Analysis of the soil to food crops transfer factor and risk assessment of multi-elements at the suburban area of Ho Chi Minh city, Vietnam using instrumental neutron activation analysis (INAA)

Multivariate analysis of potentially toxic metal contents in soil and vegetables: Enrichment, bioconcentration, translocation from soil to vegetables, and assessment of human health toxicity

The excessive accumulation of metals in agricultural soils can profoundly impact the quality of vegetables grown in contaminated soil. Understanding the bioaccumulation of these metals in vegetables is essential for assessing human exposure risks. The present study aimed to investigate the concentration of potentially toxic metals (PTMs: Fe, Mn, Cu, Zn, Al, As, Cr, Cd, and Pb) in agricultural soil and some commonly consumed vegetables (carrot, reddish, cauliflower, pumpkin, and spinach). The samples were collected from agrarian farmlands near the industrial area of Multan Road, Kasur-Pakistan. The mean contents of all metals in soil, root, and shoot samples were within the limits set by the EU, WHO, FAO, and US EPA, except for Cr in soil and Cr, Cd, and Pb in root samples. Across all analyzed vegetables, the bioconcentration factors (BCFroot and BCFshoot < 1, except As) and translocation factor (TF < 1) for all metals suggested that while these vegetables absorb metals, they generally do not accumulate or translocate them. Multivariate analysis indicated that both natural and anthropogenic activities contribute to metal contamination. The calculated hazard index (HI > 1) and cumulative cancer risk (CCR >1 × 10-3) values indicated the probability of non-carcinogenic and carcinogenic health risks for adults and children associated with the consumption of these vegetables. The findings provide critical insights for policymakers, agricultural regulators, and public health authorities to mitigate metal contamination risks and promote food safety.

Presence of Heavy Metals in Irrigation Water, Soils, Fruits, and Vegetables: Health Risk Assessment in Peri-Urban Boumerdes City, Algeria

This study investigates heavy metal contamination in soils, irrigation water, and agricultural produce (fruits: Vitis vinifera (grape), Cucumis melo var. saccharimus (melon), and Citrullus vulgaris. Schrade (watermelon); vegetables: Lycopersicum esculentum L. (tomato), Cucurbita pepo (zucchini), Daucus carota (carrot), Lactuca sativa (lettuce), Convolvulus Batatas (potato), and Capsicum annuum L. (green pepper)) in the Boumerdes region of Algeria. The concentrations of seven heavy metals (cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), lead (Pb), and zinc (Zn)) in soil and food samples were analyzed using atomic absorption spectrometry. Health risks associated with these metals were evaluated through the estimated daily intake (EDI), non-carcinogenic risks (using target hazard quotient (THQ), total target hazard quotient (TTHQ), and hazard index (HI)), and carcinogenic risks (cancer risk factor (CR)). Statistical analyses, including cluster analysis (CA) and Pearson correlation, were conducted to interpret the data. The results revealed the highest metal transfer as follows: Cd was most significantly transferred to tomatoes and watermelons; Cr to carrots; Cu to tomatoes; and Fe, Ni, Pb, and Zn to lettuce. Among fruits, the highest EDI values were for Zn (2.54·10-3 mg/day) and Cu (1.17·10-3 mg/day), with melons showing the highest Zn levels. For vegetables, the highest EDI values were for Fe (1.68·10-2 mg/day) and Zn (8.37·10-3 mg/day), with potatoes showing the highest Fe levels. Although all heavy metal concentrations were within the World Health Organization's permissible limits, the HI and TTHQ values indicated potential health risks, particularly from vegetable consumption. These findings suggest the need for ongoing monitoring to ensure food safety and mitigate health risks associated with heavy metal contamination.

The assay of soil carbon with naturally occurring cosmic ray neutrons

The detection of gamma rays induced in soil by naturally occurring cosmic ray neutrons is explored with the Geant4 Simulation Toolkit to monitor carbon sequestration in soil. The simulated soil is a uniform mixture of minerals, air, water, and soil organic carbon. As the soil organic carbon increases from 0% to 15% by volume, the mineral matter decreases, and gamma ray counts from mineral-related isotopes decrease. Characteristic gamma ray energies from a variety of elements are collected near the surface with a germanium detector. Of these, the 2.224 MeV gamma ray from hydrogen is sensitive to changes in soil organic carbon as low as 0.12% after counting for the equivalent of 3.45 days. Counting longer is recommended to reduce the sensitivity of the primary 4.438 MeV gamma ray from carbon below its current value of 2.81% in the simulation.

