Intensified urbanization, industrial processes, and agricultural practices have precipitated substantial soil deterioration, characterized by soil acidification and cadmium contamination, ultimately jeopardizing food security and human health. Cadmium accumulation is a noteworthy characteristic of wheat, the second largest food crop in China. A critical aspect of secure wheat production is grasping the influential factors behind the cadmium content found in wheat grains. Although crucial, a complete and quantifiable study into the impact of soil physicochemical characteristics and various cultivars on cadmium accumulation in wheat is unfortunately lacking. A comprehensive analysis of 56 studies, conducted using meta-analysis and decision tree techniques, revealed that cadmium levels in soil surpassed the national standard by 526% and in wheat grain by 641%, respectively, within the past 10 years. Among soil physical and chemical properties, factors such as pH, organic matter content, available phosphorus levels, and total soil cadmium concentration significantly influenced the cadmium content found in wheat grains. In soils where the pH ranges from 55 to a value less than 65, cadmium content in wheat grain exceeds the national standard by 994% and 762%, respectively. Soil organic matter levels 20 gkg-1 below 30 gkg-1 correlated with the highest (610%) proportion of cadmium in wheat grain exceeding the national standard. Soil conditions, characterized by a pH of 7.1 and total cadmium content below 160 mg/kg, were conducive to safe wheat production. Grain cadmium content and cadmium enrichment factors displayed substantial variation depending on the specific wheat cultivar. Selecting wheat cultivars with minimal cadmium uptake capacity provides an economical and efficient solution to curtail cadmium levels in wheat grains. The current investigation offers direction for the secure cultivation of wheat in cadmium-polluted agricultural land.
Eighteen-dozen soil samples, along with eighty-seven grain samples, were collected from two characteristic fields in Longyan. Employing the pollution index, Hakanson's potential ecological risk index, and the EPA's human exposure risk assessment model, the pollution status, ecological risk, and health risks associated with heavy metals (Pb, Cd, and As) in soils across different land use types were assessed. In addition to other analyses, the contributions of lead (Pb), cadmium (Cd), and arsenic (As) to soil and crop contamination were examined. The region's soils and crops, encompassing diverse use types, exhibited minimal lead (Pb), cadmium (Cd), and arsenic (As) pollution levels, as confirmed by the results. Cd, the principal soil pollutant and a significant ecological risk factor, was responsible for 553% of the total soil pollution and 602% of the total potential ecological risk. The region's agricultural lands, including soils and crops, showed a concerning abundance of lead (Pb), cadmium (Cd), and arsenic (As). Lead and cadmium, identified as the main soil pollutants and contributors to ecological risk, accounted for 442% and 516% of total pollution, and 237% and 673% of the total potential ecological risk, respectively. Crop pollution was overwhelmingly driven by lead (Pb), accounting for a staggering 606% and 517% of the overall contamination in coix and rice, respectively. For both adults and children in the two representative regions, the carcinogenic risks of Cd and As in the soil, as determined by the oral-soil exposure pathway, remained within acceptable ranges. In assessing the total non-carcinogenic risk in region, the contribution of lead (Pb) was significantly higher than that of arsenic (As), which in turn was higher than cadmium (Cd); specifically, Pb (681%) > As (305%) > Cd (138%). No risk of cancer from lead was observed when rice was consumed in the two typical regions. Selleckchem GLPG3970 The carcinogenic risk posed to adults and children by cadmium (Cd) and arsenic (As) was, respectively, significantly greater from arsenic (768%) than cadmium (227%), and from cadmium (691%) than arsenic (303%). Among the pollutants in the region, three exhibited a high non-carcinogenic risk profile. As was the primary contributor (840% and 520% respectively), exceeding the impact of Cd and Pb.
