International audience | Once released into the environment, pesticides generate transformation products (TPs) which may be of (eco-)toxicological importance. Past studies have demonstrated the difficulty to predict pesticide TP occurrence and their environmental risk by monitoring-driven approaches mostly used in current regulatory frameworks targeting only known toxicologically relevant TPs. We present a novel combined approach which identifies and categorizes known and unknown pesticide TPs in soil by combining suspect screening time-of-flight mass spectrometry with in silico molecular typology. This approach applies an empirical and theoretical pesticide TP library for compound identification by both non-target and target time-of-flight (tandem) mass spectrometry and structural elucidation through a molecular structure correlation program. In silico molecular typology was then used to group the detected TPs according to common molecular descriptors and to indirectly elucidate their environmental properties by analogy to known pesticide compounds having similar molecular descriptors. This approach was evaluated via the identification of TPs of the triazole fungicide tebuconazole occurring in a field dissipation study. Overall, 22 empirical and 12 yet unknown TPs were detected and categorized into three groups with defined environmental properties. This approach combining suspect screening time-of-flight mass spectrometry with molecular typology could be extended to other organic pollutants and used to rationalize the choice of TPs to be intensively studied towards a more comprehensive environmental risk assessment scheme.

International audience | Once released into the environment, pesticides generate transformation products (TPs) which may be of (eco-)toxicological importance. Past studies have demonstrated the difficulty to predict pesticide TP occurrence and their environmental risk by monitoring-driven approaches mostly used in current regulatory frameworks targeting only known toxicologically relevant TPs. We present a novel combined approach which identifies and categorizes known and unknown pesticide TPs in soil by combining suspect screening time-of-flight mass spectrometry with in silico molecular typology. This approach applies an empirical and theoretical pesticide TP library for compound identification by both non-target and target time-of-flight (tandem) mass spectrometry and structural elucidation through a molecular structure correlation program. In silico molecular typology was then used to group the detected TPs according to common molecular descriptors and to indirectly elucidate their environmental properties by analogy to known pesticide compounds having similar molecular descriptors. This approach was evaluated via the identification of TPs of the triazole fungicide tebuconazole occurring in a field dissipation study. Overall, 22 empirical and 12 yet unknown TPs were detected and categorized into three groups with defined environmental properties. This approach combining suspect screening time-of-flight mass spectrometry with molecular typology could be extended to other organic pollutants and used to rationalize the choice of TPs to be intensively studied towards a more comprehensive environmental risk assessment scheme.

Pesticides generate transformation products (TPs) when they are released into the environment. These TPs may be of ecotoxicological importance. Past studies have demonstrated how difficult it is to predict the occurrence of pesticide TPs and their environmental risk. The monitoring approaches mostly used in current regulatory frameworks target only known ecotoxicologically relevant TPs. Here, we present a novel combined approach which identifies and categorizes known and unknown pesticide TPs in soil by combining suspect screening time-of-flight mass spectrometry with in silico molecular typology. We used an empirical and theoretical pesticide TP library for compound identification by both non-target and target time-of-flight (tandem) mass spectrometry, followed by structural proposition through a molecular structure correlation program. In silico molecular typology was then used to group TPs according to common molecular descriptors and to indirectly elucidate their environmental parameters by analogy to known pesticide compounds with similar molecular descriptors. This approach was evaluated via the identification of TPs of the triazole fungicide tebuconazole occurring in soil during a field dissipation study. Overall, 22 empirical and 12 yet unknown TPs were detected, and categorized into three groups with defined environmental properties. This approach combining suspect screening time-of-flight mass spectrometry with molecular typology could be extended to other organic pollutants and used to rationalize the choice of TPs to be investigated towards a more comprehensive environmental risk assessment scheme.

