareness by providing information on the Campylobacter disease burden in humans increased the number of participants finding them acceptable. However, chemical wash and irradiation remained the least acceptable interventions, although highly effective at reducing Campylobacter, and were found to be never acceptable to >50% of respondents. It was found on average that food poisoning concern, previous awareness of Campylobacter and living in rural or urban areas had either no or little effect effect on the acceptability of interventions. Further, previous awareness of Campylobacter did not influence consumer concern of harmful bacteria on chicken meat. Overall, findings indicate that increasing consumer acceptability of the most effective interventions is likely to be a difficult process. PMID:24882947

  9. In situ treatment with activated carbon reduces bioaccumulation in aquatic food chains.

    PubMed

    Kupryianchyk, D; Rakowska, M I; Roessink, I; Reichman, E P; Grotenhuis, J T C; Koelmans, A A

    2013-05-01

    In situ activated carbon (AC) amendment is a new direction in contaminated sediment management, yet its effectiveness and safety have never been tested on the level of entire food chains including fish. Here we tested the effects of three different AC treatments on hydrophobic organic chemical (HOC) concentrations in pore water, benthic invertebrates, zooplankton, and fish (Leuciscus idus melanotus). AC treatments were mixing with powdered AC (PAC), mixing with granular AC (GAC), and addition-removal of GAC (sediment stripping). The AC treatments resulted in a significant decrease in HOC concentrations in pore water, benthic invertebrates, zooplankton, macrophytes, and fish. In 6 months, PAC treatment caused a reduction of accumulation of polychlorobiphenyls (PCB) in fish by a factor of 20, bringing pollutant levels below toxic thresholds. All AC treatments supported growth of fish, but growth was inhibited in the PAC treatment, which was likely explained by reduced nutrient concentrations, resulting in lower zooplankton (i.e., food) densities for the fish. PAC treatment may be advised for sites where immediate ecosystem protection is required. GAC treatment may be equally effective in the longer term and may be adequate for vulnerable ecosystems where longer-term protection suffices. PMID:23544454

  10. The biomagnification of PCBs, PCDDs, PCDFs in a simplified laboratory food chain

    SciTech Connect

    Taplin, B.; Pruell, R.; McGovern, D.; McKinney, R.

    1995-12-31

    The trophic transfer and biomagnification potential of polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs), were investigated in a simplified marine benthic food chain. Polychaetes, Nereis virens were exposed to contaminated sediment and fed to juvenile lobsters, Homarus americanus exposed to the same sediment for 112 days. Time series uptake and depuration measurements were made for lobster muscle and hepatopancreas. A nonlinear model (BIOFAC) was used to calculate uptake and depuration rate constants, bioaccumulation factors, and steady state concentrations for PCBs, PCDDs, and PCDFs. Biomagnification factors (BMFs), on a lipid weight basis, were calculated for both tissues. Lobsters accumulated PCDDs, PCDFs, and PCBs from contaminated sediment and food (polychaetes). Of the two tissues, lobster hepatopancreas, showed the highest concentrations for all compounds analyzed. Of the PCDDs and PCDFs studied, only 2,3,7,8-tetrachlorodibenzodioxin, 2,3,7,8-tetrachlorodibenzofuran, 2,3,4,7,8-pentachlorodibenzofuran, and 1,2,3,4,7,8-hexachlorodibenzofuran were detected in lobster muscle and hepatopancreas tissues. Of the PCB congeners studied, 2,2{prime},4,4{prime},5,5{prime} hexachlorobiphenyl reached the highest concentration in lobster muscle and hepatopancreas. Lobsters also accumulated non-ortho substituted PCBs in both tissues.

  11. Cerium Biomagnification in a Terrestrial Food Chain: Influence of Particle Size and Growth Stage.

    PubMed

    Majumdar, Sanghamitra; Trujillo-Reyes, Jesica; Hernandez-Viezcas, Jose A; White, Jason C; Peralta-Videa, Jose R; Gardea-Torresdey, Jorge L

    2016-07-01

    Mass-flow modeling of engineered nanomaterials (ENMs) indicates that a major fraction of released particles partition into soils and sediments. This has aggravated the risk of contaminating agricultural fields, potentially threatening associated food webs. To assess possible ENM trophic transfer, cerium accumulation from cerium oxide nanoparticles (nano-CeO2) and their bulk equivalent (bulk-CeO2) was investigated in producers and consumers from a terrestrial food chain. Kidney bean plants (Phaseolus vulgaris var. red hawk) grown in soil contaminated with 1000-2000 mg/kg nano-CeO2 or 1000 mg/kg bulk-CeO2 were presented to Mexican bean beetles (Epilachna varivestis), which were then consumed by spined soldier bugs (Podisus maculiventris). Cerium accumulation in plant and insects was independent of particle size. After 36 days of exposure to 1000 mg/kg nano- and bulk-CeO2, roots accumulated 26 and 19 μg/g Ce, respectively, and translocated 1.02 and 1.3 μg/g Ce, respectively, to shoots. The beetle larvae feeding on nano-CeO2 exposed leaves accumulated low levels of Ce since ∼98% of Ce was excreted in contrast to bulk-CeO2. However, in nano-CeO2 exposed adults, Ce in tissues was higher than Ce excreted. Additionally, Ce content in tissues was biomagnified by a factor of 5.3 from the plants to adult beetles and further to bugs. PMID:26690677

  12. Consumer acceptability of interventions to reduce Campylobacter in the poultry food chain.

    PubMed

    MacRitchie, L A; Hunter, C J; Strachan, N J C

    2014-01-01

    Reducing human Campylobacter cases has become a priority for the UK Government. However the public's views on acceptability of interventions to reduce Campylobacter in poultry production are poorly understood in the UK and in other countries around the world. The objective of the study was to investigate how increasing awareness and knowledge changes consumer acceptability of interventions that reduce human campylobacteriosis in the poultry food chain. This approach is readily applicable to other risks and associated interventions. It involved a survey of the views of consumers in the Grampian region in North East Scotland. This found that better hygiene practices on farm, freezing chicken meat and vaccination of chickens were acceptable to the majority of participants (95%, 53% & 52% respectively) whilst irradiation and chemical wash of chicken meat were acceptable to <50%. Increasing consumer awareness by providing information on the Campylobacter disease burden in humans increased the number of participants finding them acceptable. However, chemical wash and irradiation remained the least acceptable interventions, although highly effective at reducing Campylobacter, and were found to be never acceptable to >50% of respondents. It was found on average that food poisoning concern, previous awareness of Campylobacter and living in rural or urban areas had either no or little effect effect on the acceptability of interventions. Further, previous awareness of Campylobacter did not influence consumer concern of harmful bacteria on chicken meat. Overall, findings indicate that increasing consumer acceptability of the most effective interventions is likely to be a difficult process. PMID:24882947

  13. Food chain transport of nanoparticles affects behaviour and fat metabolism in fish.

    PubMed

    Cedervall, Tommy; Hansson, Lars-Anders; Lard, Mercy; Frohm, Birgitta; Linse, Sara

    2012-01-01

    Nano-sized (10(-9)-10(-7) m) particles offer many technical and biomedical advances over the bulk material. The use of nanoparticles in cosmetics, detergents, food and other commercial products is rapidly increasing despite little knowledge of their effect on organism metabolism. We show here that commercially manufactured polystyrene nanoparticles, transported through an aquatic food chain from algae, through zooplankton to fish, affect lipid metabolism and behaviour of the top consumer. At least three independent metabolic parameters differed between control and test fish: the weight loss, the triglycerides∶cholesterol ratio in blood serum, and the distribution of cholesterol between muscle and liver. Moreover, we demonstrate that nanoparticles bind to apolipoprotein A-I in fish serum in-vitro, thereby restraining them from properly utilising their fat reserves if absorbed through ingestion. In addition to the metabolic effects, we show that consumption of nanoparticle-containing zooplankton affects the feeding behaviour of the fish. The time it took the fish to consume 95% of the food presented to them was more than doubled for nanoparticle-exposed compared to control fish. Since many nano-sized products will, through the sewage system, end up in freshwater and marine habitats, our study provides a potential bioassay for testing new nano-sized material before manufacturing. In conclusion, our study shows that from knowledge of the molecular composition of the protein corona around nanoparticles it is possible to make a testable molecular hypothesis and bioassay of the potential biological risks of a defined nanoparticle at the organism and ecosystem level. PMID:22384193

  14. Accidental and deliberate microbiological contamination in the feed and food chains--how biotraceability may improve the response to bioterrorism.

    PubMed

    Knutsson, Rickard; van Rotterdam, Bart; Fach, Patrick; De Medici, Dario; Fricker, Martina; Löfström, Charlotta; Agren, Joakim; Segerman, Bo; Andersson, Gunnar; Wielinga, Peter; Fenicia, Lucia; Skiby, Jeffrey; Schultz, Anna Charlotte; Ehling-Schulz, Monika

    2011-03-01

    A next frontier of the global food safety agenda has to consider a broad spectrum of bio-risks, such as accidental and intentional contaminations in the food and feed chain. In this article, the background for the research needs related to biotraceability and response to bioterrorism incidents are outlined. Given the current scale of international trade any response need to be considered in an international context. Biotraceability (e.g. the ability to use downstream information to point to processes or within a particular food chain that can be identified as the source of undesirable agents) is crucial in any food-born outbreak and particular in the response to bioterrorism events. In the later case, tested and proven biotraceability improves the following: (i) international collaboration of validated tracing tools and detection methods, (ii) multi-disciplinary expertise and collaboration in the field of food microbiology and conceptual modeling of the food chain, (iii) sampling as a key step in biotracing (iv) optimized sample preparation procedures, including laboratory work in Biosafety level 3 (BSL-3) laboratories, (v) biomarker discovery for relevant tracing and tracking applications, and (vi) high-throughput sequencing using bio-informatic platforms to speed up the characterization of the biological agent. By applying biotraceability, the response phase during a bioterrorism event may be shortened and is facilitated for tracing the origin of biological agent contamination. PMID:21093084

  15. 40 CFR 257.3-5 - Application to land used for the production of food-chain crops (interim final).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Application to land used for the production of food-chain crops (interim final). 257.3-5 Section 257.3-5 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES CRITERIA FOR CLASSIFICATION OF SOLID WASTE DISPOSAL FACILITIES AND PRACTICES Classification of...

  16. Mineral cycling in soil and litter arthropod food chains. Three-year progress report, November 1, 1980-January 31, 1984

    SciTech Connect

    Crossley, D.A. Jr.

