Soils are both a sink and a pathway of plastic wastes, but there is a great lack of knowledge regarding their impacts on soil biota. To tackle the mechanisms of toxicity of these contaminants to soil ...invertebrates, earthworms (
Eisenia fetida
Savigny, 1826) were exposed during 28 days to different concentrations of low-density polyethylene microplastics (62, 125, 250, 500 and 1000 mg MPs kg
−1
soil
dw
) with sizes ranging between 250 and 1000 μm, in an artificial soil. The ecotoxicological responses were evaluated by analysing various oxidative stress biomarkers (catalase, glutathione S-transferase and thiobarbituric acid reactive substances), a biomarker of energy metabolism (lactate dehydrogenase) and overall organism molecular changes by Fourier transform infrared spectrometry (FTIR) and nuclear magnetic resonance (NMR) analyses. Significant effects resulting from an unbalanced oxidative stress system, expressed in terms of thiobarbituric acid reactive substances levels were recorded on earthworms exposed at the three highest concentrations tested. Despite that, no significant changes were recorded on the molecular profiles of earthworms by FTIR-ATR. NMR analysis pointed out for differences from the control, only for earthworms exposed to the lowest concentration of MPs. Considering that stress responses are complex, and involve multiple mechanisms, a cluster analysis taking into account all the parameters assessed, clearly identified two groups of earthworms separated by the concentration of 250 mg MPs kg
−1
soil
dw
, above each meaningful effects were recorded.
Urbanisation and industrialisation are on the rise all over the world. Environmental contaminants such as potentially toxic elements (PTEs) are directly linked with both phenomena. Two PTEs that ...raise greatest concern are arsenic (As) and lead (Pb) as soil and drinking water contaminants, whether they are naturally occurring or the consequence of human activities. Both elements are potential carcinogens. This paper reviews the mechanisms by which As and Pb impair metabolic processes and cause genetic damage in humans. Despite efforts to ban or limit their use, due to high persistence both continue to pose a risk to human health, which justifies the need for further toxicological research.
Transdisciplinary approaches that provide holistic views are essential to properly understand soil processes and the importance of soil to society and will be crucial in the future to integrate ...distinct disciplines into soil studies. A myriad of challenges faces soil science at the beginning of the 2020s. The main aim of this overview is to assess past achievements and current challenges regarding soil threats such as erosion and soil contamination related to different United Nations sustainable development goals (SDGs) including (1) sustainable food production, (2) ensure healthy lives and reduce environmental risks (SDG3), (3) ensure water availability (SDG6), and (4) enhanced soil carbon sequestration because of climate change (SDG13). Twenty experts from different disciplines related to soil sciences offer perspectives on important research directions. Special attention must be paid to some concerns such as (1) effective soil conservation strategies; (2) new computational technologies, models, and in situ measurements that will bring new insights to in-soil process at spatiotemporal scales, their relationships, dynamics, and thresholds; (3) impacts of human activities, wildfires, and climate change on soil microorganisms and thereby on biogeochemical cycles and water relationships; (4) microplastics as a new potential pollutant; (5) the development of green technologies for soil rehabilitation; and (6) the reduction of greenhouse gas emissions by simultaneous soil carbon sequestration and reduction in nitrous oxide emission. Manuscripts on topics such as these are particularly welcomed in Air, Soil and Water Research.
Soil pollution by potentially toxic elements (PTEs) as one of the major environmental hazards is associated with metal exploration and refining acting. In this study, forty-five topsoil samples ...surrounding a copper smelter factory were taken and analysed using standard routine methods. The total concentration, chemical fractionation and the mobility potential of As, Cd, Cr, Cu, Pb and Zn were analysed. Additionally, the spatial distribution of PTEs, the potential ecotoxicological, and human health risks was assessed. The range of total Cu was 1478–4718 mg kg
−1
, reaching up to 501.5, 21.6, 118.4, 573.5 and 943.3 mg kg
−1
for total contents of As, Cd, Cr, Pb and Zn, respectively. The potentially available fractions after sequential extraction reveal all studied PTE were dramatically mobile and available in the studied area (86%, 69.3%, 59.5%, 87.2%, 84% and 68% for As, Cd, Cr, Pb, Zn and Cu, respectively), reflecting that the concentration and accumulation of these elements are profoundly affected or originated by smelting activities and deposition of atmospheric emissions of the Cu smelting factory. The spatial distribution of all PTEs indicated that concentrations of these element near the smelter Cu-factory were elevated. Accordingly, the ecotoxicology status of the studied area suggests that significantly high risks are posed by the measured PTEs. Non-carcinogenic effects of As, Pb and Cu were significantly much higher than the recommended value (HI = 1), suggesting that these three PTEs could adversely impact children's health. For adults, only the HI value of As was greater than one.
