Chicken organs, animal feed, droppings, and ambient air were sampled at a farm in Beijing to determine the concentrations of hexachlorocyclohexane isomers (HCHs) and dichlorodiphenyltrichloroethane and metabolites (DDTs). Mean fresh weight concentrations of HCHs and DDTs were 0.122 ± 0.061 ng/g and 0.051 ± 0.038 ng/g in the muscles. These values are 1-2 orders of magnitude lower than those reported in China in 1980. Contaminated feed was the main source of HCHs and DDTs. Only 12.8% of HCH and 3.3% of DDT of the amount consumed were excreted. Accumulated quantities of HCHs and DDTs increased during growth. However, concentrations of HCHs and DDTs did not increase because of dilution from rapid growth. Based on the observed residual levels in mature chicken and the average diet of residents of China, the contributions from chicken and egg consumption to per capita daily intake of HCHs and DDTs were 487% and 88% of those of fish consumption.

Existing evidence indicated that dichlorodiphenyltrichloroethane (DDT)-containing antifouling paints were an important source of DDT residues to mariculture zones. However, the magnitude of the impact on aquafarming environment has remained largely unknown. In the present study, the concentrations of DDT and its metabolites (designated as DDXs) were determined in harbor sediment and antifouling paint samples collected from a typical mariculture zone in South China. Compositional and concentration correlation analyses implicated the DDT-containing antifouling paints for fishing boat maintenance as an important source of DDT in the mariculture zone. The annual emission of DDXs to the study region was estimated at 0.58tons/yr. Furthermore, a comparison of the expected DDT loadings in pelagic fish and field measurements indicated that fish feed especially trash fish was a major source of DDTs in the fish body. Nevertheless, the use of DDT-containing antifouling paints should be limited to prevent further deterioration in aquafarming environment.

Interest in selenium pollution and remediation technology has escalated during the past two decades. Although not known to be essential for plants, selenium is essential but could be toxic for humans and animals, depending on its concentration. A major selenium controversy in the 1980's emerged in California when the general public and scientific community became aware of selenium's potential as an environmental contaminant. After extensive research on several strategies to reduce loads of mobile Se for entering the agricultural ecosystem a plant-based technology, defined as 'phytoremediation' received increasing recognition, as a low-cost environmentally friendly approach for managing soluble Se in the soil and water environment. Successful long-term field remediation of Se by plants is, however, dependent upon acceptance and widespread use by growers, who are also concerned about potential commercial value from using the plant-based technology. Obtaining products with economic value from plants used in the cleanup of soil would certainly be an additional benefit to phytoremediation, which could help sustain its long-term use.

The integrated modelling system INITIATOR was applied to a landscape in the northern part of the Netherlands to assess current nitrogen fluxes to air and water and the impact of various agricultural measures on these fluxes, using spatially explicit input data on animal numbers, land use, agricultural management, meteorology and soil. Average model results on NH₃ deposition and N concentrations in surface water appear to be comparable to observations, but the deviation can be large at local scale, despite the use of high resolution data. Evaluated measures include: air scrubbers reducing NH₃ emissions from poultry and pig housing systems, low protein feeding, reduced fertilizer amounts and low-emission stables for cattle. Low protein feeding and restrictive fertilizer application had the largest effect on both N inputs and N losses, resulting in N deposition reductions on Natura 2000 sites of 10% and 12%, respectively.

The aim of this study is to illustrate the importance of farm scale heterogeneity on nitrogen (N) losses in agricultural landscapes. Results are exemplified with a chain of N models calculating farm-N balances and distributing the N-surplus to N-losses (volatilisation, denitrification, leaching) and soil-N accumulation/release in a Danish landscape. Possible non-linearities in upscaling are assessed by comparing average model results based on (i) individual farm level calculations and (ii) averaged inputs at landscape level. Effects of the non-linearities that appear when scaling up from farm to landscape are demonstrated. Especially in relation to ammonia losses the non-linearity between livestock density and N-loss is significant (p > 0.999), with around 20–30% difference compared to a scaling procedure not taking this non-linearity into account. A significant effect of farm type on soil N accumulation (p > 0.95) was also identified and needs to be included when modelling landscape level N-fluxes and greenhouse gas emissions.