The naturally elevated cadmium background levels, originating from carbonate rock decomposition, have drawn considerable scrutiny. Discrepancies in the soil's physical and chemical composition, cadmium concentration, and bioavailability of various parent materials in the karst environment render the total soil cadmium content inadequate as a sole criterion for evaluating cultivated land environmental quality. This study involved a systematic collection of surface soil and maize samples from parent materials (eluvium and alluvial) in typical karst areas. The content analysis of maize Cd, soil Cd, pH, and oxides allowed the revelation of Cd geochemical properties of various parent soils and the factors affecting their bioavailability. The study concluded with scientifically and practically oriented zoning suggestions for arable land, based on a predictive model. A notable divergence in the physicochemical properties of parent material soils from diverse sources was observed in the karst region, according to the results. Despite having a low cadmium content, the alluvial parent material soil demonstrated a high bioavailability of cadmium, leading to a substantial exceeding rate of cadmium in the maize crop. Soil CaO, pH, Mn, and TC levels displayed a notable inverse correlation with Cd bioaccumulation in maize, as measured by correlation coefficients of -0.385, -0.620, -0.484, and -0.384, respectively. The random forest model achieved a higher level of accuracy and precision in predicting the maize Cd enrichment coefficient than the multiple linear regression model. Based on the findings of this research, a new strategy for the secure use of cultivated land, tailored for individual plots and considering the soil's cadmium content and anticipated crop cadmium uptake, has been proposed. This strategy prioritizes the safe utilization of arable land resources.
Heavy metal (HM) contamination of soil poses a significant environmental concern in China, with regional geological factors playing a crucial role in HM accumulation. Investigations into soils formed from black shales have consistently demonstrated elevated concentrations of heavy metals, suggesting a high degree of eco-environmental vulnerability. However, relatively few investigations have been conducted on the presence of HMs in diverse agricultural products, thus obstructing the safe use of land and the secure production of food crops in black shale regions. A comprehensive analysis of heavy metals in soils and agricultural products from a typical black shale region in Chongqing examined their concentrations, pollution risks, and speciation. Soil samples from the experiment displayed an elevated presence of cadmium, chromium, copper, zinc, and selenium, but lead was not found to be enriched. Approximately 987% of all soils assessed showed contamination levels exceeding the risk screening values; additionally, a percentage of 473% of the soils exceeded the risk intervention values. Of all the pollutants, Cd was found at the highest concentrations in the study area's soils, presenting both significant pollution and potential ecological risks. A substantial portion of the Cd was present in ion-exchangeable fractions (406%), followed by residual fractions (191%) and combined weak organic matter fractions (166%). In contrast, Cr, Cu, Pb, Se, and Zn were mostly located in residual fractions. Furthermore, organic combined fractions played a role in the levels of Se and Cu, while Fe-Mn oxide combined fractions influenced the concentration of Pb. Cd's mobility and availability were found to be superior to those of other metals, according to these results. The agricultural output on display demonstrated a lackluster ability to amass heavy metals. Samples containing cadmium exceeded safety limits by approximately 187%, yet the enrichment factor was relatively low, implying a minimal threat from heavy metal pollutants. This research's outcomes might offer guidance for establishing safe agricultural protocols and land management strategies in black shale areas marked by high geological baselines.
Because of their critical role in human healthcare, quinolones (QNs), a standard antibiotic class, are deemed the WHO's top priority for critically essential antimicrobial agents. immune resistance To analyze the spatio-temporal variation and risk of QNs in soil, a collection of 18 representative topsoil samples was undertaken in September 2020 (autumn) and June 2021 (summer). High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was utilized to quantify QNs antibiotics present in soil samples, and the risk quotient method (RQ) was applied to calculate associated ecological and resistance risks. A seasonal shift was evident in QN content, diminishing from 9488 gkg-1 in autumn to 4446 gkg-1 in summer; the highest concentrations appeared in the middle portion of the region. Although the average proportion of silt remained the same, the average proportion of clay increased, while the average proportion of sand decreased; the average amounts of total phosphorus (TP), ammonia nitrogen (NH4+-N), and nitrate nitrogen (NO3-N) experienced a concomitant reduction. With regard to the content of QNs, a strong correlation was evident with soil particle size, nitrite nitrogen (NO2,N), and nitrate nitrogen (NO3,N) (P1), however, the composite resistance risk classification for QNs positioned it in the medium risk range (RQsum 1 > 01). Seasonal variations revealed a decrease in RQsum. Further investigation is warranted regarding the ecological and resistance risks posed by QNs in Shijiazhuang City's soil, as well as the need to bolster the risk management strategy for antibiotics in soil going forward.
China's urban expansion is reflected in the rising number of gas stations found within its cities. Primary immune deficiency Gas stations' fuel products, having a complex and varied composition, release various pollutants during the process of oil dispersion. The soil surrounding gas stations can absorb polycyclic aromatic hydrocarbons (PAHs), potentially harming human health. Soil samples, encompassing a depth of 0-20 cm, were collected near 117 gas stations situated in Beijing, and subsequently subjected to analysis for the presence of seven types of polycyclic aromatic hydrocarbons.