Polycyclic aromatic hydrocarbon release from a soil matrix in the in vitro gastrointestinal tract

Soil ingestion is an important exposure route by which immobile soil contaminants enter the human body. We assessed polycyclic aromatic hydrocarbon (PAH) release from a contaminated soil, containing 49 mg PAH kg(-1), using a SHIME (Simulator of the Human Intestinal Microbial Ecosystem) reactor comprising the stomach, duodenal, and colon compartments. Polycyclic aromatic hydrocarbon release was defined as that fraction remaining in the digest supernatant after centrifugation for 5 min at 1500 x g. The PAH release in the stomach digest was only 0.44% of the total PAH present in soil, resulting in PAH concentrations of 23 micrograms PAH L(-1) chyme. The lower PAH releases in duodenum (0.13%) and colon (0.30%) digests, compared with the stomach digest, were thought to be attributed to combined complexation and precipitation with bile salts, dissolved organic matter, or colon microbiota. We studied these complexation processes in an intestinal suspension more in depth by preparing mixtures of 9-anthracenepropionic acid, a Bacillus subtilis culture, and cholin as model compounds for PAHs, organic matter, and bile salts, respectively. Bile salts or organic matter in the aqueous phase initially enhance PAH desorption from soil. However, desorbed PAHs may form large aggregates with bile and organic matter, lowering the freely dissolved PAH fraction in the supernatant. Using the model compounds, mathematical equations were developed and validated to predict PAH complexation processes in the gastrointestinal tract. Contaminant release and subsequent complexation in the gut is an important prerequisite to intestinal absorption and thus bioavailability of that contaminant. The data from this research may help in understanding the processes to which PAHs are subjected in the gastrointestinal tract, before intestinal absorption.     

Spatial assessment of the economic feasibility of short rotation coppice on radioactively contaminated land in Belarus, Ukraine, and Russia. II. Monte Carlo analysis

A Monte Carlo analysis of two sequential GIS-embedded submodels, which evaluate the economic feasibility of short rotation coppice (SRC) production and energy conversion in areas contaminated by Chernobyl-derived (137)Cs, was performed to allow for variability of environmental conditions that was not contained in the spatial model inputs. The results from this analysis were compared to the results from the deterministic model presented in part I of this paper. It was concluded that, although the variability in the model results due to within-gridcell variability of the model inputs was considerable, the prediction of the areas where SRC and energy conversion is potentially profitable was robust. If the additional variability in the model input that is not contained in the input maps is also taken into account, the SRC production and energy conversion appears to be potentially profitable at more locations for both the small scale and large scale production scenarios than the model predicted using the deterministic model.     

Consumer Attitudes Towards the Development of Animal-Friendly Husbandry Systems

Recent policy developments in the area of livestock husbandry have suggested that, from the perspective of optimizing animal welfare, new animal husbandry systems should be developed that provide opportunities for livestock animals to be raised in environments where they are permitted to engage in “natural behavior.” It is not known whether consumers regard animal husbandry issues as important, and whether they differentiate between animal husbandry and other animal welfare issues. The responsibility for the development of such systems is allocated jointly between farmers, regulators, different actors in the food chain, and consumers. This research focuses on understanding consumer attitudes and preferences regarding the development and introduction of such systems, to ensure that they are acceptable to consumers as well as producers, regulators, and scientists. Consumer perceptions of animal welfare and animal husbandry practices were evaluated using quantitative consumer survey, which focused on two animal husbandry issues – farmed pigs and farmed fish. Following pilot work, 1000 representative Dutch consumers were sampled about their attitudes to either pig or fish husbandry. The results indicated that consumers think about animal welfare in terms of two broad categories related to their health and living environment, but do not think about welfare issues at a more detailed level. Greater concern was expressed about the welfare of pigs compared to fish. Consumer trust in labeling also emerged as an important issue, since consumers need to trust different food chain actors with responsibility for promoting animal welfare, and are reluctant to consider the details of animal husbandry systems. As a consequence, a transparent, enforceable, and traceable monitoring system for animal welfare friendly products is likely to be important for consumers.     

