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1.
Ecotoxicol Environ Saf ; 220: 112404, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34111660

RESUMO

Cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg) and arsenic (As) are potent toxicants to human health via dietary intake. It is imperative to establish accurate soil thresholds based on soil-plant transfer models and food safety standards for safe agricultural production. This study takes rice genotypes and soil properties into account to derive soil thresholds for five heavy metal(loid)s using the bioconcentration factors (BCF) and species sensitivity distribution (SSD) based on the food safety standard. The BCF generated from two paddy soils was calculated to investigate the sensitivity of heavy metal accumulation in nine rice cultivars in a greenhouse pot experiment. Then, empirical soil-plant transfer models were developed from a middle-sensitivity rice cultivar (Denong 2000, one selected from nine rice) grown in nineteen paddy soils with various soil properties under a proper exogenously metal(loid)s concentration gradient. After normalization, hazardous concentrations from the fifth percentile (HC5) were calculated from the SSD curves, and the derived soil thresholds were obtained from HC5 prediction models that based on the combination of pH and organic carbon (OC) or cation exchange capacity (CEC). The soil Cd threshold derived based on pH and organic carbon (pH < 7.5, OC ≥ 20 g kg-1) was 1.3-fold of those only considering pH, whereas the Pb threshold (pH > 6, CEC ≥ 20 cmolc kg-1) was 3.1 times lower than the current threshold. The derived thresholds for five elements were validated to be reliable through literature data and field experiments. The results suggested that deriving soil heavy metal(loid)s threshold using SSD method and local food safety standards is feasible and also applicable to other crops as well as other regions with potential health risks of toxic elements contamination in agricultural production.


Assuntos
Metais Pesados/normas , Oryza/crescimento & desenvolvimento , Poluentes do Solo/normas , Solo/normas , Arsênio/análise , Arsênio/normas , Cádmio/análise , Cádmio/normas , Cromo/análise , Cromo/normas , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/normas , Inocuidade dos Alimentos , Humanos , Chumbo/análise , Chumbo/normas , Mercúrio/análise , Mercúrio/normas , Metais Pesados/análise , Oryza/química , Oryza/genética , Solo/química , Poluentes do Solo/análise
2.
Bull Environ Contam Toxicol ; 105(2): 250-254, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32666193

RESUMO

Polychlorinated biphenyls (PCBs) are a class of persistent organic pollutants that pose a threat to environment and human health. Aiming at predicting PCBs risk in actual soil ecosystem, this study was conducted by chemical and biological methods to assess the bioavailability of PCBs in spiked soil, and in field-contaminated soils before or after remediation. The three chemical methods were Soxhlet, n-butanol and hydroxypropyl-ß-cyclodextrin (HPCD). Results were compared to actual PCB bioaccumulation in earthworms (Eisenia fetida). HPCD extraction was the best to predict the actual PCB bioaccumulation in all soils. The results suggest that HPCD could be an effective alternative method to earthworm toxicity test. This study provides strategy to understand the toxicity assessment in contaminated soil and soil after remediation.


Assuntos
Recuperação e Remediação Ambiental/métodos , Oligoquetos/efeitos dos fármacos , Bifenilos Policlorados/toxicidade , Poluentes do Solo/toxicidade , Solo/química , 1-Butanol/química , 2-Hidroxipropil-beta-Ciclodextrina/química , Animais , Bioacumulação , Disponibilidade Biológica , China , Ecossistema , Fertilizantes/análise , Oligoquetos/química , Bifenilos Policlorados/análise , Solo/normas , Poluentes do Solo/análise , Testes de Toxicidade
3.
Environ Geochem Health ; 42(12): 4193-4201, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32613478

RESUMO

This study investigated the contamination levels and sources of As and Cd vicinity area from Nui Phao mine that is one of the largest tungsten (W) open pit mines in the world. Soil and plant samples were collected from the study area to identify the concentrations of As and Cd using aqua-regia or HNO3 digestion. According to the Vietnamese agricultural soil criteria, all soil samples were contaminated with As and Cd. The distribution of As concentration is related to the distance from the Nui Phao mine. The higher As concentrations were measured in the area close to the mine. However, the Cd distribution in the soil showed a different pattern from As. Enrichment factor and Geoaccumulation Index (Igeo) indicated that As in the soil is derived from the mining activities, while Cd could have other geogenic or anthropogenic sources. The ranges of As and Cd concentration in polished rice grains in the Nui Phao mine area exceeded the CODEX criteria (0.2 mg/kg), which indicated extreme contamination. The arsenic concentration between soil and plant samples was determined to be a positive correlation, while the Cd concentration showed a negative correlation, implying that As and Cd have different geochemical behavior based on their sources.


