Effects of soil moisture depletion on vegetable crop uptake of pharmaceuticals and personal care products (PPCPs)

Agricultural crops have a long history of being irrigated with recycled wastewater (RW). However, its use on vegetable crops has been of concern due to the potential prevalence of microcontaminants, such as pharmaceuticals and personal care products (PPCPs) in the latter, which represents a possible health hazard to consumers. We investigated the uptake of three PPCPs (atenolol, diclofenac, and ofloxacin), at three different concentrations in irrigation water (0.5, 5, and 25 μg L^?1) in relation to three varying volumetric soil moisture depletion levels of 14 % (?4.26 kPa), 10 % (?8.66 kPa), and 7 % (?18.37 kPa) by various vegetable crop species. Experiments were conducted in a split-split block completely randomized design. PPCPs were extracted using a developed method of accelerated solvent extraction and solid phase extraction and analyzed via liquid chromatography mass spectrometry (LCMS). Results indicate that all treated crops were capable of PPCP uptake at nanogram per gram concentrations independent of the applied soil moisture depletion levels and PPCP concentrations. Ofloxacin was the chemical with the highest uptake amounts, followed by atenolol and then diclofenac. Although the results were not statistically significant, higher concentrations of PPCPs were detected in plants maintained under higher soil moisture levels of 14 % (?4.26 kPa).     

Identification of a novel hydroxylated metabolite of 2,2′,3,5′,6-pentachlorobiphenyl formed in whole poplar plants

Polychlorinated biphenyls (PCBs) are a group of persistent organic pollutants consisting of 209 congeners. Oxidation of several PCB congeners to hydroxylated PCBs (OH-PCBs) in whole poplar plants has been reported before. Moreover, 2,2′,3,5′,6-pentachlorobiphenyl (PCB95), as a chiral congener, has been previously shown to be atropselectively taken up and transformed in whole poplar plants. The objective of this study was to determine if PCB95 is atropselectively metabolized to OH-PCBs in whole poplar plants. Two hydroxylated PCB95s were detected by high-performance liquid chromatography-mass spectrometry in the roots of whole poplar plants exposed to racemic PCB95 for 30 days. The major metabolite was confirmed to be 4′-hydroxy-2,2′,3,5′,6-pentachlorobiphenyl (4′-OH-PCB95) by gas chromatography-mass spectrometry (GC-MS) using an authentic reference standard. Enantioselective analysis showed that 4′-OH-PCB95 was formed atropselectively, with the atropisomer eluting second on the Nucleodex β-PM column (E2-4′-OH-PCB95) being slightly more abundant in the roots of whole poplar plants. Therefore, PCB95 can at least be metabolized into 4′-OH-PCB95 and another unknown hydroxylated PCB95 (as a minor metabolite) in whole poplar plants. Both atropisomers of 4′-OH-PCB95 are formed, but E2-4′-OH-PCB95 has greater atropisomeric enrichment in the roots of whole poplar plants. A comparison with mammalian biotransformation studies indicates a distinctively different metabolite profile of OH-PCB95 metabolites in whole poplar plants. Our observations suggest that biotransformation of chiral PCBs to OH-PCBs by plants may represent an important source of enantiomerically enriched OH-PCBs in the environment.     

Polychlorinated biphenyls and links to cardiovascular disease

The pathology of cardiovascular disease is multi-faceted, with links to many modifiable and non-modifiable risk factors. Epidemiological evidence now implicates exposure to persistent organic pollutants, such as polychlorinated biphenyls (PCBs), with an increased risk of developing diabetes, hypertension, and obesity; all of which are clinically relevant to the onset and progression of cardiovascular disease. PCBs exert their cardiovascular toxicity either directly or indirectly via multiple mechanisms, which are highly dependent on the type and concentration of PCBs present. However, many PCBs may modulate cellular signaling pathways leading to common detrimental outcomes including induction of chronic oxidative stress, inflammation, and endocrine disruption. With the abundance of potential toxic pollutants increasing globally, it is critical to identify sensible means of decreasing associated disease risks. Emerging evidence now implicates a protective role of lifestyle modifications such as increased exercise and/or nutritional modulation via anti-inflammatory foods, which may help to decrease the vascular toxicity of PCBs. This review will outline the current state of knowledge linking coplanar and non-coplanar PCBs to cardiovascular disease and describe the possible molecular mechanism of this association.     

Mapping shifts in spatial synchrony in grassland birds to inform conservation planning

Spatial synchrony, defined as the correlated fluctuations in abundance of spatially separated populations, can be caused by regional fluctuations in natural and anthropogenic environmental population drivers. Investigations into the geography of synchrony can provide useful insight to inform conservation planning efforts by revealing regions of common population drivers and metapopulation extinction vulnerability. We examined the geography of spatial synchrony and decadal changes in these patterns for grassland birds in the United States and Canada, which are experiencing widespread and persistent population declines. We used Bayesian hierarchical models and over 50 years of abundance data from the North American Breeding Bird Survey to generate population indices within a 2° latitude by 2° longitude grid. We computed and mapped mean local spatial synchrony for each cell (mean detrended correlation of the index among neighboring cells), along with associated uncertainty, for 19 species in 2, 26-year periods, 1968–1993 and 1994–2019. Grassland birds were predicted to increase in spatial synchrony where agricultural intensification, climate change, or interactions between the 2 increased. We found no evidence of an overall increase in synchrony among grassland bird species. However, based on the geography of these changes, there was considerable spatial heterogeneity within species. Averaging across species, we identified clusters of increasing spatial synchrony in the Prairie Pothole and Shortgrass Prairie regions and a region of decreasing spatial synchrony in the eastern United States. Our approach has the potential to inform continental-scale conservation planning by adding an additional layer of relevant information to species status assessments and spatial prioritization of policy and management actions. Our work adds to a growing literature suggesting that global change may result in shifting patterns of spatial synchrony in population dynamics across taxa with broad implications for biodiversity conservation.     

