Reviewing the relevance of dioxin and PCB sources for food from animal origin and the need for their inventory,control and management

Background

In the past, cases of PCDD/F and PCB contamination exceeding limits in food from animal origin (eggs, meat or milk) were mainly caused by industrially produced feed. But in the last decade, exceedances of EU limit values were discovered more frequently for PCDD/Fs or dioxin-like(dl)-PCBs from free range chicken, sheep, and beef, often in the absence of any known contamination source.

Results

The German Environment Agency initiated a project to elucidate the entry of PCBs and PCDD/Fs in food related to environmental contamination. This paper summarizes the most important findings. Food products from farm animals sensitive to dioxin/PCB exposure—suckling calves and laying hens housed outdoor—can exceed EU maximum levels at soil concentrations that have previously been considered as safe. Maximum permitted levels can already be exceeded in beef/veal when soil is contaminated around 5 ng PCB-TEQ/kg dry matter (dm). For eggs/broiler, this can occur at a concentration of PCDD/Fs in soil below 5 ng PCDD/F–PCB-TEQ/kg dm. Egg consumers—especially young children—can easily exceed health-based guidance values (TDI). The soil–chicken egg exposure pathway is probably the most sensitive route for human exposure to both dl-PCBs and PCDD/Fs from soil and needs to be considered for soil guidelines. The study also found that calves from suckler cow herds are most prone to the impacts of dl-PCB contamination due to the excretion/accumulation via milk. PCB (and PCDD/F) intake for free-range cattle stems from feed and soil. Daily dl-PCB intake for suckler cow herds must in average be less than 2 ng PCB-TEQ/day. This translates to a maximum concentration in grass of 0.2 ng PCB-TEQ/kg dm which is less than 1/6 of the current EU maximum permitted level. This review compiles sources for PCDD/Fs and PCBs relevant to environmental contamination in respect to food safety. It also includes considerations on assessment of emerging POPs.

Conclusions

The major sources of PCDD/F and dl-PCB contamination of food of animal origin in Germany are (1) soils contaminated from past PCB and PCDD/F releases; (2) PCBs emitted from buildings and constructions; (3) PCBs present at farms. Impacted areas need to be assessed with respect to potential contamination of food-producing animals. Livestock management techniques can reduce exposure to PCDD/Fs and PCBs. Further research and regulatory action are needed to overcome gaps. Control and reduction measures are recommended for emission sources and new listed and emerging POPs to ensure food safety.

     

Communication in Ecosystem Management: A Case Study of Cross-Disciplinary Integration in the Assessment Phase of the Interior Columbia Basin Ecosystem Management Project

Effective communication is essential to the success of collaborative ecosystem management projects. In this paper, we investigated the dynamics of the Interior Columbia Basin Ecosystem Management Projects (ICBEMP) cross-disciplinary integration process in the assessment phase. Using a case study research design, we captured the rich trail of experience through conducting in-depth interviews and collecting information from internal and public documents, videos, and meetings related to the ICBEMP. Coding and analysis was facilitated by a qualitative analysis software, NVivo. Results include the range of internal perspectives on barriers and facilitators of cross-disciplinary integration in the Science Integration Team (SIT). These are arrayed in terms of discipline-based differences, organizational structures and activities, individual traits of scientists, and previous working relationships. The ICBEMP organization included a team of communication staffs (CT), and the data described the CT as a mixed group in terms of qualifications and educational backgrounds that played a major role in communication with actors external to the ICBEMP organization but a minor one in terms of internal communication. The data indicated that the CT-SIT communication was influenced by characteristics of actors and structures related to organizations and their cultures. We conclude that the ICBEMP members may not have had a sufficient level of shared understanding of central domains, such as the task at hand and ways and timing of information sharing. The paper concludes by suggesting that future ecosystem management assessment teams use qualified communications specialists to design and monitor the development of shared cognition among organization members in order to improve the effectiveness of communication and cross-disciplinary integration.     

Impact of land use on soluble organic nitrogen in soil

Although it has been hypothesized that soluble organic nitrogen (SON) plays a central role in regulating productivity in some terrestrial ecosystems, the factors controlling the size of the SON pool in soil remain poorly understood. Therefore our principal aim in this work was to assess the impact of seven different land use systems (rough and managed grassland, deciduous and coniferous woodland, heathland, wetland and tilled land) on the size of the SON and inorganic N (NO^? ₃, NH⁺ ₄) pools in the surface soil layer (0–15 cm). After extraction with deionised water, we found that in most cases the size of the water extractable organic N (WEON) pool was similar in size to the inorganic N pool. In contrast, the KCl extractable organic N (KClEON) pool constituted the dominant form of soluble N in soils under all land uses, perhaps indicating that significant amounts were held on the soil exchange phase. In contrast to inorganic N, which varied significantly with land use, the size of the KClEON and WEON pool was similar for all land uses with the exception of KClEON in tilled land, where significantly lower amounts were observed. We conclude that SON constitutes an important soil N pool in a broad range of land uses, and that its role in microbial N assimilation, plant nutrition and ecosystem responses to atmospheric N deposition warrants further attention.     

