Discharge of pharmaceutical products (PPs) through a conventional biological sewage treatment plant: MECs vs PECs?

Pharmaceuticals for human use are consumed in significant quantities and their occurrence in aquatic systems has been reported by a number of authors. In the context of environmental risk assessment, there is an increasing interest in evaluating the discharge of pharmaceutical products to surface waters through sewage treatment plants (STP). This case study was carried out on a conventional biological treatment plant (Alès, France) and focused on a set of eleven drugs representing the main therapeutic classes. Measured environmental concentrations (MECs) range from the low ng L^? 1 to 1.5 µg L^? 1 in effluent and up to few hundred ng L^? 1 in receiving surface waters. There is a good agreement between MEC and predicted environmental concentration (PEC) values for seven of the eleven investigated drugs in STP effluent. There is not such a good match between PEC and MEC values in surface waters, and this highlights the limits of this approach, at the local scale.     

Experimental investigation and modelling of tritium washout by precipitation in the area of the nuclear power plant of Paks, Hungary

Tritium occurs in nature in trace amounts, but its concentration is changing due to natural and artificial sources. Studies focusing on natural tritium have to take into account the effect of artificial sources. Also, the impact of tritium is an important issue in environmental protection, e.g. in connection with the emissions from nuclear power plants. The present work focuses on the rain washout of tritium emitted from the Paks nuclear power plant in Hungary. Rainwater collectors were placed around the plant and after a period of precipitation, rainwater was collected and analysed for tritium content. Samples were analysed using low-level liquid scintillation counting, with some also subject to the more accurate ³He ingrowth method. The results clearly show the trace of the tritium plume emitted from the plant; however, values are only about one order of magnitude higher than environmental background levels. A washout model was devised to estimate the distribution of tritium around the plant. The model gives slightly higher concentrations than those measured in the field, but in general the agreement is satisfactory. The modelled values demonstrate that the effect of the plant on rainwater tritium levels is negligible over a distance of some kilometres.     

Some observations on the geochemistry and isotopic composition of uranium in relation to the reprocessing of nuclear fuels

In order to determine whether or not uranium depleted in ²³⁵U and derived from the British Nuclear Fuels Ltd (BNFL) nuclear fuel reprocessingg plant at Sellafield, Cumbria, UK can be detected in environmental samples, we have investigated the isotopic composition of uranium in ammonium carbonate leachates from marine and terrestial samples from near Sellafield. Some show a depletion in ²³⁵U and the presence of ²³⁶U which unequivocally identifies the presence of uranium derived from BNFL. The ²³⁴U/²³⁸U activity ratio and total uranium content of samples are not significantly different from those of natural uranium abundances. The highest concentrations of uranium are found in anaerobic organic-rich silts and the lowest in sandy silts and coarse-grained sands.     

Industrial complexes and their relevance for pulp and paper mills

Advantages and disadvantages of the concept of an industrial complex are discussed. From an environmental standpoint an ideal industrial complex is one containing a group of compatible industrial plants utilizing completely each other's wastes and products as raw materials and manufacturing products with no adverse environmental impact and at a minimum of cost. A typical complex centering about a pulp and papermill is pictured in this paper. This complex produces six products for external sale and four products for internal use. In addition, all major wastes of suspended solids, cooking liquor, fillers, heat and bark are reused within the complex in the manufacture of these products. A literature review evolved typical concentrations of recoverable suspended solids in various process effluents. A mass balance was prepared assuming that the total production of fine paper is 907.2 kg × 10³ (1000 tons) per day. Little or no air or water pollution results from this complex. In addition, it is anticipated that no expensive waste-water treatment plant would be required for this complex. Ten additional practices are described which, when used, will reduce operating costs even further. A continuing study with more precise data on the production requirements for the service plants in the complex will yield a more balanced and realistic system.     