Comparison between UVA- and zero-valent iron-activated persulfate processes for degrading propylparaben

Conventional wastewater treatments are not efficient in removing parabens, which may thus end up in surface waters, posing a threat to aquatic biota and hu     

Can we infer avalanche–climate relations using tree-ring data? Case studies in the French Alps

Dendrogeomorphology is a powerful tool to determine past avalanche activity, but whether or not the obtained annually resolved chronologies are sufficiently detailed to infer avalanche–climate relationships (in terms of temporal resolution) remains an open question. In this work, avalanche activity is reconstructed in five paths of the French Alps and crossed with a set of snow and weather variables covering the period 1959–2009 on a monthly and annual (winter) basis. The variables which best explain avalanche activity are highlighted with an original variable selection procedure implemented within a logistic regression framework. The same approach is used for historical chronologies available for the same paths, as well as for the composite tree-ring/historical chronologies. Results suggest that dendrogeomorphic time series allow capturing the relations between snow or climate and avalanche occurrences to a certain extent. Weak links exist with annually resolved snow and weather variables and the different avalanche chronologies. On the contrary, clear statistical relations exist between these and monthly resolved snow and weather variables. In detail, tree rings seem to preferentially record avalanches triggered during cold winter storms with heavy precipitation. Conversely, historical avalanche data seem to contain a majority of events that were released later in the season and during episodes of strong positive temperature anomalies.     

On the Environmental Efficiency of Water Storage: the Case of a Conjunctive use of Ground and Rainwater

Rainwater harvesting, consisting in collecting runoff from precipitation, has been widely developed to stop groundwater declines and even raise water tables. However, this expected environmental effect is not self-evident. We show in a simple setting that the success of this conjunctive use depends on whether the runoff rate is above a threshold value. Moreover, the bigger the storage capacity, the higher the runoff rate must be to obtain an environmentally efficient system. We also extend the model to include other hydrological parameters and ecological damages, which respectively increase and decrease the environmental efficiency of rainwater harvesting.     

A systematic review on the adverse health effects of di-2-ethylhexyl phthalate

Di (ethylhexyl) phthalate (DEHP) is a global environmental pollutant. This study aims to systematically review the literature on health effects of exposure to DEHP including effects on reproductive health, carcinogenesis, pregnancy outcome, and respiratory system. The literature search was done through Scopus, ISI Web of Science, Google Scholar, PubMed, Medline, and the reference lists of previous review articles to identify relevant articles published to June 2016 in each subject area. The inclusion criteria were as follows: original research, cross-sectional studies, case–control studies, cohort studies, interventional studies, and review articles. Both human and animal studies were included. The search was limited to English language papers. Conference papers, editorials, and letters were not included. The systematic review was conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Overall, 152 of the 407 papers met the inclusion criteria. We provided an up-to-date comprehensive and critical assessment of both human and animal studies undertaken to explore the effects of DEHP. It revealed that in experimental studies, exposure to DEHP mainly targeted the reproductive, neurodevelopment, and respiratory systems. Human studies reported that exposure to this contaminant had carcinogenic effects and influenced neurodevelopment in early life. This systematic review underscored the adverse health effects of DEHP for pregnant women and the pediatric age group. It summarizes different response of humans and experimental animals to DEHP exposure, and some suggested underlying mechanisms.     

Potential Negative Ecological Effects of Corridors

Despite many studies showing that landscape corridors increase dispersal and species richness for disparate taxa, concerns persist that corridors can have unintended negative effects. In particular, some of the same mechanisms that underlie positive effects of corridors on species of conservation interest may also increase the spread and impact of antagonistic species (e.g., predators and pathogens), foster negative effects of edges, increase invasion by exotic species, increase the spread of unwanted disturbances such as fire, or increase population synchrony and thus reduce persistence. We conducted a literature review and meta‐analysis to evaluate the prevalence of each of these negative effects. We found no evidence that corridors increase unwanted disturbance or non‐native species invasion; however, these have not been well‐studied concerns (1 and 6 studies, respectively). Other effects of corridors were more often studied and yielded inconsistent results; mean effect sizes were indistinguishable from zero. The effect of edges on abundances of target species was as likely to be positive as negative. Corridors were as likely to have no effect on antagonists or population synchrony as they were to increase those negative effects. We found 3 deficiencies in the literature. First, despite studies on how corridors affect predators, there are few studies of related consequences for prey population size and persistence. Second, properly designed studies of negative corridor effects are needed in natural corridors at scales larger than those achievable in experimental systems. Third, studies are needed to test more targeted hypotheses about when corridor‐mediated effects on invasive species or disturbance may be negative for species of management concern. Overall, we found no overarching support for concerns that construction and maintenance of habitat corridors may result in unintended negative consequences. Negative edge effects may be mitigated by widening corridors or softening edges between corridors and the matrix. Other negative effects are relatively small and manageable compared with the large positive effects of facilitating dispersal and increasing diversity of native species. Efectos Negativos Potenciales de los Corredores