There have been reports of potential health risks for people from hydrophobic organic pollutants,such as polycyclic aromatic hydrocarbons(PAHs),polychlorinated hydrocarbons(PCHs),and organophosphate flame retardants(O...There have been reports of potential health risks for people from hydrophobic organic pollutants,such as polycyclic aromatic hydrocarbons(PAHs),polychlorinated hydrocarbons(PCHs),and organophosphate flame retardants(OPFRs).When a contaminated site is used for residential housing or public utility and recreation areas,the soil-bound organic pollutantsmight pose a threat to human health.In this study,we investigated the contamination profiles and potential risks to human health of 15 PAHs,6 PCHs,and 12 OPFRs in soils from four contaminated sites in China.We used an in vitro method to determine the oral bioaccessibility of soil pollutants.Total PAHswere found at concentrations ranging from26.4 ng/g to 987 ng/g.PCHs(0.27-14.3 ng/g)and OPFRs(6.30-310 ng/g)were detected,but at low levels compared to earlier reports.The levels of PAHs,PCHs,and OPFRs released from contaminated soils into simulated gastrointestinal fluids ranged from 1.74%to 91.0%,2.51%to 39.6%,and 1.37%to 96.9%,respectively.Based on both spiked and unspiked samples,we found that the oral bioaccessibility of pollutantswas correlated with their logKow andmolecularweight,and the total organic carbon content and pH of soils.PAHs in 13 out of 38 contaminated soil samples posed potential high risks to children.When considering oral bioaccessibility,nine soils still posed potential risks,while the risks in the remaining soils became negligible.The contribution of this paper is that it corrects the health risk of soil-bound organic pollutants by detecting bioaccessibility in actual soils from different contaminated sites.展开更多
Considerable levels of methylmercury(MeHg)have been found rice-based infant cereals as a result of MeHg transfer from the rice as a raw material to the products,hence consumption of rice products may pose a potential ...Considerable levels of methylmercury(MeHg)have been found rice-based infant cereals as a result of MeHg transfer from the rice as a raw material to the products,hence consumption of rice products may pose a potential health risk to infants who may receive cereals as the major diets and are susceptible to toxicity of MeHg.Determination of bioaccessibility of MeHg would provide a more accurate assessment of MeHg exposure through consumption of rice-based cereals,yet this information remains lacking.Further,the re-adsorption of methylmercury on the residual food will affect the accurate assessment of its bioaccessibility.Our goals in this work were 1)to determine the bioaccessibility of MeHg in infant rice cereals commonly available on the market by using a typical in vitro artificial gastrointestinal digestionmodel and 2)to evaluate the effects of MeHg re-adsorption on the in vitro assessment of MeHg bioaccessibility.The determined bioaccessibility of MeHg in the studied rice cereals after the standard dual-step(using gastric followed by intestinal juice)protocol ranged from 25%to 74%,a wide range comparable to that of fish samples observed here and in previous studies.The surprisingly higher bioaccessibility of MeHg in fish and rice cereals after the gastric step only,in comparison to after the complete two-step gastrointestinal digestion,suggests the re-adsorption of MeHg on the residual food.Separate experiments with spiked MeHg standards confirmed that the MeHg released by the acetic gastric juice was re-adsorbed on the residues during the intestinal step at neutral pH.This study provided first-hand data on the bioaccessibility of MeHg in infant rice cereals and methodological implications on using in vitro digestion to evaluate the bioaccessibility of MeHg and metal contaminants in general.展开更多
本研究开发了以乳清分离蛋白(whey protein isolate,WPI)和二十二碳六烯酸磷脂(docosahexaenoic acid-containing phospholipid,DHAPL)为复合乳化剂的水包油(oil-in-water,O/W)乳液,用于包封岩藻黄质(fucoxanthin,FX),旨在提升其热稳定...本研究开发了以乳清分离蛋白(whey protein isolate,WPI)和二十二碳六烯酸磷脂(docosahexaenoic acid-containing phospholipid,DHAPL)为复合乳化剂的水包油(oil-in-water,O/W)乳液,用于包封岩藻黄质(fucoxanthin,FX),旨在提升其热稳定性、抗氧化能力、生物可及性以及对RAW264.7巨噬细胞氧化损伤的保护作用。DHAPL-WPI复合物表现出优异的包封率(>94%),远超传统的单一WPI体系,其中长链DHAPL(如DHAPL-MP/MG)效果较优。该杂化乳化剂结构赋予乳液卓越的热稳定性,在严苛条件(75℃/0.5 h)下仍能保持超过80%的FX完整性,并在25℃条件下展现出优异的贮藏稳定性。此外,DHAPL-WPI体系克服了疏水性生物活性物质生物利用度的关键限制,在体外模拟消化中实现了70%的FX生物可及性,较游离FX提高了1.8倍。复合物的双界面抗氧化机制显著增强了自由基清除能力,使2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)阳离子自由基清除率、1,1-二苯基-2-三硝基苯肼自由基清除率提高了35%~42%,同时为RAW264.7巨噬细胞提供了强大的抗氧化应激保护作用,其中,中短链DHAPL效果更优异。本研究构建的生物活性物质负载体系为功能性食品开发提供了一种有效的包封解决方案,成功克服了食品的疏水性活性成分在热加工过程中不稳定和肠道吸收效率低的双重瓶颈问题。展开更多
