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Hexachlorobenzene in the marine environment: distribution, fate and ecotoxicological aspects.

The distribution of hexachlorobenzene (HCB) among different matrices of the marine environment has been determined. Low HCB concentrations in water (less than 0.1 ng/l) are reflected in sediments and in biota. Laboratory experiments can predict HCB levels in mussels but underestimate those for fish, suggesting distribution mechanisms such as food-chain relationships and metabolic capabilities which usually cannot be predicted from bioassays. Concentrations of HCB in sea water are so low that no toxic effects can be observed in marine biota, but in fish livers HCB may reach levels higher than those considered safe for human consumption. In the edible parts of fish generally, the levels are too low to render sea-food unusable for man. In bioconcentration experiments a lipid-related bioconcentration factor (BCF) of 3 X 10(5) was determined and several metabolites were formed, one of which was identified as methylthio-pentachlorobenzene.

Animals↗

Anatomy of deer spine and its comparison to the human spine.

The anatomical parameters of the thoracic and lumbar regions of the deer spine were evaluated and compared with the existing data of the human spine. The objective was to create a database for the anatomical parameters of the deer spine, with a view to establish deer spine as a valid model for human spine biomechanical experiments in vitro. To date, the literature has supported the use of both calf and sheep spines as a suitable model for human spine experiments as the difficulty in procuring the human cadaveric spines is well appreciated. With the advent of Bovine Spongiform Encephalopathy (BSE) and its likely transmission to human in form of new variant Creutzfeld Jakob disease (CJD), there is a slight risk of transmission to humans through food chain if proper precautions for disposal of specimen are not adhered to. There is also a significant risk of transmission through direct inoculation to the researchers (Wells et al. Vet. Rec., 1998:142:103-106), working with infected bovine and sheep spine. The deer spines are readily available and there are no reported cases of deer being carriers of prion diseases (Ministry of Agriculture, Fisheries and Food, 1998). Six complete deer spines were measured to determine 22 dimensions from the vertebral bodies, endplates, disc, pedicles, spinal canal, transverse and spinous processes, articular facets. This was compared with the existing data of the human spine in the literature. The deer and human vertebrae show many similarities in the lower thoracic and upper lumbar spine, although they show substantial differences in certain dimensions. The cervical spine was markedly different in comparison. The deer spine may represent a suitable model for human experiments related to gross anatomy of the thoracic and lumbar spine. A thorough database has been provided for deciding the validity of deer spine as a model for the human spine biomechanical in vitro experiments.

Animals↗

[Bioindications for elevated metal contents in flowing waters].

Lawful arguments of food research require an information of the concentrations of heavy metals in fishes. Whereas for the control of emissions and of river pollution the analysis on heavy metals in excellent indicator organisms - as specific submerged water plants or fish food (zoobenthic) organisms - is generally more sensitive and therefore more suitable. With analytical results there is no successive accumulation of metals in the aquatic food chain - that means no biomagnification - determinable. By the analysis of some bioindicators the degree of the environmental load due to heavy metals can be estimated. With this ecological method we are able to detect the emissions' locality and their producers.

Animals↗

Prevalence and diversity of tetracycline resistant lactic acid bacteria and their tet genes along the process line of fermented dry sausages.

In order to study the prevalence and diversity of tetracycline resistant lactic acid bacteria (Tc(r) LAB) along the process line of two different fermented dry sausage (FDS) types, samples from the raw meat, the meat batter and the fermented end product were analysed quantitatively and qualitatively by using a culture-dependent approach. Both the diversity of the tet genes and their bacterial hosts in the different stages of FDS production were determined. Quantitative analysis showed that all raw meat components of both FDS types (FDS-01 and FDS-08) contained a subpopulation of Tc(r) LAB, and that for FDS-01 no Tc(r) LAB could be recovered from the samples after fermentation. Qualitative analysis of the Tc(r) LAB subpopulation in FDS-08 included identification and typing of Tc(r) LAB isolates by (GTG)5-PCR fingerprinting, plasmid profiling, protein profiling and a characterization of the resistance by PCR detection of tet genes. Two remarks can be made when the results of this analysis for the different samples are compared. (i) The taxonomic diversity of Tc(r) LAB varies along the process line, with a higher diversity in the raw meat (lactococci, lactobacilli, streptococci, and enterococci), and a decrease after fermentation (only lactobacilli). (ii) Also the genetic diversity of the tet genes varies along the process line. Both tet(M) and tet(S) were found in the raw meat, whereas only tet(M) was found after fermentation. A possible relationship was found between the disappearing of species other than lactobacilli and tet(S), because tet(S) was only found in lacotocci, enterococci, and streptococci. These data suggest that fermented dry sausages are among those food products that can serve as vehicles for Tc(r) LAB and that the raw meat already contains a subpopulation of these bacteria. Whether these results reflect the transfer of resistant bacteria or of bacterial resistance genes from animals to man via the food chain is difficult to ascertain and may require a combination of cultivation-dependent and cultivation-independent approaches.

