scholarly journals Effects of perfluoroalkyl and polyfluoroalkyl substances on soil structure and function

2021 ◽  
Author(s):  
Baile Xu ◽  
Gaowen Yang ◽  
Anika Lehmann ◽  
Matthias C Rillig
Keyword(s):  
Soil Respiration ◽  
Litter Decomposition ◽  
Soil Structure ◽  
Bacterial Abundance ◽  
Soil Health ◽  
Anthropogenic Factors ◽  
Microbial Activities ◽  
Positive Effects ◽  
Polyfluoroalkyl Substances ◽  
Perfluoroalkyl And Polyfluoroalkyl Substances

Soils are impacted at a global scale by several anthropogenic factors, including chemical pollutants. Among those, perfluoroalkyl and polyfluoroalkyl substances (PFAS) are of concern due to their high environmental persistence, and as they might affect soil health and functions. However, data on impacts of PFASs on soil structure and microbially-driven processes are currently lacking. This study explored the effects of perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA) and perfluorobutanesulfonic acid (PFBS) at environmental-relevant nominal concentrations (1 ~ 1000 ng g-1) on soil functions, using a 6-week microcosm experiment. We measured soil respiration, litter decomposition, enzyme and microbial activities, soil aggregates, and bacterial abundance. PFAS (even at 1 ng g-1 for PFBS) significantly increased the litter decomposition, associated with positive effects on bacterial abundance, and β-glucosidase activities. This effect increased with PFAS concentrations. Soil respiration was significantly inhibited by PFAS in the 3rd week, while this effect was more variable in week 6. Water-stable aggregates were negatively affected by PFOS and PFOA, possibly related to microbial shifts. The general microbial activities and β-D-cellobiosidase and phosphatase activities were barely affected by PFAS treatments. Our work highlights the potential effects of PFAS on soil health, and we argue that this substance class could be a factor of environmental change of potentially broad relevance in terrestrial ecosystem functioning.

scholarly journals Litter Management as a Key Factor Relieves Soil Respiration Decay in an Urban-Adjacent Camphor Forest under a Short-Term Nitrogen Increment

Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 216
Author(s):  
Xuyuan Zhang ◽  
Yong Li ◽  
Chen Ning ◽  
Wei Zheng ◽  
Dayong Zhao ◽  
...  
Keyword(s):  
Soil Respiration ◽  
Litter Decomposition ◽  
Equation Modeling ◽  
Limiting Factor ◽  
Enhancement Effect ◽  
N Addition ◽  
Available N ◽  
Positive Effects ◽  
Litter Input ◽  
Litter Manipulation

Increases in bioavailable nitrogen (N) level can impact the soil carbon (C) sequestration in many forest ecosystems through its influences on litter decomposition and soil respiration (Rs). This study aims to detect whether the litter management can affect the influence of N addition on Rs. We conducted a one-year field experiment in a camphor forest of central-south China to investigate the responses of available N status and soil Rs to N addition and litter manipulation. Four N addition plots (NH4NO3; 0, 5, 15, 30 g N m−2 year−1 as N0, N1, N2, N3, respectively) were established with three nested litter treatments: natural litter input (CK), double litter input (LA), and non-litter input (LR). We found a short-lived enhancement effect of N addition on soil (NO3-N) and net nitrification (RN), but not on (NH4-N), net ammonification (RA), or mineralization (RM). N addition also decreased Rs in CK spots, but not in LA or LR spots, in which the negative effects of N additions on Rs were alleviated by either litter addition or reduction. A priming effect was also observed in LA treatments. A structural equation modeling analysis showed that litter treatments had direct positive effects on soil available N contents and Rs, which suggested that litter decomposition may benefit from litter management when N is not a limiting factor in subtropical forests.

Structure-Based Virtual Screening of Perfluoroalkyl and Polyfluoroalkyl Substances (PFASs) as Endocrine Disruptors of Androgen Receptor Activity Using Molecular Docking and Machine Learning

2020 ◽  
Author(s):  
Azhagiya Singam Ettayapuram Ramaprasad ◽  
Phum Tachachartvanich ◽  
Denis Fourches ◽  
Anatoly Soshilov ◽  
Jennifer C.Y. Hsieh ◽  
...  
Keyword(s):  
Machine Learning ◽  
Molecular Docking ◽  
Androgen Receptor ◽  
Endocrine Disruptors ◽  
Hormone Receptors ◽  
Steroid Hormone Receptors ◽  
Machine Learning Techniques ◽  
Support Vector ◽  
Polyfluoroalkyl Substances ◽  
Perfluoroalkyl And Polyfluoroalkyl Substances

Perfluoroalkyl and Polyfluoroalkyl Substances (PFASs) pose a substantial threat as endocrine disruptors, and thus early identification of those that may interact with steroid hormone receptors, such as the androgen receptor (AR), is critical. In this study we screened 5,206 PFASs from the CompTox database against the different binding sites on the AR using both molecular docking and machine learning techniques. We developed support vector machine models trained on Tox21 data to classify the active and inactive PFASs for AR using different chemical fingerprints as features. The maximum accuracy was 95.01% and Matthew’s correlation coefficient (MCC) was 0.76 respectively, based on MACCS fingerprints (MACCSFP). The combination of docking-based screening and machine learning models identified 29 PFASs that have strong potential for activity against the AR and should be considered priority chemicals for biological toxicity testing.

