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1.
Ecotoxicol Environ Saf ; 207: 111281, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32919195

RESUMO

Epidemiological studies of human and animal experiments indicated that gestational exposure to atmospheric pollutants could be followed by the abnormal placental development. However, the effects of this exposure on the placental transportation for nutrients have not been systematically investigated. In this study, fine particulate matters (PM2.5) samples were collected in Taiyuan and pregnant rodent models were administered with 3 mg/kg b.w. PM2.5 by oropharyngeal aspiration every other day starting on embryonic day 0.5 (E0.5). Then the pregnant mice were sacrificed and their placentas were collected at different time points. The results showed that maternal PM2.5 exposure (MPE) disrupted the expression of proliferating cell nuclear antigen (PCNA) at all time points and inhibited the cell proliferation in placenta. Following that, the capacity for placental nutrient transport was impaired. The changes at E18.5 were observed most significantly, showing the altered mRNA expression of amino acid, long-chain polyunsaturated fatty acid (LCPUFA), glucose and folate transporters. In addition, the glycogen content was elevated at E18.5, and the triglyceride content was increased at E13.5 and E15.5 and decreased at E18.5 in the placenta after MPE. In a word, the adverse effect induced by MPE revealed that MPE led tothe disruption on the nutrient supply to the developing fetus via modulating the abundance of placental nutrient transporters (PNT).


Assuntos
Poluentes Atmosféricos/toxicidade , Exposição Materna/efeitos adversos , Nutrientes/metabolismo , Material Particulado/toxicidade , Placenta/efeitos dos fármacos , Poluentes Atmosféricos/metabolismo , Aminoácidos/metabolismo , Animais , Transporte Biológico , Proliferação de Células/efeitos dos fármacos , Ácidos Graxos/metabolismo , Feminino , Glucose/metabolismo , Glicogênio/metabolismo , Humanos , Troca Materno-Fetal/efeitos dos fármacos , Camundongos , Material Particulado/metabolismo , Placenta/metabolismo , Placenta/patologia , Gravidez
2.
PLoS One ; 15(11): e0242698, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33211764

RESUMO

Polychlorinated biphenyls (PCBs) have been withdrawn from the market due to their toxicity, bioaccumulation capacity, and persistence. PCBs have been observed to potentially form in combustion processes under appropriate conditions and in the presence of precursors containing chlorine. The study covered a municipal waste incineration plant and an industrial waste incineration plant. The objective of the study was to assess the effect of these objects on PCB accumulation in soil and plants taking into account the distance from the emission object and wind direction. Soil samples were collected from layers: 0-5, 5-10, 10-20, and 20-30 cm. Test plants were collected from the same areas as the soil samples. The highest accumulation of PCBs was found in plants with large leaf area. Around the municipal waste incineration plant, these were Tanacetum vulgare leaves (12.45 ng/g), and around the industrial waste incineration plant-grasses (4.3 ng/g). In the case of soils, the accumulation of PCBs for both kind waste incinerators was similar, reaching approximately 3 ng/g. As the distance from the municipal waste incinerator and industrial waste incinerator increased, the accumulation of PCBs in the soil decreased. For municipal waste incinerator, no effect of wind direction on PCB accumulation in the soil was observed. In the majority of cases, the accumulation of PCBs in soils taken from the leeward side of the industrial waste incinerator was higher than that in soils from the windward side. In soils around the municipal waste incinerator, PCB compounds moved deep into the soil and reached the highest accumulation in the soil layer of 10-20 cm or 20-30 cm. In soils around the industrial waste incinerator, the highest accumulation of PCBs occurred in the soil layer of 0-5 cm.


Assuntos
Poluentes Atmosféricos , Monitoramento Ambiental , Incineração , Bifenilos Policlorados , Solo/química , Tanacetum/metabolismo , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/metabolismo , Folhas de Planta/metabolismo , Bifenilos Policlorados/análise , Bifenilos Policlorados/metabolismo , Poluentes do Solo/análise , Poluentes do Solo/metabolismo
3.
Medicine (Baltimore) ; 99(48): e23152, 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-33235076