International audience | Studying long-term trends of contaminants in Arctic biota is essential to better understand impacts of anthropogenic activities and climate change on the exposure of sensitive species and marine ecosystems. We concurrently measured temporal changes (2006e2014) in mercury (Hg) contamination of little auks (Alle alle; the most abundant Arctic seabird) and in their major zooplankton prey species (Calanoid copepods, Themisto libellula, Gammarus spp.). We found an increasing contamination of the food-chain in East Greenland during summer over the last decade. More specifically, bird contamination (determined by body feather analyses) has increased at a rate of 3.4% per year. Conversely, bird exposure to Hg during winter in the northwest Atlantic (determined by head feather analyses) decreased over the study period (at a rate of 1.5% per year), although winter concentrations remained consistently higher than during summer. By combining mercury levels measured in birds and zooplankton to isotopic analyses, our results demonstrate that inter-annual variations of Hg levels in little auks reflect changes in food-chain contamination, rather than a reorganization of the food web and a modification of seabird trophic ecology. They therefore underline the value of little auks, and Arctic seabirds in general, as bio-indicators of long-term changes in environmental contamination.

Studying long-term trends of contaminants in Arctic biota is essential to better understand impacts of anthropogenic activities and climate change on the exposure of sensitive species and marine ecosystems. We concurrently measured temporal changes (2006–2014) in mercury (Hg) contamination of little auks (Alle alle; the most abundant Arctic seabird) and in their major zooplankton prey species (Calanoid copepods, Themisto libellula, Gammarus spp.). We found an increasing contamination of the food-chain in East Greenland during summer over the last decade. More specifically, bird contamination (determined by body feather analyses) has increased at a rate of 3.4% per year. Conversely, bird exposure to Hg during winter in the northwest Atlantic (determined by head feather analyses) decreased over the study period (at a rate of 1.5% per year), although winter concentrations remained consistently higher than during summer. By combining mercury levels measured in birds and zooplankton to isotopic analyses, our results demonstrate that inter-annual variations of Hg levels in little auks reflect changes in food-chain contamination, rather than a reorganization of the food web and a modification of seabird trophic ecology. They therefore underline the value of little auks, and Arctic seabirds in general, as bio-indicators of long-term changes in environmental contamination.

International audience | Microplastics have been reported everywhere around the globe. With very limited human activities, the Arctic is distant from major sources of microplastics. However, microplastic ingestions have been found in several Arctic marine predators, confirming their presence in this region. Nonetheless, existing information for this area remains scarce, thus there is an urgent need to quantify the contamination of Arctic marine waters. In this context, we studied microplastic abundance and composition within the zooplankton community off East Greenland. For the same area, we concurrently evaluated microplastic contamination of little auks (Alle alle), an Arctic seabird feeding on zooplankton while diving between 0 and 50 m. The study took place off East Greenland in July 2005 and 2014, under strongly contrasted sea-ice conditions. Among all samples, 97.2% of the debris found were filaments. Despite the remoteness of our study area, microplastic abundances were comparable to those of other oceans, with 0.99 ± 0.62 m−3 in the presence of sea-ice (2005), and 2.38 ± 1.11 m−3 in the nearby absence of sea-ice (2014). Microplastic rise between 2005 and 2014 might be linked to an increase in plastic production worldwide or to lower sea-ice extents in 2014, as sea-ice can represent a sink for microplastic particles, which are subsequently released to the water column upon melting. Crucially, all birds had eaten plastic filaments, and they collected high levels of microplastics compared to background levels with 9.99 and 8.99 pieces per chick meal in 2005 and 2014, respectively. Importantly, we also demonstrated that little auks took more often light colored microplastics, rather than darker ones, strongly suggesting an active contamination with birds mistaking microplastics for their natural prey. Overall, our study stresses the great vulnerability of Arctic marine species to microplastic pollution in a warming Arctic, where sea-ice melting is expected to release vast volumes of trapped debris.