Assuntos
Arsênio/análise , Cádmio/análise , Mineração , Poluentes do Solo/análise , Agricultura/normas , Grão Comestível/química , Monitoramento Ambiental , Oryza/química , Solo/química , Solo/normas , Vietnã
4.
Bull Environ Contam Toxicol ; 105(2): 244-249, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32556691

RESUMO

The aim of the study was to assess the effects of silver nanoparticles (AgNPs1 = 2.7 d·nm, AgNPs2 = 6.5 d·nm) and silver nitrate (AgNO3) on Enchytraeus crypticus and Folsomia candida using toxicity tests (OECD Guideline 220, 232). A 28-day chronic toxicity study was performed to evaluate the reproduction and mortality rate. E. crypticus reproduction was more sensitive to AgNO3 with a 28dEC50 of 86.40 (62.52-119.4) mg·kg-1 dry weight (d.w.) compared to AgNPs1 (28dEC50 = 119.3 (60.4-235.6) mg·kg-1 d.w). Similarly, the reproduction of F. candida was inhibited the most by AgNO3 with a 28dEC50 of 126.2 (104.2-152.9) mg·kg-1 d.w. followed by AgNPs1 (28dEC50 = 158.7 (64.05-393.2) mg·kg-1 d.w.) and AgNPs2 (28dEC50 = 206.4 (181.9-234.1) mg·kg-1 d.w.). No mortalities were observed for tested soil invertebrates exposed to AgNPs at concentrations up to 166 mg·kg-1 d.w. of AgNPs1 and 300 mg·kg-1 d.w. of AgNPs2, respectively. It was found that silver ions are more toxic in comparison with AgNPs.


Assuntos
Artrópodes/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Oligoquetos/efeitos dos fármacos , Nitrato de Prata/toxicidade , Prata/toxicidade , Poluentes do Solo/toxicidade , Animais , Íons , Nanopartículas Metálicas/química , Reprodução/efeitos dos fármacos , Prata/química , Solo/química , Solo/normas , Poluentes do Solo/química , Testes de Toxicidade Crônica
5.
Microbiome ; 8(1): 79, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32487269

RESUMO

BACKGROUND: Soil ecosystems consist of complex interactions between biological communities and physico-chemical variables, all of which contribute to the overall quality of soils. Despite this, changes in bacterial communities are ignored by most soil monitoring programs, which are crucial to ensure the sustainability of land management practices. We applied 16S rRNA gene sequencing to determine the bacterial community composition of over 3000 soil samples from 606 sites in New Zealand. Sites were classified as indigenous forests, exotic forest plantations, horticulture, or pastoral grasslands; soil physico-chemical variables related to soil quality were also collected. The composition of soil bacterial communities was then used to predict the land use and soil physico-chemical variables of each site. RESULTS: Soil bacterial community composition was strongly linked to land use, to the extent where it could correctly determine the type of land use with 85% accuracy. Despite the inherent variation introduced by sampling across ~ 1300 km distance gradient, the bacterial communities could also be used to differentiate sites grouped by key physico-chemical properties with up to 83% accuracy. Further, individual soil variables such as soil pH, nutrient concentrations and bulk density could be predicted; the correlations between predicted and true values ranged from weak (R2 value = 0.35) to strong (R2 value = 0.79). These predictions were accurate enough to allow bacterial communities to assign the correct soil quality scores with 50-95% accuracy. CONCLUSIONS: The inclusion of biological information when monitoring soil quality is crucial if we wish to gain a better, more accurate understanding of how land management impacts the soil ecosystem. We have shown that soil bacterial communities can provide biologically relevant insights on the impacts of land use on soil ecosystems. Furthermore, their ability to indicate changes in individual soil parameters shows that analysing bacterial DNA data can be used to screen soil quality. Video Abstract.