Animals↗

Dioxin contamination in soils of Southern Vietnam.

Dioxin is the common name for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), and is abbreviated as PCDD/Fs. In the case of Southern Vietnam, is of high concern dioxin contamination in the areas affected by past-use chemical defoliants. Our study related to the zone considered as a "hot spot"--Bien Hoa Airbase and surrounding areas (Bien Hung Lake). Although the war ended over 30 years ago, the adverse effects on this territory still continue. Soil and sediment were selected for our research as they act as a sink for PCDD/Fs. The samples were taken and analyzed in CECOTOX laboratory following certified procedures. The total amounts of PCDD/Fs (2,3,7,8 related congeners) in the samples were converted into WHO-TEQ and compared with standard values proposed by Canadian environmental quality guidelines. The obtained data shows a relatively high risk (up to 20.4 times higher than (probable effect level) PEL value for sediment and 46 times higher than standard value for soil). The research is continuing on the assessment of dioxin transport in food chain. Moreover, considering the obtained data a complete solution should be found urgently to solve the problem of dioxin contamination in the studied areas.

Benzofurans↗

Exposure pathways to HCH and DDT in Cidade dos Meninos and its surrounding districts of Amapa, Figueiras and Pilar, metropolitan regions of Rio de Janeiro, Brazil.

In 1989, the Rio de Janeiro State environmental agency (FEEMA) after a preliminary survey of the site known as Cidade dos Meninos, collected and disposed in a safe area tons of a pesticide that was spread in and around the ruins of an old hexachlorocyclohexane (HCH) factory. The aim of this article is three-fold: (i) To investigate the existing HCH and DDT contamination levels in soil, water, air, vegetables and grasses at the Cidade dos Meninos site and the surrounding districts of Amapa, Figueiras and Pilar; (ii) To identify the main environmental exposure pathways present in the study area, and (iii) To propose a health hazard classification for this area. The results showed the presence of high levels of total HCH and DDT in the environmental media samples, especially in those collected in the district Cidade dos Meninos. This district is also the one that produces more food (vegetables, milk and meat) for local and outside population. The environmental data correlated to the socio-economic, food diet and local health conditions led to the identification of four complete exposure pathways to HCH and DDT (surface soil, access road, food chain and ambient air). Using the ATSDR (1996) and Magalhães (2000) criteria the site was classified in two public health hazard categories: Category II - hazard for public health, and category III - indeterminate hazard for public health.

Brazil↗

World PCBs map: storage and effects in man and his biologic environment in the 1970s.

PCB residues are found in biota all over the world. A biologic magnification of PCBs has been demonstrated in the food chain: plankton-fish-fish eating birds. A world map of the PCBs residues in biota and some of their biologic effects are given in this study. The biologic effects of PCBs are varied and may generally be explained by the induction or inhibition of the activity of a large number of enzymes, which upsets quantitatively, normal biochemical processes. Harm to reproduction, growth, development, defense systems, tissues, and organs appeared in susceptible organisms as a result of such changes or as a chain reaction to heterostases. The adverse health effects, observed in persons occupationally exposed and in those accidentally poisoned, point to the risk for the general population of an ever-increasing environmental pollution by PCBs. There is need for an integrated approach, consisting of epidemiologic studies on high risk groups in the general population and in persons occupationally exposed, as well as periodic assessment of PCB residues in man, his food, and feed supplies.

Animals↗

Application of hazard analysis critical control points (HACCP) to organic chemical contaminants in food.

Hazard Analysis Critical Control Points (HACCP) is a systematic approach to the identification, assessment, and control of hazards that was developed as an effective alternative to conventional end-point analysis to control food safety. It has been described as the most effective means of controlling foodborne diseases, and its application to the control of microbiological hazards has been accepted internationally. By contrast, relatively little has been reported relating to the potential use of HACCP, or HACCP-like procedures, to control chemical contaminants of food. This article presents an overview of the implementation of HACCP and discusses its application to the control of organic chemical contaminants in the food chain. Although this is likely to result in many of the advantages previously identified for microbiological HACCP, that is, more effective, efficient, and economical hazard management, a number of areas are identified that require further research and development. These include: (1) a need to refine the methods of chemical contaminant identification and risk assessment employed, (2) develop more cost-effective monitoring and control methods for routine chemical contaminant surveillance of food, and (3) improve the effectiveness of process optimization for the control of chemical contaminants in food.

