Environmental hazard profile of organic chemicals: An experimental method for the assessment of the behaviour of organic chemicals in the ecosphere by means of simple laboratory tests with 14C labelled chemicals

The concept of “Environmental Hazard Profile” developed at this institute has been tested with 100 ¹⁴C-labelled organic compounds. Concentration factors in activated sludge, in algae and fish were determined. The microbial degradation of the chemicals to CO₂ in activated sludge and the decomposition to CO₂ under artificial light were determined. Ranking of compounds is given in the order of falling concentration factors and accumulation in rats respectively, and decreasing rates of decomposition. Relationship between chemical structure and accumulative and degradative behaviours is demonstrated using some selected groups of chemicals, such as benzenes, phenols, biphenyls and polyaromatic hydrocarbons. Correlations between the octanol/water partition coefficient, concentration factors and rates of decomposition could be established. Evaluation of test compounds was possible using hazard profiles obtained by the sum of single test results.     

Bioconcentration potential (BCP) of 2,3,7,8-Tetrachlorodibenzop-dioxin (2,3,7,8-TCDD) in terrestrial organisms including humans

The bioconcentration factors (BCFs) of 2,3,7,8-TCDD in adipose tissue of rats, beef cattle and monkeys have been calculated. The bioconcentration potential of TCDD in man was calculated by two indirect methods: 1) from daily intake of TCDD and its measured concentrations in adipose tissues and 2) from measured half-life and measured concentrations in body fat at steady state using a linear one compartment pharmacokinetic model. The BCFs in humans calculated by both methods are between 104 and 206, or 153, respectively.     

Copepodid and adult Argestidae Por, 1986 (Copepoda: Harpacticoida) in the southeastern Atlantic deep sea: diversity and community structure at the species level

Drawing on the example of Argestidae Por, 1986b, community structure and large-scale distribution patterns of harpacticoid copepods at species level were examined in the three southeastern Atlantic deep-sea basins. The study was based on 30 multicorer deployments at depths from 5,035 to 5,655 m during the DIVA-2 expedition. The 1,176 adult and copepodid Argestidae from CIII onwards belong to 114 species. Some species occurred at all five stations; others appeared to be exclusive for single stations. Inclusion of copepodids revealed a higher similarity in species composition among the five stations than consideration of just adults and caused a slight shift toward dominance of single species in the sediments at most locations.     

Closing the phosphorus loop in England: The spatio-temporal balance of phosphorus capture from manure versus crop demand for fertiliser

Every year 90 million tonnes of housed livestock manures are produced in the UK. This is a valuable reservoir of global phosphorus (P) and a point in the cycle where it is vulnerable to being lost from the terrestrial system. Improved manure management for the effective reuse of phosphorus is vital to simultaneously tackle a major source of water pollution and reduce our dependence on imported fertilisers. This paper quantifies, for the first time, the spatial and temporal challenges of recycling the required amount of manure P from areas of livestock production to areas of crop production in eight regions of England. The analysis shows that England has a P deficit and therefore the capacity to fully utilise the manure P on arable land, but that uneven spatial distribution of livestock poses a significant challenge to closing the P loop in agriculture. Two of the eight regions were shown to have surplus manure P, with the remaining six regions having P deficits, indicating that an annual export of 4.7 thousand tonnes P (2.8 million tonnes manure) must take place from the west to the east of the country each year to balance P supply and demand. Moreover, housed manure production peaks between October and February, requiring an excess of 23.0 thousand tonnes P (15 million tonnes manure) to be stored until it can be used for crop fertilisation from March onwards. The results demonstrate the scale of the challenge in managing manure P in an agricultural system that has separated livestock production from crop production, a pattern that is echoed throughout the developed world. To overcome the spatial and temporal challenges, a logistical system is recommended that will balance the nutrient potential (nitrogen and P content and availability) and pollution potential (eutrophication, greenhouse gas emissions, particulates and nitrous oxide from transport) for cost-effective and environmentally compatible redistribution of manure P from areas of surplus to areas of deficit, when required.     

Biokonzentration von persistenten superlipophilen Chemikalien in aquatischen Organismen

According to generally accepted theory, persistent superlipophilic chemicals with logn-octanol/water partitioning coefficient (log K_ow) >6 and molecular sizes >9,5 Å, such as octachlorodibenzo-p-dioxin, decachlorobiphenyl, Mirex etc., do not significantly bioconcentrate in aquatic organisms from ambient water. In the light of new results and considerations, this hypothesis has to be revised. The most convincing argument against this hypothesis is that in all bioconcentration experiments with superlipophilic chemicals compound concentrations have been applied which exceeded water solubility by several orders of magnitude. In this paper we describe various methods how to determine bioconcentration (BCF) factors of superlipophilic compounds. As exemplified with octachlorodibenzo-p-dioxin and Mirex, BCF values evaluated by this means match well those calculated by QSARs for fish and mussels based on log K_ow and water solubility as well. As expected these BCF values exceed previous ones by several orders of magnitude. As practical consequences, we recommend for BCF evaluations of superlipophilic chemicals:

1. flow-through systems, kinetic method (OECD guideline No 305 E)
2. ambient concentrations≤water solubility.

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