Concentrations and specific loads of glyphosate, diuron, atrazine, nonylphenol and metabolites thereof in French urban sewage sludge

Indirect soil pollution by heavy metals and organics may occur when sewage sludge is used as fertilizer. It is essential to define the nature and amounts of pollutants contained in sewage sludge in order to assess environmental risk. Here, we present results from a one-year monitoring of herbicides (glyphosate, diuron and atrazine) and their major degradates in sewage sludge sampled from three wastewater treatment plants and one composting unit in the vicinity of Versailles, France. The concentrations of these compounds were determined, as well as these of the surfactant nonylphenol. We demonstrated the presence of glyphosate and aminomethylphosphonic acid at the mg kg(-1) (dry matter) level in all samples. Diuron was detected at the microg kg(-1) (d.m.) level, whereas its degradate and triazine compounds were below the limits of quantification. Nonylphenol amounts were higher than the future European limit value of 50 mg kg(-1) (d.m.).     

Shoot growth of mature Fagus sylvatica and Picea abies in relation to ozone

Epidemiological analysis of sequential growth data may be a tool in assessing ozone sensitivity of mature trees. Annual shoot growth of mature Fagus sylvatica in 83 Swiss permanent forest observation plots and of Picea abies in 61 plots was evaluated for 11 and 8 consecutive years, respectively, using branches harvested every 4 years. The data were assessed as annual deviation from average growth and related to fructification, ozone, meteorological parameters, and modelled soil water content using a mixed linear model. In beech, a significant association between ozone and shoot growth was observed which corresponded to a 7.4% growth reduction between 0 and 10 ppm h AOT40 (accumulated ozone over threshold 40). This is in the same order of magnitude as the response observed in experiments with seedlings. No interaction was found between ozone and drought parameters. In Norway spruce, shoot growth was neither associated with ozone nor with drought.     

Microbial degradation pathways of the herbicide dichlobenil in soils with different history of dichlobenil-exposure

This is the first detailed study of metabolite production during degradation of the herbicide 2,6-dichlorobenzonitrile (dichlobenil). Degradation of dichlobenil and three potential metabolites: 2,6-dichlorobenzamide (BAM), 2,6-dichlorobenzoic acid (2,6-DCBA) and ortho-chlorobenzamide (OBAM) was studied in soils either previously exposed or not exposed to dichlobenil using a newly developed HPLC method. Dichlobenil was degraded in all four soils; BAM and 2,6-DCBA were only degraded in soils previously exposed to dichlobenil (100% within 35-56 days and 85-100% in 56 days, respectively), and OBAM in all four soils (25-33% removal in 48 days). BAM produced from dichlobenil was either hydrolyzed to 2,6-DCBA or dechlorinated to OBAM, which was further hydrolyzed to ortho-chlorobenzoic acid. BAM was rapidly mineralized in previously exposed soils only. All potential metabolites and the finding that BAM was a dead-end metabolite of dichlobenil in soils not previously exposed to dichlobenil needs to be included in risk assessments of the use of dichlobenil.     

Natural Organic Matter Differently Modulates Growth of Two Closely Related Coccal Green Algal Species (6 pp)

Background

and Aim. Humic substances (HS) comprise the majority of dead and living organic carbon, including organisms. In the environment, they are considered to be chemically inert or at least refractory. Recent papers, however, show that HS (including natural organic matter – NOM, isolated by reverse osmosis) are natural chemicals which interact with aquatic organisms. They are taken up and cause a variety of stress defense reactions which are well known from man-made chemicals. These reactions include chaperon activation, induction and modulation of biotransformation enzymes, or induction of antioxidant defense enzymes. One specific reaction with freshwater plants is the reduction of photosynthetic oxygen release. In this contribution, we compare the susceptibilities (cell yield) of two closely related coccal green algae, Monoraphidium convolutum and M. minutum, towards various NOM isolates.

Methods

Cultures of M. convolutum and M. minutum were obtained from the algal collection of the Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, and from the Culture Collection of Algae, Göttingen, and maintained in a common medium. The cultures were non-axenic. The algae were exposed to 5 mg L-1 DOC of each humic material, an environmentally realistic concentration. Cell numbers were counted microscopically in Neugebauer cuvettes in 5 replicates on days 1, 4, 7, 10, 14, and 21.

Results and Discussion

Almost all NOM isolates modulated the growth of the algae. Only the NOM of a Norwegian raised peat bog lake did not reveal any significant effect with M. convolutum. In general, the results with two algal species are by no means uniform. For instance, Suwannee River NOM causes a decrease in cell density with M. minutum, but temporarily stimulates the growth of M. convolutum. The opposite applies to Aurevann NOM: Growth increase in M. minutum, but a bi-phasic response in M. convolutum. Different responses of both Monoraphidium species must be attributed to intrinsic factors of the algae rather than only to chemical features of the exposed materials, because the exposures were identical with both algal species. The reduction in growth yields can be explained as a herbicide-like mode of action that affects the photosystem II most prevalently. The growth promoting effect remains somewhat obscure. It may be due to (1) an increase in bioavailability of some trace nutrients in the presence of HS, (2) the release of some growth promoting substances by microbial or photochemical processing of the humic materials, and (3) a hormetic effect upon the exposure of HS. Hormesis means stimulation of organisms or metabolic activities when exposed to noxes in low concentrations. However, it is still open to discussion why the growth promotion only applies to one or the other, but not simultaneously to both Monoraphidium species.

