Genotoxic and mutagenic activity of environmental air samples from different rural, urban and industrial sites in Flanders, Belgium

The present study reports mutagenic and genotoxic activities associated with ambient air collected at 15 sites characteristic for urban, industrial or rural conditions in Flanders. Airborne particulates (PM10) and semi-volatile compounds were collected on quartz filters (QF) and polyurethane foam (PUF) cartridges using a high-volume sampling device. The mutagenic and genotoxic potency of the organic extracts--Soxhlet extraction with acetone--was determined by use of the Salmonella mutagenicity standard plate-incorporation assay and the Vitotox assay, respectively. Concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in the extracts were determined by reversed-phase high-performance liquid chromatography (HPLC). Ambient air samples contained significant PAH levels and mutagenic activities at all 15 sites: direct mutagenicity of up to 47 revertants per cubic meter was found in the QF extracts and more limited activity of up to 11 rev m(-3) in the PUF extracts. Metabolic activation of PUF extracts resulted in an important increase in mutagenic activity, up to 30 rev m(-3), but no such increase was observed for QF extracts. The highest values were observed outside large cities at industrial sites and at a rural site contaminated by pollution from a chemical plant at a distance of 4 km. Also at the background location near the North Sea a significant mutagenic activity was measured in the QF extracts (+S9: 9 rev m(-3); -S9: 7 rev m(-3)). Apparently, there is in Flanders a significant background exposure level to airborne mutagenicity, even in areas with limited or no nearby pollution sources. Based on the concentrations of 10 mutagenic PAHs and supposing additivity of their specific mutagenicities, only a few percent (mean 3%) of the observed indirect mutagenic activity could be explained. This implies that most mutagenic activity originated from other substances that were not identified or measured in our chemical analysis. This underscores the importance of bio-monitoring measurements.     

Genotoxic and mutagenic activity of environmental air samples from different rural, urban and industrial sites in Flanders, Belgium

The present study reports mutagenic and genotoxic activities associated with ambient air collected at 15 sites characteristic for urban, industrial or rural conditions in Flanders. Airborne particulates (PM10) and semi-volatile compounds were collected on quartz filters (QF) and polyurethane foam (PUF) cartridges using a high-volume sampling device. The mutagenic and genotoxic potency of the organic extracts – Soxhlet extraction with acetone – was determined by use of the Salmonella mutagenicity standard plate-incorporation assay and the Vitotox^® assay, respectively. Concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in the extracts were determined by reversed-phase high-performance liquid chromatography (HPLC).Ambient air samples contained significant PAH levels and mutagenic activities at all 15 sites: direct mutagenicity of up to 47 revertants per cubic meter was found in the QF extracts and more limited activity of up to 11 rev m⁻³ in the PUF extracts. Metabolic activation of PUF extracts resulted in an important increase in mutagenic activity, up to 30 rev m⁻³, but no such increase was observed for QF extracts. The highest values were observed outside large cities at industrial sites and at a rural site contaminated by pollution from a chemical plant at a distance of 4 km. Also at the background location near the North Sea a significant mutagenic activity was measured in the QF extracts (+S9: 9 rev m⁻³; −S9: 7 rev m⁻³). Apparently, there is in Flanders a significant background exposure level to airborne mutagenicity, even in areas with limited or no nearby pollution sources. Based on the concentrations of 10 mutagenic PAHs and supposing additivity of their specific mutagenicities, only a few percent (mean 3%) of the observed indirect mutagenic activity could be explained. This implies that most mutagenic activity originated from other substances that were not identified or measured in our chemical analysis. This underscores the importance of bio-monitoring measurements.     

Genotoxic, mutagenic and recombinogenic effects of rauwolfia alkaloids

In the last decade, the possible correlation between the use of reserpine and rauwolfia drugs as antihypertensive agents and breast cancer incidence has been investigated. For the purpose of evaluating the mutagenic and genotoxic effects of these drugs, reserpine and ajmalicine were studied using the SOS Chromotest and the induction of gene conversion, crossing-over and reverse mutation in the yeast diploid strain XS2316. The results indicated a lack of genotoxic, mutagenic and recombinogenic effects.     