Microplastics have been reported everywhere around the globe. With very limited human activities, the Arctic is distant from major sources of microplastics. However, microplastic ingestions have been found in several Arctic marine predators, confirming their presence in this region. Nonetheless, existing information for this area remains scarce, thus there is an urgent need to quantify the contamination of Arctic marine waters. In this context, we studied microplastic abundance and composition within the zooplankton community off East Greenland. For the same area, we concurrently evaluated microplastic contamination of little auks (Alle alle), an Arctic seabird feeding on zooplankton while diving between 0 and 50 m. The study took place off East Greenland in July 2005 and 2014, under strongly contrasted sea-ice conditions. Among all samples, 97.2% of the debris found were filaments. Despite the remoteness of our study area, microplastic abundances were comparable to those of other oceans, with 0.99 ± 0.62 m−3 in the presence of sea-ice (2005), and 2.38 ± 1.11 m−3 in the nearby absence of sea-ice (2014). Microplastic rise between 2005 and 2014 might be linked to an increase in plastic production worldwide or to lower sea-ice extents in 2014, as sea-ice can represent a sink for microplastic particles, which are subsequently released to the water column upon melting. Crucially, all birds had eaten plastic filaments, and they collected high levels of microplastics compared to background levels with 9.99 and 8.99 pieces per chick meal in 2005 and 2014, respectively. Importantly, we also demonstrated that little auks took more often light colored microplastics, rather than darker ones, strongly suggesting an active contamination with birds mistaking microplastics for their natural prey. Overall, our study stresses the great vulnerability of Arctic marine species to microplastic pollution in a warming Arctic, where sea-ice melting is expected to release vast volumes of trapped debris.

peer reviewed | Polycyclic aromatic hydrocarbons (PAHs) are pollutants that occur in mangrove sediments. Their removal by bacteria often depends on specific characteristics as the number of benzene rings they possess and their solubility. Their removal also depends on environmental factors, such as pH, temperature, oxygen, and the ability of the endogenous or exogenous microflora to metabolize hydrocarbons.With the aim of treating mangrove sediments polluted by hydrocarbons in a biological way, a biodegradation experiment was conducted using mangrove sediments artificially contaminated with a mixture of four PAHs. The study used Rhodococcus erythropolis as an exogenous bacterial strain in order to assess the biodegradation of the PAH mixture by natural attenuation, biostimulation, bioaugmentation, and a combination of biostimulation and bioaugmentation. The results showed that the last three treatments were more efficient than natural attenuation. The biostimulation/bioaugmentation combination proved to be the most effective PAH degradation treatment.

Polycyclic aromatic hydrocarbons (PAHs) are pollutants that occur in mangrove sediments. Their removal by bacteria often depends on specific characteristics as the number of benzene rings they possess and their solubility. Their removal also depends on environmental factors, such as pH, temperature, oxygen, and the ability of the endogenous or exogenous microflora to metabolize hydrocarbons. With the aim of treating mangrove sediments polluted by hydrocarbons in a biological way, a biodegradation experiment was conducted using mangrove sediments artificially contaminated with a mixture of four PAHs. The study used Rhodococcus erythropolis as an exogenous bacterial strain in order to assess the biodegradation of the PAH mixture by natural attenuation, biostimulation, bioaugmentation, and a combination of biostimulation and bioaugmentation. The results showed that the last three treatments were more efficient than natural attenuation. The biostimulation/bioaugmentation combination proved to be the most effective PAH degradation treatment.

The aim of this study was to link the concentrations of particulate matter with an aerodynamic diameter below 2.5 μm (PM₂.₅) and associated heavy metals with occurrence of wheezing and hospitalizations due to wheezing in 111 children who live near metallurgical plants in Targoviste City, Romania. A group of 72 children with high levels of immunoglobulin E (IgE) and eosinophils, as well as frequent wheezing episodes, was geolocated on digital thematic maps. Monitoring campaigns and medical assessments were performed over two consecutive years (2013–2014). The multiannual average concentrations of PM₂.₅ ranged from 4.6 to 22.5 μg m⁻³, up to a maximum value of 102 μg m⁻³. Significant correlations (p < 0.01) were observed between the locations of the children with respiratory issues and the PM₂.₅ multiannual average (r = 0.985) and PM₂.₅ maximum (r = 0.813). Fe, Ni, Cd, and Cr were the main marker elements of the emissions from steel production and metal-working facilities in the Targoviste area. The results support the hypothesis that increased PM₂.₅ levels directly influence wheezing symptom and asthma attacks in the analyzed group. IgE, eosinophils, and wheezing episodes may be considered key indicators with which to evaluate the adverse effects of PM₂.₅ air pollution on children’s health.