Consumer Product Safety↗

Inactivation of transmissible spongiform encephalopathy agents in food products by ultra high pressure-temperature treatment.

Bovine spongiform encephalopathy (BSE) contamination of the human food chain most likely resulted from nervous system tissue in mechanically recovered meat used in the manufacture of processed meats. The availability of effective decontamination methods for products considered at risk for BSE or other transmissible spongiform encephalopathies (TSEs) would be an attractive safeguard to human health, but neither of the two proven inactivating methods, autoclaving or exposure to strong alkali or bleach, are applicable to foodstuffs. Ultra high pressure-temperature treatment of foods is an effective decontamination method that can reduce the pathogen load while keeping unaltered the nutritional and organoleptic properties of the product. The application of different combinations of high pressure-temperature pulses to meat products 'spiked' with the agents of TSEs can reduce the level of infectivity by 10(3) to 10(6) mean lethal doses (LD(50)) per gram of tissue. These data indicate that the high pressure-temperature treatment is a ready-to-use and feasible strategy to reduce the risk of TSEs transmission via contaminated meat products.

Animals↗

Medicinal and other products and human and animal transmissible spongiform encephalopathies: memorandum from a WHO meeting.

The report in March 1996 of 10 human cases of a novel from of Creutzfeldt-Jakob disease in the United Kingdom, and its possible link to the agent that causes bovine spongiform encephalopathy (BSE), raises many questions about the safety of animal-derived products and by-products entering the food chain or being used in medicine. This Memorandum updates the preventive measures put forward in 1991 to minimize the risks associated with the use of bovine-derived materials in medicinal products and medical devices.

Adult↗

Development of hazard analysis by critical control points (HACCP) procedures to control organic chemical hazards in the agricultural production of raw food commodities.

Hazard Analysis by Critical Control Points (HACCP) is a systematic approach to the identification, assessment, and control of hazards in the food chain. Effective HACCP requires the consideration of all chemical microbiological, and physical hazards. However, current procedures focus primarily on microbiological and physical hazards, while chemical aspects of HACCP have received relatively little attention. In this article we discuss the application of HACCP to organic chemical contaminants and the problems that are likely to be encountered in agriculture. We also present generic templates for the development of organic chemical contaminant HACCP procedures for selected raw food commodities, that is, cereal crops,raw meats, and milk.

Agriculture↗

Natural selection of PAH-degrading bacterial guilds at coal-tar disposal sites.

Microbial activity patterns at buried coal-tar disposal sites have been under investigation for several years to determine the response of naturally occurring microflora to polycyclic aromatic hydrocarbons (PAHs) at the sites. At one site in upstate New York, data have shown enrichment of PAH-degrading bacteria in subsurface contaminated zones but not in uncontaminated zones. Similar work at a midwestern site showed that the same trends existed in a heterogeneous disposal site except that a borehole outside the plume showed some PAH-mineralization activity. Polymerase chain reaction amplification of DNA extracted from sediment samples from the New York site indicated the presence of naphthalene metabolism genes nahAc and nahR, similar to those found on the NAH7 plasmid of Pseudomonas putida G7. Significant sequence polymorphism was observed in amplified nahAc products, indicating that divergent homologs of nahAc were present in the native community. Protozoan numbers were elevated in sediment samples displaying relatively high PAH-degrading activity, suggesting that a food chain was established based on PAH-degrading bacteria. Removal of the coal-tar source at the site occurred in 1991. In 1992, sampling of three key borehole stations revealed that mixing and backfilling operations had introduced soil microorganisms into the source area and introduced 14C-PAH-mineralization activity into the previously inactive pristine area. Thus removal of the source of the contaminants and restoration at the site have altered the microbial activity patterns outside the contaminant plume as well as in the source area.

Bacteria↗

Other food borne infections.

This article presents an update of several emerging or reemerging pathogens: Yersinia, Cryptosporidia, Cyclospora, Brucella, and Mycobacterium. All of these zoonotic pathogens show evidence of food borne transmission. Yersiniosis is presented as an emerging pathogen that has as its major route of transmission preparation and consumption of pork products. New evidence is presented that supports the transmission of brucellosis via the food chain, especially through contaminated raw milk and cheese. While TB has limited transmission via raw milk, it is highlighted as a reemerging infection due to the development of multiple drug resistance. Public health veterinarians stand in an excellent position to recognize these emerging diseases and apply intervention strategies to prevent and control these infections in the future. This article is intended to raise their consciousness as to the management and medical practices that can diminish food borne transmission.

