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To understand the bioaccessibility of cadmium（Cd）in compound-contaminated soils containing cadmium and ciprofloxacin, uncontaminated soils were artificially polluted with cadmium and ciprofloxacin at 4 different treatment rates（CK:0mg·kg-1, CIP：I5mg·kg-1,II25mg kg-1, andIII50mg kg-1; Cd：80mg·kg-1）. A pot experiment was performed with three soil aging times to investigate the risk of Cd to human health using in vitrodigestion method and SHIME model. The results showed that there was no significant difference in the bioaccessibility of Cd among different soil aging times in compound-contaminated soils. Besides, the bioaccessibility of Cd decreased with soil aging time（D60

We examined forest and tree responses to decreasing nutrient availability with soil aging in a species-rich tropical montane rain forest on Mount Kinabalu, Borneo. Community composition and structure and tree growth rates were compared between two 1 ha plots on nutrient-rich young soil versus nutrient-deficient old soil. Myrtaceae and Fagaceae dominated both plots. With soil aging, the dominance of Lauraceae, stem density, basal area and aboveground biomass decreased, and the forest understory became brighter. Some dominant taxa on the old soil (Podocarpaceae and the genus Tristaniopsis in Myrtaceae) were virtually absent on the young soil; this was attributed to light limitation in the understory. Growth rates of understory trees were lower on the young soil, whereas those of canopy trees were lower on the old soil. This suggested that the growth of understory trees was limited by light on the young soil, whereas that of canopy trees was limited by nutrients on the old soil. Of the eight species that were abundant in both plots, the dominance of five species was considerably lower on the old soil, four of which also exhibited decreased maximum sizes and lower growth rates. The remaining three species showed similar dominance across plots without a decline in growth rates, although they exhibited decreased maximum sizes on the old soil. These analyses demonstrated divergent responses of species to the soil-age gradient. We suggest that the differential responses of species to decreasing nutrient availability with a concomitant increase in understory light levels explain floristic turnover with soil aging. [ABSTRACT FROM AUTHOR]

To estimate pesticide residue levels in succeeding crops based on those in soils, the relationship between pesticide concentrations in komatsuna (Brassica rapa var. perviridis) and the concentrations extracted sequentially from soils using water and acetone was investigated. The concentrations of many pesticides in komatsuna shoots showed higher positive correlation with water-extractable concentrations (CW) than total-extractable concentrations in soils, so that the CW was available for evaluating the phytoavailability of pesticides in the soil. As a result of examining the dissipation behavior of the CW, the dissipation of the CW was able to be predicted by considering time-dependent soil sorption, which could be estimated using the sorption coefficients (Kd) measured by a standard batch method. Furthermore, the present study showed that the properties of soil organic carbon such as black carbon content and the molecular structure of pesticides were important for estimating the Kd values more accurately. [ABSTRACT FROM AUTHOR]

The finding of dieldrin (88 ng/g), DDE (52 ng/g), and heptachlor epoxide (19 ng/g) in earthworms from experimental plots after a single moderate application (9 kg/ha) 45 years earlier attests to the remarkable persistence of these compounds in soil and their continued uptake by soil organisms. Half-lives (with 95 % confidence intervals) in earthworms, estimated from exponential decay equations, were as follows: dieldrin 4.9 (4.3-5.7) years, DDE 5.3 (4.7-6.1) years, and heptachlor epoxide 4.3 (3.8-4.9) years. These half-lives were not significantly different from those estimated after 20 years. Concentration factors (dry weight earthworm tissue/dry weight soil) were initially high and decreased mainly during the first 11 years after application. By the end of the study, average concentration factors were 1.5 (dieldrin), 4.0 (DDE), and 1.8 (heptachlor epoxide), respectively. [ABSTRACT FROM AUTHOR]

• Pig glue, egg and milk all experienced deterioration due to the primary and secondary structure changes. • Pig glue owned better aging resistance because of the less changes in hydrophobic amino acids, FTIR spectrum and minimum secondary structure variations. • Ultramarine accelerated the soil aging process but did not bring extra influences on the primary structure. Soil aging was the major aging form that affected great numbers of unearthed Chinese ancient artworks and would fundamentally influence the deterioration processes of the proteinaceous binders applied in polychromy artworks. The three main categories of the proteinaceous binders, pig glue, egg and milk, would present various stabilities towards soil aging due to their different characteristics, the study of which was of high importance for exploring the degradation mechanisms of polychromy artworks. In this paper, GC-MS and FTIR were applied to study the changes of the primary structure (amino acids) and secondary structure of pure pig glue, egg, milk and binder with ultramarine in a simulated anoxic, dark, microthermal, compacted stable burial environment for one year. Results illustrated that all binders experienced deterioration due to the changes in individual, different groups of amino acids and the broadening of Amide A. Comparatively, pig glue owned better aging resistance because of the less changes in hydrophobic amino acids, FTIR spectrum and minimum secondary structure variations. Moreover, ultramarine accelerated the soil aging process but did not bring extra influences on the primary structure. [ABSTRACT FROM AUTHOR]

This study examines the influence of soil aging on Standard Penetration Test (SPT) N-Vs correlations, and seismic site classification. Energy-corrected SPT-Vs correlations are developed for two regions where subsurface layering consists of soil deposits with very young geotechnical ages according to the last critical soil disturbance that occurred in the study areas. It is observed that the uncorrected correlations of the current study fall into the lower bound of the uncorrected SPT-Vs correlations existing in the literature due to soil aging effects. To better illustrate the effects of soil aging on SPT-Vs correlations, the uncorrected correlations from the literature and this study are divided into two age categories of Holocene and Pleistocene according to their geological age. Using the two age categories, the boundaries proposed in the NEHRP for different seismic site classes are divided into three zones according to their uncertainty level regarding seismic site classification. The results clearly indicate the need to consider the age of soil deposits for seismic site classification when using the SPT method to avoid incorrect seismic site classification. Additionally, it is found that the use of raw (uncorrected) SPT N values can lead to incorrect seismic site classification, with either conservative or unconservative results depending on the Energy Transfer Ratio (ETR) of the SPT hammer used for the seismic site class determination. • Two new age categories of Holocene and Pleistocene are defined for the uncorrected SPTVs correlations for sandy soils. • Energy-corrected SPT-Vs correlation should be used to avoid inconsistency between different studies caused by hammer ETR. • In the SPT method, the use of uncorrected SPT N values can lead to incorrect seismic site classification. • The age of soil needs to be considered for seismic site classification when using the SPT method. [ABSTRACT FROM AUTHOR]