Assuntos
Ecossistema , Microbiologia do Solo , Solo , Bactérias/genética , Bactérias/metabolismo , Nova Zelândia , RNA Ribossômico 16S/genética , Solo/química , Solo/normas
6.
Ecotoxicol Environ Saf ; 194: 110418, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32151872

RESUMO

The increasing accumulation of zinc (Zn) in agricultural soils has led to the need to assess the potential risk of this element for terrestrial organisms. However, the soil ecological criteria in agricultural soil as a function of soil properties have been sparsely reported. In the present study, we derived the ecological criteria (expressed as predicted no effect concentration (PNEC)) for Zn in soils, based on ecotoxicity data for 19 terrestrial species in Chinese soils, the effect of soil properties on Zn ecotoxicity, differences in species sensitivity, and differences between laboratory and realistic field conditions. First, all ecotoxicity data of Zn for terrestrial organisms in Chinese soils were collected and filtered with given criteria to obtain reliable database. Second, the ecotoxicity data were normalized using Zn ecotoxicity predictive models to eliminate the effect of soil properties on Zn ecotoxicity, and corrected with leaching and aging factors to minimize the differences in Zn ecotoxicity under laboratory and field conditions. Then, species sensitivity distribution (SSD) curves were generated with a Burr Ⅲ function based on corrected ecotoxicity data. The concentration of Zn in soil that provides ecological safety for (100 - x)% of species (HCx), was calculated from the SSD curve and HC5 was used for estimation of PNEC. Finally, we developed the predictive models for HCx by quantifying the relationship between the Zn HCx and soil properties. Results showed that soil pH was the most crucial factor affecting Zn HCx values, with HC5 values varying from 38.3 mg/kg in an acidic soil to 263.3 mg/kg in an alkaline calcareous soil. Both the two-factor (soil pH and OC) and the three-factor (soil pH, OC and CEC) models predicted HCx values well, with determination coefficients (R2) of 0.941-0.959 and 0.978-0.982, respectively. This study provides a scientific and reliable basis for the improvement of ecological risk assessment and the establishment of soil environmental quality standards.


Assuntos
Monitoramento Ambiental/métodos , Poluentes do Solo/análise , Solo , Zinco/análise , Agricultura , China , Bases de Dados Factuais , Ecotoxicologia , Modelos Teóricos , Medição de Risco , Solo/química , Solo/normas
7.
Chemosphere ; 239: 124709, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31499302

RESUMO

The effect of organic fertilizers on soil phosphorus (P) availability is usually mainly associated with the rate and forms of P applied, while they also alter the soil physical-chemical properties, able to change P availability. We aimed to highlight the impact of pH and organic C modifications in soil on the inorganic P (Pi) sorption capacity and availability as compared to the effect of P accumulation after mineral or organic fertilizers. We conducted a 10-years-old field experiment on an andosol and compared fields that had been amended with mineral or organic (dairy slurry and manure compost) fertilizers against a non-fertilized control. Water and Olsen extractions and Pi sorption experiments were realized on soils sampled after 6 and 10 years of trial. We also realized an artificial and ex situ alkalization of the control soil to isolate the effect of pH on Pi sorption capacity. Organic fertilizer application increased total P, pH, and organic C in soil. Pi-Olsen increased mainly with soil total P (r2 adj = 0.79), while Pi-water increased jointly with soil total P and pH (r2 adj = 0.85). The Pi sorption capacity decreased with organic fertilizer application. Artificial and ex situ alkalization of the control soil showed that Pi sorption capacity decreased with increasing pH. Our study demonstrated that, beyond the P fertilization rate, the increase in organic C content and even more so in pH induced by a decade of organic fertilizer applications in soil decreased the Pi sorption capacity and consequently increased Pi-water in soil.