RESUMO

This study aimed to study the effect and mechanism of action of SO2-induced oxidation on human skin keratinocytes.Different concentrations of SO2 derivatives (0, 25, 50, 100, 200, 400, and 800 µM) were used for treating HaCaT keratinocytes for 24 hours. MTT was used to evaluate the effect of each concentration on cell proliferation. HaCaT cells were randomly divided into control and SO2 groups. The control group received no treatment, whereas the SO2 group was treated with SO2 derivatives of selected concentrations for 24 hours. The levels of reactive oxygen species (ROS), malondialdehyde (MDA), and superoxide dismutase (SOD), tumor necrosis factor TNF-α (TNF-α), and interleukin-1 (IL-1-ß) in cell supernatants were detected using enzyme-linked immunosorbent assay. Real-time polymerase chain reaction was used to detect the expression of nuclear transcription factor (Nrf2) and heme oxygenase (HO)-1 mRNA. The Western blot analysis was used to test the expression levels of Nrf2, HO-1, activated caspase-3, Bcl-2, Bax, IκB, NF-κB p65 (p65), ERK1/2, p38, phospho-NF-κB p65 (p-p65), p-ERK1/2, and p-p38.SO2 derivatives (100, 200, 400, and 800 µM) could inhibit cell proliferation. SO2 derivatives increased the level of ROS, MDA, TNF-α, IL-1ß, Nrf2, HO-1, and p-p65/p65 and decreased the levels of SOD, IκB, p-ERK1/2/ERK1/2, and p-p38/p38 compared with the control group, but they had no effect on the levels of caspase-3, Bcl-2, and Bax.SO2 could inhibit the proliferation of human skin keratinocytes and induce oxidative stress and inflammation via the activation of the NF-κB pathway to inhibit the ERK1/2 and p38 pathways.


Assuntos
Poluentes Atmosféricos/efeitos adversos , Queratinócitos/metabolismo , Dióxido de Enxofre/efeitos adversos , Poluentes Atmosféricos/metabolismo , Estudos de Casos e Controles , Caspase 3/genética , Proliferação de Células/efeitos dos fármacos , /metabolismo , Heme Oxigenase-1/genética , Humanos , Proteínas I-kappa B/genética , Inflamação/metabolismo , Interleucina-1beta/metabolismo , Queratinócitos/efeitos dos fármacos , Queratinócitos/patologia , Malondialdeído/metabolismo , Fator 2 Relacionado a NF-E2/genética , NF-kappa B/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Dióxido de Enxofre/metabolismo , Superóxido Dismutase/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
4.
Chemosphere ; 254: 126863, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957281

RESUMO

In urban set up, increasing combustion and processing activities have contaminated the air with toxic heavy metals which are generally enriched on atmospheric particulate matter. Vegetation around urban area act as a sink where such metal enriched particles generally deposit on the foliar surfaces, however, role of vegetation in uptake of metals adhered on the atmospheric particulate matter is yet not explored properly and is important to study to evaluate their role as bio-remediator. The undertaken work examines the foliar surface of Morus alba for its potential to deposit and accumulate atmospheric heavy metals. Further, to understand foliar uptake mechanism and translocation of atmospheric metal enriched on particulate matter a simulated experiment was conducted by labeling the known particle size (45 µm and 120 µm) with radio labeled 65Zn, applied on the tagged leaf with two particle loads, 25 mg and 50 mg. The study showed that owing to its rough foliar surface with trichomes and grooves, Morus alba efficiently trap heavy metal enriched particles and was capable of accumulating metals from particulate matter into different plant parts. It was recorded that 65Zn adhered on different size particles was taken up by tagged leaf of mulberry and majorly translocated to the lower stem and roots. It was also inferred from the study that both particle size and particle load significantly affect the foliar uptake and translocation of atmospheric heavy metal. The study focuses on the fact that urban avenue trees are capable of taking up atmospheric heavy metals and can play a crucial role in improving air quality.


Assuntos
Poluentes Atmosféricos/metabolismo , Morus/metabolismo , Material Particulado/farmacocinética , Zinco/farmacocinética , Poluentes Atmosféricos/farmacocinética , Poluição do Ar , Biodegradação Ambiental , Tamanho da Partícula , Material Particulado/análise , Material Particulado/química , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Traçadores Radioativos , Radioisótopos de Zinco/farmacocinética
5.
J Dairy Sci ; 103(8): 7199-7209, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32475675