Integrating industrial ecology principles into a set of environmental sustainability indicators for technology assessment

This paper focuses on the environmental component of sustainability of technology, taking into account the role of industrial ecology. Assessment of environmental sustainability of technology traditionally focuses on immediate impact of technology on the environment through quantifying resource extraction and generated emissions. However, technology does not only exchange materials with the environment but also with the industrial society as a whole, the so-called industrial metabolism. A higher compatibility of a specific technology with the industrial system, as studied in industrial ecology, can result in lower resource extraction and reduced waste emission, indirectly contributing to a better environmental sustainability.Starting from the considerations above and based on the second law of thermodynamics, the paper presents a set of five environmental sustainability indicators for the assessment of products and production pathways, integrating industrial ecology principles. The indicators, all scaled between 0 and 1, take into account: (1) renewability of resources; (2) toxicity of emissions; (3) input of used materials; (4) recoverability of products at the end of their use; (5) process efficiency.The applicability of the elaborated set of indicators is illustrated for different production pathways of alcohols (petrochemical and oleochemical based), polyethylene end-of-life options and electricity production from non-renewable (natural gas and fossil oil) and renewable resources (hydropower, photovoltaic conversion of solar irradiation).     

Environmental assessment of packaging: The consumer point of view

When marketing environmentally responsible packaged products, the producer is confronted with consumer beliefs concerning the environmental friendliness of packaging materials. When making environmentally conscious packaging decisions, these consumer beliefs should be taken into account alongside the technical guidelines. Dutch consumer perceptions of the environmental friendliness of packaged products are reported and compared with the results of a life-cycle analysis assessment. It is shown that consumers judge environmental friendliness mainly from material and returnability. Furthermore, the consumer perception of the environmental friendliness of packaging material is based on the postconsumption waste, whereas the environmental effects of production are ignored. From the consumer beliefs concerning environmental friendliness implications are deduced for packaging policy and for environmental policy.     

RUNOFF,EROSION, AND SOLUTES IN THE LOWER TRUCKEE RIVER,NEVADA, DURING 19691

The Truckee River heads in the Sierra Nevada at Lake Tahoe, and terminates in Pyramid Lake. During the 1969 water year, flow about 9 miles upstream from the mouth (974,000 acre-ft) was almost four times the long-term average, due mainly to heavy winter rains and spring snowmelt. A short period of low-altitude rainfall produced the highest concentrations of suspended sediment, whereas a much longer subsequent period of snowmelt yielded a much greater total quantity of material. The upper 90 percent of the basin yielded about 260 acre-feet (630,000 tons) of sediment at the Nixon gage, whereas an estimated 2,800 acre-feet (6.8 million tons) was contributed by erosion of about 200 acres of river bank below the gage. Solute content at the gage ranged from 80 to 450 mg/l, dominated by calcium, sodium, and bicarbonate, plus silica in the most dilute snowmelt and chloride in the most concentrated low flows. Solute load totaled about 130,000 tons, of which the principal constituents in Pyramid Lake-sodium plus equivalent bicarbonate and chloride-amounted to almost 40,000 tons. The total solute load during a year of average flow may be 45,000-55,000 tons, including 18,000-22,000 tons of principal lake constituents.     

Movement of pertechnetate through soils: Hydrodynamic dispersion

Measurement of the hydrodynamic dispersion of pertechnetate (⁹⁹TcO^?₄) migrating towards the water-table complements other investigations of the partition of pertechnetate between soil solution and soil colloids. This study was performed on soil columns equilibrated with distilled water and through which a solution of ⁹⁹TcO₄NH₄ or ³⁶ClNa was percolated at constant rate. A theoretical elution curve was adjusted to the experimental points obtained from a sand column. An estimate could thus be made of the parameters characterizing the migration of pertechnetate. The model used here considered the presence of a ‘dead water’ zone in the column into which the solute penetrates by molecular diffusion only at a given rate. The elution curves obtained experimentally and theoretically have been compared with those for a non-reactive anion, ³⁶Cl^?. A simulationof the change of pertechnetate concentration in the eluate has been made for increasing values of the retention factor. The calculated curves confirm the very low mobility of this anion in soil.