Diversity of the Phytophthora infestans population in Flanders, Belgium

A total of 94 isolates of Phytophthora infestans were collected from disease outbreaks in commercial potato crops and private gardens in 2002 and 2003. The isolates were recovered successfully from single lesions of diseased potato foliage. Not from all isolates pure cultures were obtained due to contaminations with Fusarium species and bacteria. The structure of the population was analysed phenotypically. Characteristics of the isolates included in vitro growth rate, mating type, in vitro sensitivity to the phenylamide fungicide metalaxyl-M and allozyme genotype at glucose-6-phosphate isomerase (Gpi) and peptidase (Pep) loci. Significant differences in in vitro growth rate were observed among the 52 isolates by comparing the main radial growth of the isolates after 7 days. Forty seven from the isolates tested were the Al mating type. Only one isolate was characterized as A2 mating type. Isolates with sensitive, intermediate and resistant responses to metalaxyl-M were detected in the populations. Forty isolates had a growth of less then 40 % at 5 ppm metalaxyl-M. Three isolates had a growth of less then 40 % at 100 ppm metalaxyl-M. Eight isolates had a growth of more then 40 % at 5 and 100 ppm metalaxyl-M. Cellulose acetate electrophoresis was used to examine Gpi and Pep banding pattern of the population of P. infestans attacking potato in Flanders. All the isolates tested produced the 100/100 Gpi isozyme electromorph. Five different allozyme genotypes of the Pep loci were identified: 92/92, 96/96, 100/100, 92/100, 83/100.     

Do-not-resuscitate policy on acute geriatric wards in Flanders, Belgium

This study describes the historical development and status of a do-not-resuscitate (DNR) policy on acute geriatric wards in Flanders, Belgium. In 2002 (the year Belgium voted a law on euthanasia), a structured mail questionnaire was sent to all head geriatricians of acute geriatric wards in Flanders (N=94). Respondents were asked about the existence, development, and implementation of the DNR policy (guidelines and order forms). The response was 76.6%. Development of DNR policy began in 1985, with a step-up in 1997 and 200l. In 2002, a DNR policy was available in 86.1% of geriatric wards, predominantly with institutional DNR guidelines and individual, patient-specific DNR order forms. The policy was initiated and developed predominantly from an institutional perspective by the hospital. The forms were not standardized and generally lacked room to document patient involvement in the decision making process. Implementation of institutional DNR guidelines and individual DNR order forms on geriatric wards in Flanders lagged behind that of other countries and was still incomplete in 2002. DNR policies varied in content and scope and were predominantly an expression of institutional defensive attitudes rather than a tool to promote patient involvement in DNR and other end-of-life decisions.     

Detection of mutagenic activity in particulate air pollutants.

Ames's strains of Salmonella typhimurium were used to evaluate the mutagenic activity of airbone particulate materials collected at six different points in the industrial area of Ohmuta and the residential area Fukuoka. Tests were done in presence of rat-liver S-9 fraction isolated from rats that had been treated with Aroclor 1254. When the number of revertant colonies per plate was plotted against the amount of methanol extract of particulate air pollutants, using strain TA98, approximately linear relationships were observed for active samples. Generally, mutagenic activity of the samples increased in proportion to the density of air pollutants. In our system, 38--349 microng of methanol extract, from 0.225--4.51 m3 of air from the factory districts in Ohmuta City gave 100 his+ revertants per plate. On the other hand, 54--2300 microng of air pollutants, from 1.29--14.1 m3 of air from the residential districts in Fukuoka City, gave a comparable activity. Every sample from each area had mutagenic activity. Chemicals in air pollutants were fractionated by alumina column chromatography and identified by gas chromatography and mass spectrometry. More than 28 compounds, including 12 unknown substances were identified as polycyclic hydrocarbons. Twelve of these compounds are already known to be carcinogens and to induce reversions to histidine independence in strain TA98 of Salmonella.     

