Occurrence and spatiotemporal distribution of arsenic biotransformation genes in urban dust.

Microbially-mediated arsenic biotransformation plays a pivotal role in the biogeochemical cycling of arsenic; however, the presence of arsenic biotransformation genes (ABGs) in urban dust remains unclear. To investigate the occurrence and spatiotemporal distributions of ABGs, a total of one hundred and eighteen urban dust samples were collected from different districts of Xiamen city, China in summer and winter. Although inorganic arsenic species, including arsenate [As(V)] and arsenite [As(III)], were found to be predominant, the methylated arsenicals, particularly trimethylarsine oxide [TMAs(V)O] and dimethylarsenate [DMAs(V)], were detected in urban dust.

Comprehensive analysis of metal(loid)s and associated metal(loid) resistance genes in atmospheric particulate matter.

Despite global concerns about metal(loid)s in atmospheric particulate matter (PM), the presence of metal(loid) resistance genes (MRGs) in PM remains unknown. Therefore, we conducted a comprehensive investigation of the metal(loid)s and associated MRGs in PMs in two seasons (summer and winter) in Xiamen, China. According to the geoaccumulation index (I), most metal(loid)s, except for V and Mn, exhibited enrichment in PM, suggesting potential anthropogenic sources.

Roxarsone biotransformation by a nitroreductase and an acetyltransferase in Pseudomonas chlororaphis, a bacterium isolated from soil.

Roxarsone (3-nitro-4-hydroxyphenylarsonic acid, Rox), a widely used organoarsenical feed additive, can enter soils and be further biotransformed into various arsenic species that pose human health and ecological risks. However, the pathway and molecular mechanism of Rox biotransformation by soil microbes are not well studied. Therefore, in this study, we isolated a Rox-transforming bacterium from manure-fertilized soil and identified it as Pseudomonas chlororaphis through morphological analysis and 16S rRNA gene sequencing.

Identification and characterization of a phosphinothricin N-acetyltransferase from Enterobacter LSJC7.

Phosphinothricin (PPT) is a widely used and non-selective herbicide. PPT-resistance genes, especially PPT N-acetyltransferase genes, have been used in the development of transgenic PPT-resistant crops. However, there are only a limited number of available PPT-resistance genes for use in plant biotechnology.

Characteristics and provenances of rare earth elements and Nd isotopes in surface sediments of mangrove wetlands in the Jiulong River Estuary, China.

Rare earth elements (REEs) and Nd isotopes are frequently employed to determine provenance, although their characteristics and provenances in the surface sediments of mangrove wetlands are rarely analyzed. In this study, a thorough analysis of the characteristics and provenances of REEs and Nd isotopes in the surface sediments of mangrove wetland in the Jiulong River Estuary was carried out. According to the results, the mean concentration of REEs in the surface sediments was 290.

Inhibitory effect of polyethylene microplastics on roxarsone degradation in soils.

Roxarsone (3-nitro-4-hydroxyphenylarsonic acid, Rox(V)), an extensively used organoarsenical feed additive, enters soils through the application of Rox(V)-containing manure and further degrades to highly toxic arsenicals. Microplastics, as emerging contaminants, are also frequently detected in soils. However, the effects of microplastics on soil Rox(V) degradation are unknown.

[Speciation and Pollution Assessment of Heavy Metals in Mangrove Surface Sediments in Jiulong River Estuary].

The speciation of heavy metals was analyzed using modified BCR four-step extraction methods to analyze the pollution of heavy metals in surface sediments collected from the mangrove wetland in Jiulong River Estuary. Subsequently, the pollution degree and the ecological risk of heavy metals were evaluated by using the ratio of secondary phase to primary phase (RSP), risk assessment code (RAC), and modified potential ecological risk index (MRI) assessment methods. The results of BCR four-step extraction showed that Cd (52.

Bioaccessibility of microplastic-associated heavy metals using an in vitro digestion model and its implications for human health risk assessment.

Microplastics can act as carriers of heavy metals and may enter humans through ingestion and threaten human health. However, the bioaccessibility of heavy metals associated with microplastics and its implications for human health risk assessments are poorly understood. Therefore, in this study, four typical heavy metals (As(V), Cr(VI), Cd(II), and Pb(II)) and one typical microplastic (polyvinyl chloride, PVC) were chosen to estimate the human health risk of microplastic-associated heavy metals by incorporating bioaccessibility.

Randomized Trial of First-Line Tyrosine Kinase Inhibitor With or Without Radiotherapy for Synchronous Oligometastatic EGFR-Mutated Non-Small Cell Lung Cancer.