Cu, Pb, and As, which are among the most abundant metals in the aquatic environment, are also among the most health-threatened by causing diverse cellular injuries. The aim of this study was to assess and compare the potential early induction of genotoxic effects after waterborne Cu, Pb, and As exposure in European seabass, Dicentrarchus labrax, a commercial widely cultured fish, using the micronucleus (MN) assay in peripheral blood erythrocytes. Fish were exposed under laboratory conditions to nominal solutions ranging 0–10 mg/L for 24 and 96 h. Furthermore, actual metal ion concentrations were measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES) or differential pulse anodic stripping voltammetry (DPASV) in water and four fish tissues differentially related to environmental exposition and metal accumulation, i.e. the gills, liver, muscle, and brain. Dose-dependent increases of micronuclei (MNi) frequency were observed after these very short exposures; based on measured metal concentrations in water, the genotoxic effect ordered as Cu>As>Pb. Significant genotoxic effect at 0.009 mg/L Cu, 0.57 mg/L Pb, and 0.01 mg/L As was seen. For Cu and Pb these are only slightly higher, but for As it is notably lower than the USEPA criteria of maximum concentration to prevent acute toxicity in aquatic organisms. Furthermore, genotoxicity was differentially related to metal accumulation. MNi frequency correlated positively with the content of Pb in all the organs, with the content of As in liver and gills and only with the content of Cu in the brain. In conclusion, our findings raised environmental concerns because these depicted a genotoxic potential of Cu, Pb, and As after a very short exposure to low but environmentally relevant concentrations, too close to regulatory thresholds. In addition, the MN test in D. labrax could be considered an early biomarker of genotoxicity induced by these metals in fish.

Cu, Pb, and As, which are among the most abundant metals in the aquatic environment, are also among the most health-threatened by causing diverse cellular injuries. The aim of this study was to assess and compare the potential early induction of genotoxic effects after waterborne Cu, Pb, and As exposure in European seabass, Dicentrarchus labrax, a commercial widely cultured fish, using the micronucleus (MN) assay in peripheral blood erythrocytes. Fish were exposed under laboratory conditions to nominal solutions ranging 0–10 mg/L for 24 and 96 h. Furthermore, actual metal ion concentrations were measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES) or differential pulse anodic stripping voltammetry (DPASV) in water and four fish tissues differentially related to environmental exposition and metal accumulation, i.e. the gills, liver, muscle, and brain. Dose-dependent increases of micronuclei (MNi) frequency were observed after these very short exposures; based on measured metal concentrations in water, the genotoxic effect ordered as Cu > As > Pb. Significant genotoxic effect at 0.009 mg/L Cu, 0.57 mg/L Pb, and 0.01 mg/L As was seen. For Cu and Pb these are only slightly higher, but for As it is notably lower than the USEPA criteria of maximum concentration to prevent acute toxicity in aquatic organisms. Furthermore, genotoxicity was differentially related to metal accumulation. MNi frequency correlated positively with the content of Pb in all the organs, with the content of As in liver and gills and only with the content of Cu in the brain. In conclusion, our findings raised environmental concerns because these depicted a genotoxic potential of Cu, Pb, and As after a very short exposure to low but environmentally relevant concentrations, too close to regulatory thresholds. In addition, the MN test in D. labrax could be considered an early biomarker of genotoxicity induced by these metals in fish.