Animals↗

Towards a national surveillance program for antimicrobial resistance in animals and animal-derived food.

One of the major recommendations of the JETACAR report was that a comprehensive national surveillance system be established to measure antimicrobial resistance to cover medical, food-producing and veterinary areas. While there are a number of existing passive surveillance programs on a national, regional and state basis in the medical field, there are few analogous programs in the veterinary area, and none with a particular emphasis on the food chain. The Commonwealth Interdepartmental JETACAR Implementation Group is working with stakeholders to develop this aspect of the national surveillance program based on the Guidelines published by the world organisation for animal health, the Office International des Epizooties.

Animals↗

Expanding portion sizes in the US marketplace: implications for nutrition counseling.

The greater energy content of larger food portions could be contributing to the increasing prevalence of overweight. Prevention guidelines recommend "sensible" portion sizes but do not define them. The US Department of Agriculture (USDA) defines standard serving sizes for dietary guidance, and the Food and Drug Administration (FDA) defines standard servings for food labels. To use these standards in counseling, nutritionists must know the sizes of portions available in the marketplace. We determined marketplace portion sizes, identified changes in these sizes with time, and compared current marketplace portions with federal standards. Most marketplace portions exceed standard serving sizes by at least a factor of 2 and sometimes 8-fold. Portions have increased over time; those offered by fast-food chains, for example, often are 2 to 5 times larger than the original size. The discrepancy between marketplace portions and standard servings suggests the need for greater emphasis on the relationship of portion size to energy intake as a factor in weight maintenance.

Counseling↗

Variation in stakeholder opinion on countermeasures across Europe.

A compendium of agricultural countermeasures and rural waste disposal options has been compiled as part of the EC STRATEGY (Sustainable Restoration and Long-Term Management of Contaminated Rural, Urban and Industrial Ecosystems) project. The compendium was discussed by the FARMING (Food and Agriculture Restoration Management Involving Networked Groups) network of stakeholders during meetings of national panels in the UK, Finland, Belgium, Greece and France in 2002. Their preliminary feedback has been summarised in terms of whether an option is generally acceptable, unacceptable or only acceptable under specific circumstances. A considerable divergence of opinion between national panels was apparent for many of the options considered. This could be attributed to differences in geomorphology, climate, land management, infrastructure, consumer confidence, sociopolitical context and culture. Where consensus was reached between stakeholders it was generally for those countermeasures that provide public reassurance, sustain farming practices and minimise environmental impact. Furthermore, whilst there was general agreement that contaminated food should not enter the food chain, many of the options proposed for its subsequent management were not generally acceptable to stakeholders.

Agriculture↗

An outbreak of viral gastroenteritis associated with adequately prepared oysters.

Over Christmas 1993, an outbreak of food poisoning occurred among guests in a hotel in South West Scotland. Evidence from a cohort study strongly suggested that raw oysters were the vehicle for infection, probably due to a Small Round Structured Virus (SRSV). Detailed enquiry about the source and preparation of the oysters revealed no evidence of any unsafe handling at any stage in the food chain, nor any evidence of bacterial contamination. It is suggested that the present standards of preparation and monitoring are inadequate to protect the consumer, and that bacteriophage monitoring may be a useful method of screening for viral contamination in future.

Animals↗

[Creutzfeldt-Jakob disease: diagnosis, incidence, prevention and treatment].

Creutzfeldt-Jakob disease (CJD) is a rare, neurodegenerative disorder belonging to the spongiform encephalopathies. A variant form (vCJD) is most likely the result of infection with the agent that causes bovine spongiform encephalopathy (BSE). Diagnostic information can be obtained by EEG, testing cerebrospinal fluid for the presence of the 14-3-3 protein, MRI, brain biopsy, tonsil biopsy, and postmortem brain examination. Some tests, such as MRI and postmortem brain examination, can be used to distinguish between CJD and vCJD. Pathological prions in a tonsil biopsy are only found with vCJD. In the Netherlands, there are four known cases of iatrogenic CJD. On the basis of certain exposure to BSE via the food chain, cases of vCJD are also to be expected. Chloropromazine and mepacrine are known to inhibit the formation of pathological prion conformations, but clinical trials have not yet been carried out.

Animals↗