[Objective] This study aimed to investigate the existing forms and bioaccessibility of vanadium（V） from soil and mineral of Panzhihua region.[Method] The representative Xigeda soil and vanadium-titanium magnetite we...[Objective] This study aimed to investigate the existing forms and bioaccessibility of vanadium（V） from soil and mineral of Panzhihua region.[Method] The representative Xigeda soil and vanadium-titanium magnetite were collected from Panzhihua region to determine the existing forms of vanadium from soil and mineral;in vitro bionic digestion model was established to measure the bioaccessibility of vanadium.[Result] The dissolved concentrations of vanadium from farmland,mining area and vanadium-titanium magnetite in gastric juice were respectively 5.02,9.50 and 3.88 mg/kg,and the bioaccessibility ranged from 0.09% to 3.00%;the dissolved concentrations of vanadium in intestinal juice were respectively 2.98,5.43 and 4.49 mg/kg,and the bioaccessibility ranged from 0.10% to 1.78%.The content of vanadium in various existing forms varied significantly,the contents of vanadium in non-specific adsorption state and specific adsorption state were low,but residual content was completely high,which accounted for 75.06%,95.32% and 86.27% of the total content of vanadium in samples.[Conclusion] Bioaccessibility of dissolved vanadium in gastric juice was higher than that in small intestinal juice.Vanadium from soil and mineral was difficult to generate morphological transformation and migration,which was the main reason for low bioaccessibility.展开更多
Indian mustard （Brassica juncea （L.） Czern.） has shown good potential for the phytoremediation of soil contaminated with heavy metals. However, there is little information about the speciation and bioaccessibility...Indian mustard （Brassica juncea （L.） Czern.） has shown good potential for the phytoremediation of soil contaminated with heavy metals. However, there is little information about the speciation and bioaccessibility of heavy metals in soil during the decomposition of metal-rich Indian mustard leaves. Incubation experiments （1-, 3-, and 6-month） were carried out in Beijing and Hunan soil with metal-rich Indian mustard leaves addition （1% and 3%） and the effects of mustard leaves addition on the speciation and bioaccessibility of heavy metals were studied. The results showed that the addition of mustard leaves led to significant increases in pH and DOC in the Hunan soil. Both 1% and 3% of mustard leaf amendment caused the percentage of the exchangeable （F1）, precipitated with carbonates （F2）, bound to Fe/Mn oxides （F3） and bound to organic matter （F4） fractions of Pb and Cd to increase dramatically, while the percentage of the residual fraction （F5） of Cd and Pb significantly dropped in both Beijing and Hunan soils. Mustard leaf addition caused the bioaccessibility of Pb to decrease in the gastric phase, whereas the values increased in the small intestinal phase. The Cd bioaccessibility increased with mustard leaf addition in both the gastric and small intestinal phases. In conclusion, the metal-enriched mustard leaves addition induces Pb and Cd concentrations and their mobility increasing in the Beijing and Hunan soils. Therefore, heavy metal risk in metal-enriched plant leaves should be considered in phytoremediation system in which heavy metal might be brought back to soil and changed over time.展开更多