Graphic abstract
Civilian and military shooting range facilities cause environmental issues in several countries due to the accumulation of Potentially Toxic Elements; as a result of weathering of ammunitions ...accumulated into the soils. The contents and distribution of Cu, Ni, Pb and Zn were analyzed in 12 soils in an abandoned clay target shooting range at two different depths (0–15 and 15–30 cm). Single extractions (CaCl
2
and DTPA) and Tessier sequential extraction were conducted to assess the PTE mobility and the PTE distribution in the different soil geochemical fractions at both depths. High total contents of Pb were found at both soil depths, while Cu, Ni and Zn showed lower significance levels. Copper, Ni and Zn are mainly associated with the residual fraction (> 95% of total content in all cases). However, Pb was highly associated with exchangeable fractions (21–52%), showing a high mobility at both depths. With moderate-high contents of organic matter (6–12%), the studied soils have acidic values and low levels of Al, Fe and Mn oxides that favors the migration of Pb through the soil profile and potential transformation to more mobile forms (Pb
0
to Pb
2+
and Pb
4+
). Although Pb reduced downward mobility in soils, due to the specific conditions of these facilities and the lead source (weathering of ammunition), risk assessment studies on clay-target shooting and firing range facilities should study the potential migration of Pb through the soil profile.
Soil quality in urban areas is deteriorating globally due to diverse anthropogenic activities. This study assessed urban soils from Shiraz (SW Iran), a city with heterogeneous industrial activity and ...anthropogenic emissions. The objectives of this study were to (1) determine soil properties and concentrations of cobalt, chromium, iron and nickel and (2) assess the geoaccumulation index (
I
geo
), enrichment factor and pollution indices of the studied metals and their adverse impacts on environmental quality and human health. A total of 143 soil samples (0–20-cm depth) were collected from the study area, and multivariate analysis, including spatial mapping, was performed. The average concentrations of chromium and nickel exceeded the limits for residential/parkland/industrial soils according to Canadian guidelines, whereas the average cobalt concentration was less than that specified by Swedish and Canadian guidelines. A multivariate analysis (cluster analysis, Pearson correlation and principal component analysis) confirmed that the heavy metals had the same origin and that anthropogenic activities had a significant effect on the heavy metal contamination of the soil. Furthermore, the contamination factor and enrichment factor indicated that the soil samples were moderately to highly contaminated by nickel, chromium and cobalt, whereas
I
geo
indicated very high contamination in all soil samples tested. The potential ecological risk index and modified potential ecological risk index also indicated moderate to high ecological risk from the heavy metals in the urban soil samples.
Potentially toxic elements (PTE) are considered to be dangerous threats, both for human health and the environment. Here, the contamination level, sources, and ecological risks posed by PTE were ...investigated in 19 topsoils from agricultural lands in the Bandar Abbas County on the southern coast of Iran. The soil fraction <63 μm was used for the analysis of the pseudototal contents of PTE (arsenic, cadmium, cobalt, chromium, copper, lead, manganese, molybdenum, nickel, vanadium, and zinc). The results were analyzed using principal component analysis (PCA) and Pearson’s correlations, different pollution indices enrichment factor (EF), contamination factor (Cf), and modified degree of contamination (mCd), and the potential ecological risk index (PERI). The results of the pollution indices showed that the contamination levels of the studied agricultural soils are low to moderate, while the average PERI values indicate that the ecological risks of PTE range from low to high in the soils of the studied area. Correlations and PCA analyses suggest that studied elements have three possible origins: geogenic (chromium, cobalt, copper, manganese, vanadium, and zinc), anthropogenic (cadmium, nickel, phosphorus and lead) and atmospheric (arsenic) sources. These findings are helpful for the long-term assessment of PTE in the Bandar Abbas County.