    1984-01-01

    This report summarizes our analysis of trophic dynamics in soil fauna including their impact on the decomposition process, investigation of relationships between soil fauna and microflora, development and testing of models describing these processes, and documentation of rates of movement of nutrients along soil arthropod food chains.

  17. Antagonistic and synergistic toxic effects of Pb and Cd in a simple food chain: nematodes feeding on bacteria and fungi

    SciTech Connect

    Doelman, P.; Nieboer, G.; Schrooten, J.; Visser, M.

    1984-06-01

    Soil pollution with heavy metals may affect the functioning of the soil biota by inhibiting the decomposition of organic matter and may also influence food chains. This paper presents the results of an investigation on how the reproduction of soil nematodes can be influenced by feeding on bacteria or fungi contaminated with lead and cadmium.

  18. Bioaccumulation and Toxicity of Single-Walled Carbon Nanotubes to Benthic Organisms at the Base of the Marine Food Chain

    EPA Science Inventory

    As the use of single-walled carbon nanotubes (SWNTs) increases over time, so does the potential for environmental release. This research aimed to determine the toxicity, bioavailability, and bioaccumulation of SWNTs in marine benthic organisms at the base of the food chain. The t...

  19. LITERATURE REVIEW AND EVALUATION OF THE EPA FOOD-CHAIN (KENAGA) NOMOGRAM, AN INSTRUMENT FOR ESTIMATING PESTICIDE RESIDUES ON PLANTS

    EPA Science Inventory

    The Kenaga nomogram is a simple device developed by the U.S. Environmental Protection Agency (EPA) in the early 1980s and is currently used to predict the maximum potential pesticide residue levels in the food chain of wildlife before pesticide registration. o evaluate the accura...

  20. Terrestrial model food chain and environmental chemicals. I. Transfer of sodium [14C]pentachlorophenate between springtails and carabids.

    PubMed

    Gruttke, H; Kratz, W; Weigmann, G; Haque, A

    1988-06-01

    A model soil food chain of a ruderal ecosystem has been constructed in order to study the uptake, transfer, and accumulation of [14C]pentachlorophenate (PCP-Na). The model was based on three food levels, viz. baker's yeast, collembola, and carabid beetles, and the contaminant chemical introduced was via initial food. Continuous exposure of the organisms to the test chemical resulted in a significant uptake and transfer of radiocarbon into the food chain elements. Bioaccumulation of radiocarbon in the body tissues of the organisms was low, as large amounts taken up were quickly eliminated through the excrements. The radiocarbon level of prey animals was about 100 times higher than that of their predators, but there was only small difference in concentration between collembolas and yeast. This was probably because of a faster excretion of the chemical by the beetles than by the collembolas. During the test period no conversion of [14C]PCP-Na took place in the yeast, but the collembolas and beetles metabolized 50 and 59%, respectively. Criteria are proposed for successful implementation of food chain models. PMID:3049045

  1. Human and animal health risk assessments of chemicals in the food chain: Comparative aspects and future perspectives

    SciTech Connect

    Dorne, J.L.C.M.; Fink-Gremmels, J.

    2013-08-01

    Chemicals from anthropogenic and natural origins enter animal feed, human food and water either as undesirable contaminants or as part of the components of a diet. Over the last five decades, considerable efforts and progress to develop methodologies to protect humans and animals against potential risks associated with exposure to such potentially toxic chemicals have been made. This special issue presents relevant methodological developments and examples of risk assessments of undesirable substances in the food chain integrating the animal health and the human health perspective and refers to recent Opinions of the Scientific Panel on Contaminants in the Food Chain (CONTAM) of the European Food Safety Authority (EFSA). This introductory review aims to give a comparative account of the risk assessment steps used in human health and animal health risk assessments for chemicals in the food chain and provides a critical view of the data gaps and future perspectives for this cross-disciplinary field. - Highlights: ► Principles of human and animal health risk assessment. ► Data gaps for each step of animal health risk assessment. ► Implications of animal risk assessment on human risk assessment. ► Future perspectives on chemical risk assessment.

  2. Terrestrial model food chain and environmental chemicals. I. Transfer of sodium (/sup 14/C)pentachlorophenate between springtails and carabids

    SciTech Connect

    Gruttke, H.; Kratz, W.; Weigmann, G.; Haque, A.

    1988-06-01

    A model soil food chain of a ruderal ecosystem has been constructed in order to study the uptake, transfer, and accumulation of (/sup 14/C)pentachlorophenate (PCP-Na). The model was based on three food levels, viz. baker's yeast, collembola, and carabid beetles, and the contaminant chemical introduced was via initial food. Continuous exposure of the organisms to the test chemical resulted in a significant uptake and transfer of radiocarbon into the food chain elements. Bioaccumulation of radiocarbon in the body tissues of the organisms was low, as large amounts taken up were quickly eliminated through the excrements. The radiocarbon level of prey animals was about 100 times higher than that of their predators, but there was only small difference in concentration between collembolas and yeast. This was probably because of a faster excretion of the chemical by the beetles than by the collembolas. During the test period no conversion of (/sup 14/C)PCP-Na took place in the yeast, but the collembolas and beetles metabolized 50 and 59%, respectively. Criteria are proposed for successful implementation of food chain models.

  3. [Transfer characteristics of cadmium in soil-vegetable-insect food chain].

    PubMed

    Ding, Ping; Zhuang, Ping; Li, Zhi-An; Xia, Han-Ping; Tai, Yi-Ping; Lu, Huan-Ping

    2012-11-01

    Taking two kinds of vegetables (Brassica rapa and Amaranthus mangostanus) and one insect species (Prodenia litura) as test materials, a greenhouse pot experiment was conducted to study the transfer characteristics of cadmium (Cd) in soil-vegetable-insect food chain and the distribution patters of different Cd chemical forms in the organs of the two vegetables. With the increasing concentration of applied Cd in soil, the biomass of the two vegetables decreased significantly, while the Cd concentration in the vegetables had a significant increase. The Cd concentration in the vegetable organs decreased in the order of stem > root > leaf for A. mangostanus, and of stem > leaf > root for B. rapa. The Cd concentration in P. litura larvae also increased with the increasing concentration of Cd in soil, and the maximum Cd concentration in the P. litura larvae on B. rapa and A. mangostanus was 36.7 and 46.3 mg x kg(-1), respectively. In the feces of the larvae on B. rapa and A. mangostanus, the Cd concentration was up to 190 and 229.8 mg x kg(-1), respectively, suggesting that the most part of Cd absorbed by P. litura larvae was excreted out of their bodies via feces. In the organs of the two vegetables, NaCl-extractable Cd was the dominant Cd form (> 70%), followed by d-H2O- and ethanol-extractable Cd, while the HAc-extractable Cd (insoluble cadmium phosphate), HCl-extractable Cd (insoluble cadmium oxalate), and residual Cd only had a very low concentration. Such a present pattern of different Cd forms in vegetable organs could be conducive to the Cd transfer in the food chain. P. litura could ease Cd poison by excreting large amount of absorbed Cd via feces, and effectively restrict the transfer of Cd to next trophic level. Since B. rapa and A. mangostanus could accumulate large amount of Cd in their biomass, the two vegetables were suggested not to be planted in highly Cd-contaminated soil. PMID:23431799

  4. The Belgian PCB/dioxin incident: analysis of the food chain contamination and health risk evaluation.

    PubMed

    Bernard, Alfred; Broeckaert, Fabrice; De Poorter, Geert; De Cock, Ann; Hermans, Cédric; Saegerman, Claude; Houins, Gilbert

    2002-01-01

    The Belgian PCB incident occurred at the end of January 1999 when a mixture of polychlorinated biphenyls (PCBs) contaminated with dioxins was accidentally added to a stock of recycled fat used in the production of animal feeds. Although signs of poultry poisoning were noticed by February, 1999, the source and the extent of the contamination were discovered only in May 1999, when it appeared that more than 2500 farms could have been supplied with contaminated feeds. This resulted in a major food crisis, which rapidly extended to the whole country and could be resolved only by the implementation of a large PCB/dioxin food monitoring program. Screening for PCB contamination was based on the determination of the seven PCB markers. When PCB concentrations exceeded the tolerance levels of 0.1 (milk), 0.2 (poultry, bovine, and pig meat), or 1 (animal feed) microg/g fat, dioxins (17 PCDD/Fs congeners) were also determined. At the end of December 1999, the database contained the results of more than 55,000 PCB and 500 dioxin analyses. The study of PCB levels and profiles in contaminated feeds delivered to poultry or pig farms confirmed that the Belgian PCB incident was due to a single source of PCB oil introduced into the food chain at the end of January 1999. This PCB oil had a congeners pattern closely matched to a mixture of Aroclor 1260/1254 in the proportion 75/25. The total amount of PCBs added to recycled fats was estimated at 50 kg (sum of the seven markers) or approximately 150 kg total PCBs, which corresponds to about 100 liters of PCB oil. This PCB mixture contained about 1g TEQ dioxins (more than 90- contributed by PCDFs) and about 2g TEQ dioxin-like PCBs. The proportions of PCB 52 and 101 congeners were fairly constant in animal feeds, excluding the possibility of secondary contamination due to fat recycling from contaminated animals. The highest concentrations of PCBs and dioxins were found in poultry and especially in the reproduction animals (hens and chicks

  5. Trophic assimilation efficiency markedly increases at higher trophic levels in four-level host-parasitoid food chain.

    PubMed

    Sanders, Dirk; Moser, Andrea; Newton, Jason; van Veen, F J Frank

    2016-03-16

    Trophic assimilation efficiency (conversion of resource biomass into consumer biomass) is thought to be a limiting factor for food chain length in natural communities. In host-parasitoid systems, which account for the majority of terrestrial consumer interactions, a high trophic assimilation efficiency may be expected at higher trophic levels because of the close match of resource composition of host tissue and the consumer's resource requirements, which would allow for longer food chains. We measured efficiency of biomass transfer along an aphid-primary-secondary-tertiary parasitoid food chain and used stable isotope analysis to confirm trophic levels. We show high efficiency in biomass transfer along the food chain. From the third to the fourth trophic level, the proportion of host biomass transferred was 45%, 65% and 73%, respectively, for three secondary parasitoid species. For two parasitoid species that can act at the fourth and fifth trophic levels, we show markedly increased trophic assimilation efficiencies at the higher trophic level, which increased from 45 to 63% and 73 to 93%, respectively. In common with other food chains, δ(15)N increased with trophic level, with trophic discrimination factors (Δ(15)N) 1.34 and 1.49‰ from primary parasitoids to endoparasitic and ectoparasitic secondary parasitoids, respectively, and 0.78‰ from secondary to tertiary parasitoids. Owing to the extraordinarily high efficiency of hyperparasitoids, cryptic higher trophic levels may exist in host-parasitoid communities, which could alter our understanding of the dynamics and drivers of community structure of these important systems. PMID:26962141