Background: Adding radiotherapy (RT) to systemic therapy improves progression-free survival (PFS) and overall survival (OS) in oligometastatic non-small cell lung cancer (NSCLC). Whether these findings translate to epidermal growth factor receptor (EGFR)-mutated NSCLC remains unknown. The SINDAS trial (NCT02893332) evaluated first-line tyrosine kinase inhibitor (TKI) therapy for EGFR-mutated synchronous oligometastatic NSCLC and randomized to upfront RT vs no RT; we now report the prespecified interim analysis at 68% accrual.

[Occurrence Characteristics of Microplastics in Mangrove Sediments in the Jiulong River Estuary and the Association with Heavy Metals].

The abundance and morphological characteristics of microplastics in the surface sediments of mangrove wetlands in the Jiulong River estuary were analyzed. The main sources of microplastics were also explored in detail. The results showed that the abundance of microplastics ranged from 640 to 1140 n·kg (dry sediment), with an average of 935 n·kg, exhibiting a medium level compared with other domestic and abroad mangrove areas.

Incorporating bioaccessibility and source apportionment into human health risk assessment of heavy metals in urban dust of Xiamen, China.

Heavy metals in urban dust could pose noticeable human health risks, but there are few studies focusing on comprehensive human health risk assessment with the incorporation of both bioaccessibility and source apportionment in urban dust. Thus, fifty-eight urban dust samples were collected from kindergartens in Xiamen to analyze the bioaccessibility-based, source-specific health risk of heavy metals (V, Co, Ni, As, Mo, Cr, Mn, Cu, Zn, and Pb). Most heavy metals, except for V and Mn, were significantly enriched in urban dust based on their values of geoaccumulation index (I) and may be influenced by human activities.

[Bioaccessibility and Health Risks of the Heavy Metals in Soil-Rice System of Southwest Fujian Province].

The bioaccessibility and health risks of heavy metals in soil-rice system of southwestern Fujian province were studied by combining a simple bioavailability extraction method (SBET) with a health risk assessment model. The results showed that some heavy metals in the agricultural soils and rice of southwestern Fujian province were enriched. The contents of Cd, Zn, Pb, and Cu were greater than the screening value of soil pollution risk for agricultural land (GB 15618-2018) by 32.

Bioaccumulation and biotransformation of arsenic in Leptolyngbya boryana.

Leptolyngbya boryana (L. boryana) is a typical filamentous cyanobacterium that is widely distributed in aquatic ecosystems and is considered to play an important role in the arsenic biogeochemical cycle. Our results showed that L.

Provenance and bioaccessibility of rare earth elements in atmospheric particles in areas impacted by the optoelectronic industry.

Rare earth elements (REEs) are widely used in optoelectronic industries, and they can be emitted into the environment and may induce biological effects. In this study, we investigated the provenance and bioaccessibility of REEs in atmospheric particles (APs) collected from areas impacted by the optoelectronic industry. The geoaccumulation index (I) values showed that Y, Eu, and Tb were much more enriched in the APs from the optoelectronic recycling sites than in those from the optoelectronic producing sites and were not enriched in the APs from the optoelectronic administrative sites and background sites.

[Source Appointment of Heavy Metals in Agricultural Soils of the Jiulong River Basin Based on Positive Matrix Factorization].

In order to study the source appointment of heavy metals in agricultural soils of the Jiulong River Basin, Fujian Province, China. 71 agricultural soil samples were collected in July 2017. The concentrations of heavy metals in agricultural soils were determined by inductively coupled plasma mass spectrometry (ICP-MS) and atomic fluorescence spectrometry (AFS).

[Migration and Source Analysis of Heavy Metals in Vertical Soil Profiles of the Drylands of Xiamen City].

The concentrations of eight heavy metal elements (V, Cr, Co, Ni, Cu, Zn, Sr, and Pb) and the isotopic composition of Pb and Sr were determined in vertical soil profiles of the drylands of Xiamen City using ICP-MS and TIMS. The vertical distributions and leaching migration patterns of the heavy metals were also analyzed. The results showed that most of the heavy metals (except for Sr) were not enriched relative background values at most profile depths, which indicated that heavy metal content is less affected by exogenous sources.

[Sources Analysis and Health Risk Assessment of Polycyclic Aromatic Hydrocarbons in the PM Fraction of Fugitive Dust in Nanchang City].

In order to understand the sources and health risks of polycyclic aromatic hydrocarbons in the PM fraction of road dust and soil dust in Nanchang city, PM samples were collected by a resuspension sampler and the concentrations of sixteen polycyclic aromatic hydrocarbons (PAHs) were detected. The results showed that the ΣPAHs of the road dust ranged from 48.85 to 166.