Environmental scenarios for the future nitrogen policy in Flanders,Belgium

The agricultural sector accounts for two thirds of nitrogen losses in Flanders, Belgium. Since 1991 both the government and the farmers have been taking measures to reduce the nitrogen surplus. Initially, the manure policy was aimed at distributing the manure surplus equally across Flanders. At the same time, the growth of livestock was stopped by a strict licensing policy, which required "command and control" measures. In recent years, the policy has switched to the use of individual target commitments by farmers. The Flemish manure policy will be tightened even more as a result of international pressures. An ex ante evaluation of possible policy options was carried out using three different scenarios spread out until 2010 (Business As Usual, Additional Measures, and Sustainable Development). To do this, a sector-economic, regionalized, environmental, comparative static, partial equilibrium, mathematical programming model of the Flemish agriculture was developed. The nitrogen emission into the agricultural soil was calculated by means of a regional soil balance. European targets can only be reached with manure processing, reduced fertilizer usage, and a strong reduction of intensive livestock breeding activities. The atmospheric deposition of nitrogen compounds will strongly decrease in 2010 if additional measures are taken. This will also result in a strong reduction of nitrous oxide emissions.     

Relationships between structure and mutagenic activity of environmental chemicals

This review analyzes relationships between chemical structure and biological activity for several series of compounds. Its focus is on mutagenicity and carcinogenicity and the predictability of these properties on the basis of the chemical structure. Examples are selected from monocyclic aromatic amines, benzidine derivatives, aminoazobenzene derivatives, nitrofurans, aflatoxins, and sterigmatocystins. Results from mutagenicity tests in Salmonella typhimurium are summarized, and their correlation with carciogenicity is discussed. The review is concluded with generalizations on the usefulness of studies on relationships between chemical structure and mutagenic activity.     

Biotic index for sediment quality assessment of watercourses in Flanders, Belgium

Today, assessment of freshwater sediments in Flanders is based on the TRIAD approach in which physical-chemical, biological and ecotoxicological data are combined. No prior experience existing in Flanders with the biological assessment of the sediment quality, several biotic indices were compared on a first set of 80 samples taken in different types of lowland watercourses. This information resulted in a first selection of suitable indices consisting of a newly created Biotic Sediment Index (BSI) and the Percentage Mentum Deformities in Chironomus (Diptera, Chironomidae larvae). The starting point of the BSI was the Belgian Biotic Index (BBI) based on a combination of the taxa diversity and the presence or absence of specific indicator groups. For the refinement of the BSI, a new set of data related to the benthic macroinvertebrate communities sampled by means of a grab in more than 400 sites was collected. Community analysis by means of multivariate techniques, combining biological information with physical-chemical and ecotoxicological data was the basis for this further refinement and the scientific foundation of the original BSI. Major amendments relate to the scores assigned to the indicator groups. This refined BSI is representative for the degree of pollution, unbiased by the type of sediment and the origin of the river basin. Like the BBI, the BSI scores can vary between 10 (excellent sediment quality) and 0 (very bad sediment quality). The index values can be converted into 4 quality classes to be represented by means of a colour code.     

Palaeolimnological aspects of a Late-Glacial shallow lake in Sandy Flanders,Belgium

A summary account is given of the development of a small Late-Glacial lake at Snellegem-St. Andries, Belgium. Sedimentation, hydrology, water quality and biotic succession clearly depended on climatic conditions and catchment processes (soil stability and leaching, vegetation). Special attention is drawn to a period of low water level near the end of the Allerød and the abundance of Fragilaria in certain periods.     

Spatio-temporal dynamics of the parasitic nematode Anguillicola crassus in Flanders, Belgium

Despite Egusa's earlier warning of the damage that the parasitic nematode Anguillicola crassus could inflict on the European eel Anguilla anguilla, its introduction in Europe was a fact in the early 1980s. Based on an elaborate dataset on Anguillicola crassus infection of 11 river catchments, this paper presents the results of a detailed study on the dispersal of the parasite in Flanders, Belgium, and the host-parasite relationship. In addition, data from 1986 and 1997 are used for comparative purposes, providing a perspective on the temporal infection pattern over 15 yr. The presence of A. crassus in Flanders was first discovered in 1985; 2 yr later a survey revealed a prevalence of 34.1% and a mean infection intensity of 5.5, based on adult nematodes only, and 10 yr later the parasite was present at all 11 sites sampled. Prevalence had increased to 62.5 % but the mean infection intensity had decreased to 3.9 adults per infected eel. Finally, in the year 2000, a third study revealed that A. crassus was present in 139 of 140 investigated sites; a further increase in prevalence to 68.7% and a decrease in mean infection intensity to 3.4 adults per infected eel was observed. When all larval stages were taken into account, mean prevalence amounted to 88.1% and mean intensity to 5.5 adults. The high infection level in Flanders is thought to be the result of restocking with glass eel and yellow eel, both of which are susceptible to A. crassus. The general infection parameters were similar in all 11 river catchments. It is possible that in Flanders both prevalence and mean infection intensity are stabilizing due to density-dependent regulation of the parasite infrapopulation. Fibrotic swimbladder walls were observed, mainly in large eels, and 20% of the total number of nematodes consisted of encapsulated larvae in the surveys of 1997 and 2000; 8 cases of swimbladder regeneration were observed.     