The contamination of potentially toxic elements (PTEs) in agricultural soils is a serious concern around the globe, and modelling approaches is imperative in order to determine the possible hazards ...linked with PTEs. These techniques accurately assess the PTEs in soil, which play a pivotal role in eliminating the weaknesses in determining PTEs in soils. This paper aims to predict the concentration of Cu, Co and Pb using neural networks (NNs) based on multilayer perceptron (MLP) and boosted regression trees (BT). Statistical performance estimation factors were rummage-sale to measure the performance of developed models. Comparison of the coefficient of correlation and root mean squared error suggest that MLP-established models perform better than BT-based models for predicting the concentration of Cu and Pb, whereas BT models perform better than MLP established models at predicting the concentration of Co.
Lead isotopes have been widely used to assess the sources of Pb in the soil environment since lead isotopes ratios have a specific signature that allows us to use them as environmental tracers. ...However, some lead sources are difficult to be identified. This article contains the lead isotope data from soils and shot pellets collected in an abandoned shooting range (NW Spain). Twelve soil and three-shot pellet samples were randomly collected and analyzed using MC-ICP-MS. The isotope ratios are shown, and analyses proved that Pb originated predominantly from the used shot pellets. Contaminated soils exhibited an isotopic composition (206Pb/207Pb, 208Pb/204Pb, 206Pb/204Pb and 208Pb/206Pb) close to some shot pellets from different manufacturers. These results offer new, valuable data for other researchers working on lead contamination research and the identification sources of Pb for adjacent areas to shooting-range facilities and for wildlife ecotoxicology. Still, the use of several ammunitions derived from different sources, such as recycled Pb, showed that it is hard to identify the lead source and these kinds of facilities.
This study aims to understand the adsorption/desorption process in six agricultural soils of two antibiotics, Ciprofloxacin (CIP) and Trimethoprim (TRI), widely used today and the influence of pH on ...this process. Antibiotics can reach the soil through the application of sludge and effluents from wastewater treatment plants and are directly influenced by changes in pH, once in the soil. Therefore, this study with batch experiments allows us to know the adsorption process in a pH range between 2 and 12, in six soils with different organic carbon content, between 1% and 7.7%. The results obtained show that the adsorption of CIP has its maximum at pH between 5 and 7; above and below this range, the adsorption decreases. The soils with the highest organic carbon content (between 4.4% and 7.7%) are those with the highest adsorption. The values for each forms in which the CIP molecule is found are: for K
d
CIP
+,
between 0.887 and 8.289 L kg
−1
; for K
d
CIP
−
, between 0.670 and 5.440 L kg
−1
, while for K
d
CIP
0
, the values do not differ from 0, except soils 1 and 3, whose values are 0.206 and 0.615 L kg
−1
, respectively. Regarding TRI, the maximum adsorption takes place at acidic pHs, below 6 for all soils. Above these values, desorption decreases. The K
d
values for each of the species vary between 0.085 and 0.218 L kg
−1
for K
d
TRI
+
, between 0.011 and 0.056 L kg
−1
for K
d
TRI
0
, and between 0.092 and 0.189 L kg
−1
for K
d
TRI
−
. For both antibiotics, the highest adsorption was achieved in the soil with the highest organic carbon content (7.7%). Comparing both antibiotics, we see that CIP presents the highest adsorption, and in the case of desorption, for CIP, it varies between 3.7% and 75.8%, with the maximum desorption at basic pHs. In the case of TRI, desorption is higher, varying between 9.4% and 99.1%, with the maximum around neutrality, except for two soils, whose maximums are at pH of 4.3 and 9.5. These results should be taken into account, as once they reach the soil, pH will be a determining factor in their behaviour and fate.
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