Cadmium(Cd)pollution in agricultural soils has exerted a serious threat due to continuous application of pesticides,fertilizers,and wastewater irrigation.The present study aimed to test the efficiency of KOH-modified ...Cadmium(Cd)pollution in agricultural soils has exerted a serious threat due to continuous application of pesticides,fertilizers,and wastewater irrigation.The present study aimed to test the efficiency of KOH-modified and non-modified rice straw-derived biochar(KBC and BC,respectively)for reducing Cd solubility and bioavailability in Cd-contaminated soil.Cadmium-contaminated soil was incubated for 60 d with 15 and 30 g kg-1 BC and KBC.At the end of incubation,Cd mobility was estimated by the European Community Bureau of Reference sequential extraction and toxicity characteristic leaching procedure(TCLP),while bioavailability was determined using 1 molL-1 NH4NO3 extraction.The bioavailability risk index and bioaccessibility,assessed by a simple bioaccessibility extraction test,of Cd were used to examine the potential effects of Cd on living organisms.The results indicated that application of both KBC and BC significantly increased soil p H,cation exchange capacity,nutrients,and organic carbon.The soluble fraction of Cd was significantly decreased by 30.3%and 27.4%,respectively,with the addition of KBC and BC at 30 g kg-1 compared to the control(without biochar addition).Similarly,the bioaccessible Cd was significantly decreased by 32.4%and 25.2%,respectively,with the addition of KBC and BC at 30 g kg-1 compared to the control.In addition,both KBC and BC significantly reduced Cd leaching in the TCLP and NH4NO3-extractable Cd in the amended soil compared to the control.The reduction in Cd solubility and bioaccessibility by KBC and BC may be due to significant increases in soil pH and surface complexation.Overall,KBC at an application rate of 30 g kg-1 demonstrated positive results as soil amendment for Cd immobilization,and reduced bioaccessible Cd in contaminated soil.展开更多
Rice consumption can be a major pathway for mercury（Hg） exposure, which can cause health hazards to Chinese residents. To accurately assess the potential health risks, the bioaccessibility of Hg in rice samples coll...Rice consumption can be a major pathway for mercury（Hg） exposure, which can cause health hazards to Chinese residents. To accurately assess the potential health risks, the bioaccessibility of Hg in rice samples collected at background and Hg-contamination sites was examined using four in vitro methods. The results showed that 〈 50% of the total mercury（THg） was bioaccessible in the studied rice samples. The THg bioaccessibility in the rice samples collected at the Hg-contaminated site was higher than that observed at the background area. The bioaccessibility of arsenic（As） and cadmium（Cd） was also evaluated for comparison of the four in vitro methods used in this study. The Physiologically Based Extraction Test was found to be the most accurate method based on the consistency of the results compared to those reported in previous studies. The estimated daily intakes of THg via rice consumption using the bioaccessibility data were found to meet the recommendation value set by the JECFA and the WHO in both sites. However, the potential health risk was not negligible at the Hg-contaminated sites, due to the high THg concentration and bioaccessibility in the rice samples.展开更多
Mercury(Hg) in rice is drawing mounting concern since methylmercury(MeHg) was found capable of accumulating in rice. In-vitro bioaccessibility is a feasible and reliable method to assess the health effects of Hg in ri...Mercury(Hg) in rice is drawing mounting concern since methylmercury(MeHg) was found capable of accumulating in rice. In-vitro bioaccessibility is a feasible and reliable method to assess the health effects of Hg in rice and has been utilized in a number of studies. This study was done to investigate the impact of cultivar, planting location, and cooking on the total mercury(THg) and MeHg bioaccessibility of rice, for which multiple statistical analysis methods were used to analyze the significance of their effects. The THg concentrations of rice samples taken from non-Hg contaminated areas of China were all below 15 ng/g and their MeHg concentrations were below 2 ng/g. Cooking could significantly reduce the MeHg bioaccessibility of rice because the MeHg was mainly combined with protein and the protein will be denatured during the cooking process, and then the denatured MeHg is difficult to be dissolved into the liquid phase. Indica-and japonica-type rice cultivars did not show significant differentiation in either the concentration of Hg or its bioaccessibility. However, the glutinous rice type differed significantly from the above rice types, and it showed greater bioaccessibility of THg and MeHg due to its distinct protein contents and starch properties. Planting location can affect the Hg concentration in rice and THg bioaccessibility but has a limited impact on MeHg bioaccessibility. Based on these results, two macro factors(rice cultivar, planting location) are presumed to impact Hg bioaccessibility by how they affect micro factors(i.e., Hg forms).展开更多