Assuntos
Fertilizantes , Fósforo/química , Solo/química , Adsorção , Carbono , Concentração de Íons de Hidrogênio/efeitos dos fármacos , Esterco , Minerais , Fósforo/análise , Fósforo/farmacologia , Solo/normas
8.
Environ Pollut ; 256: 113145, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31662249

RESUMO

Distinct cropland acidification has been reported in China due to nitrogen (N) fertilizer overuse. However, the impacts on food production and thereby on food security are largely unknown. Yield losses in the period 1980-2050 were therefore assessed by simulating soil pH changes combined with derived pH-yield relationships for wheat, maize and rice. If the N fertilizer input continues to increase at 1% annually, the predicted average soil pH decline is about one unit and relative yield losses are expected to increase from approximately 4%-24% during 2010-2050. If the N fertilizer increase stops in 2020 (N2020), the expected losses are approximately 16% in 2050, which is comparable to a scenario of 100% crop residue return (100%RR). However, if 30% of the N fertilizer is replaced by manure N (30%MR), the losses reduce to near 5% in 2050. Soil acidification was predicted to reverse and expected losses are only 2.5% in 2050 in a combined scenario of N2020, 100%RR and 30%MR. Our results illustrate the potential food insecurity induced by cropland acidification and address the necessity of mitigation.


Assuntos
Produção Agrícola/métodos , Produtos Agrícolas/crescimento & desenvolvimento , Abastecimento de Alimentos , Solo/química , China , Fertilizantes/análise , Abastecimento de Alimentos/normas , Concentração de Íons de Hidrogênio , Esterco/análise , Nitrogênio/análise , Oryza/crescimento & desenvolvimento , Risco , Solo/normas , Triticum/crescimento & desenvolvimento , Zea mays/crescimento & desenvolvimento
9.
Environ Monit Assess ; 192(1): 13, 2019 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31811402

RESUMO

Solarisation application by mulching the soil with a polyethene plastic film has a significant influence on soil thermal characteristics (TCs), which, in turn, show a strong impact on soil energy balance and agricultural productivity. In countries like Iraq with highly populated cities, such as Baghdad, that need large quantities of agriproducts, this kind of clean energy should play a key role in sustainable agricultural production. However, little is known about the effects of different soil solarisation systems in specific cultivated fields for this country characterised by an arid climate and silty clay soils. Therefore, an experimental study was conducted to investigate changes in soil TCs under different soil solarisation systems (black and clear plastics) at three different soil depths in a two-factor factorial design. Also, both the black and clear plastic plots were compared with a control (without mulch) plot treatment. Three different soil TCs were assessed, namely soil thermal flux (qℎ), soil thermal conductivity (k), and soil volumetric heat capacity (Cv). The results of this study indicated that the soil solarisation application had a significant influence on soil TCs. Soil qℎ decreased with increasing soil depth, while k and Cv exhibited an opposite trend. The black plastic mulch treatment produced higher soil qℎ, k, and Cv values than both the clear plastic and the control treatments. Moreover, high diurnal variability of the TCs was also registered, and the clear plastic conserved a higher temperature than the black one during the night hours. During daylight, the black mulch reached a maximum temperature of 70 °C. It is recommended that more research should be conducted to get new insights on the interplay of the different seasons, and different crops and soil types.


Assuntos
Agricultura/métodos , Monitoramento Ambiental , Plásticos , Solo/normas , Temperatura , Iraque , Estações do Ano , Solo/química
10.
Ecotoxicol Environ Saf ; 183: 109569, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31454751

RESUMO

Dibutyl phthalate (DBP) is a ubiquitous soil contaminant. We have investigated the sorption, degradation and residue of DBP in 20 types of agricultural soils and aimed to identify the major soil properties that dominate the fate of DBP. Sorption isotherms of DBP in all soils were fitted well with the Freundlich model. The sorption coefficient (Kf) varied between 3.99 and 36.1 mg1-1/nL1/n/kg. Path analysis indicated that 59.9% of variation in Kf could be explained by the combination of pH, organic carbon (OC) and clay content. Degradation of DBP in the 20 soils was well described by the first-order kinetic model, with half-lives (t1/2) ranging from 0.430 to 4.99 d. The residual DBP concentration after 60 d of incubation (R60) ranged from 0.756 to 2.15 mg/kg and the residual rates ranged from 3.97% to 9.63%. The Kf value was significantly positively correlated with t1/2 and R60. Moreover, soil pH, microbial biomass carbon (Cmic) and OC were identified as dominating factors that explained 84.4% of variation in t1/2. The R60 data indicated 72.2% of its variability attributable to the combination of OC and Cmic. The orders of the relative importance of dominating factors on the Kf, t1/2 and R60 were OC > pH > clay, Cmic > pH > OC and OC > Cmic, respectively. This work contributes to better understand the fate of DBP in soils and make scientific decisions about accelerating its dissipation in different soils.