Bacillus thuringiensis, nucleopolyhedrosis virus,and pheromones: Environmental considerations and uncertainties in large-scale insect control

The mode of action, extent of use, and the current knowledge on environmental fate and toxicity of three biological insecticides [Bacillus thuringiensis (B.t.), nucleopolyhedrosis virus (NPV), and pheromones] are reviewed. Data gaps, environmental uncertainties in any large-scale use, and proposed registration guidelines which may lead to more extensive use are discussed. B.t. disappears rapidly from plant foliage on exposure to sunlight and/or moisture, although it may persist in dry soil for several months or years. Foliar-applied NPVs are also inactivated by sunlight; the halflife on cotton leaves is 20–25 h. In the soil, NPVs may remain active for several years. Pheromones volatilize readily and do not persist in plant or in soil. Limited available data indicate that B.t. and pheromones do not persist in aquatic environments; quantitative data are unavailable for NPVs. Based on bioassay data, the three insecticides exhibit undetectable to low toxicity to nontarget organisms; there are also no reports of human disease or injury due to exposure to these pesticides and no bioaccumulation is expected with normal application. Except for B.t. which has been used in a limited large-scale applications, pest control uses of NPVs and pheromones are still in experimental stages. Areas of uncertainties requiring research and development include potential adverse health and ecological impacts in any large-scale and widespread use and efficacy and cost relative to synthetic chemical pesticides.     

Pre-concentration of naturally occurring radionuclides and the determination of (212)Pb from fresh waters

A novel technique has been developed for determining the ²¹²Pb activity of fresh waters. This is of interest to environmental monitoring programmes that utilise gross α-activity methods to screen for anthropogenic radionuclides. The contribution from ²¹²Pb varies, and is difficult to experimentally measure due to its relatively short half-life (t_½ = 10.6 h) and low environmental activity (<0.1 Bq l⁻¹). The use of a three-stage technique that encompasses a unique form of pre-concentration, separation and analysis by liquid scintillation counting allows a lower detection limit of 0.006 Bq l⁻¹ with a chemical yield of 92.5 ± 5.6%. The measurement can be obtained within 7 h of sample collection, and is calculated using the radioactive decay of ²¹²Bi. Other naturally occurring radionuclides may also be extracted using the pre-concentration stage of the technique, with efficiencies above 90% at a range of pH values.     

Dynamic model for radionuclide uptake in lichen

Samples of atmospheric particulate material and terrestrial plants, including lichens, were collected in New Brunswick, Canada between 1980 and 1983 and analyzed for a wide range of artificial and naturally-occuring radionuclides, including fission products (¹⁴¹Ce, ¹⁴⁴Ce, ¹⁰³Ru, ¹⁰⁶Ru, ⁹⁵Zr and ¹³⁷Cs) derived from the 16 October 1980 Chinese nuclear test. Activity ratios of some of the short-lived fission products in air particulates and lichens are in reasonable agreement with those predicted from fission product yields for nuclear weapons tests, indicating that only minor fractionation occurred for these radionuclides during their transport through air particulate and lichen environmental phases. The ⁷Be inventories measured in a suite of lichen (Cladonia rangiferina) samples were used to calibrate each lichen plant for its collection efficiency for atmospheric particulates and fallout radioactivity.A lichen model has been developed to predict lichen inventories of radioactivity for different lichen growth functions and bio-elimination rates. Assuming that lichen growth results in a linear increase in surface area with time, the experimental results yield biological residence times of 1–2 years for ²¹⁰Pb and Pu and 5–8 years for ¹³⁷Cs. The more efficient retention of ¹³⁷Cs is probably due to its physiological uptake in lichen plants as a proxy for potassium, as evidenced by an observed, inverse relationship between ¹³⁷Cs and ⁴⁰K activities in lichen.     

