Cleaner production in Danish fish processing – experiences,status and possible future strategies

Danish fish processing industry has been one of the pioneers regarding implementation of cleaner production and environmental management systems. This article describes the experiences with cleaner production (CP) among leading Danish industries producing pickled herring and canned mackerel. The article emphasizes two case studies of ‘first mover’ companies, but data from other ‘proactive’ companies are also included.The article provides an overview of different types of CP solutions, improvement potentials, synergistic effects and possible trade-offs. The development of the applied solutions from the late 1980s until today are analysed and recommendations to future strategies at company level and policy level are provided.It is concluded that significant environmental improvements have been obtained for the analysed companies – especially concerning reductions in water consumption, wastewater emissions, and utilisation of fish ‘waste’ for valuable by-products. Still, more focus could be placed on the reduction of energy consumption, change of packaging types, and environmental impacts in other stages of the products life cycle.Authorities and companies have mainly focused on on-site reductions of wastewater emissions, but life cycle assessments show that more attention should be given to the reductions of environmental impacts in other parts of the product chain, e.g. fishing operations and transport as well.     

Simulation of the Environmental Impact of an Airport on the Surrounding Air Quality

It is the purpose of this study to demonstrate the procedure involved in simulating those average and maximum pollutant concentrations at or around an airport which fall under the control of the Clean Air Act. The information is useful, when planning new or expanding existing airports, when estimating the impact of airports on the surrounding air quality, and when assessing the effectiveness of control procedures. Simulation of airport air quality requires the accurate assessment of the temporal and spatial emission patterns. This involves the tabulation of air traffic density by type and engine, make and model of aircraft, and engine mode number; the use of fuel by different aircraft; the pollutant emission rates by engine model and operational mode; the allocation of emission rates to the respective runways, turn-off points, taxi-ways, and parking areas, and the time each aircraft spent in the different operational modes. The resulting emission pattern for the Honolulu International Airport reflects scheduled and unscheduled commercial and military jet and piston aircraft and nonaircraft operations. Using this and the appropriate meteorological information average and maximum surface concentrations were calculated and compared with local ambient air quality standards. The calculation of concentrations is based on a newly developed diffusion model incorporating harmonic mean wind speeds for every degree of wind direction as determined by a Parzen maximum likelihood interpolation technique, and the assumption of log-normal concentration distributions. It is shown that for some pollutants the air quality standards are substantially exceeded, and it is concluded that airports may have a considerable adverse impact on their surrounding air quality.     

Regime shift in a coastal marine ecosystem

We demonstrate changes in ecosystem stable states in a coastal lagoon that are consistent with what a regime shift would hypothesize. In the nutrient-stressed Ringk?bing Fjord, Denmark, a small change in one variable (salinity) facilitated by a change in sluice management, caused a sudden regime shift from a bottom-up controlled turbid state, into a top-down controlled clear-water state. The change in dominating pathway of organic matter production from pelagic turnover to benthic-pelagic coupling was facilitated by new recruitment and growth of existing suspension-feeding clams, Mya arenaria. With the invasion of clams, benthic grazing became the key feature of the biological structure. Phytoplankton composition and zooplankton abundance were also affected by the change in biological structure. The small, but sudden, increase in salinity caused by the change in sluice management led to a dramatic reduction in biomass and coverage of benthic vegetation and thus affected herbivorous waterbird populations. In recent years, plant coverage has been increasing, as can be expected with increased water transparency. The regime shift has some major implications for coastal water management and revealed some conflicts between different types of nature and environmental protection legislation.     

Impact of increasing atmospheric CO2 concentrations on global climate: Potential consequences and corrective measures

The increase in the concentration of CO₂ in the atmosphere is closely related to man's activities. There is much concern that this increase might be a major factor contributing to global climatic change. This review analyses the potential climatic impact of these increasing CO₂ concentrations, discusses the potential consequences of the resulting climatic changes, and presents possible solutions to the CO₂ problem.     

A Comparison of Skin Temperatures and Clothing Microclimate During Moderate Intermittent Exercise in the Cold Between One and Two Layers of Cotton and Polypropylene Underwear

The purpose of this study was to compare the effects of 2 kinds of underwear made from hydrophobic and hydrophilic fabrics on the mean skin temperatures and clothing microclimate (temperature, humidity) in participants performing intermittent exercise in cold environmental conditions.

One or 2 layers of cotton underwear (C1, C2) with a 2-piece long-sleeved shirt and long-legged trousers, and 1 or 2 layers of polypropylene underwear (P1, P2) with a 2-piece long-sleeved shirt and long-legged trousers were used as experimental underwear. In addition, the participants wore a 2-piece ski suit as 100% polyester clothing including 100% polyester padding. Ten young adult females volunteered as participants. The experiments were performed in a climatic chamber at an ambient temperature (T_a) of 0°C and an air velocity of 0.26 m s^?1.