Ecological Integrity Assessment of Lakes Using Fish Communities: An Example from Traunsee Exposed to Intensive Fishing and to Effluents from the Soda Industry

In order to analyse potential influences of soda industryeffluents on the ecological integrity of Traunsee (TS) weinvestigated the fish community of the lake in comparison witha reference lake (Hallstättersee HS) and used a reconstructionfrom the (older) literature concerning the original speciescomposition of Traunsee. Published `Index of Biotic Integrity(IBI)' metrics were considered to be of limited value due tothe relatively low species number in the oligotrophic, Alpinelake. Therefore we included, in addition to speciescomposition, studies on egg distribution, larval fishdensities, life-history parameters (i.e. growth, maturity,fecundity, age and size composition), stress levels and heavymetal content of the dominant whitefish (Coregonuslavaretus), as well as overall fish density and biomass (usinghydroacoustics) to assess the ecological status of the fishcommunity. Two of the original 18 species have disappearedfrom the lake, presumably in connection with the introductionof non-native eel (Anguilla anguilla) and theconstruction of a power plant in the outflow. Silt from grindedlimestone together with highly alkaline pore waters is emittedvia industrial wastewater from Sodaworks and covers part of thelake bottom. We observed that eggs of whitefish were spawnedmainly in the main inflowing river and close to the shore, thusavoiding the silty areas and making the anticipated damage tothe reproductive potential of whitefish neglectable. This wascorroborated by larval surveys done weekly on both lakes fromJanuary to May, which showed halve the density of whitefishlarvae in TS compared to HS. Estimates of potentially spawningfish from hydroacoustic surveys resulted in a ratio of 1(TS) :3 (HS). Analysis of whitefish revealed that they are growingfaster in TS and have higher fecundity leading to somecompensation of lower abundance. High levels of fishing in TSmight have led to this pattern and to depressed yields asindicated by the age composition. Level of oxidative stress andheavy metal content were not discernible from the referencelake. Therefore we concluded that negative impacts on theecological status of the fish community resulted from fisheriesmismanagement and a power plant situated in the outflow of thelake, considered to have damaged spawning places for somespecies, but not from soda industry effluents.     

Smart Growth in a Small Urban Setting: the challenges of building an acceptable solution

Smart growth policies direct development towards existing communities already served by roads, sewer systems and other infrastructure. The increased development in these communities in turn should enable them to benefit from a stronger tax-base, more efficient use of their schools and other public facilities, and the renewed economic vitality of their urban centres. These goals and objectives appear to complement and support the efforts of urban mayors to attract new property tax rateables and better-paying jobs, but they may conflict with the desires of residents to reduce densities and improve the quality of life. We use a visual GIS-based model to assist five small contiguous older suburbs individually and collectively to evaluate their current redevelopment plans and to understand the implications of their land-use decisions on the quality of life in their communities. By bringing them together as a group, and our raising broader redevelopment and impact issues, they have begun to rethink how these properties could be best used to meet the community's needs and to see them in the context of similar redevelopment plans within their mini-region. One of the changes emerging is a greater role for certain types of residential development and a concurrent reduction in the amount of commercial space being considered. The authors would like to thank the Geraldine R. Dodge Foundation for funding this project, the Somerset County Planning Board and mayors of the five towns for actively supporting and participating in the study and the Regional Planning Partnership for its co-operation and assistance in refining its GOZ model to promote regional planning from the bottom up. The authors accept full responsibility for the ideas and recommendations in this report.     