  6. Trophic assimilation efficiency markedly increases at higher trophic levels in four-level host–parasitoid food chain

    PubMed Central

    Moser, Andrea; van Veen, F. J. Frank

    2016-01-01

    Trophic assimilation efficiency (conversion of resource biomass into consumer biomass) is thought to be a limiting factor for food chain length in natural communities. In host–parasitoid systems, which account for the majority of terrestrial consumer interactions, a high trophic assimilation efficiency may be expected at higher trophic levels because of the close match of resource composition of host tissue and the consumer's resource requirements, which would allow for longer food chains. We measured efficiency of biomass transfer along an aphid-primary–secondary–tertiary parasitoid food chain and used stable isotope analysis to confirm trophic levels. We show high efficiency in biomass transfer along the food chain. From the third to the fourth trophic level, the proportion of host biomass transferred was 45%, 65% and 73%, respectively, for three secondary parasitoid species. For two parasitoid species that can act at the fourth and fifth trophic levels, we show markedly increased trophic assimilation efficiencies at the higher trophic level, which increased from 45 to 63% and 73 to 93%, respectively. In common with other food chains, δ15N increased with trophic level, with trophic discrimination factors (Δ15N) 1.34 and 1.49‰ from primary parasitoids to endoparasitic and ectoparasitic secondary parasitoids, respectively, and 0.78‰ from secondary to tertiary parasitoids. Owing to the extraordinarily high efficiency of hyperparasitoids, cryptic higher trophic levels may exist in host–parasitoid communities, which could alter our understanding of the dynamics and drivers of community structure of these important systems. PMID:26962141

  7. Surf zone diatoms: A review of the drivers, patterns and role in sandy beaches food chains

    NASA Astrophysics Data System (ADS)

    Odebrecht, Clarisse; Du Preez, Derek R.; Abreu, Paulo Cesar; Campbell, Eileen E.

    2014-10-01

    The accumulation of high biomass of diatoms in the surf zone is a characteristic feature of some sandy beaches where the wave energy is sufficiently high. A few species of diatoms, called surf diatoms, thrive in this harsh environment. The main processes driving the spatial and temporal distribution of surf diatoms as well as their standing biomass and growth were described twenty to thirty years ago based on studies conducted on the western coast of the United States of America and South African beaches. Since then, over fifty locations around the world have been reported to have surf diatom accumulations with most (three-quarters) of these being in the southern hemisphere. Their occurrence is controlled by physical and chemical factors, including wave energy, beach slope and length, water circulation patterns in the surf zone and the availability of nutrients to sustain the high biomass. The main forces driving the patterns of temporal variability of surf diatom accumulations are meteorological. In the short term (hours), the action of wind stress and wave energy controls the diatom accumulation. In the intermediate time scale (weeks to months), seasonal onshore winds of sufficient strength, as well as storm events are important. Furthermore, anthropogenic disturbances that influence the beach ecosystem as well as large-scale events, such as the El Niño Southern Oscillation, may lead to significant changes in surf diatom populations in the long term (inter-annual). Surf diatoms form the base of a short and very productive food chain in the inshore of the sandy beaches where they occur. However, the role of surf diatoms in the microbial food web is not clear and deserves further studies.

  8. Methyl sulfone PCB and DDE metabolites in the polar bear (Ursus maritimus) food chain

    SciTech Connect

    Letcher, R.J.; Norstrom, R.J.; Muir, D.C.G.

    1995-12-31

    An important Arctic marine food chain is polar bear, ringed seal (Phoca hispida) and Arctic cod (Boreogadus saida). The Arctic is relatively uncontaminated by chlorinated hydrocarbon contaminants (CHCs). However, high levels of CHCs are bioaccumulated through the marine food web. Methyl sulfone (MeSO{sub 2})-PCB and -DDE metabolites are major CHCs in polar bear, although the proportion of MeSO{sub 2}-PCBs derived from PCB metabolism and/or MeSO{sub 2}-PCB bioaccumulation from the diet is unknown. For this reason, the structure and concentration of MeSO{sup 2}-PCB and -DDE metabolites, PCBs and DDE were determined in whole body Arctic cod, the liver, adipose, lung and muscle of ringed seal and ten tissues of polar bear from the Resolute Bay area of the Canadian Arctic. Preliminary analysis of the ratios of MeSO{sub 2}-PCBs in bear fat and liver to their parent PCBs in seal blubber suggested that CB-49 and CB-87 result in a higher proportion of metabolites in bear than the other PCB congeners, assuming that the MeSO{sup 2}-PCBs are not themselves accumulated from the diet. Bio-availability of the precursor PCBs for subsequent metabolism may also be a factor. The absence in bears of MeSO{sub 2}-metabolites of other metabolizable PCBs in seal may indicate that some MeSO{sub 2}-PCBs are not formed or that they are formed and further metabolized. The MeSO{sub 2}-PCB and -DDE levels and congener patterns among seal and bear tissues and the difference in tissue distribution between species will also be compared. In polar bear, the s-MeSO{sub 2}-PCB to S-PCB and s-MeSO{sub 2}-DDE to DDE ratios were highest in liver, indicating preferred storage.

  9. Price, promotion, and availability of nutrition information: a descriptive study of a popular fast food chain in New York City.

    PubMed

    Basch, Corey Hannah; Ethan, Danna; Rajan, Sonali

    2013-11-01

    Legislation in NYC requires chain restaurants to post calorie information on menu boards in an effort to help consumers make more informed decisions about food and beverage items they are purchasing. While this is a step in the right direction in light of the current obesity epidemic, there are other issues that warrant attention in a fast food setting, namely the pricing of healthy food options, promotional strategies, and access to comprehensive nutrition information. This study focused on a popular fast-food chain in NYC. The study's aims were threefold: (1) to determine the cost differential between the healthiest meal item on the chain's general menu and meal items available specifically on a reduced cost menu for one dollar (US$1.00); (2) to identify and describe the promotions advertised in the windows of these restaurants, as well as the nutrition content of promoted items; and (3) to ascertain availability of comprehensive nutrition information to consumers within the restaurants. We found the healthiest meal item to be significantly higher in price than less nutritious meal items available for $1.00 (t=146.9, p<.001), with the mean cost differential equal to $4.33 (95% CI: $4.27, $4.39). Window promotions generally advertised less healthful menu items, which may aid in priming customers to purchase these versus more healthful options. Comprehensive nutrition information beyond calorie counts was not readily accessible prior to purchasing. In addition to improving access to comprehensive nutrition information, advertising more of and lowering the prices of nutritious options may encourage consumers to purchase healthier foods in a fast food setting. Additional research in this area is needed in other geographic locations and restaurant chains.  PMID:24171876

  10. WASTOX (WATER QUALITY ANALYSIS SIMULATION FOR TOXICS), A FRAMEWORK FOR MODELING THE FATE OF TOXIC CHEMICALS IN AQUATIC ENVIRONMENTS. PART 2. FOOD CHAIN

    EPA Science Inventory

    A food chain bioaccumulation mathematical framework was developed as part of a broader framework for modeling the fate of toxic chemicals in natural water systems, entitled WASTOX. A user's guide for WASTOX (PB85-152882) was published in August 1984. The food chain component of W...

  11. A half-century of production-phase greenhouse gas emissions from food loss & waste in the global food supply chain.

    PubMed

    Porter, Stephen D; Reay, David S; Higgins, Peter; Bomberg, Elizabeth

    2016-11-15

    Research on loss & waste of food meant for human consumption (FLW) and its environmental impact typically focuses on a single or small number of commodities in a specific location and point in time. However, it is unclear how trends in global FLW and potential for climate impact have evolved. Here, by utilising the Food and Agriculture Organization's food balance sheet data, we expand upon existing literature. Firstly, we provide a differentiated (by commodity, country and supply chain stage) bottom-up approach; secondly, we conduct a 50-year longitudinal analysis of global FLW and its production-phase greenhouse gas (GHG) emissions; and thirdly, we trace food wastage and its associated emissions through the entire food supply chain. Between 1961 and 2011 the annual amount of FLW by mass grew a factor of three - from 540Mt to 1.6Gt; associated production-phase (GHG) emissions more than tripled (from 680Mt to 2.2Gt CO2e). A 44% increase in global average per capita FLW emissions was also identified - from 225kg CO2e in 1961 to 323kg CO2e in 2011. The regional weighting within this global average changing markedly over time; in 1961 developed countries accounted for 48% of FLW and less than a quarter (24%) in 2011. The largest increases in FLW-associated GHG emissions were from developing economies, specifically China and Latin America - primarily from increasing losses in fruit and vegetables. Over the period examined, cumulatively such emissions added almost 68Gt CO2e to the atmospheric GHG stock; an amount the rough equivalent of two years of emissions from all anthropogenic sources at present rates. Building up from the most granular data available, this study highlights the growth in the climate burden of FLW emissions, and thus the need to improve efficiency in food supply chains to mitigate future emissions. PMID:27432722

  12. Modeling bioaccumulation and biomagnification of nonylphenol and its ethoxylates in estuarine-marine food chains.

    PubMed

    Korsman, John C; Schipper, Aafke M; de Vos, Martine G; van den Heuvel-Greve, Martine J; Vethaak, A Dick; de Voogt, Pim; Hendriks, A Jan

    2015-11-01

    There are several studies on bioaccumulation and biomagnification of nonylphenol (NP) and its ethoxylates (NPEOs), but their toxico-kinetic mechanisms remain unclear. In the present investigation, we explored the accumulation of NP and NPEOs in estuarine-marine food chains with a bioaccumulation model comprising five trophic levels. Using this model, we estimated uptake and elimination rate constants for NPEOs based on the organisms' weight and lipid content and the chemicals' Kow. Further, we calculated accumulation factors for NP and NPEOs, including biota-sediment accumulation factors (BSAF) and biomagnification factors (BMF), and compared these to independent field measurements collected in the Western Scheldt estuary in The Netherlands and field data reported in the literature. The estimated BSAF values for NP and total NPEOs were below 1 for all trophic levels. The estimated BMF values were around 1 for all trophic levels except for the highest level (carnivorous mammals and birds). For this trophic level, the estimated BMF value varied between 0.1 and 2.4, depending on the biotransformation capacity. For all trophic levels, except primary producers, the accumulation estimates that accounted for biotransformation of NPEOs into NP were closer to the field data than model estimates that did not include biotransformation, indicating that NP formation by biotransformation of NPEOs might occur in organisms. PMID:26026901

  13. Evidence for a terpene-based food chain in the Gulf of Alaska

    SciTech Connect

    Button, D.K.