To determine the potential input sources of polybrominated diphenyl ethers (PBDEs) to fish farming environments in South China, samples of seven various environmental matrices were collected from October 2006-September 2007. Tri- to deca-BDEs were detected in all samples analyzed, with mean concentrations (±standard deviations) at 5.7 ± 3.6 ng/L in pond water, 15 ± 11 ng/g dry wt. in pond sediment, 12 ± 3.8 ng/g dry wt. in bank soil, 21 ± 20 ng/g lipid wt. in fish, and 93 ± 62 ng/g lipid wt. in fish feeds. In addition, BDE-209 was the major constituent in all samples except fish and BDE-47 was predominant in fish samples. Relatively high abundances of BDE-49 were detected in all the samples compared to those in the penta-BDE technical products. Several bioaccumulation factors were evaluated. Finally, statistical analyses suggested that fish feed, as well as pond water at a lesser degree, may have been the major source of PBDEs in freshwater farmed fish.

An analytical procedure for the determination of Hg in otter (Lontra longicaudis) feces was developed, to separate fish scales for the identification of the animal diet. Samples were washed with ultra-pure water and the suspension was sampled and transferred for digestion. The solubilization was performed with nitric-perchloric acid mixture, and detection carried out by the atomic fluorescence spectrometry (AFS). The quality of the analytical procedure was assessed by analyzing in-house standard solutions and certified reference materials. Total Hg concentrations were in the range of 7.6-156 ng g-1 (July 2004), 25.6-277 ng g-1 (January 2005) and 14.6-744 ng g-1 (May 2005) that is approximately the same order of magnitude for all samples collected in two reservoirs at the Tiete River, Brazil. Although Hg concentrations varied with sampling periods and diet, high levels were correlated to the percentage of carnivorous fish scales present in the otter feces. The importance of otter feces preparation for Hg analysis, focusing the food web.

Background, aim, and scope Organoarsenical-containing animal feeds that promote growth and resistance to parasites are mostly excreted unchanged, ending up in nearby wastewater storage lagoons. Earlier work documented the partial transformation of organoarsenicals, such as, 3-nitro-4-hydroxyphenylarsonic acid (roxarsone) to the more toxic inorganic arsenate [As(V)] and 3-amino-4-hydroxyphenylarsonic acid (3-AHPAA). Unidentified roxarsone metabolites using liquid chromatography coupled to inductively coupled plasma mass spectrometry (LC/ICP-MS) were also inferred from the corresponding As mass balance. Earlier batch experiments in our laboratory suggested the presence of organometallic (Cu) complexes during relevant roxarsone degradation experiments. We hypothesized that organocopper compounds were complexed to roxarsone, mediating its degradation in field-collected swine wastewater samples from storage lagoons. The objective of this study was to investigate the role of organometallic (Cu) complexes during roxarsone degradation under aerobic conditions in swine wastewater suspensions, using electrospray ionization mass spectrometry (ES-MS). Materials and methods Two swine wastewater samples differing in % solids content and total recoverable Cu concentrations were reacted with 500 ppb of roxarsone under aerobic conditions for 16 days. LC/ICP-MS and ES-MS were used for As speciation analyses, and characterization of metal-organoarsenical complexes in swine wastewater subsamples, respectively. Results and discussion An organocopper roxarsone metabolite was found only in the high-Cu wastewater sample, suggesting the role of Cu in roxarsone degradation under aerobic conditions. The organocopper metabolite was not found in the low-Cu wastewater sample, because roxarsone did not undergo degradation under aerobic conditions even after 16 days. Conclusions Aerobic degradation of organoarsenicals (roxarsone) has not been documented before. Preliminary dataset from this study illustrates the direct and/or indirect association of particulate Cu in catalyzing roxarsone degradation under aerobic conditions in samples with high % solids content. Recommendations and perspectives Concerns regarding the degradation of roxarsone in wastewater to the more toxic inorganic As may be partially linked to the presence of particulate Cu. The presence of Cu in wastewater-suspended particle surfaces has never been coupled before to organoarsenicals degradation reactions, thus, further studies are needed to elucidate the related reaction mechanisms and pathways. Water depth-dependent solid particle distribution profiles in wastewater storage lagoons could provide empirical evidence towards the design of effective degradation practices for nitrophenol-containing compounds, such as, organoarsenical-containing antibiotics, or explosive munitions compounds.