Eco-balance analysis of land use combinations to minimize environmental impacts and maximize farm income in northern Japan

Relationships among global warming potential (GWP), farmland surplus nitrogen (FSN) and income for major land uses in the Ikushunbetsu watershed were compared using the eco-balance method. An empirical model was created for carbon dioxide, methane and nitrous oxide for both uplands and paddy rice using monitoring data from 22 fields. The greenhouse gas emissions were converted into GWP, whereas yield and FSN were obtained from interviews with farmers and a literature survey. Land use distribution was obtained by ground surveys in 2002, 2005 and 2007. The analysis showed that paddy rice and soybeans were characterized by a high GWP, low FSN and high income, whereas onions and vegetables had a high FSN but low GWP and moderate income. Wheat showed a negative GWP in some years, and abandoned areas always exhibited negative values. The total GWPs for the region were 14,184, 11,085 and 8,337 Mg CO₂ year⁻¹ for 2002, 2005 and 2007, respectively. The contribution of paddy rice to GWP was highest, ranging from 40 to 75%. To find optimal land use combinations that provide higher incomes and lower GWPs and FSNs than at present, all possible land use combinations were analyzed by changing the land use proportion from 0 to 100% at an interval of 10%. The number of land use combinations meeting the requirements in the three investigated years was 205. Abandoned area, which had the smallest environmental load, was included in every land use combination, indicating that land uses with low environmental impacts should be maintained at a certain proportion to mitigate the environmental load accompanying land uses with high production.     

Medical radioisotopes in the environment – following the pathway from patient to river sediment

Motivated by the detection of ¹³¹I in river sediment in routine long-term surveillance samples, a systematic short-term study of the wastewater treatment chain was planned and conducted. Inflow, effluent and primary sludge were collected on a daily basis during two weeks at a regional wastewater treatment plant. Samples were investigated by gamma spectroscopy. Four medically used isotopes could be identified (¹³¹I and ^99mTc regularly, ¹⁵³Sm and ¹²³I sporadically). The concentration levels coincide well with literature data for ¹³¹I, and with our own long-term data for ¹³¹I and ^99mTc for the same plant. Cosmogenic ⁷Be activity in primary sludge correlated well with rainfall intensity. Surface sediment was sampled at low tide at both shores of the river, up- and downstream of the plant. ¹³¹I was identified in all samples, with a sharp maximum (about 100 Bq kg⁻¹ d.m.) at the discharge point of the plant and lower levels elsewhere, decreasing monotonically in downstream direction. ⁷Be and ¹³⁷Cs showed the same behaviour, but no peak at the discharge point. Predictions from simple equilibrium models for the transport and sedimentation of ¹³¹I show good agreement with the experimental data and suggest that the wastewater treatment plant is the main source for this isotope.     

Plant uptake of neptunium-237 and technetium-99 under field conditions

Plant uptake of ⁹⁹Tc freshly added to soils was compared with uptake of ⁹⁹Tc ‘aged’ in soil for more than a decade. A combination of alkaline soil and freshly added ⁹⁹Tc resulted in elevated uptake into radish foliage (plant/soil concentration ratios ranged from 37 to 46). Neptunium-237 was freshly added to all soils. Neptunium uptake via plant roots into foliage was strongly affected by soil pH. Neptunium uptake was greatest from acidic soils. The observed plant/soil concentration ratios for ²³⁷Np under field conditions were approximately 10⁻² from acidic soils (pH 5·6–5·7) and were comparable to field concentration ratios for ²³⁹Pu, that is 10⁻³, from a basic soil (pH 7·5).     

Changes in Vegetation Cover and Socio-Economic Transitions in a Coastal Lagoon (Kalametiya, Sri Lanka), As Observed by Teledetection and Ground Truthing, Can be Attributed to an Upstream Irrigation Scheme