    1984-11-01

    A mixture of /sup 14/C-terpenes was prepared from conifer seedlings and introduced into fresh seawater samples taken near Seward, Alaska. Initial rates of oxidation by the indigenous bacteria were linear and faster than the rates of toluene oxidation. Turnover times were 4 to 19 days. Autoradiographic measurements with /sup 3/H-terpenes indicated that at least 10% of the 0.6 x 10/sup 9/ to 2.7 x 10/sup 9/ bacteria per liter present could catabolize terpenes. The rate of terpene oxidation, 24 ..mu..g of terpenes per g of cells per h with 3 ..mu..g of terpenes added per liter, was a constant function of bacterial biomass. The specific affinity of the process was estimated to be between 8.1 and 81 liter/g of cells per h, indicating a high state of induction and the probable presence of terpenes. Terpene-oxidizing bacteria were grown on (/sup 14/C)alanine and added to fresh seawater samples. Transfer of the bacterial radioactivity into larger particles at a rate of 146 pg/liter per h from the 2.3 x 10/sup 9/ organisms added indicated that any terpenes present would participate in the food chain. 45 references, 5 figures, 7 tables.

  14. Soil-food chain-pesticide wildlife relationships in aldrin-treated fields

    USGS Publications Warehouse

    Korschgen, L.J.

    1970-01-01

    Soil-food-chain-pesticide wildlife relationships were investigated to learn the concentration of pesticide residues present in soils, macro-invertebrates, vertebrates, and seeds as a result of annual applications of aldrin at recommended rates for pest control. Two central Missouri cornfields treated witb aldrin at 1 lb/acre, for 16 and 15 of the past 17 years, were selected for study during 1965-67. Primary samples collected for residue analyses included soils, earthworms (Lumbricidae), crickets (GryIlidae), and two kinds of ground beetles (Carabidae) obtained during early April, June, August, and October. Vertebrates and plant seeds collected during 1967 included white-footed mice (Peromyscus maniculatus), toads (Bufo americanus), snakes (Thamnophis sirtalis and Pituophis sayi), corn (Zea Mays), foxtail (Setaria Faberii), and annual sunflower (Helianthus annuus). Pesticide residues consisted primarily of dieldrin, the degradation product of aldrin. Combined aldrin and dieldrin residues, as two field all-season averages, wet weight basis, were: soils, 0.31 ppm; earthworms, 1.49 ppm; crickets, 0.23 ppm; Harpalus ground beetles, 1.10 ppm; Poecilus ground beetles, 9.67 ppm; white-footed mice, 0.98 ppm; toads, 3.53 ppm; garter snakes, 12.35 ppm; and corn, foxtail, and sunflower seeds less than 0.02 ppm each. Unusually high average residues (37.48 ppm) in Poecilus beetles during June, 1967, were attributed to abnormally high soil moisture and predacious feeding habits of these insects.

  15. Biotransformation and Incorporation into Proteins along a Simulated Terrestrial Food Chain

    SciTech Connect

    Unrine, J.M., B.P. Jackson and W.A. Hopkins

    2007-01-01

    Selenium is an essential trace element in vertebrates, but there is a narrow concentration range between dietary requirement and toxicity threshold. Although a great deal is known about the biochemistry of Se from a nutritional perspective, considerably less attention has been focused on the specific biochemistry of Se as an environmental toxicant. Recent advances in hyphenated analytical techniques have provided the capability of quantifying specific chemical forms of Se in biological tissues as well as the distribution of Se among macromolecules. We applied liquid chromatography coupled to inductively coupled plasma mass spectrometry to investigate biotransformations of selenomethionine along a simulated terrestrial food chain consisting of selenomethionine exposed crickets (Acheta domesticus) fed to western fence lizards (Sceloporus occidentalis). Evidence was obtained for selenomethionine biotransformation as well as for sex-specific differences in the metabolism of Se compounds and their subsequent incorporation into proteins in the lizard. The results demonstrate the complexities involved in trophic transfer of Se due to the potential for extensive biotransformation and the species- and even sex-specific nature of these biotransformations.

  16. Changes in contaminant distributions with trophic level in a marine food chain study

    SciTech Connect

    Pruell, R.J.; Johnson, M.W.; Taplin, B.K.; McGovern, D.G.; Montmarquet, B.T.

    1994-12-31

    A laboratory study was designed to investigate the transfer of chlorinated organic contaminants from sediments to marine biota in a simplified marine food chain. Sediments collected from the Passaic River, NJ, which contained high concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), PCBs and chlorinated pesticides, were used as the contamination source. Polychaete worms (Nereis virens) were exposed to Passaic River sediment for 70 days to allow steady-state concentrations to be achieved and then these organisms were fed to a crustacean, the American lobster (Homarus americanus). Contaminant distributions were altered significantly as they passed from sediments to polychaetes and then to the lobster. PCDDs and PCDFs containing four or five chlorines were accumulated by the polychaetes and lobster; however, the highly chlorinated congeners were not accumulated. PCB patterns in lobsters indicated that these organisms metabolized many PCB congeners. Coplanar PCBs did not appear to be metabolized and therefore became enriched relative to total PCB levels in the lobsters. Lobsters also greatly altered the ratios of chlordane and DDT series compounds relative to those in the sediments and polychaetes.

  17. Biodetection of potential genotoxic pollutants entering the human food chain through ashes used in livestock diets.

    PubMed

    Sanchez-Vicente, Laura; Herraez, Elisa; Briz, Oscar; Nogales, Rogelio; Molina-Alcaide, Eduarda; Marin, Jose J G

    2016-08-15

    Ash derived from energy generation is used as a source of minerals in livestock feeds. The microbial biosensor recApr-Luc2 was built to detect genotoxic hazard in recycled ash. Escherichia coli SOS gene (recA, lexA, dinI and umuC) expression in response to cisplatin-induced DNA damage led to the selection of the recA promoter. The biosensor required functional RecA expression to respond to genotoxic heavy metals (Cr>Cd≈Pb), and polluted ash induced a strong recApr-Luc2 response. In human liver and intestinal cells, heavy metals induced acute toxicity (Cr>Cd>Pb) at concentrations sufficient to activate recApr-Luc2. Cytostatic effects, including genotoxicity, were cell- and metal-dependent, apart from Cr. In agreement with the recApr-Luc2 bioassay, Cr had the strongest effect in all cells. In conclusion, recApr-Luc2 could be useful for evaluating the genotoxic risk of pollutants present in ash that might be concentrated in animal products and, thus, entering the human food chain. PMID:27006217

  18. Probabilistic accident consequence uncertainty analysis: Food chain uncertainty assessment. Volume 1: Main report

    SciTech Connect

    Brown, J.; Goossens, L.H.J.; Kraan, B.C.P.

    1997-06-01

    This volume is the first of a two-volume document that summarizes a joint project conducted by the US Nuclear Regulatory Commission and the European Commission to assess uncertainties in the MACCS and COSYMA probabilistic accident consequence codes. These codes were developed primarily for estimating the risks presented by nuclear reactors based on postulated frequencies and magnitudes of potential accidents. This document reports on an ongoing project to assess uncertainty in the MACCS and COSYMA calculations for the offsite consequences of radionuclide releases by hypothetical nuclear power plant accidents. A panel of sixteen experts was formed to compile credible and traceable uncertainty distributions for food chain variables that affect calculations of offsite consequences. The expert judgment elicitation procedure and its outcomes are described in these volumes. Other panels were formed to consider uncertainty in other aspects of the codes. Their results are described in companion reports. Volume 1 contains background information and a complete description of the joint consequence uncertainty study. Volume 2 contains appendices that include (1) a summary of the MACCS and COSYMA consequence codes, (2) the elicitation questionnaires and case structures for both panels, (3) the rationales and results for the panels on soil and plant transfer and animal transfer, (4) short biographies of the experts, and (5) the aggregated results of their responses.

  19. Observed and Modeled Tritium Concentrations in the Terrestrial Food Chain near a Continuous Atmospheric Source

    SciTech Connect

    Davis, P.A.; Kim, S.B.; Chouhan, S.L.; Workman, W.J.G.

    2005-07-15

    Tritium concentrations were measured in a large number of environmental and biological samples collected during 2002 at two dairy farms and a hobby farm near Pickering Nuclear Generating Station in Ontario, Canada. The data cover most compartments of the terrestrial food chain in an agricultural setting and include detailed information on the diets of the local farm animals. Ratios of plant OBT concentration to air moisture HTO varied between 0.12 and 0.56, and were generally higher for the forage crops collected at the dairy farms than for the garden vegetables sampled at the hobby farm. Animal OBT to air HTO ratios were more uniform, ranging from 0.18 to 0.45, and were generally higher for the milk and beef samples from the dairy farms than for the chicken products from the hobby farm. The observed OBT concentrations in plants and animals were compared with predictions of IMPACT, the model used by the Canadian nuclear industry to calculate annual average doses due to routine releases. The model performed well on average for the animal endpoints but overestimated concentrations in plants by a factor of 2.