scholarly journals Presence of Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) In Food Contact Materials (FCM) and Its Migration to Food

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1443
Author(s):  
Arabela Ramírez Carnero ◽  
Antía Lestido-Cardama ◽  
Patricia Vazquez Loureiro ◽  
Letricia Barbosa-Pereira ◽  
Ana Rodríguez Bernaldo de Quirós ◽  
...  
Keyword(s):  
Fast Food ◽  
Food Packaging ◽  
Health Concern ◽  
Contact Materials ◽  
Food Contact Materials ◽  
Food Contact ◽  
Contaminated Food ◽  
Polyfluoroalkyl Substances ◽  
And Storage ◽  
Perfluoroalkyl And Polyfluoroalkyl Substances

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are synthetic chemical compounds widely used in different industry fields including food contact materials (FCM), providing resistance to fat and humidity, and non-stick properties. PFAS enter into the food chain directly from the intake of contaminated food or indirectly from the migration of the FCM into the food. This exposure published in different research highlights a public health concern. Therefore, it is necessary to perform analysis of the content of different FCM and evaluate the migration from the FCM under normal conditions of use and storage. This bibliographical review proves that different perfluoroalkyl and polyfluoroalkyl compounds are detected in fast food packaging, microwave popcorn bags, and frying pans, among others. Furthermore, it shows the conditions or factors that favor the migration of the PFAS from the FCM into the food.

Impacts of switching tillage to no-tillage and vice versa on soil structure, enzyme activities, and prokaryotic community profiles in Argentinean semi-arid soils

2021 ◽  
Author(s):  
L A Gabbarini ◽  
E Figuerola ◽  
J P Frene ◽  
N B Robledo ◽  
F M Ibarbalz ◽  
...  
Keyword(s):  
Community Structure ◽  
Soil Structure ◽  
Management Practices ◽  
Soil Health ◽  
Amplicon Sequencing ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Prokaryotic Community ◽  
C Cycle

Abstract The effects of tillage on soil structure, physiology, and microbiota structure were studied in a long-term field experiment, with side-to-side plots, established to compare effects of conventional tillage (CT) vs. no-till (NT) agriculture. After 27 years, part of the field under CT was switched to NT and vice versa. Soil texture, soil enzymatic profiles, and the prokaryotic community structure (16S rRNA genes amplicon sequencing) were analysed at two soil depths (0–5, 5–10 cm) in samples taken 6, 18, and 30 months after switching tillage practices. Soil enzymatic activities were higher in NT than CT, and enzymatic profiles responded to the changes much earlier than the overall prokaryotic community structure. Beta diversity measurements of the prokaryotic community indicated that the levels of stratification observed in long-term NT soils were already recovered in the new NT soils thirty months after switching from CT to NT. Bacteria and Archaea OTUs, which responded to NT were associated with coarse soil fraction, SOC and C cycle enzymes while CT responders were related to fine soil fractions and S cycle enzymes. This study showed the potential of managing the soil prokaryotic community and soil health through changes in agricultural management practices.

scholarly journals Fungal traits important for soil aggregation

2019 ◽  
Author(s):  
Anika Lehmann ◽  
Weishuang Zheng ◽  
Masahiro Ryo ◽  
Katharina Soutschek ◽  
Rebecca Rongstock ◽  
...  
Keyword(s):  
Soil Health ◽  
Well Being ◽  
Systematic Investigation ◽  
Fungal Species ◽  
Soil Aggregation ◽  
Aminopeptidase Activity ◽  
Aggregate Formation ◽  
Negative Effects ◽  
Saprobic Fungi ◽  
Positive Effects

AbstractSoil health and sustainability is essential for ecosystem functioning and human well-being. Soil structure, the complex arrangement of soil into aggregates and pore spaces, is a key feature of soils under the influence of soil life. Soil biota, and among them filamentous saprobic fungi, have well-documented effects on soil aggregation. However, it is unclear what fungal properties, or traits, contribute to the overall positive effect on soil aggregation. So far, we lack a systematic investigation of a broad suite of fungal species for their trait expression and the relation of these traits to their soil aggregation capability.Here, we apply a trait-based approach to a set of 15 traits measured under standardized conditions on 31 fungal strains including Ascomycota, Basidiomycota and Mucoromycota, all isolated from the same soil.We found a spectrum of soil aggregate formation capability ranging from neutral to positive and large differences in trait expression among strains. We identified biomass density (positive effects), leucine aminopeptidase activity (negative effects) and phylogeny as important modulators of fungal aggregate formation capability. Our results point to a typical suite of traits characterizing fungi that are good soil aggregators; this could inform screening for fungi to be used in biotechnological applications, and illustrates the power of employing a trait-based approach to unravel biological mechanisms of soil aggregation, which could now be extended to other organism groups.

Degradation and Removal Methods for Perfluoroalkyl and Polyfluoroalkyl Substances in Water

2016 ◽  
Vol 33 (9) ◽  
pp. 615-649 ◽  
Author(s):  
Nancy Merino ◽  
Yan Qu ◽  
Rula A. Deeb ◽  
Elisabeth L. Hawley ◽  
Michael R. Hoffmann ◽  
...  
Keyword(s):  
Polyfluoroalkyl Substances ◽  
Perfluoroalkyl And Polyfluoroalkyl Substances
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