DEBRIS FLOWS THROUGH DIFFERENT FOREST AGE CLASSES IN THE CENTRAL OREGON COAST RANGE1

ABSTRACT: Debris flows in the Pacific Northwest can play a major role in routing sediment and wood stored on hillslopes and in first‐through third‐order channels and delivering it to higher‐order channels. Field surveys following a large regional storm event investigated 53 debris flows in the central Oregon Coast Range to determine relationships among debris flow characteristics and the age class of the surrounding forest. The volume of sediment and wood delivered by debris flows was strongly correlated with runout length. Debris flows that initiated at roads were significantly longer than nonroad related failures, and road related landslides were an order of magnitude larger than nonroad related landslides. Clearcuts and roads tended to have more numerous contributing landslides relative to second growth and mature forests. No statistically significant difference in the average debris flow runout length was detected among the forest age classes, although debris flows initiating in clearcuts and mixed forest and at roads occasionally supported extremely long runout lengths that were outside the range of variability observed in completely forested basins. The size of wood in deposits was not correlated with the size of trees on the adjacent slopes, suggesting that the majority of wood in debris flow deposits was from remobilization of wood previously stored in low order channels.     

An ecosystem perspective on potential impacts of drilling fluid discharges on seagrasses

Potential effects of oil drilling fluid discharges uponThalassia seagrass ecosystems were examined using seagrass core microcosms. Observed experimental effects, summarized in this article, included changes in both autotrophic (Thalassia and epiphyte) and heterotrophic (dominant benthic macroinvertebrates) species, and the processes of primary productivity and decomposition. The physical disturbance related to greater turbidity and sedimentation caused some effects, while others seemed a direct response to the toxic constituents of drilling fluids. Using these experimental results and the case ofThalassia and drilling fluids as a case study, we explore general methodological and philosophical issues for ecotoxicology and, furthermore, focus upon the challenge of providing a scientific basis for judging acceptability of environmental changes likely to ensue from human activities.     

Role of wetlands in reducing phosphorus loading to surface water in eight watersheds in the Lake Champlain Basin

A landscape-level approach was applied to eight rural watersheds to assess the role that wetlands play in reducing phosphorus loading to surface waters in the Lake Champlain Basin. Variables summarizing various characteristics of wetlands within a watershed were calculated using a geographic information system and then compared to measured phosphorus loading through multiple regression analyses. The inclusion of a variable based on the area of riparian wetlands located along low- and medium-order streams in conjunction with the area of agricultural and nonwetland forested lands explained 88% of the variance in phosphorus loading to surface waters. The best fit model coefficients (P_load = 0.86Ag + 0.64For – 30Ripwet + 160) suggest that a hectare of riparian wetland may be many times more important in reducing phosphorus than an agricultural hectare is in producing phosphorus. These results provide additional support for the concept that protection of riparian wetlands is an important management strategy for controlling stream water quality in multiuse landscapes.     

Characteristics and predictors of recidivist drink-drivers

Objective: The current study compared characteristics of nonrecidivist versus recidivist drink-drivers and of recidivists in their first versus second appearance at Back on Track (BOT), the remedial measures program for impaired drivers in Ontario, Canada.

Methods: Information from 59,134 convicted drivers who participated in BOT between 2000 and 2010 was examined to identify drivers who completed the program a second time following reconviction.

Results: A total of 586 recidivists were identified. Compared to nonrecidivist drivers, recidivists at first attendance were more likely to be male and had higher scores on measures of alcohol dependence and adverse legal consequences of substance use. Compared to nonrecidivist drivers, recidivists at second attendance were significantly older, had a higher income, were more likely to be retired, and were less likely to be employed part-time. They had fewer legal problems. Recidivists reported fewer drinking days and fewer drinks per occasion but greater use of benzodiazepines than nonrecidivists and had higher scores on a measure of future risk of alcohol- and drug-related problems. Comparison of recidivists' characteristics at first versus second attendance confirmed many of these findings, with second-time recidivists reporting fewer drinks per drinking day and greater use of benzodiazepines and having higher scores on a measure of future substance use problems than first-time recidivists.

Conclusions: Results suggest that identification of drivers at increased risk of recidivism may be possible at first program attendance by examining indicators of increased alcohol-related problems. In addition, recidivists appear to show a greater readiness to change at second attendance. Implications for remedial program development and recommendations for future research are discussed.     

Ecological research for integrated coastal zone management: Introduction

Two Special Features on integrated coastal zone management, especially along the Mediterranean Sea, result from a MeDCOAST conference held in Hammamet (Tunisia). 20–25 October 2001. In this first Special Feature some papers are presented on ecological and biological research related to integrated coastal zone management. All over Europe coastal environments are threatened by human activities such as urbanization, industrial development, fisheries, aquaculture, recreation and tourism. Research has to be developed that can be applied to similar case studies in different countries. Methods of monitoring are necessary and baseline data have to be available in order to judge the significance of changes in the abjotic and biotic environment. Examples of studies included in this Special Feature are mainly from southern banks of the Mediterranean Sea but there is also an example from Estonia and one from the Canary Islands.