  20. Mechanisms of compensatory dynamics in zooplankton and maintenance of food chain efficiency under toxicant stress.

    PubMed

    Mano, Hiroyuki; Tanaka, Yoshinari

    2016-03-01

    Communities with species that are tolerant to environmental stresses may be able to maintain the ecosystem functions under the stress, because the tolerant species can compensate for the loss of sensitive species. In this study, we focused on the food chain efficiency (FCE), the trophic transfer across three trophic levels, as an important process for ecosystem function, and examined the conditions under which such compensation could occur with aquarium experiments using an insecticide (methomyl) as the stressor. Our aquariums included one of two pairs of insecticide-tolerant and insecticide-sensitive cladoceran species, and a fish as the predator. The response of FCE to the insecticide stress, as indicated by the fish biomass production, depended on the zooplankton species combinations. FCE and total zooplankton biomass were maintained in the pair in which the compensatory changes of species abundances were clear, whereas they decreased in the pair in which the compensatory changes were not clear. This indicated the compensatory dynamics in the zooplankton community responsible for the observed resistance to the stress. We inferred the driving factors for the compensatory dynamics and the community resistance with respect to species traits of ecological importance, and concluded that a dissimilarity between species as regards the tolerance trait and a clear trade-off between the tolerance and the competitive ability was required to drive the compensatory dynamics, and a similarity or a superiority of the tolerant species as regards the functional effect trait (the predator avoidance and the reproductive potential) were required to maintain FCE. PMID:26683817

  1. Inter-annual changes in detritus-based food chains can enhance plant growth response to elevated atmospheric CO2.

    PubMed

    Hines, Jes; Eisenhauer, Nico; Drake, Bert G

    2015-12-01

    Elevated atmospheric CO2 generally enhances plant growth, but the magnitude of the effects depend, in part, on nutrient availability and plant photosynthetic pathway. Due to their pivotal role in nutrient cycling, changes in abundance of detritivores could influence the effects of elevated atmospheric CO2 on essential ecosystem processes, such as decomposition and primary production. We conducted a field survey and a microcosm experiment to test the influence of changes in detritus-based food chains on litter mass loss and plant growth response to elevated atmospheric CO2 using two wetland plants: a C3 sedge (Scirpus olneyi) and a C4 grass (Spartina patens). Our field study revealed that organism's sensitivity to climate increased with trophic level resulting in strong inter-annual variation in detritus-based food chain length. Our microcosm experiment demonstrated that increased detritivore abundance could not only enhance decomposition rates, but also enhance plant growth of S. olneyi in elevated atmospheric CO2 conditions. In contrast, we found no evidence that changes in the detritus-based food chains influenced the growth of S. patens. Considered together, these results emphasize the importance of approaches that unite traditionally subdivided food web compartments and plant physiological processes to understand inter-annual variation in plant production response to elevated atmospheric CO2. PMID:25953075

  2. From Puffins to Plankton: A DNA-Based Analysis of a Seabird Food Chain in the Northern Gulf of Maine

    PubMed Central

    Bowser, A. Kirsten; Diamond, Antony W.; Addison, Jason A.

    2013-01-01

    The predator-prey interactions within food chains are used to both characterize and understand ecosystems. Conventional methods of constructing food chains from visual identification of prey in predator diet can suffer from poor taxonomic resolution, misidentification, and bias against small or completely digestible prey. Next-generation sequencing (NGS) technology has become a powerful tool for diet reconstruction through barcoding of DNA in stomach content or fecal samples. Here we use multi-locus (16S and CO1) next-generation sequencing of DNA barcodes on the feces of Atlantic puffin (Fratercula arctica) chicks (n=65) and adults (n=64) and the stomach contents of their main prey, Atlantic herring (Clupea harengus, n=44) to investigate a previously studied food chain. We compared conventional and molecular-derived chick diet, tested the similarity between the diets of puffin adults and chicks, and determined whether herring prey can be detected in puffin diet samples. There was high variability in the coverage of prey groups between 16S and CO1 markers. We identified more unique prey with our 16S compared to CO1 barcoding markers (51 and 39 taxa respectively) with only 12 taxa identified by both genes. We found no significant difference between the 16S-identified diets of puffin adults (n=17) and chicks (n=41). Our molecular method is more taxonomically resolved and detected chick prey at higher frequencies than conventional field observations. Many likely planktonic prey of herring were detected in feces from puffin adults and chicks, highlighting the impact secondary consumption may have on the interpretation of molecular dietary analysis. This study represents the first simultaneous molecular investigation into the diet of multiple components of a food chain and highlights the utility of a multi-locus approach to diet reconstruction that is broadly applicable to food web analysis. PMID:24358258

  3. From puffins to plankton: a DNA-based analysis of a seabird food chain in the northern Gulf of Maine.

    PubMed

    Bowser, A Kirsten; Diamond, Antony W; Addison, Jason A

    2013-01-01

    The predator-prey interactions within food chains are used to both characterize and understand ecosystems. Conventional methods of constructing food chains from visual identification of prey in predator diet can suffer from poor taxonomic resolution, misidentification, and bias against small or completely digestible prey. Next-generation sequencing (NGS) technology has become a powerful tool for diet reconstruction through barcoding of DNA in stomach content or fecal samples. Here we use multi-locus (16S and CO1) next-generation sequencing of DNA barcodes on the feces of Atlantic puffin (Fratercula arctica) chicks (n=65) and adults (n=64) and the stomach contents of their main prey, Atlantic herring (Clupea harengus, n=44) to investigate a previously studied food chain. We compared conventional and molecular-derived chick diet, tested the similarity between the diets of puffin adults and chicks, and determined whether herring prey can be detected in puffin diet samples. There was high variability in the coverage of prey groups between 16S and CO1 markers. We identified more unique prey with our 16S compared to CO1 barcoding markers (51 and 39 taxa respectively) with only 12 taxa identified by both genes. We found no significant difference between the 16S-identified diets of puffin adults (n=17) and chicks (n=41). Our molecular method is more taxonomically resolved and detected chick prey at higher frequencies than conventional field observations. Many likely planktonic prey of herring were detected in feces from puffin adults and chicks, highlighting the impact secondary consumption may have on the interpretation of molecular dietary analysis. This study represents the first simultaneous molecular investigation into the diet of multiple components of a food chain and highlights the utility of a multi-locus approach to diet reconstruction that is broadly applicable to food web analysis. PMID:24358258

  4. Price, Promotion, and Availability of Nutrition Information: A Descriptive Study of a Popular Fast Food Chain in New York City

    PubMed Central

    Basch, Corey Hannah; Ethan, Danna; Rajan, Sonali

    2013-01-01

    Legislation in NYC requires chain restaurants to post calorie information on menu boards in an effort to help consumers make more informed decisions about food and beverage items they are purchasing. While this is a step in the right direction in light of the current obesity epidemic, there are other issues that warrant attention in a fast food setting, namely the pricing of healthy food options, promotional strategies, and access to comprehensive nutrition information. This study focused on a popular fast-food chain in NYC. The study’s aims were threefold: (1) to determine the cost differential between the healthiest meal item on the chain’s general menu and meal items available specifically on a reduced cost menu for one dollar (US$1.00); (2) to identify and describe the promotions advertised in the windows of these restaurants, as well as the nutrition content of promoted items; and (3) to ascertain availability of comprehensive nutrition information to consumers within the restaurants. We found the healthiest meal item to be significantly higher in price than less nutritious meal items available for $1.00 (t = 146.9, p < .001), with the mean cost differential equal to $4.33 (95% CI $4.27, $4.39). Window promotions generally advertised less healthful menu items, which may aid in priming customers to purchase these versus more healthful options. Comprehensive nutrition information beyond calorie counts was not readily accessible prior to purchasing. In addition to improving access to comprehensive nutrition information, advertising more of and lowering the prices of nutritious options may encourage consumers to purchase healthier foods in a fast food setting. Additional research in this area is needed in other geographic locations and restaurant chains. PMID:24171876

  5. Organic carbon cycling in abyssal benthic food chains: numerical simulations of bioenhancement by sewage sludge

    NASA Astrophysics Data System (ADS)

    Rowe, Gilbert T.

    1998-05-01

    The hypothetical bioenhancement of the endemic benthic biota on an oligotrophic abyssal plain by organic carbon has been investigated with mathematical simulation experiments. First, the responses of the biomass and respiration to seasonal variations in the rain of organic carbon (POC) have been simulated in a simplified benthic assemblage (sediment organic carbon, sediment-dwelling heterotrophs (bacteria, meiofauna, macrofauna and detritus feeding megafauna) and predatory megafauna), with no added organic matter. These calculations were based on measured standing stocks and respiration in the central North Pacific (5.8 km depth, 31°N Lat.×159°W Long.). The dynamic relationships in this natural "oligotrophic" food chain were then subjected to added inputs of organic carbon presumed to be in sewage sludge. Two examples are presented: a modest but continuous input of organic carbon (100 mg C m -2 d -1) and a year-long pulse of the same intensity. The continuous input forced the biomass and community respiration to steadily increase until they reached steady state in 15 years at values similar to those found on a typical continental shelf. The pulse exhibited the same pattern, but biomass and respiration returned to levels found under natural oligotrophic conditions several years after cessation of intensified carbon loading. The responses of the sediment community to added organic matter were validated using information from a deep-ocean sewage disposal site (DWD106) off the coast of New Jersey. The models are also used to illustrate an approach for estimating possible transfers of potentially toxic contaminants, such as total polycyclic aromatic hydrocarbons (tPAHs), in lipid-rich eggs. In the future it will be necessary to validate model results with deep-ocean in situ experiments.

  6. Differential bioaccumulation of potentially toxic elements in benthic and pelagic food chains in Lake Baikal.

    PubMed

    Ciesielski, Tomasz M; Pastukhov, Mikhail V; Leeves, Sara A; Farkas, Julia; Lierhagen, Syverin; Poletaeva, Vera I; Jenssen, Bjørn M

    2016-08-01

    Lake Baikal is located in eastern Siberia in the center of a vast mountain region. Even though the lake is regarded as a unique and pristine ecosystem, there are existing sources of anthropogenic pollution to the lake. In this study, the concentrations of the potentially toxic trace elements As, Cd, Pb, Hg, and Se were analyzed in water, plankton, invertebrates, and fish from riverine and pelagic influenced sites in Lake Baikal. Concentrations of Cd, Hg, Pb and Se in Lake Baikal water and biota were low, while concentrations of As were similar or slightly higher compared to in other freshwater ecosystems. The bioaccumulation potential of the trace elements in both the pelagic and the benthic ecosystems differed between the Selenga Shallows (riverine influence) and the Listvenichnyĭ Bay (pelagic influence). Despite the one order of magnitude higher water concentrations of Pb in the Selenga Shallows, Pb concentrations were significantly higher in both pelagic and benthic fish from the Listvenichnyĭ Bay. A similar trend was observed for Cd, Hg, and Se. The identified enhanced bioavailability of contaminants in the pelagic influenced Listvenichnyĭ Bay may be attributed to a lower abundance of natural ligands for contaminant complexation. Hg was found to biomagnify in both benthic and pelagic Baikal food chains, while As, Cd, and Pb were biodiluted. At both locations, Hg concentrations were around seven times higher in benthic than in pelagic fish, while pelagic fish had two times higher As concentrations compared to benthic fish. The calculated Se/Hg molar ratios revealed that, even though Lake Baikal is located in a Se-deficient region, Se is still present in excess over Hg and therefore the probability of Hg induced toxicity in the endemic fish species of Lake Baikal is assumed to be low. PMID:27130338

  7. Food-chain transfer of U-series radionuclides in a northern Saskatchewan aquatic system

    SciTech Connect

    Swanson, S.M.