Conclusion

and Perspectives. Exposure of the closely related coccal green algal species to humic material changes their growth characteristics. Since the reactions are not consistent within the two species and the various humic materials, it seems that the less sensitive species is favored by HS exposure. The environmental relevance, however, is subject to future studies.     

ESPR´s Total Environment

Environmental Science and Pollution Research -     

Organic pollutants in compost and digestate. Part 2. Polychlorinated dibenzo-p-dioxins, and -furans, dioxin-like polychlorinated biphenyls, brominated flame retardants, perfluorinated alkyl substances, pesticides, and other compounds

Compost and digestate are important recycling fertilizers and have beneficial effects on soil parameters. However, they can contain significant amounts of organic pollutants. Here, the first comprehensive data set on dibenzo-p-dioxins and -furans (PCDD/F), dioxin-like polychlorinated biphenyls (DL-PCB), brominated flame retardants, perfluorinated alkyl substances (PFAS), pesticides, phthalates, nonylphenol and chlorinated paraffins (CP) in source-separated compost and digestate from Switzerland is presented (n = 3-18). The median summation 17PCDD/F and summation 12DL-PCB concentrations were at 3.2 ng I-TEQ kg(-1)dry weight (dw) and 3.0 ng WHO-TEQ kg(-1)dw, respectively. Brominated diphenyl ether 209 (BDE 209) accounted for 72% of the total polyBDE content (10 microg kg(-1)dw). Hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA) levels were at 100 and 0.51 microg kg(-1)dw, respectively. PFAS were identified for the first time in compost and digestate (median concentration 6.3 microg kg(-1)dw, summation 21compounds). Out of 269 pesticides analysed, 30 fungicides, 14 herbicides, eight insecticides and one acaricide were detected. Di-(2-ethylhexyl)phthalate (DEHP) median concentration accounted for 280 microg kg(-1)dw and nonylphenol was below the detection limit of 1 mg kg(-1)dw. The sum of short and medium chain CP was between 90 and 390 microg kg(-1)dw. The concentrations observed were at or above the levels found in background soils, which are the main recipient of compost and digestate. Where actually applied, compost can contribute considerably to the total input of organic pollutants to the soil. However, on a total Swiss agricultural area base, inputs seem to be limited.     

Serial polygyny and colony genetic structure in the monogynous queenless ant Diacamma cyaneiventre

Serial polygyny, defined as the temporal succession of several reproductive females in a colony, occurs in some monogynous social insects and has so far attracted little attention. Diacamma cyaneiventre is a queenless ponerine ant found in the south of India. Colonies are headed by one singly mated worker, the gamergate. After the death of the gamergate or her absence following colony fission, the gamergate is replaced by a newly eclosed nestmate worker. After a replacement, colonies go through short-lived periods in which two matrilines of sisters co-occur. This is a situation which can be described as serial polygyny. To measure the consequences of serial polygyny, a genetic analysis was performed on 449 workers from 46 colonies of D. cyaneiventre using five microsatellite loci. The presence of more than one matriline among workers of the same nest was detected in 19% of colonies, indicating a recent change of gamergate. The average genetic relatedness among nestmate workers was 0.751 and did not significantly differ from the theoretical expectation under strict monogyny and monandry (0.75). A simple analytical model of the temporal dynamics of serial polygyny was developed in order to interpret these results. We show that the rate of gamergate turnover relative to the rate of worker turnover is the crucial parameter determining the level of serial polygyny and its effect on the genetic structure of colonies. This parameter, estimated from our data, confirms that serial polygyny occurs in D. cyaneiventre but is not strong enough to influence significantly the average genetic relatedness among workers.     

A schematic sampling protocol for contaminant monitoring in raptors

Birds of prey, owls and falcons are widely used as sentinel species in raptor biomonitoring programmes. A major current challenge is to facilitate large-scale biomonitoring by coordinating contaminant monitoring activities and by building capacity across countries. This requires sharing, dissemination and adoption of best practices addressed by the Networking Programme Research and Monitoring for and with Raptors in Europe (EURAPMON) and now being advanced by the ongoing international COST Action European Raptor Biomonitoring Facility. The present perspective introduces a schematic sampling protocol for contaminant monitoring in raptors. We provide guidance on sample collection with a view to increasing sampling capacity across countries, ensuring appropriate quality of samples and facilitating harmonization of procedures to maximize the reliability, comparability and interoperability of data. The here presented protocol can be used by professionals and volunteers as a standard guide to ensure harmonised sampling methods for contaminant monitoring in raptors.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01341-9) contains supplementary material, which is available to authorized users.     

Antagonistic effect of natural habitat conversion on community adjustment to climate warming in nonbreeding waterbirds

Although the impacts of climate and land-use changes on biodiversity have been widely documented, their joint effects remain poorly understood. We evaluated how nonbreeding waterbird communities adjust to climate warming along a gradient of land-use change. Using midwinter waterbird counts (132 species) at 164 major nonbreeding sites in 22 Mediterranean countries, we assessed the changes in species composition from 1991 to 2010, relative to thermal niche position and breadth, in response to regional and local winter temperature anomalies and conversion of natural habitats. We observed a low-level, nonsignificant community adjustment to the temperature increase where natural habitat conversion occurred. At the sites affected by natural habitat conversion, the relative increase of warm-dwelling species in response to climate warming was 6 times lower and the relative species decline was 3 times higher than in the sites without natural habitat conversion. We found no evidence of community adjustment to climate warming when natural habitat conversion was >5% over 15 years. This strong negative effect suggests an antagonistic interaction between climate warming and habitat change. These results underline the importance of habitat conservation in community adjustment to climate warming.