RESUMO

Records of methane emissions from 1,501 cows on 14 commercial farms in 4 regions of Spain were collected from May 2018 to June 2019. Methane concentrations (MeC) were measured using a nondispersive infrared methane detector installed within the feed bin of the automatic milking system during 14- to 21-d periods. Rumination time (RT; min/d) was collected using collars with a tag that registered time (minutes) spent eating and ruminating. The means of MeC and methane production (MeP) were 1,254.28 ppm and 182.49 g/d, respectively; mean RT was 473.38 min/d. Variance components for MeC, MeP, and RT were estimated with REML using pedigree and genomic information in a single-step model. Heritabilities for MeC and MeP were 0.11 and 0.12, respectively. Rumination time showed a slightly larger heritability estimate (0.17). The genetic correlation between MeP and MeC was high (>0.95), suggesting that selection on either trait would lead to a positive correlated response on the other. Negative correlations were estimated between RT and MeC (-0.24 ± 0.38) and MeP (-0.43 ± 0.35). Methane concentration and MeP had slightly positive correlations with milk yield (0.17 ± 0.39 and 0.21 ± 0.36), protein percentage (0.08 ± 0.32 and 0.30 ± 0.45), protein yield (0.22 ± 0.41 and 0.31 ± 0.35), fat percentage (0.02 ± 0.40 and 0.27 ± 0.36), and fat yield (0.27 ± 0.28 and 0.29 ± 0.28) from bivariate analyses. Rumination time had positive correlations with milk yield (0.41 ± 0.75) and protein yield (0.26 ± 0.57) and negative correlations with fat yield (-0.45 ± 0.32), protein percentage (-0.15 ± 0.38), and fat percentage (-0.40 ± 0.47). A positive approximated genetic correlation was estimated between fertility and MeC (0.10 ± 0.05) and MeP (0.18 ± 0.05), resulting in slightly higher CH4 production when selecting for better fertility [days open estimated breeding values (EBV) are expressed with mean 100 and SD 10, inversely related to days from calving to conception; that is, greater days open EBV implies better fertility]. Positive correlations were also estimated for stature with MeC and MeP (0.30 ± 0.04 and 0.43 ± 0.04, respectively). Other type traits (chest width, udder depth, angularity, and capacity) were positively correlated with methane traits, possibly because of higher milk yield and higher feed intake from these animals. Rumination time showed positive EBV correlations with production traits and type traits, and negative correlations with somatic cell count and body condition score. Based on the genetic correlations and heritabilities estimated in this study, methane is measurable and heritable, and estimates of genetic correlations suggest no strong opposition to current breeding objectives in Spanish Holsteins.


Assuntos
Bovinos/genética , Fertilidade/genética , Metano/metabolismo , Leite/metabolismo , Seleção Genética , Poluentes Atmosféricos/metabolismo , Animais , Cruzamento , Bovinos/fisiologia , Contagem de Células/veterinária , Indústria de Laticínios , Ingestão de Alimentos , Feminino , Genômica , Gases de Efeito Estufa , Lactação , Glândulas Mamárias Animais/fisiologia , Linhagem , Fenótipo , Espanha
6.
Chemosphere ; 256: 127093, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32470731

RESUMO

Bio-trickling filters (BTFs) can be used for the treatment of hydrophobic VOC-contaminated air. To improve treatment performance, two novel polydimethylsiloxane (PDMS) packing media were produced and trialled in BTFs inoculated with Cladophialophora fungus. The BTF packed with PDMS/foam ceramic composite filler showed superior performance: rapid start-up within 3 days, rapid restart within 7 days after starvation for 1 month, a maximum toluene elimination capacity (EC) of 264.4 g m-3·h-1 at an empty bed residence time of 10 s, and a pressure drop that was controllable by adjusting the nutrient supply regime. High-throughput sequencing was used to analyse the effect of spatial position on the microbial communities in the top and bottom filler layers. Meanwhile, by investigating the EC in the vertical direction of the BTF, spatial heterogeneity in the fungal degradation of a hydrophobic VOC was preliminarily explored.


Assuntos
Biodegradação Ambiental , Reatores Biológicos , Siloxanas/química , Compostos Orgânicos Voláteis/metabolismo , Aerossóis , Poluentes Atmosféricos/metabolismo , Cerâmica , Dimetilpolisiloxanos , Filtração , Fungos/metabolismo , Tolueno , Compostos Orgânicos Voláteis/análise
7.
Environ Geochem Health ; 42(10): 3185-3198, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32303945

RESUMO

Mercury (Hg) exchange at the plant leaf-atmosphere interface is an important issue when considering vegetation as a sink or source of this global pollutant. The aim of the study described here was to clarify this process by studying Hg exchange under laboratory conditions with a plant model, namely Epipremnum aureum. The desorption and absorption processes were studied under similar conditions in natural daylight. Hg exchange was measured at the foliar surface, and micrometeorological parameters and stomatal conductance were assessed. The results of the Hg exchange study showed different rhythms for the two processes, i.e. desorption (14-196 ng m-2 day-1) was slower than absorption (170-1341 ng m-2 day-1). The daily cycle was more complex in the desorption process, with a maximum when stomatal conductance was high but also with high values during nocturnal hours and a trend to absorption in the mornings. The daily absorption cycles were relatively simple, with values that coincided with positive stomatal conductance values and null values during nocturnal hours. The main factors involved in desorption were stomatal conductance and temperature, but other factors may need to be considered. The absorption process only involved total gaseous Hg, stomatal conductance and relative humidity. A net balance of the two experiments provided data on the amount of Hg transferred per unit leaf area (167 ng m-2 for desorption and 9213 ng m-2 for absorption), which implies total amounts of 23 ng of Hg desorbed and 1280 ng absorbed during the whole experiment. Finally, the reversible/non-reversible nature of the Hg exchange process must be reconsidered bearing in mind that Hg within the leaf can be emitted if changes in ambient conditions are appropriate to favour this process.