Detection of mutagenic activity in urine samples using a new concentration procedure

A study performed with cyclophosphamide (CP) and nor-nitrogen mustard (NNM), one of its main urinary metabolites, has shown that separation on Polygosil C-18 resin is preferable to one on XAD-2 resin as a means of concentrating the mutagenic activity present in urine of rats given cytostatics such as CP. Mutagenic activity was detected, using Salmonella typhimurium tester strain TA1535. While NNM is irreversibly bound to XAD-2 resin, it can be recovered after elution with methanol on Polygosil C-18. The better efficacity of Polygosil C-18 in concentrating CP and its metabolite(s) was confirmed with experiments with urine of rats treated with increasing doses of CP.     

MEMOR: A database of archeological human remains collections from Flanders,Belgium

The aim of this article is to describe a newly created open access database of archeological human remains collections from Flanders, Belgium. The MEMOR database ( www.memor.be ) was created to provide an overview of the current practices of loans, reburial, and the research potential of human skeletons from archeological sites currently stored in Flanders. In addition, the project aimed to provide a legal and ethical framework for the handling of human remains and was created around stakeholder involvement from anthropologists, geneticists, contract archeologists, the local, regional and national government agencies, local and national government, universities, and representatives of the major religions. The project has resulted in the creation of a rich database with many collections available for study. The database was created using the open-source Arches data management platform that is freely available for organizations worldwide to configure in accordance with their individual needs and without restrictions on its use. Each collection is linked to information about the excavation and the site the remains originate from, its size and time period. In addition, a research potential tab reveals whether any analyses were performed, and whether excavation notes are available with the assemblage. The database currently contains 742 collections, ranging in size from 1 to over 1000 individuals. New collections will continue to be added when new assemblages are excavated and studied. The database can also be expanded to include human remains collections from other regions and other material categories, such as archaeozoological collections.     

Genotoxic and mutagenic effects of lipid-coated CdSe/ZnS quantum dots

We proposed to evaluate the genotoxicity and mutagenicity of a new quantum dots (QDs) nanoplatform (QDsN), consisting of CdSe/ZnS core–shell QDs encapsulated by a natural fusogenic lipid (1,2-di-oleoyl-sn-glycero-3-phosphocholine (DOPC)) and functionalized by a nucleolipid N-[5′-(2′,3′-di-oleoyl) uridine]-N′,N′,N′-trimethylammoniumtosylate (DOTAU). This QDs nanoplatform may represent a new therapeutic tool for the diagnosis and treatment of human cancers. The genotoxic, mutagenic and clastogenic effects of QDsN were compared to those of cadmium chloride (CdCl₂). Three assays were used: (1) the Salmonella/microsome assay with four tester strains, (2) the comet assay and (3) the micronucleus test on CHO cells. The contribution of simulated sunlight was studied in the three assays while oxidative events were only explored in the comet assay in aliquots pretreated with the antioxidant l-ergothioneine. We found that QDsN could enter CHO-K1 cells and accumulate in cytoplasmic vesicles. It was not mutagenic in the Salmonella/mutagenicity test whereas CdCl₂ was weakly positive. In the dark, both the QDsN and CdCl₂ similarly induced dose-dependent increases in single-strand breaks and micronuclei. Exposure to simulated sunlight significantly potentiated the genotoxic activities of both QDsN and CdCl₂, but did not significantly increase micronucleus frequencies. l-Ergothioneine significantly reduced but did not completely suppress the DNA-damaging activity of QDsN and CdCl₂. The present results clearly point to the genotoxic properties and the risk of long-term adverse effects of such a nanoplatform if used for human anticancer therapy and diagnosis in the future.     