The major findings are summarized as follows: (a) Although the clothing microclimate humidity was not different within the ski suit of outer clothing between C1 and P1, it was significantly higher in P2 than in C2; (b) Clothing microclimate temperature inside the ski suit did not differ between C1 and P1, whereas it was significantly higher in P2 than in C2; (c) The thermal gradient between innermost and outermost of clothing microclimate at back level did not show any difference between C1 and P1, but it was significantly higher in C2 than in P2. These results are discussed in terms of thermal physiology and clothing sciences.     

Calculation of Clothing Insulation by Serial and Parallel Methods: Effects on Clothing Choice by IREQ and Thermal Responses in the Cold

Cold protective clothing was studied in 2 European Union projects. The objectives were (a) to examine different insulation calculation methods as measured on a manikin (serial or parallel), for the prediction of cold stress (IREQ); (b) to consider the effects of cold protective clothing on metabolic rate; (c) to evaluate the movement and wind correction of clothing insulation values.

Tests were carried out on 8 subjects. The results showed the possibility of incorporating the effect of increases in metabolic rate values due to thick cold protective clothing into the IREQ model. Using the higher thermal insulation value from the serial method in the IREQ prediction, would lead to unacceptable cooling of the users. Thus, only the parallel insulation calculation method in EN 342:2004 should be used. The wind and motion correction equation (No. 2) gave realistic values for total resultant insulation; dynamic testing according to EN 342:2004 may be omitted.     

Cultured amniotic fluid cells for prenatal diagnosis of lysosomal storage disorders: A methodological study

The influence of culture conditions on the ultrastructure and enzyme activities of amniotic fluid cells are reported. Morphological changes were determined as a function of the number of lysosomal-like inclusion bodies per cell, and these results correlated to the activity of Thiexosaminidase, a-mannosidase, β-glucuronidase, arylsulphatase C and 5′ nucleotidase. The parameters examined were pH of the culture media, type of media, increasing cell passage and day of harvest. Our results indicate that enzyme activities are less sensitive to changes in culture conditions as compared to ultrastructural changes. We therefore recommend that in order to obtain reliable ultrastructural results for the diagnosis of storage disorders, cultures should be grown in MEM as the culture medium, the pH of the medium carefully monitored to remain below pH 7·4, examining the cultures no later than the eighth cell passage and no later than the 10th day after subculture.     

Precipitator energization utilizing an energy conserving pulse generator

The performance of a conventional two-electrode type precipitator collecting high resistivity dust can be improved by pulse energization. Pulses of a suitable duration and repetition rate superimposed on the DC voltage permit higher peak-voltage without sparkover, improve particle charging and current distribution, and allow independent regulation of the precipitator voltage and current. A considerable quantity of energy, however, is required for each pulse to charge the precipitator to the pulse voltage level. For high pulse voltages only a minor part of this energy is necessary for the discharge current in the precipitator. For reasons of economy, the recovery of the energy stored in the precipitator capacitance during each pulse is therefore extremely important for pulse energization of large precipitators. An energy conserving pulse generator with pulse transformer, a pulse initiating switch element, and a feed-back diode for the energy recovery is described. The design and the instrumentation of a pilot precipitator specially developed for the comparison of different kinds of precipitator energization are outlined. The ability of the applied pulse energization system for controlling the corona discharge current independently of the precipitator voltage is demonstrated. Further, results from field tests showing the performance of the system under operating conditions are presented.     

Influence of nutrient levels on uptake and effects of mercury, cadmium, and lead in water spinach

In Southeast Asia the aquatic macrophyte water spinach (Ipomoea aquatica Forsk.) is a popular vegetable that is cultivated in freshwater courses. These often serve as recipients for domestic and other sorts of wastewater that often contain a variety of pollutants, such as heavy metals. In addition, fertilizers are frequently used where water spinach is cultivated commercially for the food market. To estimate the importance of ambient nutrient concentrations for accumulation of mercury (Hg), cadmium (Cd), and lead (Pb) in water spinach, plants were exposed to nutrient solutions of different strength and with varying metal concentrations. Metal-induced toxic effects, which might possibly affect the yield of the plants, were also studied. The lower the nutrient strength in the medium was, the higher the metal concentrations that accumulated in the different plant parts and the lower the metal concentration in the medium at which metal-induced toxic effects occurred. Accordingly, internal metal concentrations in the plants were correlated to toxic effects. Plants exposed to metals retained a major proportion of the metals in the roots, which had a higher tolerance than shoots for high internal metal concentrations.