Assuntos
Poluentes Atmosféricos/metabolismo , Araceae/metabolismo , Monitoramento Ambiental , Mercúrio/metabolismo , Folhas de Planta/fisiologia , Absorção Fisiológica
8.
Bull Environ Contam Toxicol ; 104(4): 444-448, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32152686

RESUMO

Urban horticulture and community gardening have become more and more popular in the past years, however, the risk of bioaccumulation of atmospheric polyaromatic hydrocarbons (PAHs) in vegetables grown in polluted areas cannot be neglected. In our study, the No. 227 OECD GUIDELINE FOR THE TESTING OF CHEMICALS: Terrestrial Plant Test: Vegetative Vigour Test was followed to assess foliar uptake of PAHs from aqueous extract of an urban aerosol. Using lettuce (Lactuca sativa) as a test organism, significant accumulation was experienced. The highest bioconcentration factors (BCFs) were experienced for naphthalene and for anthracene, pyrene and fluoranthene showed the lowest bioaccumulation potential. BCF of each PAH showed strong correlation with molecular weight. The standard protocol defined by the Guideline made it possible to assess bioaccumulation pattern under controlled laboratory conditions.


Assuntos
Poluentes Atmosféricos/análise , Bioacumulação , Monitoramento Biológico/métodos , Alface/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Aerossóis , Poluentes Atmosféricos/metabolismo , Alface/metabolismo , Modelos Teóricos , Folhas de Planta/química , Folhas de Planta/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo
9.
Chemosphere ; 250: 126263, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32088616

RESUMO

The coupling between ferrous iron and methane production has important global implications, with iron ions acting as electron acceptors for anaerobic oxidation of methane (AOM) and inhibitors of methanogenesis in different environments, including floodplain soils. In this sense, we analyzed the relationship between Fe(II) concentration and methane production in soil layers collected at 0-15 cm and 15-30 cm from flooded-forest and -agroforestry in Amazonian clear water floodplain incubated in anaerobic batch reactors using acetate, formate and glucose as organic sources. High throughput sequencing of archaeal and bacterial 16S rRNA genes was employed to assess the abundance and composition of the active methanogenic and methanotrophic microbial groups potentially involved in Fe(III)-dependent AOM in the soil used as inoculum. Positive correlation was revealed between Fe(II) concentration and methane production, with higher accumulation of Fe(II) in incubated soil layer collected at 0-15 cm in both forest and agroforestry sites for all the three organic sources. The accumulation of Fe(II) in the incubated soil evidenced the oxidation of Fe(III) potentially by Methanobacterium, Desulfobulbus and 'Candidatus methanoperedens nitroreducens' living in anaerobic condition at this soil layer. The results point out to the microbial ferric iron reduction as an important potential pathway for anaerobic organic matter decomposition in Amazonian floodplain, evidencing methanogenesis suppression by Fe(III) reduction in flooded-forest and -agroforestry in Amazonian clear water river floodplain.


Assuntos
Poluentes Atmosféricos/metabolismo , Inundações , Metano/metabolismo , Microbiologia do Solo , Anaerobiose , Archaea/metabolismo , Brasil , Compostos Férricos/metabolismo , Florestas , Água Doce , Ferro/metabolismo , Methanosarcinales/metabolismo , Oxirredução , RNA Ribossômico 16S/genética , Solo
10.
Artigo em Inglês | MEDLINE | ID: mdl-32004916

RESUMO

Leaf senescence is a catabolic process that emits volatile organic compounds (VOCs). In densely planted monocultures these VOC emissions occur in outbursts that might be relevant for the local air quality since these VOCs are typically oxygenated. The VOC emissions of a high-density poplar (Populus) bioenergy plantation were monitored along with meteorological parameters, CO2 and H2O exchanges, canopy greenness, and leaf area index during the second half of the year 2015. The emissions of 25 VOCs peaked at the beginning of September, coinciding with the onset of senescence. Together these VOC emissions amounted to a total of 2.85 mmol m-2, translated into 98.3 mg C m-2. The emission peak was mainly composed of oxygenated VOCs as methanol, acetic acid, and lipoxygenase products that are all typical for catabolic processes. So, the senescence process of the poplar plantation was very well reflected in the peak of VOC emissions.


