Analysis of ecosystem resilience in Jiuzhaigou Valley Scenic Area under the effect of geohazards

The effects of geohazards on the ecological environment and ecological spatial pattern have received wide attention from scholars. However, the positive role played by ecological restoration projects on the environment and in the reduction of geohazards has usually been neglected. Jiuzhaigou Valley Scenic Area is a world natural heritage area, has a high incidence of geohazards, and is a demonstration area for ecological restoration projects. Based on remote sensing technology, this paper adopted an InVEST model (Integrated Valuation of Ecosystem Services and Tradeoffs) and ecological landscape index to extract information about spatio-temporal changes in Jiuzhaigou from 2013 to 2020. This study utilized a quantitative analysis of the ecological recoverability of Jiuzhaigou in cases of artificial restoration and spontaneous restoration under different types of geohazards. Results showed that forests play a vital role in maintaining and controlling habitat quality; artificial restoration can significantly ameliorate the impact of geohazards on the scenic area. As of 2020, the forested scenic area recovered 3.868 km2, and the habitat quality index rebounded to 98.88% of the historical high. The ecological restoration project significantly shortened the scenic area recover time of its ecosystem service capability

Determination, source analysis and preliminary risk assessment of benzoic acid in rice wine

Objective To analyze the concentration and source of benzoic acid in rice wine and evaluate the health risk of dietary benzoic acid intake from rice wine among adult consumers in China. Methods 231 samples of rice wine and 15 samples of raw materials were collected from five main rice wine production areas in China, including Shandong, Zhejiang, Jiangsu, Fujian and Shanghai; the content of benzoic acid and its precursors were determined by high performance liquid chromatography; the sources of benzoic acid in rice wine were analyzed by the benzaldehyde and phenylalanine simulation test and the real sample acceleration test; the benzoic acid intake among adult consumers was evaluated by simple distribution assessment method. Results In all rice wine samples, the detection rate of benzoic acid was 99.13% (229/231), the concentration range of benzoic acid was ND (not detectable) -37.00 mg/L, and the average was 2.28 mg/L. In 98 end products, the detection rate of benzoic acid was 100.00% (98/98), the concentration range of benzoic acid was ND-1.60 mg/L, and the average was 0.52 mg/L; in 133 base wine samples, the detection rate of benzoic acid was 98.50% (131/133), the content range of benzoic acid was ND-37.00 mg/L, and the average was 3.58 mg/L. The result of source analysis showed that the benzoic acid in rice wine mainly came from raw materials, degradation of phenylalanine and oxidation of benzaldehyde. Exposure assessment result showed that the average exposure of benzoic acid for rice wine consumers in China was 0.001 mg/kg BW, accounting for 0.02% of the acceptable daily intake (ADI); and the 95th percentile was 0.005 mg/kg BW, accounting for 0.1% of the ADI. Conclusion The detection rate of benzoic acid in rice wine was high but the concentration was low. Source analysis result indicated that benzoic acid in rice wine mainly came from raw materials, degradation of phenylalanine and oxidation of benzaldehyde; the health risk of benzoic acid exposure to adult rice wine consumers in China was low

The effect of friction behavior on the migration of metal elements from stainless-steel articles for food contact

Objective To evaluate the effect of friction behavior on migration levels of metal elements from stainless-steel articles for food contact. Methods The migration levels of metal elements from used and new stainless-steel articles were compared according to GB 4806.9-2016 and Council of Europe Resolution CM/Res (2013) 9. The migration conditions were boiling in 4% acetic acid for 30 min followed by at room temperature for 24 h and soaking in 5 g/L citric acid at 100 ℃ for 2 h, respectively. Meanwhile, the impact of dynamic friction on migration were investigated on new stainless-steel articles, where the friction method were referred to the GB/T 32095.2-2015 standard. Migration of metal elements complied with the corresponding standard. Results Based on the European standard, migration of lead in the first migration test was above limit of quantitation (LOQ) in all five used stainless-steel articles after friction, but none in new ones. The quantification rate of chromium in the first migration test in 80% (4/5) of used stainless-steel articles were above LOQ after friction by GB 4806.9-2016 standard while were 20% (1/5) in new ones. The migration level of Cr was higher by GB 4806.9-2016 standard than by European resolution in single dynamic friction study. Results from the dynamic friction experiments indicated that the migration of Cr and Ni reached equilibrium after 3 times of friction. Conclusion The migration condition in GB 4806.9-2016 standard had stronger leaching ability for Cr from stainless-steel articles than that in European resolution. Friction behavior promoted corrosion and metal element migration of stainless steel. Long-term used stainless-steel products had higher lead and chromium migration than new products, but without safety risks

Evaluation of six satellite-based terrestrial latent heat flux products in the vegetation dominated Haihe river basin of north China

In this study, six satellite-based terrestrial latent heat flux (LE) products were evaluated in the vegetation dominated Haihe River basin of North China. These LE products include Global Land Surface Satellite (GLASS) LE product, FLUXCOM LE product, Penman-Monteith-Leuning V2 (PML_V2) LE product, Global Land Evaporation Amsterdam Model datasets (GLEAM) LE product, Breathing Earth System Simulator (BESS) LE product, and Moderate Resolution Imaging Spectroradiometer (MODIS) (MOD16) LE product. Eddy covariance (EC) data collected from six flux tower sites and water balance method derived evapotranspiration (WBET) were used to evaluate these LE products at site and basin scales. The results indicated that all six LE products were able to capture the seasonal cycle of LE in comparison to EC observations. At site scale, GLASS LE product showed the highest coefficients of determination (R2) (0.58, p 2), followed by FLUXCOM and PML products. At basin scale, the LE estimates from GLASS product provided comparable performance (R2 = 0.79, RMSE = 18.8 mm) against WBET, compared with other LE products. Additionally, there was similar spatiotemporal variability of estimated LE from the six LE products. This study provides a vital basis for choosing LE datasets to assess regional water budget

