Heavy metal(loid)s in agriculture soils, rice, and wheat across China: Status assessment and spatiotemporal analysis.

Heavy metal(loid)s (HMs) accumulation in agricultural soils, rice, and wheat is of particular concern in China, while the status and spatio-temporal distribution of HMs in the soil-crops system have been rarely reported at the national scale. This study aimed to summarize the overall pollution status, spatiotemporal patterns, and drivers of HMs in agricultural soil, rice, and wheat nationwide. The metal-polluted data from 1030 agricultural soils, rice, and wheat in China were collected from the literature published from 2000 to 2022. The results showed that Cd was the most prevailing contaminant in soils based on its spatiotemporal distribution and accumulation. The pollution cases and severe pollution percentage of Cd (103 %) and Hg (128 %) show an increasing trend pattern. Mining activities are the main anthropogenic sources of agricultural soil HMs in China. Cd and Pb had the highest exceedance rate in rice (33.5 and 32.2 %) and wheat (25.8 and 30.3 %). The rice from Hunan, Fujian, and Guangxi showed the highest average concentration of Cd and Pb, respectively, while wheat samples from Hubei had the greatest exceedance rate of Pb. Besides, HMs in crops was not usually corresponding to soil HMs but increased gradually from north to south areas. Several mitigation strategies and accurate health risk assessments model of HMs based on bioavailability were also proposed and recommended. Collectively, this review provides valuable information to improve the management of farmland nationwide, optimize the accurate risk assessment, and reduce HMs pollution.

Heavy metal(loid)s in agricultural soil from main grain production regions of China: Bioaccessibility and health risks to humans.

Unintentional ingestion of metal-contaminated soils may pose a great threat to human health. To accurately evaluate the health risks of heavy metal(loid)s in soils, their bioaccessibility has been widely determined by in vitro assays and increasingly employed to optimize the assessment parameters. Given that, using meta-analysis, we analyzed the literature on farmland heavy metal(loid)s (As, Cd, Cr, Cu, Hg, Pb, Ni, and Zn) in Chinese main grain production regions, and collected their total and bioaccessibility data to accurately assess their human health risks. Monte Carlo simulation was used to reduce the uncertainty in metal concentration, intake rate, toxicity coefficient, and body weight. We found that the mean concentration (0.47 mg/kg) and geological accumulation index (Igeo, 0-5.24) of Cd were the priority position of controlling metals. Moreover, children are more vulnerable to carcinogenic risks than adults. Soil mineralogy, physicochemical properties, Fe, and the types of in vitro assays are the influencing factors of bioaccessibility discrepancy. Furthermore, appropriate bioaccessibility determination methods can be adapted according to the differences in ecological receptors for the risk assessment, like developing a "personalized assessment" scheme for polluted farmland soil management. Collectively, bioaccessibility-based models may provide an accurate and effective approach to human health risk assessment.

The oral bioaccessibility and gingival cytotoxicity of metal(loid)s in wild vegetables from mining areas: Implication for human oral health.

Background: Heavy metal(loid)s are frequently detected in vegetables posing potential human health risks, especially for those grown around mining areas. However, the oral bioaccessibility and gingival cytotoxicity of heavy metals in wild vegetables remain unclear. Methods: In this study, we assessed the total and bioaccessible Cr, As, Cd, Pb, and Ni in four wild vegetables from mining areas in Southwest China. In addition, the cytotoxicity and underlying mechanisms of vegetable saliva extracts on human gingival epithelial cells (HGEC) were studied. Results: The Plantago asiatica L. (PAL) showed the highest bioaccessible Cr, As, Cd, and Pb, while the greatest bioaccessible Ni was in Taraxacum mongolicum (TMM). The Pteridium aquilinum (PAM), Chenopodium album L. (CAL), and TMM extracts decreased cell viability, induced apoptosis, caused DNA damage, and disrupted associated gene expressions. However, PAL extracts which have the highest bioaccessible heavy metals did not present adverse effects on HGEC, which may be due to its inhibition of apoptosis by upregulating p53 and Bcl-2. Conclusion: Our results indicated that polluted vegetable intake caused toxic effects on human gingiva. The heavy metals in vegetables were not positively related to human health risks. Collectively, both bioaccessibility and toxic data should be considered for accurate risk assessment.

