Impact of common cytostatic drugs on pollen fertility in higher plants

Cytostatic drugs are among the most toxic chemicals which are produced. Many of them cause damage of the genetic material which may affect the fertility of higher organisms. To study the impact of the widely used anticancer drugs [cisplatin (CisPt), etoposide (Et), and 5-fluorouracil (5-FU)] on the reproduction of higher plants, pollen abortion experiments were conducted with species which belong to major plant families, namely with Tradescantia paludosa (Commelinaceae), Arabidopsis thaliana (Brassicaceae), Chelidonium majus (Papaveraceae), and Alisma plantago-aquatica (Alismataceae). All compounds increased the frequencies of abortive grains. The lowest effective doses were in general in a narrow range (i.e., 1 and 10 mg/kg of dry soil). The effects of the individual drugs were similar in T. paludosa, A. plantago-aquatica, and Ch. majus, while A. thaliana was consistently less sensitive. The highest abortion rate was obtained in most experiments with CisPt, followed by 5-FU and Et. Comparisons of the doses which caused effects in the present experiments in the different species with the predicted environment concentrations and with the levels of the cytostatics which were detected in hospital wastewaters show that the realistic environmental concentrations of the drugs are 4–6 orders of magnitude lower. Therefore, it is unlikely that these drugs affect the fertility of higher plants in aquatic and terrestrial ecosystems.     

Use of passive sampling devices for monitoring and compliance checking of POP concentrations in water

Background

The state of the art of passive water sampling of (nonpolar) organic contaminants is presented. Its suitability for regulatory monitoring is discussed, with an emphasis on the information yielded by passive sampling devices (PSDs), their relevance and associated uncertainties. Almost all persistent organic pollutants (POPs) targeted by the Stockholm Convention are nonpolar or weakly polar, hydrophobic substances, making them ideal targets for sampling in water using PSDs. Widely used nonpolar PSDs include semi-permeable membrane devices, low-density polyethylene and silicone rubber.

Results and discussion

The inter-laboratory variation of equilibrium partition constants between PSD and water is mostly 0.2?C0.5 log units, depending on the exact matrix used. The sampling rate of PSDs is best determined by using performance reference compounds during field deployment. The major advantage of PSDs over alternative matrices applicable in trend monitoring (e.g. sediments or biota) is that the various sources of variance including analytical variance and natural environmental variance can be much better controlled, which in turn results in a reduction of the number of analysed samples required to obtain results with comparable statistical power.

Conclusion

Compliance checking with regulatory limits and analysis of temporal and spatial contaminant trends are two possible fields of application. In contrast to the established use of nonpolar PSDs, polar samplers are insufficiently understood, but research is in progress to develop PSDs for the quantitative assessment of polar waterborne contaminants. In summary, PSD-based monitoring is a mature technique for the measurement of aqueous concentrations of apolar POPs, with a well-defined accuracy and precision.     

Metabolism of gamma‐hexachlorocyclohexah (HCH) in vivo. Metabolism of orally administered gamma‐2,3,4,5,6‐pentachlorocyclohexen (PCCH)

Abstract

Mexacarbate (4‐dimethylamino‐3,5‐xylyl N‐methylcarbamate) insecticide has potential for use in spruce budworm (Choristoneura fumiferana Clem.) control operations in Canada. Its persistence and fate in balsam fir (Abies balsamea (L.) Mill.), litter and soil samples were studied by spraying aerially oil‐based and water‐based formulations, each at 70 g A.I./ha over a coniferous forest near Bathurst, New Brunswick. The oil‐based formulation gave the maximum concentration of the chemical in the substrates studied. In fir needles, the highest concentrations observed were 0.51 ppm and 0.19 ppm (fresh weight) for the oil‐based and emulsion formulations respectively, 1 h after application. The residue levels decreased very rapidly with a half‐life of approximately 5 h. Three and eight days after the spray application of the emulsion and oil formulations respectively, the concentrations of mexacarbate in foliage decreased to trace levels ( 0.008 ppm). Only very low levels of residue were detected in litter and soil. The peak concentrations for the two formulations ranged from 0.02 to 0.11 ppm (fresh weight) in litter and from 0.01 to 0.06 ppm (fresh weight) in soil. The residue levels in both litter and soil decreased to below the detection limit (0.005 ppm) within 1 d. The ground deposit levels found on glass plates and the droplet density and size spectra measured on Kromekote® cards reflected the variations in concentrations found in fir needles, litter and soil samples and correlated with the observed maximum concentrations in them. Under the stipulated use pattern, mexacarbate concentrations found in the terrestrial components studied were low and are not likely to have any undue adverse effects on non‐target species.     

Operating problems in anaerobic digestion plants resulting from nitrogen in MSW

Organic waste and municipal solid waste usually contain considerable amounts of different nitrogen compounds, which may inhibit anaerobic degradation processes and cause problems in the downstream and peripheral devices. This refers particularly to the different process stages of anaerobic digestion, to wastewater treatment, and to exhaust air treatment. Neither the knowledge about nitrogen problems nor the technologies for elimination of nitrogen compounds from the wastewater or the exhaust air of anaerobic digestion can be regarded as state-of-the-art. Most of the technologies in question have already been applied in other areas, but are barely tested for application in anaerobic digestion plants. The few performance data and experiences at hand were mainly derived from pilot and demonstration facilities. In this paper, the problem of nitrogen will be discussed in detail according to the separate problem fields based on the authors' experience, as well as on the basis of a review of the relevant literature. Furthermore, possible solutions will be proposed and the need for further research and development will be formulated.     

