The concurrent decline of soil lead and children’s blood lead in New Orleans Howard W. Mielke , Christopher R. Gonzales , Eric T. Powell , Mark A. S. Laidlaw , Kenneth J. Berry , Paul W. Mielke Jr. , and Sara Perl Egendorf PNAS first published October 14, 2019 https://doi.org/10.1073/pnas.1906092116 Significance The inextricable link between topsoil lead (Pb) and children’s blood lead (BPb) has not been widely accepted. Pb is associated with multiple health adversities. Urban residents are at risk from exposure to legacy Pb dust in topsoil resulting from smelting, industrial discharges, leaded gasoline emissions, leaded paint, and incineration. In New Orleans, topsoil median Pb decreased in ∼15 y from 99 mg/kg to 54 mg/kg, or ∼2.4 mg⋅kg⋅y −1 . In ∼12 y, children’s median BPb declined from 3.6 μg/dL to 1.3 μg/dL, or ∼0.2 μg⋅dL⋅y −1 . We argue that depletion of topsoil Pb is an important factor in the continuous dec...
Climate warming alters subsoil but not topsoil carbon dynamics in alpine grassland Juan Jia Zhenjiao Cao Chengzhu Liu Zhenhua Zhang Li Lin Yiyun Wang Negar Haghipour Lukas Wacker Hongyan Bao Thorston Dittmar Myrna J. Simpson Huan Yang Thomas W. Crowther Timothy I. Eglinton Jin‐Sheng He Xiaojuan Feng Subsoil contains more than half of soil organic carbon (SOC) globally and is conventionally assumed to be relatively unresponsive to warming compared to the topsoil. Here, we show substantial changes in carbon allocation and dynamics of the subsoil but not topsoil in the Qinghai‐Tibetan alpine grasslands over 5 years of warming. Specifically, warming enhanced the accumulation of newly synthesized ( 14 C‐enriched) carbon in ...
Author : Moura-Bueno, J. M. Dalmolin, R. S. D. ten Caten, A. Dotto, A. C. Dematte, J. A. M. Year : 2019 Title : Stratification of a local VIS-NIR-SWIR spectral library by homogeneity criteria yields more accurate soil organic carbon predictions Journal : Geoderma Comment : The aim of this research was to i) characterize and identify differences among spectra obtained for subtropical soils samples, ii) evaluate different pre-processing techniques and multivariate methods to propose SOC prediction models from the spectral data and iii) evaluate the performance of SOC prediction models calibrated from the stratification of a local library. Spectral reflectance measurements were performed in the laboratory with a spectroradiometer in the range of 350–2500 nm. Six pre-processing techniques were applied to the spectra (including derivatives, normalization and non-linea...
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