Assuntos
Dibutilftalato/análise , Microbiologia do Solo , Poluentes do Solo/análise , Solo/química , Adsorção , Agricultura , Carbono/análise , Concentração de Íons de Hidrogênio , Cinética , Solo/normas
11.
Biol Rev Camb Philos Soc ; 94(5): 1857-1880, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31270944

RESUMO

Mycorrhizal fungi benefit plants by improved mineral nutrition and protection against stress, yet information about fundamental differences among mycorrhizal types in fungi and trees and their relative importance in biogeochemical processes is only beginning to accumulate. We critically review and synthesize the ecophysiological differences in ectomycorrhizal, ericoid mycorrhizal and arbuscular mycorrhizal symbioses and the effect of these mycorrhizal types on soil processes from local to global scales. We demonstrate that guilds of mycorrhizal fungi display substantial differences in genome-encoded capacity for mineral nutrition, particularly acquisition of nitrogen and phosphorus from organic material. Mycorrhizal associations alter the trade-off between allocation to roots or mycelium, ecophysiological traits such as root exudation, weathering, enzyme production, plant protection, and community assembly as well as response to climate change. Mycorrhizal types exhibit differential effects on ecosystem carbon and nutrient cycling that affect global elemental fluxes and may mediate biome shifts in response to global change. We also note that most studies performed to date have not been properly replicated and collectively suffer from strong geographical sampling bias towards temperate biomes. We advocate that combining carefully replicated field experiments and controlled laboratory experiments with isotope labelling and -omics techniques offers great promise towards understanding differences in ecophysiology and ecosystem services among mycorrhizal types.


Assuntos
Micorrizas/classificação , Micorrizas/fisiologia , Plantas/microbiologia , Microbiologia do Solo , Solo/normas , Simbiose , Carbono/metabolismo , Ecossistema , Nitrogênio/metabolismo , Fósforo/metabolismo , Fenômenos Fisiológicos Vegetais , Raízes de Plantas/microbiologia , Solo/química , Estresse Fisiológico/fisiologia , Árvores/microbiologia , Árvores/fisiologia
12.
Environ Pollut ; 250: 839-848, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31051395

RESUMO

The effect of different Na concentrations on the fate of trace metals (Cd, Cu, Ni, Zn) in standard OECD soil was evaluated by performing soil leaching column experiments. Five Na concentrations added in synthetic irrigation water (0, 1, 5, 10, 50 mM) were studied in order to evaluate the fate of the metals contained in both the irrigation water leachate and the soil layer. In all experiments, metals mostly accumulated on the top soil layer (0-0.5 cm), at variable concentrations according to the Na content in the artificial irrigation water. Nevertheless, concentration peaks of metal contamination occurred at different sampling time in the soil leachates depending on the metal and on influent water sodicity. Peaks of metals in the leachate appeared simultaneously with the release of organic matter and/or release of Al, suggesting significant involvement of colloids in metals transport. Sodium concentration (10-50 mM) was demonstrated to highly reduce colloidal mobilization leading to the accumulation of more than 95% of the influent metal in the top soil layer. Conversely, low Na concentrations (1-5 mM) favored colloidal transport leading to the recovery of metals in the soil leachates.