Eisenia andrei earthworms were exposed for 7 and 14 days to six samples of soil taken from around an abandoned lead (Pb) mine and characterized by different levels of metal contamination (S6-S1, this latter being the most contaminated soil). The organisms were analyzed for metal bioaccumulation and for biological parameters as biomarkers of stress (lysosomal membrane stability; lipofuscin lysosomal content; lysosomal/cytoplasmic volume ratio) and genotoxicity (Micronucleus frequency). Chemical analysis showed the loads of Pb, Cd, Zn, and Cu in the worms following exposure. Among the stress biomarkers, lysosomal membrane stability was significantly affected in the coelomocytes of the earthworms exposed already 7 days to different contaminated soils. Organisms exposed for 14 days to S1 showed in the cells of the chloragogenous tissue, a particularly relevant increase in lipofuscin, a biomarker of oxidative stress, and an increase in the lysosome/cytoplasm volume ratio, indicating stressful condition at the tissue level. Moreover, in the same conditions, a decrease in total body weight was observed. At the longer exposure time, the coelomocytes of worms exposed to S1, S2, and S3 (soils with higher metal concentrations) showed a significant increase in micronuclei (MNi) frequency. Expressions of the P21 and topoisomerase genes, which are involved in DNA repair, showed significant up-regulation in the cells of worms exposed to S1, S2, S3, S4 and to a less extend S6. This may indicate that the worms were only able to successfully reduce the level of DNA damage in S4 and S5 if considering MN frequency data. The biomarker data was integrated by the Earthworm Expert System, allowing an objective interpretation of the complex biological data and clearly defining the areas in which the presence of chemicals is toxic for the edaphic organisms.

Eisenia andrei earthworms were exposed for 7 and 14 days to six samples of soil taken from around an abandoned lead (Pb) mine and characterized by different levels of metal contamination (S6-S1, this latter being the most contaminated soil). The organisms were analyzed for metal bioaccumulation and for biological parameters as biomarkers of stress (lysosomal membrane stability; lipofuscin lysosomal content; lysosomal/cytoplasmic volume ratio) and genotoxicity (Micronucleus frequency). Chemical analysis showed the loads of Pb, Cd, Zn, and Cu in the worms following exposure. Among the stress biomarkers, lysosomal membrane stability was significantly affected in the coelomocytes of the earthworms exposed already 7 days to different contaminated soils. Organisms exposed for 14 days to S1 showed in the cells of the chloragogenous tissue, a particularly relevant increase in lipofuscin, a biomarker of oxidative stress, and an increase in the lysosome/cytoplasm volume ratio, indicating stressful condition at the tissue level. Moreover, in the same conditions, a decrease in total body weight was observed. At the longer exposure time, the coelomocytes of worms exposed to S1, S2, and S3 (soils with higher metal concentrations) showed a significant increase in micronuclei (MNi) frequency. Expressions of the P21 and topoisomerase genes, which are involved in DNA repair, showed significant up-regulation in the cells of worms exposed to S1, S2, S3, S4 and to a less extend S6. This may indicate that the worms were only able to successfully reduce the level of DNA damage in S4 and S5 if considering MN frequency data. The biomarker data was integrated by the Earthworm Expert System, allowing an objective interpretation of the complex biological data and clearly defining the areas in which the presence of chemicals is toxic for the edaphic organisms.