[Assessment of the Speciation and Pollution of Heavy Metals in Paddy Soils from the Jiulong River Basin].

Speciation characteristics of twelve heavy metals in 71 paddy soils from the Jiulong River Basin were analyzed using inductively coupled plasma mass spectrometry (ICP-MS) and the modified BCR protocol. The risk assessment coding method (RAC), ratio of secondary phase and primary phase (RSP), and geoaccumulation index (I) were applied to evaluate the pollution degree of heavy metals in the area. The results show that most of these elements are abundant in the paddy soils and the speciation characteristics of different heavy metals vary.

[Pollution Assessment and Source Analysis of Metals in PM in Haicang District, Xiamen City, China].

To determine the spatial-temporal distributions and potential sources of metals in PM and assess health risks from heavy metals, 348 PM samples were collected in the Haicang District of Xiamen, China from April 2015 to January 2016. Metals (K, Ca, Na, Mg, Al, Zn, Cu, Fe, Ti, As, V, Mn, Ba, Co) in PM were detected using an X-ray fluorescence analyzer (XRF). Pollution assessment was performed via enrichment factor calculation and health risk assessment.

[Seasonal Variation and Source Apportionment of Water-Soluble Ions in PM in Quanzhou City].

In this study, the seasonal characteristics of water-soluble ions (WSIs) present in fine particulate matter (PM) in Quanzhou City were investigated. PM samples were collected at five different sites in the city from March 2014 to January 2015 and the concentrations of Na, NH, K, Ca, Mg, F, Cl, NO, and SO were determined by ion-exchange chromatography. In order to identify the sources of these WSIs, the positive matrix factorization (PMF) analysis was applied.

[Composition Characteristics and Sources Apportionment of Lanthanoid in PM of Quanzhou].

Samples of PM were collected from 5 sites in Quanzhou in March, April and July, 2014. The concentrations of lanthanoid and other trace metals in the PM were determined by Inductively Coupled Plasma Mass Spectrometry(ICP-MS). The total lanthanoid concentration (Σ), the ratio of light-lanthanoid(L Loid, including, La, Ce, Pr, Nd, Sm and Eu) to heavy-lanthanoid(H Loid, including Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu) in PM were 2.

[Assessment of Heavy Metal Pollution and Tracing Sources by Pb & Sr Isotope in the Soil Profile of Woodland in Quanzhou].

The contents of 8 heavy metal elements (Sr, Ni, Fe, Cr, Cu, Mn, Pb, Zn) and the lead & strontium isotope composition of soil profile of woodland in Quanzhou city were analyzed by AAS and ICP-MS, respectively. A modified BCR four-step sequential extraction procedure was carried out to obtain the speciation fractionation of heavy metals in the soil profile from 4 stations. The results of the heavy metal elements and the speciation fractionation of heavy metals in the soil profile showed that the heavy metal pollution in the woodland in Quanzhou was relatively light, and the main pollution factor was Sr.

[Fractionation and Contamination Assessment of Metal Elements in the Surface Sediments of Yundang Lagoon in Xiamen].

Total concentrations of 15 metal elements in the surface sediments of Yundang Lagoon in Xiamen were determined using ICP-MS. The fractions were extracted by a modified BCR method. The results indicated that in different areas of Yundang Lagoon, the order of the concentrations of Cd, Cu, Sr, Pb, Zn and U was:outer lagoon > ditch > inner lagoon, the order for Cr, Co, Ni, V, Fe, Li, Rb and Mn was:inner lake > outer lake > ditch.

[Speciation and Ecological Risk of Heavy Metals in Surface Sediments from Jiulong River].

Speciation characteristics of fifteen heavy metals in seventeen surface sediments from Jiulong River was analyzed using the modified BCR protocol and dilute HNO method, respectively. The results of the modified BCR protocol showed that most of the elements (Fe, Ni, V, Tl, Ba, Sb, Ga, Cr and Sr) existed mainly in residual fractions, and extractable fraction was dominant for Mn (83.8%), followed by Cd, Pb, Zn, Co and Cu (80.

[Geochemical Characteristics and Source Apportionment of Rare Earth Elements in the Dustfall of Quanzhou City].

Rare earth elements (REE) have certain properties as tracing elements which result in their special geochemical characteristics. In order to study the geochemical characteristics of REE in the dustfall and their sources, 34 dustfall samples were collected in five functional areas and potential source areas of Quanzhou City, then REE compositions, distribution patterns and characteristic parameters were analyzed together with ternary diagrams and characteristic parameter diagrams, for investigating the main provenance. The results showed that ∑REE in the dustfall presented significant spatial difference with the sequence of industrial area>heavy traffic area > commercial area > residential area > agricultural area.