To more reasonably evaluate human intake of PBDEs via dust ingestion, bioaccessibility should be taken into account. Previously, we developed an in vitro method to determine the bioaccessibility of PBDEs in food. Here...To more reasonably evaluate human intake of PBDEs via dust ingestion, bioaccessibility should be taken into account. Previously, we developed an in vitro method to determine the bioaccessibility of PBDEs in food. Here, this method was adapted to determine the bioaccessibility of PBDEs in dust and the digestion conditions that influenced the bioaccessibility of PBDEs were optimized. The digestion conditions included the incubation time of dust in the intestinal digestion solution （T）, the bile concentration in the intestinal digestion solution （Chile）, and the ratio of the volume of the intestinal digestion solution to dust （R）. The influence of the concentrations of individual PBDE congeners （CpBDE） on the bioaccessibility of PBDEs was also investigated. Cetral composite design was used to build an experimental model and set experimental parameters, and response surface methodology was used to analyze the obtained data. The results showed that the bioaccessibility of PBDEs increased with the increases of Chile and R, and was independent of T and CpSDE. Under the digestion conditions with Chile and R being at 4.0-7.0 g/L and 150-250, respectively, the bioaccessibility of PBDEs in the method-dust varied from 39.2% to 72.8%, which were comparable with the bioaccessibility or bioavailability of PBDEs in dust/soil in the literature. Thus, the in vitro method to measure the bioaccessibility of PBDEs in dust was established and validated. Finally, the bioaccessibility of PBDEs in four natural dust samples, which ranged from 36.1% to 43.3%, were determined using the adapted method.展开更多
Mercury（Hg）, mainly in cinnabar species, has been used in medicine for thousands of years in China, and worldwide concern has been raised on its toxicity. In this work, the amount of bioaccessible mercury in 16 Chin...Mercury（Hg）, mainly in cinnabar species, has been used in medicine for thousands of years in China, and worldwide concern has been raised on its toxicity. In this work, the amount of bioaccessible mercury in 16 Chinese patent medicines（CPMs） was measured by using an in vitro simulated digestion system, consisting of simulated gastric and intestinal fluid, to investigate the bioavailability of mercury in CPMs and evaluate its potential risk to human health. Total mercury and mercury in the gastrointestinal extracts were measured by inductively coupled plasma mass spectrometry（ICP-MS）. The levels of total Hg in 16 CPMs ranged from not detected to 11.89 mg/g, with a mean value of 1.13 mg/g, while the extractable Hg ranged from not detected to 4.37 μg/g, with a mean value of 0.42 μg/g.Mercury bioaccessibility varied significantly in the investigated CPMs, depending on the ingredient. Compared to the CPMs without cinnabar（2.5%–30.9%）, the percentage of mercury in the gastrointestinal supernatants for CPMs with cinnabar was quite a bit lower（0.037%）. By comparing with the Food and Agricultural Organization/World Health Organization Joint Expert Committee on Food Additives（FAO/WHO） safety guideline, the average daily intake dose（ADD） of Hg in the medicines was then calculated to access the risk of mercury to human health from taking CPMs.展开更多