Assuntos
Metais Pesados/análise , Sódio/análise , Poluentes do Solo/análise , Solo , Oligoelementos/análise , Irrigação Agrícola/normas , Coloides/análise , Modelos Teóricos , Organização para a Cooperação e Desenvolvimento Econômico , Solo/química , Solo/normas
13.
Environ Pollut ; 250: 883-891, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31085474

RESUMO

This article contains a brief overview of the European and Spanish environmental law framework for the prevention of soil contamination, for the management of contaminated soils and for consumers health protection in relation to agricultural crops. Some important aspects of the legislative framework for the prevention and management of soil contamination include recognising the possible risk to both human health and ecosystems that certain agricultural and industrial activities pose given the use of organic and inorganic chemical substances of a hazardous nature and pathogenic microorganisms. It is worth highlighting the milestone that many national constitutions include about the right to the environment. This right entails the obligation to protect it and to, therefore, protect soil from any degradation, including contamination. Legislation that protects soil from contamination and, consequently human health and ecosystems, is related mainly to agricultural activities (use of sewage sludge on farmlands, use of wastewater for irrigation, use of organic fertilisers and pesticides), and to industrial and commercial soil-contaminating activities. Consumer protection may be achieved through a legal system of environmental liability, specific measures to prevent contaminants entering soil, managing contaminated soils and a food traceability system. It is crucial to make the penalties for soil contamination offenses, and for violators of protective prohibitions, effective, proportionate and dissuasive. Global standards and guidelines on soil contamination could provide national legislative systems with substantive and procedural legal mechanisms to help prevent and manage soil contamination.


Assuntos
Produção Agrícola/legislação & jurisprudência , Produtos Agrícolas/crescimento & desenvolvimento , Poluição Ambiental/legislação & jurisprudência , Inocuidade dos Alimentos , Solo , Poluição Ambiental/análise , Poluição Ambiental/prevenção & controle , Contaminação de Alimentos/análise , Contaminação de Alimentos/prevenção & controle , Regulamentação Governamental , Humanos , Praguicidas/análise , Esgotos/química , Solo/química , Solo/normas , Espanha
14.
Environ Monit Assess ; 191(4): 257, 2019 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-30929074

RESUMO

In order to study the effect of biochar application as simple and enriched, on the soil nutrients status in the salinity conditions, a research was conducted as a factorial arrangement based on completely randomized design (CRD) with three replicates. The biochar (grape pruning residues) was applied in three levels (0, 2% biochar, and 2% enriched biochar by rock phosphate and cow manure). Also, the salinity treatment was considered in three levels (2, 4.5, and 9 dSm-1). After treating the soil, it was incubated in polyethylene containers for a 70-day period at 25 °C and 70% field capacity moisture regime. The results showed that salinity significantly affected the soil pH, electrical conductivity (EC), calcium, magnesium, sodium, basal respiration, and nitrifying bacteria frequency (P < 0.001) and chloride concentration (P < 0.01). Also, the biochar significantly affected the pH, organic carbon, concentration of total nitrogen, phosphorous, solution potassium, sodium, iron, zinc, copper, basal respiration, and nitrifying bacteria frequency (P < 0.001) of the soil. The interaction effect of biochar and salinity levels was significant on soil sodium concentration (P < 0.01) and pH (P < 0.05). In comparison with the control treatment, the enriched biochar, decreased soil pH (about 1.4%) and increased the phosphorous, iron, and zinc up to 36%, 29%, and 36%, respectively and simple biochar increased the Nitrogen and Potassium up to 46% and 48%, respectively. In general, it was concluded that both types of the biochars lowered the sodium concentration of the soil in different salinity levels due to high potential of biochar for sodium absorption which this ability may be considered in saline soils remediation.


Assuntos
Carvão Vegetal/química , Monitoramento Ambiental/métodos , Salinidade , Solo/química , Animais , Bovinos , Recuperação e Remediação Ambiental , Feminino , Esterco/análise , Nitrogênio/análise , Fosfatos/análise , Fósforo/análise , Solo/normas , Microbiologia do Solo/normas
15.
Environ Pollut ; 249: 703-715, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30933768