    1985-11-01

    Levels of Total U, 226Ra, and 210Pb in water, sediments, insects and fish were measured in a stream and a lake affected by U mill effluents and in three uncontaminated systems (one creek and two lakes). Radionuclide levels were significantly elevated in water, sediments and biota at contaminated sites. Radionuclide concentration declined with each successive trophic level due primarily to very low assimilation efficiency. Fish radionuclide concentrations varied with season but did not vary with age or year of sampling. Distribution coefficients were high; therefore, a large proportion of radionuclides entering the systems go to the solid phase. Organisms feeding on or near sediments had higher radionuclide levels than pelagic species. There is a potential for long-term cycling of radionuclides from sediments through food chains due to low flux and sedimentation rates. With the exception of water-insects and water-fish all transfer coefficients (TC) were low, usually less than one. Control TCs were greater than TCs in contaminated areas. Radium-226 and 210Pb TCs declined dramatically at the insect-fish level. Uranium uptake from water by insects and fish was much less than 226Ra or 210Pb uptake. Uptake from sediments was similar for all nuclides in insects but 210Pb sediment-fish TCs differed from 226Ra or U TCs. The critical pathway in the contaminated area was sediments-insects-forage fish-whitefish-man. Estimated internal dose rates to large fish in the contaminated area were 1-2 rad/y. Dose to humans from consumption of one fish serving per week for 1 y was 2% of the International Commission on Radiological Protection (ICRP) annual limit for the general public.

  8. Managing ochratoxin A risk in the grape-wine food chain.

    PubMed

    Visconti, Angelo; Perrone, Giancarlo; Cozzi, Giuseppe; Solfrizzo, Michele

    2008-02-01

    The main source of ochratoxin A (OTA) in the wine food chain is the infection of grapes by "black aspergilli" in the field. OTA-producing black aspergilli include principally Aspergillus carbonarius, followed by A. niger and possibly A. tubingensis. They are opportunistic fungi that develop particularly on damaged berries at ripening, although they may occur and form OTA on grapes from veraison to harvest. Climatic conditions (high humidity and temperature) and geographical location are important factors favouring OTA accumulation in grape berries. The severity of aspergillus rot is influenced by excessive irrigation and rainfall prior to harvest, which causes berry splitting. In addition, berry wounds caused by insect attack provide preferential entries for black aspergilli. High OTA levels occur in grapes severely damaged by the grape moth, Lobesia botrana, particularly in Mediterranean areas. Some grape varieties display greater susceptibility to aspergillus rot due to intrinsic genetic characteristics and bunch conformation (i.e. compact>sparse). Control measures for toxigenic mycoflora in the vineyards must consider these critical control points. Proper fungicidal and insecticidal treatments can reduce OTA contamination. Nevertheless, knowledge about the fate of OTA and its distribution in wine and winery by-products is important to manage OTA risk in contaminated stock. In our wine-making experiments, only 4% of the OTA present in grapes remained in the wine--the majority is retained in pressed grape pomaces. OTA concentration remained unchanged in wine after a 1-year aging as well as in all liquid fractions collected during vinification (i.e. must, free run wine, and wine after first and second decantation). Activated carbon can reduce OTA levels in wine but negatively affects wine quality. PMID:18286409

  9. Food-Safety Hazards in the Pork Chain in Nagaland, North East India: Implications for Human Health

    PubMed Central

    Fahrion, Anna Sophie; Jamir, Lanu; Richa, Kenivole; Begum, Sonuwara; Rutsa, Vilatuo; Ao, Simon; Padmakumar, Varijaksha P.; Deka, Ram Pratim; Grace, Delia

    2013-01-01

    Pork occupies an important place in the diet of the population of Nagaland, one of the North East Indian states. We carried out a pilot study along the pork meat production chain, from live animal to end consumer. The goal was to obtain information about the presence of selected food borne hazards in pork in order to assess the risk deriving from these hazards to the health of the local consumers and make recommendations for improving food safety. A secondary objective was to evaluate the utility of risk-based approaches to food safety in an informal food system. We investigated samples from pigs and pork sourced at slaughter in urban and rural environments, and at retail, to assess a selection of food-borne hazards. In addition, consumer exposure was characterized using information about hygiene and practices related to handling and preparing pork. A qualitative hazard characterization, exposure assessment and hazard characterization for three representative hazards or hazard proxies, namely Enterobacteriaceae, T. solium cysticercosis and antibiotic residues, is presented. Several important potential food-borne pathogens are reported for the first time including Listeria spp. and Brucella suis. This descriptive pilot study is the first risk-based assessment of food safety in Nagaland. We also characterise possible interventions to be addressed by policy makers, and supply data to inform future risk assessments. PMID:24368430

  10. Food-safety hazards in the pork chain in Nagaland, North East India: implications for human health.

    PubMed

    Fahrion, Anna Sophie; Jamir, Lanu; Richa, Kenivole; Begum, Sonuwara; Rutsa, Vilatuo; Ao, Simon; Padmakumar, Varijaksha P; Deka, Ram Pratim; Grace, Delia

    2014-01-01

    Pork occupies an important place in the diet of the population of Nagaland, one of the North East Indian states. We carried out a pilot study along the pork meat production chain, from live animal to end consumer. The goal was to obtain information about the presence of selected food borne hazards in pork in order to assess the risk deriving from these hazards to the health of the local consumers and make recommendations for improving food safety. A secondary objective was to evaluate the utility of risk-based approaches to food safety in an informal food system. We investigated samples from pigs and pork sourced at slaughter in urban and rural environments, and at retail, to assess a selection of food-borne hazards. In addition, consumer exposure was characterized using information about hygiene and practices related to handling and preparing pork. A qualitative hazard characterization, exposure assessment and hazard characterization for three representative hazards or hazard proxies, namely Enterobacteriaceae, T. solium cysticercosis and antibiotic residues, is presented. Several important potential food-borne pathogens are reported for the first time including Listeria spp. and Brucella suis. This descriptive pilot study is the first risk-based assessment of food safety in Nagaland. We also characterise possible interventions to be addressed by policy makers, and supply data to inform future risk assessments. PMID:24368430

  11. [Experimental study of vibrio parahaemolyticus (biotype 2) transfer from water and sediments to benthic marine food chain organisms].

    PubMed

    Gauthier, M J; Clement, R

    1979-04-01

    Transfer of Vibrio parahaemolyticus (biotype 2) from sediments to water and from water to benthic marine organisms was studied experimentally using a streptomycin-resistant strain. Transmission by trophic pathways was also studied using reconstituted marine food chains (Mytilus edulis, Nereis diversicolor, Carcinus maenas, Scorpaena porcus, Mus musculus). Water colonization by sediments could be observed only at temperatures above 16 degrees C. Sediments could well constitute a disseminating reservoir for these germs, their cycle in water being dependent of the cycle followed in the sediments. Contamination of animal organisms is essentially effected by a direct mean, either water or sediments; transfer by trophic pathways being negligible. Infection of land consumers (mice) is linked quantitatively to the nature of the last marine organism of the food chain since bacteria can flourish in the digestive tract of certain animals (Carcinus maenas). PMID:487292

  12. Transfer of radionuclides from high polluted bottom sediments to marine organisms through benthic food chain in post Fukushima period

    NASA Astrophysics Data System (ADS)

    Bezhenar, Roman; Jung, Kyung Tae; Maderich, Vladimir; Willemsen, Stefan; de With, Govert; Qiao, Fangli

    2015-04-01

    A catastrophic earthquake and tsunami occurred on March 11, 2011 and severely damaged the Fukushima Daiichi Nuclear Power Plant (FDNPP) that resulted in an uncontrolled release of radioactivity into air and ocean. Around 80% of the radioactivity released due to the FDNPP accident in March-April 2011 was either directly discharged into the ocean or deposited onto the ocean surface from the atmosphere. A large amount of long-lived radionuclides (mainly Cs-137) were released into the environment. The concentration of radionuclides in the ocean reached a maximum in mid-April of 2011, and then gradually decreased. From 2011 the concentration of Cs-137 in water essentially fell except the area around the FDNPP where leaks of contaminated water are continued. However, in the bottom sediment high concentrations of Cs-137 were found in the first months after the accident and slowly decreased with time. Therefore, it should be expected that a time delay is found of sediment-bound radionuclides in marine organisms. For the modeling of radionuclide transfer from highly polluted bottom sediments to marine organisms the dynamical food chain model BURN-POSEIDON (Heling et al, 2002; Maderich et al., 2014) was extended. In this model marine organisms are grouped into a limited number of classes based on their trophic level and type of species. These include: phytoplankton, zooplankton, fishes (two types: piscivorous and non-piscivorous), crustaceans, and molluscs for pelagic food chain and bottom sediment invertebrates, demersal fishes and bottom predators for benthic food chain and whole water column predators feeding by pelagial and benthic fishes. Bottom invertebrates consume organic parts of bottom sediments with adsorbed radionuclides which then migrate through the food chain. All organisms take radionuclides directly from water as well as via food. In fishes where radioactivity is not homogeneously distributed over all tissues of the organism, it is assumed that radionuclide

  13. Transmission and Accumulation of Nano-TiO2 in a 2-Step Food Chain (Scenedesmus obliquus to Daphnia magna).

    PubMed

    Chen, Jinyuan; Li, Herong; Han, Xiaoqian; Wei, Xiuzhen

    2015-08-01

    The recent increase in nanomaterial usage has led to concerns surrounding its health risks and environmental impact. The food chain is an important pathway for high-trophic-level organisms absorbing and enriching nanomaterials. Our study therefore simulated nanometer titanium dioxide (nano-TiO2) transfer along a 2-step food chain, from the unicellular alga Scenedesmus obliquus to the water flea Daphnia magna. We also explored the effect of sodium dodecyl benzene sulfonate (SDBS) on nano-TiO2 bioavailability. A suspension of 10 mg/L nano-TiO2 was optimally dispersed in aqueous solutions by 5 mg/L SDBS. After 72 h, S. obliquus growth was not significantly affected by 10 mg/L nano-TiO2, 5 mg/L SDBS and their mixed suspension. SDBS not only improved nano-TiO2 stability in water, but also increased its uptake in S. obliquus and enhanced its accumulation in D. magna. Our study suggests that nano-TiO2 is mildly toxic to S. obliquus, and can be transferred along the aquatic food chain with a biomagnification effect. PMID:26091814

  14. Use of stable carbon and nitrogen isotopes to trace the larval striped bass food chain in the Sacramento-San Joaquin Estuary, California, April to September 1985

    USGS Publications Warehouse

    Rast, Walter; Sutton, J.E.