Nano-enabled silicone-rubber articles for feeding or chewing could be a source of metallic nanoparticles(NPs)directly exposed to infants and young children.However,the impact of steam disinfection on release of NPs an...Nano-enabled silicone-rubber articles for feeding or chewing could be a source of metallic nanoparticles(NPs)directly exposed to infants and young children.However,the impact of steam disinfection on release of NPs and the related potential risks to children's health are unknown.Here,we investigated contents and form of Ag and Zn in 57 nano-enabled silicone-rubber baby bottle teats,pacifiers,and teethers of seven countries and examined the impacts of steam disinfection on in vitro bioaccessibility(IVBA)of Ag and Zn in the articles.Nearly 89%articles had a mixture of Ag-and Zn-containing NPs and the teethers had relatively high Ag and Zn contents(up to 501 and 254μg/g,respectively).Steam disinfection caused rubber decomposition into micro(nano)plastics(0.54-15.7μm)and NP release from the interior of bulk rubber and micro-sized plastics,thus enhancing the IVBA of Ag and Zn by up to 5.5 times.The findings provide insights into mechanisms for NP release by steam disinfection.Though oral exposure risk assessment suggested low health concerns on individual metal release,our study points out the need to assess the potential health risks of child co-exposure to metallic NPs and micro(nano)plastics.展开更多
The immobilization of co-contaminants of organic and inorganic pollutants by biochar is an efficient remediation strategy. However, the effect of biochar amendments on the bioaccessibility of the co-contaminants in dr...The immobilization of co-contaminants of organic and inorganic pollutants by biochar is an efficient remediation strategy. However, the effect of biochar amendments on the bioaccessibility of the co-contaminants in dry versus flooded soils has rarely been compared. In batch experiments, bamboo-derived biochar（BB） had a higher sorption capacity for phenanthrene（Phe）/pyrene（Pyr）/zinc（Zn） than corn straw-derived biochar（CB）, while CB had a higher sorption capacity for lead（Pb） than BB. After 150 days of incubation, the amendments of 2% CB, 0.5% BB and 2% BB effectively suppressed the dissipation and reduced the bioaccessibility of Phe/Pyr by 15.65%/18.02%, 17.07%/18.31%and 25.43%/27.11%, respectively, in the aerobic soils. This effectiveness was more significant than that in the anaerobic soils. The accessible Zn/Pb concentrations were also significantly lower in the aerobic soils than in the anaerobic soils, regardless of treatments.The Gram-negative bacterial biomass and the Shannon–Weaver index in the aerobic soil amended with 2% CB were the highest. The soil microbial community structure was jointly affected by changes in the bioaccessibility of the co-contaminants and the soil physiochemical properties caused by biochar amendments under the two conditions. Therefore, dry land farming may be more reliable than paddy soil cultivation at reducing the bioaccessibility of Phe/Pyr/Zn/Pb and enhancing the soil microbial diversity in the short term.展开更多
基金supported by the National Key Research and Development Program of China(No.2019YFC1804604)Basic and Applied Basic Research Foundation of Guangdong Province(No.2021A1515010018).
文摘There have been reports of potential health risks for people from hydrophobic organic pollutants,such as polycyclic aromatic hydrocarbons(PAHs),polychlorinated hydrocarbons(PCHs),and organophosphate flame retardants(OPFRs).When a contaminated site is used for residential housing or public utility and recreation areas,the soil-bound organic pollutantsmight pose a threat to human health.In this study,we investigated the contamination profiles and potential risks to human health of 15 PAHs,6 PCHs,and 12 OPFRs in soils from four contaminated sites in China.We used an in vitro method to determine the oral bioaccessibility of soil pollutants.Total PAHswere found at concentrations ranging from26.4 ng/g to 987 ng/g.PCHs(0.27-14.3 ng/g)and OPFRs(6.30-310 ng/g)were detected,but at low levels compared to earlier reports.The levels of PAHs,PCHs,and OPFRs released from contaminated soils into simulated gastrointestinal fluids ranged from 1.74%to 91.0%,2.51%to 39.6%,and 1.37%to 96.9%,respectively.Based on both spiked and unspiked samples,we found that the oral bioaccessibility of pollutantswas correlated with their logKow andmolecularweight,and the total organic carbon content and pH of soils.PAHs in 13 out of 38 contaminated soil samples posed potential high risks to children.When considering oral bioaccessibility,nine soils still posed potential risks,while the risks in the remaining soils became negligible.The contribution of this paper is that it corrects the health risk of soil-bound organic pollutants by detecting bioaccessibility in actual soils from different contaminated sites.