Assuntos
Envelhecimento , Populus , Compostos Orgânicos Voláteis , Envelhecimento/metabolismo , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/metabolismo , Folhas de Planta/metabolismo , Populus/metabolismo , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/metabolismo
11.
Environ Pollut ; 260: 113906, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31972416

RESUMO

We investigated the degradation of polycyclic aromatic hydrocarbons (PAHs) during long-range transport. Aerosols were collected simultaneously at remote sites on Tuoji Island, China; Fukue Island, Japan; and the Cape Hedo Atmosphere and Aerosol Measurement Station (CHAAMS), Okinawa, Japan in April, October, and December from 2012 to 2013. These remote sites were convenient for investigating the degradation of PAHs during long-range transport. PAHs were analyzed via gas chromatography/mass spectrometry. We identified air masses that passed over all sites and combined our measurements with a chemical transport model. We estimated the relative contributions of the PAHs at the three sites by normalizing the PAH concentrations to elemental carbon. Benzo[a]pyrene persisted in 5-16% of samples. The results of this study are consistent with laboratory studies in which secondary organic aerosol (SOA) coatings protected PAHs from degradation by ozone. We detected an inhibition of the degradation PAHs by SOA coatings by collecting PAHs simultaneously at the three sites. To elucidate the major sources of the SOAs, we carried out a positive matrix factorization analysis to identify the major sources of SOA coating, which controls the lifetime of PAHs. In spring and winter, the contribution of vehicle emissions was higher (46%) at Tuoji Island than at CHAAMS (13%). In contrast, the contribution of coal combustion was higher at CHAAMS (59%) than at Tuoji Island (28%). This result implies that during long-range transport, PAHs derived from coal combustion are more slowly degraded than PAHs derived from vehicle emissions. We found that the viscosity of SOA coatings derived from vehicle emissions in China was low, and the corresponding PAHs were rapidly degraded. In contrast, the viscosity of SOA coatings derived from coal combustion was high, and degradation of the corresponding PAHs was relatively slow. These results imply that PAHs derived from coal combustion have long lifetime.


Assuntos
Poluentes Atmosféricos , Monitoramento Ambiental , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/metabolismo , China , Carvão Mineral , Ilhas , Japão , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Estações do Ano
12.
Chemosphere ; 247: 125800, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31927182

RESUMO

Long-term operational stability of biotrickling filters (BTFs) degrading volatile organic compounds (VOCs) is dependent on both physicochemical as well as biological properties. Effects of increasingly stressful levels of air pollutants on the microbial structure of biofilms within BTFs are not well understood, especially for VOCs such as styrene. To investigate the relationship between biofilm biodiversity and operational stability, the temporal dynamics of a biofilm from a biotrickling filter subjected to stepwise increasing levels of air polluted with styrene was investigated using 16S rDNA pyrosequencing and PCR-denaturing gradient gel electrophoresis (PCR-DGGE). As styrene contaminant loads were increased, microbial community composition was distinctly altered and diversity was initially reduced in early stages but gradually stabilized and increased diversity in later stages, suggesting a recovery and acclimatization period within the microbial community during incremental exposure of the pollutant. Although temporary reductions in known styrene-degrading bacterial genera (Pseudomonas and Rhodococcus) occurred under increased styrene loads, stable BTF performance was maintained due to functional redundancy. New candidate genera for styrene degradation (Azoarcus, Dokdonella) were identified in conditions of high styrene loads, and may have supported the observed stable BTF performance throughout the experiment. Styrene inlet load was found to be important modulator of community composition and may have been partly responsible for the observed temporary reductions of Pseudomonas. Notable differences between dominant genera detected via pyrosequencing compared to species detected by PCR-DGGE suggests that simultaneous implementation of both techniques is valuable for fully characterizing dynamic microbial communities.


Assuntos
Bactérias/isolamento & purificação , Biodegradação Ambiental , Biodiversidade , Biofilmes/efeitos dos fármacos , Filtração/instrumentação , Estireno/farmacologia , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/metabolismo , Poluentes Atmosféricos/farmacologia , Bactérias/metabolismo , Reatores Biológicos/microbiologia , Eletroforese em Gel de Gradiente Desnaturante/métodos , Eletroforese em Gel de Gradiente Desnaturante/normas , Filtração/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Sequenciamento de Nucleotídeos em Larga Escala/normas , Microbiota/efeitos dos fármacos , Estireno/metabolismo , Compostos Orgânicos Voláteis/metabolismo
13.
Sci Total Environ ; 704: 135325, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-31839317