In situ transformations of fine lead oxide particles in different soils

We present a field application of a new in situ technique to analyze phase transformations of fine lead oxide particles (50-100mum) in different soils directly in the field over 18 months. After the first month of exposure to a calcareous sand we found newly precipitated secondary mineral phases on the lead oxide. The samples exposed to two loamy soils (Dystric Cambisol and Luvisol) showed only very few traces of new phases. We identified the new phases as mainly lead-hydroxy carbonates (hydrocerussite). Whereas the results confirm the transformation of lead phases to lead carbonates in calcareous soil, they also show that an easily soluble phase such as PbO may persist in soils virtually unweathered for more than one year. The formation of a weathering crust is therefore not necessarily needed for preservation of easily soluble phases. The use of experimental in situ methods is thus giving new information on contaminant mineral behavior under field conditions.     

Global fate of POPs: current and future research directions

For legacy and emerging persistent organic pollutants (POPs), surprisingly little is still known in quantitative terms about their global sources and emissions. Atmospheric transport has been identified as the key global dispersal mechanism for most legacy POPs. In contrast, transport by ocean currents may prove to be the main transport route for many polar, emerging POPs. This is linked to the POPs' intrinsic physico-chemical properties, as exemplified by the different fate of hexachlorocyclohexanes in the Arctic. Similarly, our current understanding of POPs' global transport and fate remains sketchy. The importance of organic carbon and global temperature differences have been accepted as key drivers of POPs' global distribution. However, future research will need to understand the various biogeochemical and geophysical cycles under anthropogenic pressures to be able to understand and predict the global fate of POPs accurately.     

Seasonal differences and within-canopy variations of antioxidants in mature spruce (Picea abies) trees under elevated ozone in a free-air exposure system

The effect of free-air ozone fumigation and crown position on antioxidants were determined in old-growth spruce (Picea abies) trees in the seasonal course of two consecutive years (2003 and 2004). Levels of total ascorbate and its redox state in the apoplastic washing fluid (AWF) were increased under double ambient ozone concentrations (2xO3), whilst ascorbate concentrations in needle extracts were unchanged. Concentrations of apoplastic and symplastic ascorbate were significantly higher in 2003 compared to 2004 indicating a combined effect of the drought conditions in 2003 with enhanced ozone exposure. Elevated ozone had only weak effects on total glutathione levels in needle extracts, phloem exudates and xylem saps. Total and oxidised glutathione concentrations were higher in 2004 compared to 2003 and seemed to be more affected by enhanced ozone influx in the more humid year 2004 compared to the combined effect of elevated ozone and drought in 2003 as observed for ascorbate.     

Survey of organochlorine pesticides in horticultural soils and there grown Cucurbitaceae

Organochlorine pesticides (OCP) are still found in food and feed crops although they were applied about 40 years ago. There is a considerable knowledge gap concerning the extent of soil and crop contamination by OCP. We performed two surveys in 2002 and 2005 to assess the loads of OCP in 41 Swiss horticultural fields under organic and conventional production and corresponding Cucurbitaceae fruits (cucumbers, zucchini, and pumpkin), whereas these fields stay for intensive agricultural production in Europe. In addition, soil organic carbon, texture, and pH were measured also. OCP were detected in 27 out of 41 fields (65.9%). The farming practice had no influence on the contamination or level of OCP in soil. The sum of OCP-loads per field ranged from <0.01 to 1.3mgkg(-1) dry soil and pentachloroaniline (PCA, 2.1mgkg(-1)), p,p'-DDT (0.5mgkg(-1)), and p,p'-DDE and dieldrin (0.4mgkg(-1)) were the most detected pesticides over all investigated soils. PCA (up to 0.02mgkg(-1)), dieldrin (up to 0.04mgkg(-1)), alpha-chlordane and cis-heptachloroepoxide (<0.01mgkg(-1)) were detected in five cucumber samples out of 41 Cucurbitaceae samples. Statistical analysis revealed no significant influence of the measured soil properties on the OCP-load of soils and cucumbers, although there is evidence that the bioavailability of OCP in soils to Cucurbitaceae plants was influenced by the sorption of the compounds to soil organic matter and by the polarity of the pesticide molecules. It is suggested, that OCP contamination is widespread in all European regions with intensive plant production and associated pesticide use, and deserves more attention with respect to save food production.     

Trace element accumulation in woody plants of the Guadiamar Valley, SW Spain: a large-scale phytomanagement case study

Phytomanagement employs vegetation and soil amendments to reduce the environmental risk posed by contaminated sites. We investigated the distribution of trace elements in soils and woody plants from a large phytomanaged site, the Guadiamar Valley (SW Spain), 7 years after a mine spill, which contaminated the area in 1998. At spill-affected sites, topsoils (0-25 cm) had elevated concentrations of As (129 mg kg(-1)), Bi (1.64 mg kg(-1)), Cd (1.44 mg kg(-1)), Cu (115 mg kg(-1)), Pb (210 mg kg(-1)), Sb (13.8 mg kg(-1)), Tl (1.17 mg kg(-1)) and Zn (457 mg kg(-1)). Trace element concentrations in the studied species were, on average, within the normal ranges for higher plants. An exception was white poplar (Populus alba), which accumulated Cd and Zn in leaves up to 3 and 410 mg kg(-1) respectively. We discuss the results with regard to the phytomanagement of trace element contaminated sites.