Genotoxic activity of m-nitrobenzaldehyde

m-Nitrobenzaldehyde (MNB) was evaluated for mutagenic activity using the Ames microbial mutagenicity test and for its ability to induce DNA single-strand breaks in rat hepatocytes as measured by alkaline elution. MNB was tested in S. typhimurium strains TA1535, TA1537, TA1538, TA98, and TA100, both with and without pretreatment with liver microsomes (S9) isolated from rats pretreated with Aroclor 1254. MNB produced 2-fold or greater increases in revertants in TA1538, both with and without S9, and in TA100 with S9 only. A 2-fold increase in revertants was seen in TA98, but only at the highest dose tested which did not produce inhibition of background growth. MNB caused a greater than 3-fold increase in elution slope, with DNA alkaline elution assay, but only at highly cytotoxic doses and, therefore, is not considered genotoxic in this system. It is concluded that MNB possesses weak genotoxic activity.     

Seasonal variations in mutagenic activity of air pollutants at an industrial district of Silesia

Organic material from airborne particulate pollutants collected over a 7-month period at a highly industrialized region in Silesia (Poland) was tested for mutagenicity using the Ames test. Sequential elution solvent chromatography (SESC) was used for the separation of crude benzene extracts. Five out of 8 fractions showed mutagenic activity with differential direct and indirect responses. The mutagenicity of each active fraction was tested during the whole sampling period (from August to February 1984/1985) and seasonal variations were observed. All of the fractions, except fraction 3, showed only quantitative distinctions in mutagenic potential, expressed as a number of revertants per m3 of air. Over a period of 7 months, a steady increase of activity of fractions 2 and 4 was observed but the type of mutagenic response, indirect and direct respectively, remained unchanged in the summer and winter months. Fraction 3 (the most abundant component, probably containing polar derivatives of PAHs and heterocyclics) differed quantitatively and qualitatively between summer and winter time. From August to December samples showed enhanced mutagenic potency upon addition of rat liver microsomal enzymes, whereas in January a 4-5-fold increase in direct response was noted. This significant increase in direct mutagenic activity was accompanied by a considerable decrease in mean air temperature and resulted most probably from the intensive use of coal for domestic heating.     

A comparison of macrophyte indices in headwaters of rivers in Flanders (Belgium)

Macrophytes were monitored in 48 headwater rivers in Flanders (Belgium). Only 26 sites had macrophyte vegetation, which was used to calculate five different indices and scores. These indices originated from UK, France, Czech Republic and Germany. Macrophytes were significantly correlated with a number of habitat variables, such as transect size, river width, slope, Huet zonation, distance to source, shadowing and average depth. For the substrate there were significant negative correlations with the fine particle sizes and a positive correlation with the coarse particles. A multivariate analysis of the macrophytes in these headwaters showed three groupings, essentially separated on basis of water hardness and pH.     

Forest ecosystem assessment,changes in biodiversity and climate change in a densely populated region (Flanders,Belgium)

Abstract

Throughout the world, forest covers one-third of the land's area. Present and historical human activities caused tremendous land use changes and triggered the onset of unseen climate changes. Yet, these socio-economically based environmental changes interfere with services that forests provide to mankind from global to local scales. Densely populated regions such as Flanders (Belgium), with over 430 people per km², have the dubious honour to serve as examples of extreme human induced forest changes. The issue of forest biodiversity is reviewed in the light of the Millennium Ecosystem Assessment scheme. Flanders is a poorly forested region (11% forest cover); supporting services are consequently low. Merely 16% of that area has known 230 years of continuous forest cover, representing forest with the highest current biodiversity. Also, the demands for regulating services are growing and the limits may have been reached. Provisioning services may increase again in future when demands for, for example bio-energy, increase. Cultural services, particularly the recreational function, have increased greatly. Human well-being in Flanders partly depends on the services provided by forest ecosystems. However, as demands on forests are huge, a shift to a sustainable use of forest resources will be essential to assure its beneficial role for present and future generations.