RESUMO

Biotrickling filters (BTFs) applied to hydrophobic volatile organic compounds (VOCs) suffer from limited mass transfer. Phase transfer kinetic and equilibrium effects limit the biodegradation of hydrophobic VOCs especially at high concentrations. This study evaluates two strategies for overcoming the problem. First, a natural process was used to enhance the aqueous availability of styrene, a hydrophobic VOC model, by inoculating the BTF with a mixture of biosurfactant-generating bacteria. This method achieved a maximum elimination capacity (ECmax) of 139 g m-3h-1 in the BTF at an empty bed residence time (EBRT) of 60s. The highest concentrations of the biosurfactants surfactin and rhamnolipid were 205 and 86 mg L-1, respectively, in this step. Sequencing 16S rRNA confirmed the presence of biosurfactant-producing bacteria capable of biodegrading styrene in the BTF including Bacillus sonorensis, Bacillus subtilis, Lysinibacillus sphaericus, Lysinibacillus fusiformis, Alcaligenes feacalis, Arthrobacter creatinolyticus, and Kocuria rosea. Second, the effect of adding H2O2 to the recycle liquid on the BTF performance was determined. The biodegradation and mineralization of styrene in the BTF operated at a loading rate of 266 g m-3h-1 and H2O2/styrene molar ratio of 0.05 with EBRT as short as 15 s were 94% and 53%, respectively, with the EC of 250 g m-3h-1. High concentrations of antioxidant enzymes (peroxidase and catalase: 56 and 7 U gbiomass-1, respectively) were produced and biosurfactant generation was increased in this step, contributing to enhanced styrene biodegradation and mineralization. The styrene biodegradation and mineralization values in the BTF in the last day operated under similar conditions but without H2O2 were 11.4% and 5.3%, respectively. The bacterial population had no considerable change in the BTF after adding H2O2. Accordingly, stimulating the BTF inoculated with biosurfactant-generating bacteria with H2O2 is a promising strategy for improving the biodegradation of hydrophobic VOCs.


Assuntos
Poluentes Atmosféricos/metabolismo , Biodegradação Ambiental , Estireno/metabolismo , Poluentes Atmosféricos/análise , Reatores Biológicos , Peróxido de Hidrogênio , Estireno/análise , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/metabolismo
14.
Environ Geochem Health ; 42(2): 483-497, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31342217

RESUMO

Aerobic methanotrophs in paddies serve as methane (CH4) filters and thereby reduce CH4 emissions. Amending soil with waste products can mitigate CH4 emissions in crops, but little is known about the impacts of amendments with steel slag and biochar on the populations and activities of aerobic methanotrophs in rice cropland. We used real-time quantitative PCR detecting system and high-throughput sequencing to determine the effects of slag and biochar amendments on CH4 emission, abundance, and community structure of methanotrophs, and the relationships between soil properties and the abundance and community composition of methanotrophs during the rice growing season in both early and late paddies. Soil salinity and pH were significantly higher for an amendment with both slag and biochar than the control in both the early and late paddies, and pH was significantly higher for a slag amendment in the late paddy. Cumulative CH4 emission was lower for the slag and slag + biochar amendments than the control in early paddy by-34.1%. Methanotrophic abundance was three- and sixfold higher for the slag + biochar amendment than the control in the early and late paddies (p < 0.05), respectively. The abundance of different groups of methanotrophs varied among the treatments. The relative abundance of Methylosarcina was higher for the slag amendment than the control, and the relative abundance of Methylomonas was lower for biochar, and slag + biochar amendments than the control. The relative abundance of Methylocystis was higher for the slag and slag + biochar amendments than the control in the early paddy, and the relative abundance of Methylocystis was higher for the slag, biochar, and slag + biochar amendments in the late paddy. Univariate and multivariate analyses indicated that the higher abundance of methanotrophic bacteria for the slag and slag + biochar amendments was correlated with soil pH, salinity, soil organic carbon, and C/N ratio, and the relative abundances of Methylocystis, Methylomonas, and Methylosarcina were associated with the effective mitigation of CH4 emission in the paddies. A discriminant general analysis indicated that the total population of methanotrophs was larger for the slag + biochar amendment than the control, and that this effect was only weakly correlated with changes in the soil properties, demonstrating that this effect on the size and species composition of methanotrophic soil populations was mostly associated with a direct effect of the slag + biochar amendment.


Assuntos
Poluentes Atmosféricos/análise , Carvão Vegetal/química , Metano/análise , Microbiologia do Solo , Resíduos , Poluentes Atmosféricos/metabolismo , Recuperação e Remediação Ambiental , Metalurgia , Metano/metabolismo , Oryza/crescimento & desenvolvimento , Estações do Ano , Solo/química
15.
Artigo em Inglês | MEDLINE | ID: mdl-31662034

RESUMO

Toluene is highly toxic and mutagenic, and it is generally used as an industrial solvent. Thus, toluene removal from air is necessary. To solve the problem of reducing high toluene concentrations with a short gas retention time (GRT), a quorum-sensing molecule [N-(3-oxododecanoyl)-L-homoserine lactone] (OHL) was added to a biotrickling filter (BTF). In this study, a BTF was used to treat synthetic and natural waste gases containing toluene. An extensive analysis was performed to understand the removal efficiency, removal characteristics, and bacterial community of the BTF. The addition of 20 µM OHL to the BTF significantly improved toluene removal, and more than 99.2% toluene removal was achieved at a GRT of 0.5 min when natural waste gas containing toluene (590-1020 ppm or 2.21-3.83 g m-3) was introduced. The maximum inlet load for toluene was 337.9 g m-3 h-1. Moreover, the BTF exhibited satisfactory adaptability to shock loading and shutdown operations. Pseudomonadaceae (33.0%) and Comamonadaceae (26.3%) were predominant bacteria in the system after a 98-day operation. These bacteria were responsible for toluene degradation. The optimal moisture content and low pressure drop for system operations demonstrated that the BTF was energy and cost efficient. Therefore, processing through a BTF with OHL is a favorable technique for toluene treatment.