Mechanisms of Cd-Induced Cytotoxicity in Normal Human Skin Keratinocytes: Implication for Human Health.

Cadmium (Cd) is one of the toxic heavy metals found widely in the environment. Skin is an important target organ of Cd exposure. However, the adverse effects of Cd on human skin are still not well known. In this study, normal human skin keratinocytes (HaCaT cells) were studied for changes in cell viability, morphology, DNA damage, cycle, apoptosis, and the expression of endoplasmic reticulum (ER) stress-related genes (XBP-1, BiP, ATF-4, and CHOP) after exposure to Cd for 24 h. We found that Cd decreased cell viability in a concentration-dependent manner, with a median lethal concentration (LC50) of 11 µM. DNA damage induction was evidenced by upregulation of the level of γ-H2AX. Furthermore, Cd induced G0/G1 phase cell cycle arrest and apoptosis in a dose-dependent manner and upregulated the mRNA levels of ER stress biomarker genes (XBP-1, BiP, ATF4, and CHOP). Taken together, our results showed that Cd induced cytotoxicity and DNA damage in HaCaT cells, eventually resulting in cell cycle arrest in the G0/G1 phase and apoptosis. In addition, ER stress may be involved in Cd-induced HaCaT apoptosis. Our data imply the importance of reducing Cd pollution in the environment to reduce its adverse impacts on human skin.

Effects of soil-extractable metals Cd and Ni from an e-waste dismantling site on human colonic epithelial cells Caco-2: Mechanisms and implications.

E-wastes release toxic metals including Cd, Cu, Ni, Pb and Zn into nearby soils during dismantling process. However, their adverse effects and the associated mechanisms on human intestinal epithelium are poorly understood. In this study, their toxic effects on human colonic epithelial cells Caco-2 and the underlying mechanisms were assessed basing on three soils from Wenling e-waste dismantling site. Since soil-extractable metals are more available for gastrointestinal absorption, we used phosphate buffer saline solution to extract metals at solid to liquid ratio of 1:2. Among metals, total Cd and Ni exceeded the risk screening values in three soils, being 3.8-8.8 and 42.4-155 mg/kg. Furthermore, high extractable-metals at 5.9, 1.9, and 0.87 mg/kg Cd (20-67%) and 4.6, 6.4, and 12.4 mg/kg Ni (3.6-29%) were observed for Soil-1, -2 and -3, respectively. All three extracts triggered cytotoxicity, with Soil-2 showing the strongest inhibition of cell viability. Higher production of reactive oxygen species and stronger inhibition of antioxidant enzymes SOD1 and CAT were observed in Soil-2 and -3. Upregulation of proinflammatory mediators (IL-1ß, IL-8 and TNF-α) and apoptosis-regulatory genes (GADD45α, Caspase-3, and Caspase-8) were observed. Our data suggest that soil extracts induced cytotoxicity, oxidative damage, inflammatory response, and cell apoptosis in Caco-2 cells, indicating soil ingestion from e-waste dismantling site may adversely impact human health.

Establishment of a BALB/c Mouse Model for Assessing the Degree of Inebriation Induced by Luzhou-Flavor Liquors.

This investigation was carried out to determine the differences in the degree of inebriation induced by Luzhou-flavor liquors having the same ethanol content. A BALB/c mouse model was used to test the effects of two liquors on the loss of the righting reflex (LORR) and the duration (DUR) of the LORR, as indices of the degree of inebriation. The blood ethanol concentration, blood acetaldehyde concentration, acetylcholinesterase activity in the hippocampus, and concentrations of dopamine and serotonin in the striatum were also determined. The degrees of inebriation induced by the two liquors were 0.694 and 0.404, as quantified by LORR and LORR DUR. The liquor that induced the lower degree of inebriation also induced lower blood ethanol and blood acetaldehyde concentrations. Moreover, it had no significant effects on acetylcholinesterase activity in the hippocampus or on the concentrations of dopamine or serotonin in the striatum. Chinese liquors with the same ethanol content can be distinguished by the degree of inebriation they induce. A relationship was found between the internal composition of the liquor and the degree of inebriation it induced. Our data support choosing liquors with low degrees of inebriation to reduce their harmful effects.