基金supported by the National Natural Science Foundation of China(No.22306111)Shandong Provincial Natural Science Foundation of China(Nos.ZR2022QB242 and ZR2020ZD20).
文摘Considerable levels of methylmercury(MeHg)have been found rice-based infant cereals as a result of MeHg transfer from the rice as a raw material to the products,hence consumption of rice products may pose a potential health risk to infants who may receive cereals as the major diets and are susceptible to toxicity of MeHg.Determination of bioaccessibility of MeHg would provide a more accurate assessment of MeHg exposure through consumption of rice-based cereals,yet this information remains lacking.Further,the re-adsorption of methylmercury on the residual food will affect the accurate assessment of its bioaccessibility.Our goals in this work were 1)to determine the bioaccessibility of MeHg in infant rice cereals commonly available on the market by using a typical in vitro artificial gastrointestinal digestionmodel and 2)to evaluate the effects of MeHg re-adsorption on the in vitro assessment of MeHg bioaccessibility.The determined bioaccessibility of MeHg in the studied rice cereals after the standard dual-step(using gastric followed by intestinal juice)protocol ranged from 25%to 74%,a wide range comparable to that of fish samples observed here and in previous studies.The surprisingly higher bioaccessibility of MeHg in fish and rice cereals after the gastric step only,in comparison to after the complete two-step gastrointestinal digestion,suggests the re-adsorption of MeHg on the residual food.Separate experiments with spiked MeHg standards confirmed that the MeHg released by the acetic gastric juice was re-adsorbed on the residues during the intestinal step at neutral pH.This study provided first-hand data on the bioaccessibility of MeHg in infant rice cereals and methodological implications on using in vitro digestion to evaluate the bioaccessibility of MeHg and metal contaminants in general.
基金Supported by National Natural Science Foundation of China(41101484)Discipline Innovation and Intelligence Plan for Colleges(B08037)International Cooperation Project of Ministry of Science and Technology(2011DFA101222)~~
文摘[Objective] This study aimed to investigate the existing forms and bioaccessibility of vanadium（V） from soil and mineral of Panzhihua region.[Method] The representative Xigeda soil and vanadium-titanium magnetite were collected from Panzhihua region to determine the existing forms of vanadium from soil and mineral;in vitro bionic digestion model was established to measure the bioaccessibility of vanadium.[Result] The dissolved concentrations of vanadium from farmland,mining area and vanadium-titanium magnetite in gastric juice were respectively 5.02,9.50 and 3.88 mg/kg,and the bioaccessibility ranged from 0.09% to 3.00%;the dissolved concentrations of vanadium in intestinal juice were respectively 2.98,5.43 and 4.49 mg/kg,and the bioaccessibility ranged from 0.10% to 1.78%.The content of vanadium in various existing forms varied significantly,the contents of vanadium in non-specific adsorption state and specific adsorption state were low,but residual content was completely high,which accounted for 75.06%,95.32% and 86.27% of the total content of vanadium in samples.[Conclusion] Bioaccessibility of dissolved vanadium in gastric juice was higher than that in small intestinal juice.Vanadium from soil and mineral was difficult to generate morphological transformation and migration,which was the main reason for low bioaccessibility.
基金supported by the National High Technology Research and Development Program(863)of China(No.2008AA06Z336)the National Natural Science Foundation of China(No.20607028,20977110).