Assuntos
Poluentes Atmosféricos/isolamento & purificação , Filtração/métodos , Microbiota , Percepção de Quorum , Tolueno/isolamento & purificação , 4-Butirolactona/análogos & derivados , 4-Butirolactona/metabolismo , Poluentes Atmosféricos/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Biodegradação Ambiental , Reatores Biológicos/microbiologia , Filtração/instrumentação , Gases/isolamento & purificação , Gases/metabolismo , Homosserina/análogos & derivados , Homosserina/metabolismo , Microbiota/genética , Tolueno/metabolismo
16.
Environ Sci Pollut Res Int ; 26(36): 36754-36763, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31741276

RESUMO

Stereocaulon sorediiferum is expected to be a Cu-hyperaccumulator lichen and has fluorescent substances. To clarify the relationship between the fluorescence (FL) of the lichen and its Cu concentration, we collected S. sorediiferum samples at Cu-contaminated and uncontaminated sites in Japan, determined the concentration of Cu, K, Mg, Al, Ca, Mn, Fe, Zn, chlorophyll a,b, and total carotenoids in them, analyzed lichen secondary metabolites and fluorescent substances extracted from them, and measured the FL of them and their extracts. We found that the FL intensity of S. sorediiferum samples is significantly negatively correlated with their Cu concentration. The application of its FL for Cu monitoring may allow a new nondestructive quantitative method for assessing Cu contamination. The spectroscopic and chromatographic analysis shows that the fluorescent substances negatively correlated with Cu concentration are not major lichen secondary metabolites (lobaric acid and atranorin) and remain after immersion in acetone. The correlation analysis and the comparison with the causal relationship between Cu concentration and the chlorophyll a/b ratio suggest that the reason for the decrease in FL intensity with increasing Cu concentration is a structural change of the fluorescent substances by accumulated Cu. These findings lead to a better understanding of the relationship between the FL of S. sorediiferum and its Cu concentration and provide new insights into fluorescent lichen substances.


Assuntos
Poluentes Atmosféricos/toxicidade , Ascomicetos/efeitos dos fármacos , Cobre/toxicidade , Fluorescência , Poluentes Atmosféricos/metabolismo , Ascomicetos/metabolismo , Clorofila , Clorofila A , Cobre/análise , Cobre/metabolismo , Depsídeos , Hidroxibenzoatos , Japão , Lactonas , Líquens/química , Líquens/efeitos dos fármacos , Salicilatos
17.
J Dairy Sci ; 102(12): 11153-11168, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31587912

RESUMO

Global warming caused by greenhouse gas emissions is a threat to the survival of humans and other organisms living on Earth. The greenhouse gases released from the dairy sector of New Zealand accounted for 18.2 Mt of carbon dioxide equivalent (CO2-eq) in 2016, mainly from methane generated by enteric fermentation in the rumen of milking cows and their replacement stock. A productivity commission established by the New Zealand government in 2018 estimated that methane emissions from livestock needed to be reduced from 2016 levels by 10 to 22% by 2050 (i.e., 2.8 to 6.1 million t lower), so as to restrict future increases in global temperature to less than 2°C. In this study, we evaluated genetic effects of 8 traits included in the New Zealand national dairy breeding objective, on 3 types of methane emissions metrics: gross methane emissions per dairy cow per year (E), methane emissions per hectare (EH), and methane emissions intensity per milk protein equivalents (EI), as carbon dioxide equivalents. These effects were then aligned with recent genetic changes in these traits brought about by breeding schemes, so that the overall genetic trend for each metric into the future was estimated. The results showed that EH and EI are currently being reduced at rates of -2.31 kg of CO2-eq per hectare per cow per year (current average is 6,915 kg of CO2-eq/ha per cow per year) and -0.04 kg of CO2-eq per kg of milk protein equivalents per cow per year, respectively (current average is 9.7 kg of CO2-eq/milk protein-eq per cow per year). These improvements directly reflect increased production efficiency through selection for farm profitability. If the pastureland area in New Zealand remains the same, at the same productivity and with no increase in supplementation rates from external land sources, in 20 years gross emissions would be reduced by only 0.6%, or 89 Mt. Increased production efficiency will likely result in corresponding changes to the stocking rate, to fully utilize the pasture resource available, and might further encourage a greater rate of intensification via supplementary feeding. Both consequences of current genetic selection could negate any benefits for the national greenhouse gas inventory. New selection criteria for reduced methane production are needed to help achieve New Zealand's national methane reduction targets.