    1989-01-01

    To assess one potential cause for the decline of the striped bass fishery in the Sacramento-San Joaquin Estuary, stable carbon and nitrogen isotope ratios were used to examine the trophic structures of the larval striped bass food chain, and to trace the flux of these elements through the food chain components. Study results generally confirm a food chain consisting of the elements, phytoplankton/detritus-->zooplankton/Neomysis shrimp-->larval striped bass. The stable isotope ratios generally become more positive as one progresses from the lower to the higher trophic level food chain components, and no unusual trophic structure was found in the food chain. However, the data indicate an unidentified consumer organism occupying an intermediate position between the lower and higher trophic levels of the larval striped bass food chain. Based on expected trophic interactions, this unidentified consumer would have a stable carbon isotope ratio of about 28/mil and a stable nitrogen isotope ratio of about 8/mi. Three possible feeding stages for larval striped bass also were identified, based on their lengths. The smallest length fish seem to subsist on their yolk sac remnants, and the largest length fish subsist on Neomysis shrimp and zooplankton. The intermediate-length fish represent a transition stage between primary food sources and/or use of a mixture of food sources. (USGS)

  15. Issues of Food Chain Security and Case Studies in the Czech Army

    NASA Astrophysics Data System (ADS)

    Komar, Ales; Vasicka, Pavlina

    Food supply system is fundamental extremely open complex. Global challenge is acknowledged and must be considered because food is important source of existence and can be used as a desirable terrorist vehicle. Raw material and food featured intentional versus accidental contamination. Manifestation of global challenges, aspiration for sustainable development and appearance of terrorism create the new paradigm for threats to food safety and defence management.

  16. Is food allergen analysis flawed? Health and supply chain risks and a proposed framework to address urgent analytical needs.

    PubMed

    Walker, M J; Burns, D T; Elliott, C T; Gowland, M H; Mills, E N Clare

    2016-01-01

    Food allergy is an increasing problem for those affected, their families or carers, the food industry and for regulators. The food supply chain is highly vulnerable to fraud involving food allergens, risking fatalities and severe reputational damage to the food industry. Many facets are being pursued to ameliorate the difficulties including better food labelling and the concept of thresholds of elicitation of allergy symptoms as risk management tools. These efforts depend to a high degree on the ability reliably to detect and quantify food allergens; yet all current analytical approaches exhibit severe deficiencies that jeopardise accurate results being produced particularly in terms of the risks of false positive and false negative reporting. If we fail to realise the promise of current risk assessment and risk management of food allergens through lack of the ability to measure food allergens reproducibly and with traceability to an international unit of measurement, the analytical community will have failed a significant societal challenge. Three distinct but interrelated areas of analytical work are urgently needed to address the substantial gaps identified: (a) a coordinated international programme for the production of properly characterised clinically relevant reference materials and calibrants for food allergen analysis; (b) an international programme to widen the scope of proteomics and genomics bioinformatics for the genera containing the major allergens to address problems in ELISA, MS and DNA methods; (c) the initiation of a coordinated international programme leading to reference methods for allergen proteins that provide results traceable to the SI. This article describes in more detail food allergy, the risks of inapplicable or flawed allergen analyses with examples and a proposed framework, including clinically relevant incurred allergen concentrations, to address the currently unmet and urgently required analytical requirements. Support for the

  17. Current food chain information provides insufficient information for modern meat inspection of pigs.

    PubMed

    Felin, Elina; Jukola, Elias; Raulo, Saara; Heinonen, Jaakko; Fredriksson-Ahomaa, Maria

    2016-05-01

    Meat inspection now incorporates a more risk-based approach for protecting human health against meat-borne biological hazards. Official post-mortem meat inspection of pigs has shifted to visual meat inspection. The official veterinarian decides on additional post-mortem inspection procedures, such as incisions and palpations. The decision is based on declarations in the food chain information (FCI), ante-mortem inspection and post-mortem inspection. However, a smooth slaughter and inspection process is essential. Therefore, one should be able to assess prior to slaughter which pigs are suitable for visual meat inspection only, and which need more profound inspection procedures. This study evaluates the usability of the FCI provided by pig producers and considered the possibility for risk ranking of incoming slaughter batches according to the previous meat inspection data and the current FCI. Eighty-five slaughter batches comprising 8954 fattening pigs were randomly selected at a slaughterhouse that receives animals from across Finland. The mortality rate, the FCI and the meat inspection results for each batch were obtained. The current FCI alone provided insufficient and inaccurate information for risk ranking purposes for meat inspection. The partial condemnation rate for a batch was best predicted by the partial condemnation rate calculated for all the pigs sent for slaughter from the same holding in the previous year (p<0.001) and by prior information on cough declared in the current FCI (p=0.02) statement. Training and information to producers are needed to make the FCI reporting procedures more accurate. Historical meat inspection data on pigs slaughtered from the same holdings and well-chosen symptoms/signs for reporting, should be included in the FCI to facilitate the allocation of pigs for visual inspection. The introduced simple scoring system can be easily used for additional information for directing batches to appropriate meat inspection procedures. To

  18. Radionuclides in the lichen-caribou-human food chain near uranium mining operations in northern Saskatchewan, Canada.

    PubMed Central

    Thomas, P A; Gates, T E

    1999-01-01

    The richest uranium ore bodies ever discovered (Cigar Lake and McArthur River) are presently under development in northeastern Saskatchewan. This subarctic region is also home to several operating uranium mines and aboriginal communities, partly dependent upon caribou for subsistence. Because of concerns over mining impacts and the efficient transfer of airborne radionuclides through the lichen-caribou-human food chain, radionuclides were analyzed in tissues from 18 barren-ground caribou (Rangifer tarandus groenlandicus). Radionuclides included uranium (U), radium (226Ra), lead (210Pb), and polonium (210Po) from the uranium decay series; the fission product (137Cs) from fallout; and naturally occurring potassium (40K). Natural background radiation doses average 2-4 mSv/year from cosmic rays, external gamma rays, radon inhalation, and ingestion of food items. The ingestion of 210Po and 137Cs when caribou are consumed adds to these background doses. The dose increment was 0.85 mSv/year for adults who consumed 100 g of caribou meat per day and up to 1.7 mSv/year if one liver and 10 kidneys per year were also consumed. We discuss the cancer risk from these doses. Concentration ratios (CRs), relating caribou tissues to lichens or rumen (stomach) contents, were calculated to estimate food chain transfer. The CRs for caribou muscle ranged from 1 to 16% for U, 6 to 25% for 226Ra, 1 to 2% for 210Pb, 6 to 26% for 210Po, 260 to 370% for 137Cs, and 76 to 130% for 40K, with 137Cs biomagnifying by a factor of 3-4. These CRs are useful in predicting caribou meat concentrations from the lichens, measured in monitoring programs, for the future evaluation of uranium mining impacts on this critical food chain. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 PMID:10378999

  19. Exposure to endocrine disrupting compounds via the food chain: Is packaging a relevant source?

    PubMed

    Muncke, Jane

    2009-08-01

    Contamination of foodstuffs by environmental pollutants (e.g. dioxins, metals) receives much attention. Until recently, food packaging as a source of xenobiotics, especially those with endocrine disrupting properties, has received little awareness despite its ubiquitous use. This article reviews the regulations and use of endocrine disrupting compounds (EDCs) in food packaging and discusses their presence within the context of new toxicology paradigms. I focused on substances known to be legally used in food packaging that have been shown to exhibit endocrine disruptive effects in biological systems. I compiled a list of 50 known or potential EDCs used in food contact materials and examined data of EDCs leaching from packaging into food, with a focus on nonylphenol. I included recent advances in toxicology: mixture effects, the developmental origins of adult disease hypothesis, low-dose effects, and epigenetics. I especially considered the case of bisphenol A. The core hypothesis of this review is that chemicals leaching from packaging into food contribute to human EDCs exposure and might lead to chronic disease in light of the current knowledge. Food contact materials are a major source of food contaminants. Many migrating compounds, possibly with endocrine disruptive properties, remain unidentified. There is a need for information on identity/quantity of chemicals leaching into food, human exposure, and long-term impact on health. Especially EDCs in food packaging are of concern. Even at low concentrations, chronic exposure to EDCs is toxicologically relevant. Concerns increase when humans are exposed to mixtures of similar acting EDCs and/or during sensitive windows of development. In particular, non-intentionally added substances (NIAS) migrating from food contact materials need toxicological characterization; the overall migrate of the finished packaging could be evaluated for biological effects using bioassays. The widespread legal use of EDCs in food

  20. Environmental and Economic Impacts of Localizing Food Systems: The Case of Dairy Supply Chains in the Northeastern United States.

    PubMed

    Nicholson, Charles F; He, Xi; Gómez, Miguel I; Gao, H O; Hill, Elaine

    2015-10-20

    We developed and evaluated an empirical model of the U.S. dairy supply chain with a high degree of spatial and product disaggregation to assess the impacts of increasing localization of the northeast region's fluid milk supply on food miles, supply chain costs, greenhouse gas and criteria pollutant emissions, economic activity, and employment. Evaluation included comparison to regional production values and sensitivity analysis of demand and unit cost assumptions. Our analysis compares a baseline to two localization scenarios based on state boundaries and multiple-state subregions. Localization scenarios increased total distances fluid milk traveled by 7-15%, overall supply chain costs by 1-2%, and emissions of greenhouse gases (CO2 equivalent) criteria pollutants such as oxides of nitrogen and particulate matter smaller than 2.5 μm associated with fluid milk transportation by 7-15% per month. The impacts of localization on employment and economic activity are positive, but changes are small on a percentage basis. Our analyses indicate that the definition used for localization has an impact on outcomes and that efforts to localize food systems may benefit from a more systems-oriented approach. PMID:26401757

  1. In vivo visual evaluation of nanoparticle transfer in a three-species terrestrial food chain.

    PubMed

    Chae, Yooeun; Kim, Shin Woong; An, Youn-Joo

    2016-05-01

    Nanoparticles (NPs) are increasingly being used, and they present the risk of being introduced into food webs. Numerous studies have been conducted to evaluate the toxicological effects of NPs in the aquatic and freshwater environments and their transfer to upper-level trophic organisms. However, information on the transfer and consequent effects of NPs on soil invertebrates is still limited. In this study, we assessed the transfer of quantum dots (QDs) through a three-species terrestrial food chain that consisted of the yeast Saccharomyces cerevisiae, the collembolan Folsomia candida, and the pill bug Armadillidium vulgare, as well as their biodistribution in vital organs using fluorescence analytical techniques. To visualize QD incorporation and biodistribution in F. candida, longitudinal and transversal sections were observed after short-term (3 d) and long-term (12 d) feeding with QD-treated yeast. QDs were located only in the intestine of F. candida and excreted within 1-2 d. QDs were also transferred to the pill bug by feeding, and remained in its intestine. This study showed the transfer of NPs through a model terrestrial food chain and indicated the potential hazards of released NPs for organisms at different trophic levels. PMID:26933900

  2. Proteomics for Drug Resistance on the Food Chain? Multidrug-Resistant Escherichia coli Proteomes from Slaughtered Pigs.