Documentation of Phytotoxic Compounds Existing in Parthenium hysterophorus L. Leaf and Their Phytotoxicity on Eleusine indica (L.) Gaertn. and Digitaria sanguinalis (L.) Scop

The utilization of the invasive weed, Parthenium hysterophorus L. for producing value-added products is novel research for sustaining our environment. Therefore, the current study aims to document the phytotoxic compounds contained in the leaf of parthenium and to examine the phytotoxic effects of all those phytochemicals on the seed sprouting and growth of Crabgrass Digitaria sanguinalis (L.) Scop. and Goosegrass Eleusine indica (L.) Gaertn. The phytotoxic substances of the methanol extract of the P. hysterophorus leaf were analyzed by LC-ESI-QTOF-MS=MS. From the LC-MS study, many compounds, such as terpenoids, flavonoids, amino acids, pseudo guaianolides, and carbohydrate and phenolic acids, were identified. Among them, seven potential phytotoxic compounds (i.e., caffeic acid, vanillic acid, ferulic acid, chlorogenic acid, quinic acid, anisic acid, and parthenin) were documented, those are responsible for plant growth inhibition. The concentration needed to reach 50% growth inhibition in respect to germination (EC_g50), root length (EC_r50), and shoot length (EC_s50) was estimated and the severity of phytotoxicity of the biochemicals was determined by the pooled values (rank value) of three inhibition parameters. The highest growth inhibition was demarcated by caffeic acid, which was confirmed and indicated by cluster analysis and principal component analysis (PCA). In the case of D. sanguinalis, the germination was reduced by 60.02%, root length was reduced by 76.49%, and shoot length was reduced by 71.14% when the chemical was applied at 800 μM concentration, but in the case of E. indica, 100% reduction of seed germination, root length, and shoot length reduction occurred at the same concentration. The lowest rank value was observed from caffeic acids in both E. indica (rank value 684.7) and D. sanguinalis (909.5) caused by parthenin. It means that caffeic acid showed the highest phytotoxicity. As a result, there is a significant chance that the parthenium weed will be used to create bioherbicides in the future.

Bioaccumulation characteristics, transfer model of heavy metals in soil-crop system and health assessment in plateau region, China

This study investigated the bioaccumulation and transfer of heavy metals including Cd, Cr, Cu, Mn, Ni, Pb and Zn in soil-crop system in Lhasa, and assessed the health risks of the edible part of the crops. The results showed that the average values of Cd, Cr, Cu, Mn, Ni, Pb and Zn were 0.15, 44.55, 24.68, 532.40, 22.47, 38.18 and 73.99 mg kg^-1 in natural soil, and 0.16, 46.93, 38.45, 559.13, 23.23, 40.03 and 83.29 mg kg^-1 in cultivated soil, respectively. Highland barley and wheat had the strongest ability to accumulate Zn in grain, the BCF values were 0.24 and 0.27, respectively, significant differences in the distribution of metal contents in crop root, stem, leaf and grain were observed. Root presented larger accumulation capacity in most metals, Zn and Cu was easily transferred in the plant organs, most metals in this study presented difficult to migrate from root to grain. The transfer peak of most metals in soil-crop system appeared from stem to leaf. The concentrations of Cr and Mn in crop grains could be predicted according to the multiple linear regression models. THQ and HI values of heavy metals in edible parts of both highland barley and wheat were below the safety threshold of 1, indicating no detrimental effects posed to adults health. This study helps to understand the accumulation and transfer of heavy metals in soil-crop system in plateau region.

Soil fertility and land sustainability in Usangu Basin-Tanzania

Soil fertility determines crop growth, productivity and consequently determines land productivity and sustainability. Continuous crop production exploits plant nutrients from soils leading to plant nutrient imbalance, thus affecting soil productivity. This study was conducted to monitor soil fertility status in soils of Usangu agro-ecosystem to establish management strategies. To assess soil fertility status in Usangu agro-ecosystem in Southern Highland Tanzania; 0–30 cm depth soil samples were taken for organic carbon, soil pH, N, P, Ca, K, Mg, S, Al, and micronutrients such as Zn, Mn, Cu, Fe, and Cr analyses by various established standard analytical methods. The results indicated most micronutrients were available in the deficient amount in many studied sites except for Fe and Mn, which were observed to be above optimum requirement. Based on critical levels established in other areas, 90 % of the soils were ranked as N, P, K, and Mg deficient. The micronutrients (Cu, Fe, and Zn) were inadequate in all soils resulting in limited crop growth and productivity. A high concentration of trace metals was detected in agricultural soils, this might affect plant nutrients availability and leading to environmental contamination affecting land productivity and sustainability. The study found that Usangu agro-ecosystem has deprived of soil fertility leading to poor crop growth and productivity. The authors recommend the addition of supplemental materials rich in plant nutrients such as inorganic fertilizer, manure, crop residues, and treated wastes to improve soil fertility for improved productivity and land sustainability.