Background, aim and scope The paper presents concentrations of trace elements in blood of homebred animals (cows and sheep) from Southern Serbia (Bujanovac) and the contents of natural and anthropogenic radionuclides and some heavy metals in feed. The region of Southern Serbia was exposed to contamination by depleted uranium ammunition during NATO attacks in 1999 and therefore, is of great concern to environmental pollution and human and animal health. Materials and methods Conventional instrumental and epithermal neutron activation analyses are used to measure trace elements in cow and sheep blood samples collected randomly at six locations in the region of Bujanovac (village of Borovac) in the spring of 2005. Samples of feed (grass and crops: corn, wheat and oats), collected on the same locations (households), are analysed for the contents of radionuclides on an HPGe detector (Ortec, relative efficiency 23%) by standard gamma spectrometry. The content of Hg, Pb and Cd in feed is determined by standard atomic absorption spectrometry on the VarianSpectra220/ThermoSolar GFS97 spectrometer. Results Concentrations of 29 elements (Na, Al (P), Cl, K, Sc, Cr, Mn, Ni, Fe, Co, Zn, Se, As, Br, Sr, Rb, Sb, In, I, Ba, Cs, La, Nd, Eu, Sm, Tb, Hf, Ta and Th) are determined in blood of the examined animals. In feeds, natural ⁴⁰K is found in all of the samples, cosmogenic ⁷Be and fission product ¹³⁷Cs are detected only in the grass samples, while heavy metals Hg, Cd and Pb are found in the range of 0.01-0.02, 0.84-1.15 and 0.74-7.34 mg/kg, respectively. Calculated soil-to-blood transfer factors are in a wide range of 8·10⁻⁶ to 64, as a result of varying significance of the elements in animal metabolism and feeding habits. Discussion The results of trace elements' concentrations in animal blood are in good agreement with available data for K, Ni, Zn, Se and Rb. Higher Br concentrations in animal blood are most probably caused by large biomass burning events during blood sampling. Very low concentration of Fe in cows and sheep confirms the results of previous biochemical studies on animal anaemia in the region. High concentration of As correlates with geochemical peculiarities of the Balkans and is also likely influenced by the use of pesticides in the agricultural production. For some of the elements (La, Nd, Eu, Sm, Tb, Sb, Hf, Ta, Th, In, Ba, Sr, Sc and Cs), there are few or no literature data. Therefore, some of the presented data are significant not only for the country and the region, but on a wider scale. Activities of natural radionuclides in feeds are within the average values reported for the region, while the activities of ²¹⁰Pb and ²³⁵/²³⁸U are below the limit of detection. This is in accordance with previous investigations showing no widespread contamination by depleted uranium in the area. Contents of Hg and Pb in feeds are below the nationally permissible levels, unlike the content of Cd which exceeds it, probably caused by the use of phosphate fertilisers and fossil fuel combustion in the area. Conclusions In general, the concentrations of trace elements in blood of homebred cows and sheep are in good agreement with reference materials, available literature data and the results of previous studies in the area. The exceptions are Fe, As and Br. The contents of natural and anthropogenic radionuclides in feeds are within the expected levels, and there are no signs of contamination by depleted uranium or other fission products. Apart from Cd, there are no signs of pollution by heavy metals in feeds. The highly sensitive method of instrumental neutron activation analysis provides data on the concentration of some elements in animal blood not previously reported for the region and elsewhere. Recommendations and perspectives The presented study is a part of the long term ongoing project on the health risk assessment on animals and humans in the region. The collected data is intended to provide a base for the animal and human risk assessment as well as an estimate of the general pollution status of the environment in the region. Since some of the investigated elements are classified as important trace elements for livestock, the results could also be used to balance and improve the animal diet and thus, improve the growth and reproduction rate.