    PubMed

    Ramos, Sónia; Silva, Nuno; Hébraud, Michel; Santos, Hugo M; Nunes-Miranda, Júlio Dinis; Pinto, Luís; Pereira, José E; Capelo, José-Luis; Poeta, Patrícia; Igrejas, Gilberto

    2016-06-01

    Understanding global drug resistance demands an integrated vision, focusing on both human and veterinary medicine. Omics technologies offer new vistas to decipher mechanisms of drug resistance in the food chain. For example, Escherichia coli resistance to major antibiotics is increasing whereas multidrug resistance (MDR) strains are now commonly found in humans and animals. Little is known about the structural and metabolic changes in the cell that trigger resistance to antimicrobial agents. Proteomics is an emerging field that is used to advance our knowledge in global health and drug resistance in the food chain. In the present proteomic analysis, we offer an overview of the global protein expression of different MDR E. coli strains from fecal samples of pigs slaughtered for human consumption. A full proteomic survey of the drug-resistant strains SU60, SU62, SU76, and SU23, under normal growth conditions, was made by two-dimensional electrophoresis, identifying proteins by MALDI-TOF/MS. The proteomes of these four E. coli strains with different genetic profiles were compared in detail. Identical transport, stress response, or metabolic proteins were discovered in the four strains. Several of the identified proteins are essential in bacterial pathogenesis (GAPDH, LuxS, FKBPs), development of bacterial resistance (Omp's, TolC, GroEL, ClpB, or SOD), and potential antibacterial targets (FBPA, FabB, ACC's, or Fab1). Effective therapies against resistant bacteria are crucial and, to accomplish this, a comprehensive understanding of putative resistance mechanisms is essential. Moving forward, we suggest that multi-omics research will further improve our knowledge about bacterial growth and virulence on the food chain, especially under antibiotic stress. PMID:27310477

  3. The response of foodborne pathogens to osmotic and desiccation stresses in the food chain.

    PubMed

    Burgess, Catherine M; Gianotti, Andrea; Gruzdev, Nadia; Holah, John; Knøchel, Susanne; Lehner, Angelika; Margas, Edyta; Esser, Stephan Schmitz; Sela Saldinger, Shlomo; Tresse, Odile

    2016-03-16

    In combination with other strategies, hyperosmolarity and desiccation are frequently used by the food processing industry as a means to prevent bacterial proliferation, and particularly that of foodborne pathogens, in food products. However, it is increasingly observed that bacteria, including human pathogens, encode mechanisms to survive and withstand these stresses. This review provides an overview of the mechanisms employed by Salmonella spp., Shiga toxin producing E. coli, Cronobacter spp., Listeria monocytogenes and Campylobacter spp. to tolerate osmotic and desiccation stresses and identifies gaps in knowledge which need to be addressed to ensure the safety of low water activity and desiccated food products. PMID:26803272

  4. Mineral cycling in soil and litter arthropod food chains. Annual progress report, February 1, 1983-January 31, 1984

    SciTech Connect

    Crossley, D.A. Jr.

    1983-09-30

    This annual report describes progress in research on the influence of soil fauna on the general process of terrestrial decomposition. The major goal is to investigate the regulation of decomposition by soil arthropods. Methods have included radioactive tracer measurements of food chain dynamics, rates of nutrient or mineral element flow during decomposition, and simulation modeling. This year's report describes significant progress in defining the influence of soil arthropods in stimulating microbial immobilization of nutrients. Preliminary efforts to define the importance of the soil-litter macroarthropods are also reported.

  5. Mineral cycling in soil and litter arthropod food chains. Progress report, November 1, 1981-January 31, 1983

    SciTech Connect

    Crossley, D.A. Jr.

    1982-09-01

    Progress is reported for research projects on nutrient dynamics during terrestrial decomposition, as influenced by soil arthropods. Radioactive tracers are used as analogs of nutrients, to measure material movement along food chains and dynamics of processes during decomposition. Forest floor systems from which arthropods were excluded, or in which microfloral activity was depressed, trapped incoming nutrients from canopy throughfall at different rates. Faunal stimulation of microfloral activities could not be demonstrated, but drought conditions disturbed the experiment. Turnover measurements for radionuclides in collembolans are also reported, and compared with information on mites and other arthropods.

  6. Effects of the Food Manufacturing Chain on the Viability and Functionality of Bifidobacterium animalis through Simulated Gastrointestinal Conditions.

    PubMed

    Charnchai, Pattra; Jantama, Sirima Suvarnakuta; Prasitpuriprecha, Chutinun; Kanchanatawee, Sunthorn; Jantama, Kaemwich

    2016-01-01

    The viability and functionality of probiotics may be influenced by industrial production processes resulting in a decrease in probiotic efficiency that benefit the health of humans. This study aimed to investigate the probiotic characteristics of Bifidobacterium strains isolated from fecal samples of healthy Thai infants. In the present work, three local strains (BF014, BF052, and BH053) belonging to Bifidobacterium animalis showed a great resistance against conditions simulating the gastrointestinal tract. Among these, B. animalis BF052 possessed considerable probiotic properties, including high acid and bile tolerance, strong adhesion capability to Caco-2 cells, and inhibitory activity against pathogens including Salmonella typhimurium and Vibrio cholerae. This strain also exhibited a high survival rate compared to commercial strains during storage in a wide variety of products, including pasteurized milk, soy milk, drinking yogurt, and orange juice. The impact of food processing processes as well as the freeze-drying process, storage of freeze-dried powders, and incorporation of freeze-dried cells in food matrix on probiotic properties was also determined. The stability of the probiotic properties of the BF052 strain was not affected by food processing chain, especially its resistance in the simulated gastrointestinal conditions and its adherence ability to Caco-2 cells. It indicates that it satisfies the criteria as a potential probiotic and may be used as an effective probiotic starter in food applications. PMID:27333286

  7. Effects of the Food Manufacturing Chain on the Viability and Functionality of Bifidobacterium animalis through Simulated Gastrointestinal Conditions

    PubMed Central

    Jantama, Sirima Suvarnakuta; Prasitpuriprecha, Chutinun; Kanchanatawee, Sunthorn

    2016-01-01

    The viability and functionality of probiotics may be influenced by industrial production processes resulting in a decrease in probiotic efficiency that benefit the health of humans. This study aimed to investigate the probiotic characteristics of Bifidobacterium strains isolated from fecal samples of healthy Thai infants. In the present work, three local strains (BF014, BF052, and BH053) belonging to Bifidobacterium animalis showed a great resistance against conditions simulating the gastrointestinal tract. Among these, B. animalis BF052 possessed considerable probiotic properties, including high acid and bile tolerance, strong adhesion capability to Caco-2 cells, and inhibitory activity against pathogens including Salmonella typhimurium and Vibrio cholerae. This strain also exhibited a high survival rate compared to commercial strains during storage in a wide variety of products, including pasteurized milk, soy milk, drinking yogurt, and orange juice. The impact of food processing processes as well as the freeze-drying process, storage of freeze-dried powders, and incorporation of freeze-dried cells in food matrix on probiotic properties was also determined. The stability of the probiotic properties of the BF052 strain was not affected by food processing chain, especially its resistance in the simulated gastrointestinal conditions and its adherence ability to Caco-2 cells. It indicates that it satisfies the criteria as a potential probiotic and may be used as an effective probiotic starter in food applications. PMID:27333286

  8. Hepatitis E Virus in Pork Food Chain, United Kingdom, 2009–2010

    PubMed Central

    Berto, Alessandra; Martelli, Francesca; Grierson, Sylvia

    2012-01-01

    We investigated contamination by hepatitis E virus (HEV) in the pork production chain in the United Kingdom. We detected HEV in pig liver samples in a slaughterhouse, in surface samples from a processing plant, and in pork sausages and surface samples at point of sale. Our findings provide evidence for possible foodborne transmission of HEV during pork production. PMID:22840183

  9. Accumulation of organochlorines and brominated flame retardants in estuarine and marine food chains: field measurements and model calculations.

    PubMed

    Veltman, Karin; Hendriks, Jan; Huijbregts, Mark; Leonards, Pim; van den Heuvel-Greve, Martine; Vethaak, Dick

    2005-10-01

    Food chain accumulation of organochlorines and brominated flame retardants in estuarine and marine environments is compared to model estimations and fresh water field data. The food chain consists of herbivores, detritivores and primary and secondary carnivores i.e. fish, fish-eating birds and marine mammals. Accumulation of polychlorinated biphenyls is predicted well by OMEGA for herbi-detritivores and primary and secondary carnivorous fish. Ratios are similar to those found for fresh water species. Accumulation ratios for fish-eating birds and mammals are overestimated by the model, which is attributed partly to biotransformation of meta-para unsubstituted congeners. Additionally, birds may feed in other less polluted areas. For brominated diphenylethers (BDE) accumulation patterns are highly species and congener specific. Accumulation depends on both K(ow) and metabolization capacities. BDE47 is the predominant congener in lower trophic levels. For marine birds and mammals accumulation ratios of BDE99 and 100 are similar to or higher than ratios of persistent PCBs. PMID:15893330

  10. From gelatinous to muscle food chain: rock cod Patagonotothen ramsayi recycles coelenterate and tunicate resources on the Patagonian Shelf.

    PubMed

    Arkhipkin, A; Laptikhovsky, V

    2013-11-01

    Stomach contents of 4808 fishes of 20 species caught in the eastern part of the Patagonian Shelf between 1999 and 2012 were analysed to assess dietary contributions of gelatinous plankton resources. Gelatinous plankton occurred in diets of seven species with two species, Patagonotothen ramsayi and Squalus acanthias, having >10% ctenophores in their diet. Consumption of gelatinous plankton was important in P. ramsayi and was strikingly seasonal, with maximum occurrence (up to 46% of non-empty stomachs) in late summer to autumn. Ctenophores were most abundant in P. ramsayi of 25-34 cm total length, L(T) whereas salps were more frequent in larger >35 cm L(T) individuals. In winter to spring, occurrence of gelatinous plankton in diets was minimal, reflecting their overall seasonal abundance in the ocean. The recent increase in abundance of P. ramsayi has enabled the species to recycle a significant proportion of the ecosystem production from gelatinous dead end to the main muscular food chain via seasonal reliance on ctenophores, jellyfish and tunicates. This additional influx of production that has been diverted from the gelatinous food chain favours the increase in abundance of several piscivorous top predators and affects the trophic web structure of the Patagonian Shelf ecosystem. PMID:24580663