According to some non-scholarly reports, Kalametiya lagoon (dry zone of southern Sri Lanka, formerly 8.9 km², now 7.5 km²) had been a moderately or high salinity water body and a very important centre of prawn fishery until the late 1960s. Most of the lagoon area had remained open water until then. An upstream irrigation project, the Udawalawa irrigation scheme, came into operation in 1967, increasing the freshwater inflow to the lagoon. The flora, fauna and water quality of the lagoon was reported to have changed since then.The lagoon now is a shallow coastal water body with low salinity water. More than 75% of the lagoon is covered by freshwater species or mangrove species characteristic for water with a low salinity: Eichhornia crassipes, Typha latifolia resp. Sonneratia caseolaris. There is actually no commercially important fishery in the lagoon.The present study was carried out to assess scientifically the said changes in the vegetation within a GIS, using aerial photographs taken in 1956 and 1994 and IRS IC, PAN+LISS III satellite images of 1997 in combination with ground surveys and information from a questionnaire-based survey.It appeared from this work that the aerial cover by Sonneratia caseolaris has increased by more than 30 times over the period from 1956 to the recent dates. Also, the lagoon area with open water has been drastically reduced during the same period as a result of spreading of freshwater and low salinity plant species. The results strongly suggest that the locally reported changes (fisheries decline, water salinity decrease) can be corroborated by the observed profound changes in plant cover and that upstream water works may have had strong impacts on this ecosystem, thus causing these changes.This study couples data obtained from retrospective aerial photograph series, from spaceborne imaging, from actual ground surveys and from questionnaires amongst elderly people to reconstruct decadal environmental change, thus attempting to fill the gap of lacking historical environmental data.     

Cs uptake by four plant species and Cs-K relations in the soil-plant system as affected by Ca(OH)2 application to an acid soil

Three rates of Ca(OH)₂ were applied to an acid soil and the ¹³⁴Cs uptake by radish, cucumber, soybean and sunflower plants was studied. The ¹³⁴Cs concentration in all plant species was reduced from 1.6-fold in the sunflower seeds to 6-fold in the soybean vegetative parts at the higher Ca(OH)₂ rate. Potassium (K) concentration in plants was also reduced, but less effectively. The significantly decreased ¹³⁴Cs-K soil to plant distribution factors (D.F.) clearly suggest a stronger effect of soil liming on ¹³⁴Cs than on K plant uptake. This observation was discussed in terms of ionic interactions in the soil matrix and within the plants. The results also indicated that the increased Ca²⁺ concentration in the exchange phase and in the soil solution along with the improved root activity, due to the soil liming, enhanced the immobilization of ¹³⁴Cs in the soil matrix and consequently lowered the ¹³⁴Cs availability for plant uptake.     

The application of fucus vesiculosus as a bioindicator of 60Co concentrations in the Danish Straits

The occurrence of ⁶⁰Co in the Danish Straits is investigated by applying the seaweed Fucus vesiculosus as a bioindicator. In order to describe different dispersion situations, three areas have been studied separately: the North Sea, where it is possible to measure ⁶⁰Co from sources in France and/or the UK; the Kattegat, where the sources are the Swedish nuclear power plants Ringhals and Barsebäck; and the Sound, where the initial mixing of the release from Barsebäck takes place. A power function can be estimated for the Kattegat and the Sound describing the content of ⁶⁰Co in Fucus as a function of distance from Barsebäck. Problems of uncertainty related to differences in environmental parameters are discussed and new investigations to improve the use of Fucus as a bioindicator are suggested.     

Study of the comparative dynamics of the incorporation of tissue free-water tritium (TFWT) in bulrushes (Typha latifolia) and carp (Cyprinus carpio) in the Almaraz nuclear power plant cooling reservoir

The Almaraz nuclear power plant (Spain) uses the water of Arrocampo reservoir for cooling, and consequently raises the radioactive levels of the aquatic ecosystem of this reservoir. From July 2002 to June 2005, monthly samples of surface water, bulrushes (Typha latifolia) and carp (Cyprinus carpio) were collected from this reservoir. They were analyzed to determine the temporal evolution of the levels of ³H in surface water and of its transfer from the surface water to free-water in the tissues (TFWT) of the aforementioned two organisms. The tritium levels in the surface water oscillate with a biannual period, with their values in the study period ranging between 53 and 433 Bq/L. The incorporation of tritium to bulrushes and carp was fairly similar, the respective mean concentration factors being 0.74 and 0.8 (unitless, as Bq/L tissue water per Bq/L reservoir water). The temporal evolution of the levels fairly closely followed that observed for the surface water tritium, although detailed analysis showed the dominant periodicity for the bulrushes to be annual. This difference reflects the influence on the incorporation of tritium to bulrushes of diverse environmental and metabolic factors, especially evapotranspiration and the seasonal growth of this plant.     