文摘Indian mustard （Brassica juncea （L.） Czern.） has shown good potential for the phytoremediation of soil contaminated with heavy metals. However, there is little information about the speciation and bioaccessibility of heavy metals in soil during the decomposition of metal-rich Indian mustard leaves. Incubation experiments （1-, 3-, and 6-month） were carried out in Beijing and Hunan soil with metal-rich Indian mustard leaves addition （1% and 3%） and the effects of mustard leaves addition on the speciation and bioaccessibility of heavy metals were studied. The results showed that the addition of mustard leaves led to significant increases in pH and DOC in the Hunan soil. Both 1% and 3% of mustard leaf amendment caused the percentage of the exchangeable （F1）, precipitated with carbonates （F2）, bound to Fe/Mn oxides （F3） and bound to organic matter （F4） fractions of Pb and Cd to increase dramatically, while the percentage of the residual fraction （F5） of Cd and Pb significantly dropped in both Beijing and Hunan soils. Mustard leaf addition caused the bioaccessibility of Pb to decrease in the gastric phase, whereas the values increased in the small intestinal phase. The Cd bioaccessibility increased with mustard leaf addition in both the gastric and small intestinal phases. In conclusion, the metal-enriched mustard leaves addition induces Pb and Cd concentrations and their mobility increasing in the Beijing and Hunan soils. Therefore, heavy metal risk in metal-enriched plant leaves should be considered in phytoremediation system in which heavy metal might be brought back to soil and changed over time.
基金financially supported by the National Science and Technology Support Program of China(No.2015BAD05B02)
文摘Cadmium(Cd)pollution in agricultural soils has exerted a serious threat due to continuous application of pesticides,fertilizers,and wastewater irrigation.The present study aimed to test the efficiency of KOH-modified and non-modified rice straw-derived biochar(KBC and BC,respectively)for reducing Cd solubility and bioavailability in Cd-contaminated soil.Cadmium-contaminated soil was incubated for 60 d with 15 and 30 g kg-1 BC and KBC.At the end of incubation,Cd mobility was estimated by the European Community Bureau of Reference sequential extraction and toxicity characteristic leaching procedure(TCLP),while bioavailability was determined using 1 molL-1 NH4NO3 extraction.The bioavailability risk index and bioaccessibility,assessed by a simple bioaccessibility extraction test,of Cd were used to examine the potential effects of Cd on living organisms.The results indicated that application of both KBC and BC significantly increased soil p H,cation exchange capacity,nutrients,and organic carbon.The soluble fraction of Cd was significantly decreased by 30.3%and 27.4%,respectively,with the addition of KBC and BC at 30 g kg-1 compared to the control(without biochar addition).Similarly,the bioaccessible Cd was significantly decreased by 32.4%and 25.2%,respectively,with the addition of KBC and BC at 30 g kg-1 compared to the control.In addition,both KBC and BC significantly reduced Cd leaching in the TCLP and NH4NO3-extractable Cd in the amended soil compared to the control.The reduction in Cd solubility and bioaccessibility by KBC and BC may be due to significant increases in soil pH and surface complexation.Overall,KBC at an application rate of 30 g kg-1 demonstrated positive results as soil amendment for Cd immobilization,and reduced bioaccessible Cd in contaminated soil.
文摘Rice consumption can be a major pathway for mercury（Hg） exposure, which can cause health hazards to Chinese residents. To accurately assess the potential health risks, the bioaccessibility of Hg in rice samples collected at background and Hg-contamination sites was examined using four in vitro methods. The results showed that 〈 50% of the total mercury（THg） was bioaccessible in the studied rice samples. The THg bioaccessibility in the rice samples collected at the Hg-contaminated site was higher than that observed at the background area. The bioaccessibility of arsenic（As） and cadmium（Cd） was also evaluated for comparison of the four in vitro methods used in this study. The Physiologically Based Extraction Test was found to be the most accurate method based on the consistency of the results compared to those reported in previous studies. The estimated daily intakes of THg via rice consumption using the bioaccessibility data were found to meet the recommendation value set by the JECFA and the WHO in both sites. However, the potential health risk was not negligible at the Hg-contaminated sites, due to the high THg concentration and bioaccessibility in the rice samples.