RESUMO

Persistent organic pollutants (POPs) including PCDD/Fs, PCBs and organochlorine pesticides (OCPs) are among the most important and hazardous pollutants of soil. Food producing animals such as chicken, beef, sheep and goats can take up soil while grazing or living outdoors (free-range) and this can result in contamination. In recent decades, large quantities of brominated flame retardants such as polybrominated diphenyl ethers (PBDEs), short-chain chlorinated paraffins (SCCPs) and per- and polyfluorinated alkylated substances (PFAS) have been produced and released into the environment and this has resulted in widespread contamination of soils and other environmental matrices. These POPs also bioaccumulate and can contaminate food of animal origin resulting in indirect exposure of humans. Recent assessments of chicken and beef have shown that surprisingly low concentrations of PCBs and PCDD/Fs in soil can result in exceedances of regulatory limits in food. Soil contamination limits have been established in a number of countries for PCDD/Fs but it has been shown that the contamination levels which result in regulatory limits in food (the maximum levels in the European Union) being exceeded, are below all the existing soil regulatory limits. 'Safe' soil levels are exceeded in many areas around emission sources of PCDD/Fs and PCBs. On the other hand, PCDD/F and dioxin-like PCB levels in soil in rural areas, without a contamination source, are normally safe for food producing animals housed outdoors resulting in healthy food (e.g. meat, eggs, milk). For the majority of POPs (e.g. PBDEs, PFOS, PFOA, SCCP) no regulatory limits in soils exist. There is, therefore, an urgent need to develop appropriate and protective soil standards minimising human exposure from food producing animals housed outdoors. Furthermore, there is an urgent need to eliminate POPs pollution sources for soils and to control, secure and remediate contaminated sites and reservoirs, in order to reduce exposure and guarantee food safety.


Assuntos
Dibenzofuranos Policlorados/análise , Monitoramento Ambiental/legislação & jurisprudência , Inocuidade dos Alimentos , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análise , Poluentes do Solo/análise , Solo/normas , Animais , Ovos/análise , Monitoramento Ambiental/métodos , Humanos , Carne/análise , Solo/química
16.
Environ Sci Pollut Res Int ; 26(17): 17195-17203, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31012070

RESUMO

To explore the possibility of using flue gas desulfurization gypsum (FGDG) for inhibiting phosphorus (P) loss due to agricultural runoff, a 3-year study was performed in the farmlands of Chongming Dongtan between 2012 and 2015. Five different quantities of FGDG were used to treat the soil, and the effects of different treatments on the characteristics of soil P and crop growth were investigated. The results showed that 2 years after application of FGDG, the soil density at a depth of 0-10 cm decreased by 4.35-7.97%, the porosity increased by 1.77-11.0%, and the topsoil permeability increased by 0.87-3.81 times. Although the use of FGDG did not change the total P concentration in the soil, it decreased the concentration of sodium bicarbonate extractable P in the soil. Compared to the control, the average extractable P concentration at depths of 0-10 cm, 10-20 cm, and 20-30 cm decreased by 22.0-46.1%, 26.9-40.5%, and 22.8-34.8%, respectively. The inorganic P in the soil increased as the amount of FGDG increased, and the increase was mainly as Ca-P in the forms Ca2-P and Ca10-P. The decrease in bicarbonate extractable P and increase in inorganic P in the soil did not affect the growth of the crops, and the biomass and output of the crops increased compared to the control. Therefore, FGDG can enhance soil P immobilization, thus reducing soluble P runoff from farm fields, and improving water quality in receiving lakes and rivers while maintaining P nutrition to the crops.


Assuntos
Sulfato de Cálcio/química , Conservação dos Recursos Naturais/métodos , Fósforo/análise , Solo/química , Agricultura , China , Gases/química , Solo/normas
17.
Chemosphere ; 224: 634-636, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30849623

RESUMO

We aimed to develop an ex situ method for evaluating soil quality using soil algae. The soil algae pipe assay involves application and sampling of algae and flow cytometry. As it can be performed in a greenhouse, the assay was effective for pot tests and conducive for soil quality assessment. This novel assay will enable broader toxicity testing.