Assuntos
Poluentes Atmosféricos/metabolismo , Cruzamento , Bovinos/metabolismo , Gases de Efeito Estufa/metabolismo , Metano/metabolismo , Animais , Dióxido de Carbono/análise , Bovinos/genética , Indústria de Laticínios/métodos , Feminino , Fermentação , Aquecimento Global , Leite , Proteínas do Leite/metabolismo , Nova Zelândia
18.
Nat Commun ; 10(1): 3866, 2019 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-31530803

RESUMO

Particle transfer across the placenta has been suggested but to date, no direct evidence in real-life, human context exists. Here we report the presence of black carbon (BC) particles as part of combustion-derived particulate matter in human placentae using white-light generation under femtosecond pulsed illumination. BC is identified in all screened placentae, with an average (SD) particle count of 0.95 × 104 (0.66 × 104) and 2.09 × 104 (0.9 × 104) particles per mm3 for low and high exposed mothers, respectively. Furthermore, the placental BC load is positively associated with mothers' residential BC exposure during pregnancy (0.63-2.42 µg per m3). Our finding that BC particles accumulate on the fetal side of the placenta suggests that ambient particulates could be transported towards the fetus and represents a potential mechanism explaining the detrimental health effects of pollution from early life onwards.


Assuntos
Poluentes Atmosféricos/metabolismo , Exposição Materna/efeitos adversos , Troca Materno-Fetal , Placenta/metabolismo , Fuligem/metabolismo , Poluentes Atmosféricos/toxicidade , Bélgica , Biópsia , Estudos de Coortes , Ecotoxicologia , Feminino , Humanos , Microscopia Eletrônica de Transmissão , Permeabilidade , Placenta/patologia , Placenta/ultraestrutura , Gravidez , Características de Residência/estatística & dados numéricos , Fuligem/análise , Fuligem/toxicidade
19.
Bull Environ Contam Toxicol ; 103(5): 750-755, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31555848

RESUMO

With increasing urbanization and industrialization, clean air is becoming a scarce resource. During the present investigation, concentrations of metals (Pb, Ni and Zn) in the atmosphere and their subsequent deposition in the lungs of two common avian species, common myna, Acridotheres tristis (n = 30) and bank myna, A. ginginianus (n = 20), captured from urban areas of Lahore city and semi-urban areas of Pattoki city 80 km away from main city of Lahore were determined. The obtained results were analyzed statistically using Independent sample t test and Pearson's correlation. A comparison of trace metal concentrations in air of both the cities was also carried out. Statistically, significant variations were recorded for Pb (t (7) = - 4.276, p = 0.001) while non-significant differences were observed for both Ni (t (7) = 0.049, p = 0.962) and Zn (t (7) = 1.555, p = 0.146).


Assuntos
Poluentes Atmosféricos/metabolismo , Aves/metabolismo , Monitoramento Ambiental/métodos , Pulmão/metabolismo , Metais Pesados/metabolismo , Oligoelementos/metabolismo , Animais , Bioacumulação , Cidades , Paquistão , Urbanização
20.
Environ Sci Pollut Res Int ; 26(29): 29620-29638, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31463756

RESUMO

Mosses were proved as an ideal and reliable biomonitor as well as an indicator of atmospheric trace metal pollution. They are used as model indicator species of air pollution since long back due to their simple structure, genetic diversity, totipotency, rapid colony-forming ability, and high metal resistance behavior. Bryomonitoring technique is gradually being popularized as an economically viable procedure for estimating the degrees of environmental health and evaluating the toxic pollutants in biosphere. Thus, in the present scenario, many parts of the world use these organisms for monitoring the air pollution. This article describes an overview of the relationship of terrestrial mosses with trace metals with respect to their uptake, accumulation, and toxification as well as detoxification and tolerance mechanisms. The review article explicitly expresses the caliber of the cryptogamic mosses in establishing the pristine environment around the world. It also highlights the underpinning mechanisms and potential for future research directions. We have referred more than 250 articles, which deals with the assessment and impact of different heavy metals on 52 numbers of different moss species belongs to different climatic zones. The present review covers the research work in this area carried out worldwide since 1965.


Assuntos
Poluentes Atmosféricos/análise , Briófitas/efeitos dos fármacos , Briófitas/fisiologia , Monitoramento Ambiental/métodos , Metais Pesados/análise , Poluentes Atmosféricos/metabolismo , Poluentes Atmosféricos/toxicidade , Poluição do Ar , Briófitas/química , Bryopsida/química , Metais Pesados/metabolismo , Metais Pesados/toxicidade
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