RISK21: risk analyzing tool on dietary exposure of phthalic acid esters

Objective To analyze the risks of dietary exposure of diethylhexyl phthalate (DEHP), dibutyl phthalate (DBP), diisononyl phthalate (DINP), butylbenzyl phthalate (BBP), diisobutyl phthalate (DIBP), dimethyl phthalate (DMP) and diethyl phthalate (DEP) to 2-6 years children in China using RISK21, so as to provide risk management strategy for phthalic acid esters (PAEs). Methods RISK PLOT module was used to analyze and rank risks, with toxicity as Y-axis and exposure as X-axis and margin of exposure (MOE) and uncertainty factor as parameters. Matrix calculation was conducted, risks level and rank of 7 kinds of PAEs to 2-6 years children were illustrated by visualized graphs. TTC PLOT module was used to analyze risks of DMP, DEP and DIBP, which were lacking of toxicity data. Results RISK PLOT showed that the risks of 7 kinds of PAEs for general population located in the green area, which demonstrated that they had low risk to 2-6 years children, and the risks of high food consumption population ranked in descending order were DBP, DIBP, DEHP, DMP, DEP, DINP and BBP. TTC PLOT showed that the risks of DMP, DEP and DIBP were lower than the corresponding threshold of toxicological concern (TTC) that demonstrated low risks. Conclusion RISK21 framework and tools could be a very useful tool for risk assessment and further risk management, and low risks of dietary exposure of 7 kinds of PAEs to 2-6 years children in China by RISK21 analyzing

Dietary Exposure Assessment of Rare Earth Elements in the Chinese Population

Rare earth elements (REEs) are widely found in foods. A high intake of REEs may have associations with adverse effects on human health. This study aimed to investigate the concentrations of REEs in foods in China and to assess the risk of dietary REEs exposure in the Chinese population. The mean concentrations of the total REEs in 27,457 food samples from 11 food categories ranged from 0.04 to 1.41 mg/kg. The daily mean dietary exposure of the total REEs was 1.62 μg/kg BW in the general Chinese population and ranged from 1.61 to 2.80 μg/kg BW in different sex–age groups. The high consumer exposure (95th percentile, P95) was 4.83 μg/kg BW, 9.38% of the temporary ADI (tADI) of REEs (51.5 μg/kg BW). None of the P95 exposure exceeded the tADI in all of the sub-groups. Lanthanum, cerium, and yttrium accounted for approximately 63% of the total exposure of the 16 REEs. The hazard index of 16 REEs was far below 1. Therefore, the health risk of dietary REEs exposure in the general Chinese population was low. No cumulative risk was found for the 16 REEs in China. The results indicate there was no need to stipulate the limits of REEs in foods

Dietary Exposure to Glutamates of 2- to 5-Year-Old Toddlers in China Using the Duplicate Diet Method

A duplicate diet collection method was used to estimate dietary exposure to glutamates in children aged 2–5 years in selected provinces of China. Daily duplicate diet samples were collected from 86 healthy toddlers over three consecutive days. Glutamates were analyzed using ultra-high-pressure liquid chromatography–MS/MS (UHPLC–MS/MS). Results showed that the highest glutamates content was found in mixed meals, at 5.12 mg/kg, followed by powdered formula (3.89 mg/kg), and milk and dairy products (2.29 mg/kg). The total mean daily dietary exposure for subjects was 0.20 mg/kg BW, and P95 daily dietary exposure was 0.44 mg/kg BW, both below the acceptable daily intake (ADI) (120 mg/kg BW) recommended by the Joint (FAO/WHO) Expert Committee on Food Additives (JECFA) and the ADI (30 mg/kg BW) set by the European Food Safety Authority (EFSA). Hence it can be considered that glutamates exposure would cause low risk in this group

Evaluation of Six Satellite-Based Terrestrial Latent Heat Flux Products in the Vegetation Dominated Haihe River Basin of North China

In this study, six satellite-based terrestrial latent heat flux (LE) products were evaluated in the vegetation dominated Haihe River basin of North China. These LE products include Global Land Surface Satellite (GLASS) LE product, FLUXCOM LE product, Penman-Monteith-Leuning V2 (PML_V2) LE product, Global Land Evaporation Amsterdam Model datasets (GLEAM) LE product, Breathing Earth System Simulator (BESS) LE product, and Moderate Resolution Imaging Spectroradiometer (MODIS) (MOD16) LE product. Eddy covariance (EC) data collected from six flux tower sites and water balance method derived evapotranspiration (WBET) were used to evaluate these LE products at site and basin scales. The results indicated that all six LE products were able to capture the seasonal cycle of LE in comparison to EC observations. At site scale, GLASS LE product showed the highest coefficients of determination (R2) (0.58, p < 0.01) and lowest root mean square error (RMSE) (28.2 W/m2), followed by FLUXCOM and PML products. At basin scale, the LE estimates from GLASS product provided comparable performance (R2 = 0.79, RMSE = 18.8 mm) against WBET, compared with other LE products. Additionally, there was similar spatiotemporal variability of estimated LE from the six LE products. This study provides a vital basis for choosing LE datasets to assess regional water budget