[Sequence analysis of G glycoprotein gene of human respiratory syncytial virus].

OBJECTIVE: To understand the variation of G glycoprotein gene of human respiratory syncytial virus (HRSV) obtained from Sichuan in 2010 and determine the dominant genotypes. METHODS: G glycoprotein gene of seven cases of subtype A and eleven cases of subtype B of HRSV were amplified by RT-PCR and sequenced. The phylogenetic trees were constructed to determine the subtype of samples. And then, the genetic variations of the second hypervariable region of G glycoprotein gene were studied. RESULTS: The nucleotide genetic distances of G glycoprotein gene in subtype A and subtype B HRSV were 0.022 +/- 0.005 and 0.073 +/- 0.010, respectively. Transitions were more prevalent than transversions, GA -AG were the most frequent transitions detected among group A viruses, while UC+CU transitions were the most among group B. Phylogenetic analyses demonstrated that 7 subtype A virus could be clustered into one genotype, genotype GA2, and 11 subtype B virus could be clustered into two genotypes, GB2 and BA. The length of G protein gene in group A was all 298aa, but in group B included 295aa, 312aa and 315aa. Selective pressure was purifying selection in both subtypes. 9 positively selected sites in group A and 1 in group B on the second hypervariable region of G protein were identified. CONCLUSION: GA2, GB2 and BA were the main genotype. The changes may favor virus escape from the host immune response including the variation of the G protein gene length, frequency of nucleotide changes and selective pressure.

[Gene sequence and antigenic epitope variation within the F protein of respiratory syncytial virus in Sichuan, China].

OBJECTIVE: To investigate the variation of cytotoxic T-lymphocyte (CTL) and neutralizing epitopes in F protein of respiratory syncytial virus (RSV) isolated in Sichuan. METHODS: Nearly full-length of F protein gene of 10 strains of RSV isolated in Sichuan was amplified by RT-PCR and sequenced. The genetic variations, especially the CTL and neutralizing antibody epitopes within different subtypes and genotypes were analyzed and compared. RESULTS: The F protein of RSV is highly conserved within the two subtypes, with the P-distances of nucleotide and amino acids were 0.102 +/- 0.005 and 0.058 +/- 0.006, respectively. Neutralizing epitopes 47F and L4 were conserved between the subtypes, but RS-348 and 7C2 were only conserved within the subtypes. CTL epitopes HLA B * 57, HLA A * 01 and HLA Cw * 12 were conserved only within subtype A. There were specific different sites between the subtypes. CONCLUSION: The sequences of F protein from Sichuan RSV isolates were highly conserved, so as the epitopes on F-protein within subtypes, the identified CLT epitopes in subtype A may not be recognized in subtype B virus.

[Detection and genotyping of rotavirus in diarrhea infant feces in Chengdu].

OBJECTIVE: To study the genotype of rotavirus and the genetic variations of the major neutralization antigen VP4 of group A rotavirus in fecal samples from infants with diarrhea in Chengdu, Sichuan province, China. METHODS: The fecal specimens were collected from infant patients with diarrhea in the spring of 2010 at West China Second University Hospital. Reverse transcription polymerase chain reaction (RT-PCR) was performed to identify rotavirus G serotypes and P genotypes. VP4 gene fragments of the virus were amplified from two strains drawn randomly from the prevailing genotype and cloned into a T-A clone vector to generate the recombinants for sequencing. RESULTS: A group rotaviruses were detected in 13 of 75 specimens (17.3%). Serotype G1 was the predominant type (7/13) and two were serotype G3, four strains' serotypes were unidentified. Analysis of P gene demonstrated that genotype P [8] was the predominant type (6/13), whereas only two P[4] genotype were detected and genotypes for two strains were not determined. G1P [8] was the predominant type of G/P dominance combination (5/13). Sequencing results of the VP4 gene for the analyzed two strains implied that they were genotype P[8] with a 97% homology in sequence. Compared with the standard strain, homologies were also more than 90%. CONCLUSION: Rotavirus is one of the major etiological agents of viral diarrhea among infants in Chengdu. G1 was the dominant type G in Chengdu. G1P[8] was the predominant type of G/P dominance combination.