Assuntos
Bioensaio/métodos , Solo/normas , Chlamydomonas reinhardtii , Citometria de Fluxo , Poluentes do Solo/análise , Testes de Toxicidade/métodos
18.
Ecotoxicol Environ Saf ; 174: 475-483, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30856559

RESUMO

Nickel (Ni) is a toxic metal, but studies on Ni toxicity to soil-dwelling springtail are fairly limited, and did not consider the effects of various soil properties and long aging time. To address this, the chronic toxicity of Ni to model organism-Folsomia candida in relation to soil properties and aging time were evaluated in the laboratory study. The results showed that compared to the soils aged only for 7 d, the concentrations causing 50% mortality (LC50) and inhibiting 50% reproduction (EC50) basing measured total Ni in four soils aged for 120 d increased by 1.30-1.94 fold and 1.27-1.82 fold, respectively. Furthermore, the aging effects significantly correlated with soil pH. The toxicity values of Ni differed in ten soils aged for 120 d, the LC50 values were 279-4025 mg/kg and the EC50 values were 133-1148 mg/kg. When calculating the toxicity values basing water soluble and CaCl2 extracted Ni, the variations in LC50 values between ten soils decreased, while the variations in EC50 values increased. Regression analysis indicated that soil pH was the most important single factor predicting soil Ni toxicity to springtail, the combination of soil pH and OM could best explain Ni toxicity variance in ten soils (89.1% of the variance in LC50 values and 89.6% of the variance in EC50 values).


Assuntos
Artrópodes/efeitos dos fármacos , Níquel/toxicidade , Poluentes do Solo/toxicidade , Solo/química , Animais , Artrópodes/fisiologia , Relação Dose-Resposta a Droga , Dose Letal Mediana , Reprodução/efeitos dos fármacos , Solo/normas , Fatores de Tempo , Testes de Toxicidade
19.
Chemosphere ; 224: 212-219, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30822727

RESUMO

Non-ionic surfactants (Triton X-100 and Brij 30) and core-crosslinked amphiphilic polymer (CCAP) nanoparticles were used as extractants in the ex situ soil washing of silt loam soil contaminated with large quantities of petroleum oil, and their soil-washing performances were compared. Following washing with the surfactants, highly turbid aqueous solutions containing large numbers of soil and petroleum oil particles were produced. In contrast, the CCAP nanoparticles successfully extracted the petroleum oils from the soil samples without the formation of such a turbid aqueous solution. In addition, the CCAP nanoparticles extracted 96% of the petroleum oils, which is a significantly larger quantity than that by Brij 30 and Triton X-100 under equivalent conditions. Indeed, owing to their crosslinked micelle-like structure, the CCAP nanoparticles maintained their nanostructure even upon contact with a highly contaminated silt loam soil matrix, thereby resulting in the extraction of only the hydrophobic oily contaminants from the soil matrix and avoiding the formation of dispersions of soil particles and hydrophobic contaminants. As such, CCAP nanoparticles could be considered as suitable washing materials for highly contaminated silt loam soils.


Assuntos
Nanopartículas/química , Petróleo/análise , Polímeros/química , Poluentes do Solo/análise , Solo/química , Tensoativos/química , Recuperação e Remediação Ambiental , Micelas , Octoxinol/química , Polidocanol/química , Solo/normas
20.
Ecotoxicol Environ Saf ; 174: 189-196, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30826545

RESUMO

Previous research on soil remediation focused on soil properties and not on its effects on soil ecosystems. The present study investigated the adverse effects of soil physicochemical changes due to remediation on the biological indicators Chlorococcum infusionum and Chlamydomonas reinhardtii (algae) and Eisenia andrei (earthworm). Soil physicochemical properties, concentrations of total, bioavailable, and water-soluble heavy metals in soil were measured before and after remediation. Changes in soil pH, electrical conductivity, total nitrogen, and total phosphorous immediately after soil remediation were the primary causes of the biomass and photosynthetic activity inhibition observed in C. infusionum and C. reinhardtii, and the survival, normality, and burrowing behavior decrease observed in E. andrei in remediated soils showing dramatic changes in those properties. These findings suggest that remediated soils need some time to recover before restoring their functions, although heavy metals are no longer contaminating the soil.


Assuntos
Chlamydomonas reinhardtii/efeitos dos fármacos , Recuperação e Remediação Ambiental , Metais Pesados/toxicidade , Oligoquetos/efeitos dos fármacos , Poluentes do Solo/toxicidade , Solo/química , Animais , Disponibilidade Biológica , Metais Pesados/análise , Fotossíntese/efeitos dos fármacos , Solo/normas , Poluentes do Solo/análise , Análise de Sobrevida
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