A study of radium uptake by the water-lily Nymphaea violacea (Lehm) from contaminated sediment

The rate and extent of radium-226 accumulation from sediment by the water-lily Nymphaea violacea (Lehm) were assessed. The plants were collected from Magela Creek, Northern Territory, Australia and grown in ²²⁶RaCl₂-labelled laboratory sediment over a period of 570 days. The nominal sediment activity of 5 Bq g⁻¹ dry weight was 100 times that of the naturally occurring concentration.In the roots and rhizomes, ²²⁶Ra accumulated on plant surfaces. This result was confirmed by autoradiographic studies which showed the presence of an iron-containing plaque on the surface of these tissues with which the radium was closely associated. Little radium reached the pith of the rhizomes and acropetal translocation was not detected. The average concentration ratio for growing rhizomes was 0·22. Assuming first order accumulation kinetics and likely incremental environmental concentrations, this Aboriginal dietary tissue could become dose-limiting within 50 years.The foliar accumulation of radium originating from the sediment was predominately due to contamination via the sediment-water-plant pathway. Differences in foliar radium concentrations in plants of different ages were due to differential biomass turnover rates. Plants with faster biomass turnover had higher average radium concentrations.     

Concentrations of (137)Cs in summer pasture plants that reindeer feed on in the reindeer management area of Finland

Samples of summer pasture plants that reindeer feed on were collected in order to study ¹³⁷Cs concentrations in different plant species and in species nested in certain site types, and to study the regional distribution of ¹³⁷Cs in the Finnish reindeer management area. Plant species were categorized by the site types of mineral soil forest (xeric heath forest and mesic heath forest) and peatland. A third category called ’other plant species’ included plants with various site types, poorly determined species and species with poor statistics. The ¹³⁷Cs concentrations in different site types differed significantly. The mean ¹³⁷Cs concentrations of the whole reindeer management area in the xeric heath forest plant species was 44 ± 27 Bq/kg dw, in the mesic heath forest plant species 75 ± 59 Bq/kg dw and in the peatland plant species 219 ± 150 Bq/kg dw. The peatland species uptake ¹³⁷Cs more efficiently than plant species of mineral soil forests. A particularly efficient collector of ¹³⁷Cs was Trichophorum sp. It is suggested that Trichophorum sp. could be used as an indicator species for reindeer summer fodder plants. The highest concentrations of ¹³⁷Cs were found in Southern Lapland and the lowest in Northern Lapland. Today, the concentrations of ¹³⁷Cs in summer pasture plants that reindeer feed on in Finland are at such a level that there is no need to avoid any plant species. In the case of future nuclear fallout, reindeer grazing in peatlands would increase concentrations of ¹³⁷Cs in reindeer meat.     

Environmentally compatible energy resource production—consumption pattern (case study: Iran)

Like all rapidly developing countries, the government of Iran (GOI) has to integrate environment priorities into its energy sector. In order to integrate environmental concerns into energy sector, an Energy-Environment Review (EER) may be considered as the mainstreaming tool capable of examining the interface between energy and the environment. The results of the EER should be interpreted, in the light of the objective of the 4th Five Year Development Plan in Iran, to achieve fast and sustainable growth and accelerate the transition to a market economy. In particular, the suggested actions will promote economic efficiency use of energy resources through a proper allocation of scarce resources, including environmental resources, so as to achieve economic efficiency and environmental and social protection. This paper comprises: (A) an analysis of the current situation with regards to energy production and consumption; (B) an evaluation of the growth prospects with regard to energy production and consumption; (C) the identification of environmental issues induced by the generation and use of energy and estimation of the associated costs of damages; (D) the evaluation of the extent of contribution to the climate-change phenomenon through emission of greenhouse gases; (E) the evaluation of the proposed mitigation measures for the previously identified environmental problems; and (F) conclusions and recommendations. The EER-Iran assessed the total health damage from air pollution in 2001 at about 56  ×  10¹² Rials (US $ seven billion); equivalent to 8.4% of nominal GDP. In the absence of the price reform and control policies, the EER-Iran estimated that the damage in Iran in the money of 2001, will grow to 155  ×  10¹² Rials (US $ nine billion) by 2019. This is equivalent to 10.9% of nominal GDP, i.e., a large percentage of a larger GDP. Of this total, 107  ×  10¹² Rials (US $ 8.4 billion) come from transport sector. The damage cost to the global environment from the flaring of natural gas, assessed on the basis of a carbon price of US $ 10/ton CO₂, is found to be approximately US $ 600 million per year. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