Background, Aims and Scope: Current dredged material disposal alternatives have several limitations. Options for dealing with dredged materials include leaving them alone, capping them with clean sediments, placing them in confined facilities, disposing of them at upland sites, treating them chemically, or using them for wetlands creation or other beneficial uses. The ability to reuse lake-dredge materials (LDM) for agricultural purposes is important because it reduces the need for offshore disposal and provides an alternative to disposal of the materials in landfills. Often these materials can be obtained at little or no cost to the farmers or landowners. Thus, forage production offers an alternative to waste management since nutrients in the LDM are recycled into crops that are not directly consumed by humans. The objective of this study (Part 2) were to: (1) assess dredge materials from Lake Panasoffkee, Florida as a soil amendment to establish bahiagrass (BG) in a subtropical beef cattle pasture in Sumter County, Florida; and (2) determine the effect of LDM application on the crude protein (CP) and nutrient uptake of BG. This series of two papers aims at providing assessment of the efficacy of lake-dredged materials especially its implication to environment (soil quality, Part 1) and agriculture (forage quality and pasture establishment. Part 2). Methods: The experimental treatments that were evaluated consisted of different ratios of natural soil (NS) to LDM: LDMO (100% NS:0% LDM); LDM25 (75% NS:25% LDM); LDM50 (50% NS:50% LDM); LDM75 (25% NS:75% LDM); and LDM100 (0% NS:100% LDM). Bahiagrass plots at its early establishment were cut to a 5-cm stubble height on Julian days 112 and harvested to the same stubble height on Julian days 238 and on Julian days 546 following the double-ring method. Field layout was based on the principle of a completely randomized block design with four replications. Plant samples harvested at 546 Julian days were ground to pass through a 1-mm mesh screen in a Wiley mill. Ground forage was analyzed for crude protein. Ground forage samples were also analyzed for tissue P, K, Ca, Mg, Mn, Cu, Fe, Al, and Mo concentrations using an ICP spectroscopy. The effects of dredged materials addition on forage yield and on crude protein and nutrient uptake that were taken at 546 Julian days were analyzed statistically following the PROC ANOVA procedures. Results and Discussion: Part 1 of this study demonstrated that the heavy and trace metal contents of LDM were below the probable effect levels and threshold effect levels. As such, the agricultural or livestock industry could utilize these LDM to produce forages. Results showed consistently and significantly (p < or = 0.001) higher BG biomass production and CP from plots amended with LDM than those of BG planted on plots with 0% LDM. Forage yield of BG during its establishment increased linearly (Forage Yield = 1724.3 + 25.64*LDM; R2 = 0.83; p < or = 0.0001) with increasing rates of LDM application. The CP of BG also varied significantly with varying levels of LDM applications. The tissues of BG with 100% LDM had the greatest CP content while the lowest CP content was from the control plots (LDMO). The CP of BG increased linearly with increasing rates of LDM application. The crude protein response to BG application can be described by a linear equation: Crude Protein = 10.38 + 0.052*LDM; R2 = 0.85 p < or = 0.0001. Addition of LDM had increased the levels of Ca by about 1811 % when compared with the level of soil Ca among plots with no LDM application. Liming the field could have some direct and indirect effects on the chemical status of the soils. The physiological functions performed by Ca in plants are not clearly defined, but it has been suggested that Ca favors the formation of and increases the protein content of mitochondria. Conclusions: Beneficial uses of dredged materials from LP, Florida are both economical and environmental. Often these materials can be obtained at little or no cost to the farmers or landowners. Results showed that dredged materials can be used as soil amendments (lime and fertilizer) for early establishment of BG in beef cattle pastures. Environmentally, dredging of sediments that are rich in CaCO3 should restore the 19.4-sq km LP by removing natural sediments from the lake bottom to improve the fishery, water quality, and navigation of the lake. The nutritional uptake of BG grown in unfertile sandy soils of Sumter County was enhanced significantly (p < or = 0.001) by LDM addition. Uptake of TKN, TP, K, Ca, and Mg were remarkably increased as a result of LDM. Recommendation and Outlook: Land application of LDM from LP may not only provide substantial benefits that will enhance the environment, community, and society in south Florida, but also in other parts of the world especially those areas with forage-based beef cattle pastures and similar climatic conditions. The heavy and trace metal contents of these materials were below the PEL and TEL (see Part 1). As such, the agricultural or livestock industry could utilize these LDM to produce forages. LDM should be regarded as a beneficial resource, as a part of the ecological system. Although our results have demonstrated the favorable and beneficial effects of added LDM on the early establishment of BG in pasture fields., further studies are still needed not only in pastures of south Florida, but also in other areas with subtropical or tropical climatic conditions to determine whether the environmental and ecological implications of LDM application are satisfied over the longer term.