International audience | The present study compares concentrations and chemical profiles of an extended range of persistent organic pollutants (dioxins, polychlorobiphenyls, brominated flame retardants and organochlorine pesticides) in breast milk samples from French (n = 96), Danish (n = 438) and Finnish (n = 22) women. Median exposure levels observed in French women (WHO-TEQ2005 PCDD/F = 6.1 pg/g l.w., WHO-TEQ2005 dl-PCB = 4.3 pg/g l.w., sum of 6 ndl-PCB = 85.2 ng/g l.w., sum of 7 i-PBDE = 1.5 ng/g l.w.) appeared overall lower than in Danish and Finnish women for all examined POPs, except for α-HBCD (2-fold higher level at 0.6 ng/g l.w.). Furthermore, the observed exposure levels of dioxins and PCBs were higher in Danish women (WHO-TEQ2005 PCDD/F = 13.2 pg/g l.w., WHO-TEQ2005 dl-PCB = 6.6 pg/g l.w., sum of 6 ndl-PCB = 162.8 ng/g l.w.) compared to Finnish women (WHO-TEQ2005 PCDD/F = 9.0 pg/g l.w., WHO-TEQ2005 dl-PCB = 4.6 pg/g l.w., sum of 6 ndl-PCB = 104.0 ng/g l.w.), whereas the concentrations of PBDEs were similar for Danish and Finnish women (sum of 7 i-PBDE = 4.9 and 5.2 ng/g l.w. respectively). The organochlorine (OC) pesticide contamination profile, determined in a subset of French samples, was dominated by p,p’-DDE (56.6%), followed by β-HCH (14.2%), HCB (9.7%) and dieldrin (5.2%), while other compounds were only minor contributors (&lt;5%). The three countries appeared to be discriminated by the observed contamination patterns of the PCDD/F versus PCB, and the 1,2,3,6,7,8-HxCDD versus 1,2,3,4,7,8-HxCDD ratios, in addition to the relative contributions of specific congeners to the contamination profile (PCBs #118 and #156, PBDEs #28, #47, #99 and #153). In conclusion, unique chemical signatures were observed for each country on the basis of some POP congeners. Future biomonitoring studies will need to consider the high variability of individual exposure profiles in relation to multiple exposure sources but also physiological and metabolic differences.

The present study compares concentrations and chemical profiles of an extended range of persistent organic pollutants (dioxins, polychlorobiphenyls, brominated flame retardants and organochlorine pesticides) in breast milk samples from French (n = 96), Danish (n = 438) and Finnish (n = 22) women. Median exposure levels observed in French women (WHO-TEQ2005 PCDD/F = 6.1 pg/g l.w., WHO-TEQ2005 dl-PCB = 4.3 pg/g l.w., sum of 6 ndl-PCB = 85.2 ng/g l.w., sum of 7 i-PBDE = 1.5 ng/g l.w.) appeared overall lower than in Danish and Finnish women for all examined POPs, except for α-HBCD (2-fold higher level at 0.6 ng/g l.w.). Furthermore, the observed exposure levels of dioxins and PCBs were higher in Danish women (WHO-TEQ2005 PCDD/F = 13.2 pg/g l.w., WHO-TEQ2005 dl-PCB = 6.6 pg/g l.w., sum of 6 ndl-PCB = 162.8 ng/g l.w.) compared to Finnish women (WHO-TEQ2005 PCDD/F = 9.0 pg/g l.w., WHO-TEQ2005 dl-PCB = 4.6 pg/g l.w., sum of 6 ndl-PCB = 104.0 ng/g l.w.), whereas the concentrations of PBDEs were similar for Danish and Finnish women (sum of 7 i-PBDE = 4.9 and 5.2 ng/g l.w. respectively). The organochlorine (OC) pesticide contamination profile, determined in a subset of French samples, was dominated by p,p’-DDE (56.6%), followed by β-HCH (14.2%), HCB (9.7%) and dieldrin (5.2%), while other compounds were only minor contributors (<5%). The three countries appeared to be discriminated by the observed contamination patterns of the PCDD/F versus PCB, and the 1,2,3,6,7,8-HxCDD versus 1,2,3,4,7,8-HxCDD ratios, in addition to the relative contributions of specific congeners to the contamination profile (PCBs #118 and #156, PBDEs #28, #47, #99 and #153). In conclusion, unique chemical signatures were observed for each country on the basis of some POP congeners. Future biomonitoring studies will need to consider the high variability of individual exposure profiles in relation to multiple exposure sources but also physiological and metabolic differences.