Study of soil-plant transfer of 226Ra under greenhouse conditions

A soil-plant transfer study was performed using soil from a former uranium ore processing factory in South Bohemia. We present the results from greenhouse experiments which include estimates of the time required for phytoremediation. The accumulation of ²²⁶Ra by different plant species from a mixture of garden soil and contaminated substrate was extremely variable, ranging from 0.03 to 2.20 Bq ²²⁶Ra/g DW. We found differences in accumulation of ²²⁶Ra between plants from the same genus and between cultivars of the same plant species. The results of ²²⁶Ra accumulation showed a linear relation between concentration of ²²⁶Ra in plants and concentration of ²²⁶Ra in soil mixtures. On the basis of these results we estimated the time required for phytoremediation, but this appears to be too long for practical purposes.     

Variation among chlorine concentration ratios for native and agronomic plants

Variation among plant/soil concentration ratios (CRs) for important radionuclides requires attention because it is a major source of uncertainty in nuclear environmental safety assessments. For agronomic plants, variation among plant species is easy to deal with because there are relatively few species. In natural settings, there are vastly more species and the question becomes how to develop representative statistical distributions of CRs. Chlorine (Cl) is a good element with which to address this problem, because ³⁶Cl is a key radionuclide in nuclear waste disposal and yet stable Cl is easily measured in the environment. We measured CRs (dry weight basis) for Cl among edible parts of agronomic plants at one site, and found a geometric mean (GM) of 10, a geometric standard deviation (GSD) of 1.9 and a range of 5–66. When the GM was weighted by the relative contributions of the various plants to the human diet, it rose to 16. Among native plants at five sites, each site representative of a specific environment, the GMs were 4.0–13 and the GSDs were 2.9–6.2. The CRs for individual species ranged from 0.8 to 170. However, when weighted by relative contributions of the plants to selected animal diets, the GMs were as high as 50. The conclusions are that: the variation in CR for agronomic plants is a subset of the variation among native or all plants, variation among species (the GSD) can be sixfold, and variation among species is large enough that typical diets of specific animals could expose them to several-fold higher amounts of Cl (or ³⁶Cl) than expected from generic CR values.     

Technologically enhanced 210Pb and 210Po in iron and steel industry

Iron and steel manufacture has been ranked as the largest industrial source of environmental contamination in the USA; the wastes generated in their production processes contain heavy elements that can be a source of contamination, and natural radionuclides that can produce an occupational and/or public radiological impact. In this work the potential occupational effective dose rate (μSv/y) due to inhalation in four integrated steel-making factories from Egypt has been evaluated, by assuming a well defined scenario and with basis in the ²¹⁰Pb and ²¹⁰Po activity concentrations determined in ore and wastes collected in the aforementioned factories. Activity concentrations, in Bq/kg, of ²¹⁰Pb and ²¹⁰Po, and leachable Pb and Fe were measured using gamma-ray spectrometry based on HPGe detector, alpha particle spectrometry based on PIPS detector, and inductively coupled plasma-mass spectrometry (ICP-MS). Levels of ²¹⁰Pb and ²¹⁰Po in the range of <DL-4238 and 1-5660 Bq/kg, respectively, were found. According to the assumed scenarios, the occupational exposures by inhalation are much lower than the recommended annual effective dose limit, although the environmental impact due to waste storage and/or use should be considered based on case by case evaluation.