基金supported by the research fund of Guizhou Minzu University (No. GZMUZK[2021]YB14)the open research fund of Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education of the People’s Republic of China (No. QJH-KY[2020]247)。
文摘Mercury(Hg) in rice is drawing mounting concern since methylmercury(MeHg) was found capable of accumulating in rice. In-vitro bioaccessibility is a feasible and reliable method to assess the health effects of Hg in rice and has been utilized in a number of studies. This study was done to investigate the impact of cultivar, planting location, and cooking on the total mercury(THg) and MeHg bioaccessibility of rice, for which multiple statistical analysis methods were used to analyze the significance of their effects. The THg concentrations of rice samples taken from non-Hg contaminated areas of China were all below 15 ng/g and their MeHg concentrations were below 2 ng/g. Cooking could significantly reduce the MeHg bioaccessibility of rice because the MeHg was mainly combined with protein and the protein will be denatured during the cooking process, and then the denatured MeHg is difficult to be dissolved into the liquid phase. Indica-and japonica-type rice cultivars did not show significant differentiation in either the concentration of Hg or its bioaccessibility. However, the glutinous rice type differed significantly from the above rice types, and it showed greater bioaccessibility of THg and MeHg due to its distinct protein contents and starch properties. Planting location can affect the Hg concentration in rice and THg bioaccessibility but has a limited impact on MeHg bioaccessibility. Based on these results, two macro factors(rice cultivar, planting location) are presumed to impact Hg bioaccessibility by how they affect micro factors(i.e., Hg forms).
基金supported by the National Basic Research Program (973) of China (No. 2008CB418205)the Earmarked Fund of the State Key Laboratory of Organic Geochemistry (No. OGL-200903)+1 种基金the National Nature Science Foundation of China (No. 20807026,40830744)the Shanghai Leading Academic Disciplines (No. S30109)
文摘To more reasonably evaluate human intake of PBDEs via dust ingestion, bioaccessibility should be taken into account. Previously, we developed an in vitro method to determine the bioaccessibility of PBDEs in food. Here, this method was adapted to determine the bioaccessibility of PBDEs in dust and the digestion conditions that influenced the bioaccessibility of PBDEs were optimized. The digestion conditions included the incubation time of dust in the intestinal digestion solution （T）, the bile concentration in the intestinal digestion solution （Chile）, and the ratio of the volume of the intestinal digestion solution to dust （R）. The influence of the concentrations of individual PBDE congeners （CpBDE） on the bioaccessibility of PBDEs was also investigated. Cetral composite design was used to build an experimental model and set experimental parameters, and response surface methodology was used to analyze the obtained data. The results showed that the bioaccessibility of PBDEs increased with the increases of Chile and R, and was independent of T and CpSDE. Under the digestion conditions with Chile and R being at 4.0-7.0 g/L and 150-250, respectively, the bioaccessibility of PBDEs in the method-dust varied from 39.2% to 72.8%, which were comparable with the bioaccessibility or bioavailability of PBDEs in dust/soil in the literature. Thus, the in vitro method to measure the bioaccessibility of PBDEs in dust was established and validated. Finally, the bioaccessibility of PBDEs in four natural dust samples, which ranged from 36.1% to 43.3%, were determined using the adapted method.
基金supported by the National Basic Research Program (973) of China (No. 2013CB430004)the National Natural Science Foundation of China (Nos. 21120102040, 21075130)
文摘Mercury（Hg）, mainly in cinnabar species, has been used in medicine for thousands of years in China, and worldwide concern has been raised on its toxicity. In this work, the amount of bioaccessible mercury in 16 Chinese patent medicines（CPMs） was measured by using an in vitro simulated digestion system, consisting of simulated gastric and intestinal fluid, to investigate the bioavailability of mercury in CPMs and evaluate its potential risk to human health. Total mercury and mercury in the gastrointestinal extracts were measured by inductively coupled plasma mass spectrometry（ICP-MS）. The levels of total Hg in 16 CPMs ranged from not detected to 11.89 mg/g, with a mean value of 1.13 mg/g, while the extractable Hg ranged from not detected to 4.37 μg/g, with a mean value of 0.42 μg/g.Mercury bioaccessibility varied significantly in the investigated CPMs, depending on the ingredient. Compared to the CPMs without cinnabar（2.5%–30.9%）, the percentage of mercury in the gastrointestinal supernatants for CPMs with cinnabar was quite a bit lower（0.037%）. By comparing with the Food and Agricultural Organization/World Health Organization Joint Expert Committee on Food Additives（FAO/WHO） safety guideline, the average daily intake dose（ADD） of Hg in the medicines was then calculated to access the risk of mercury to human health from taking CPMs.
基金supported by the Key-Area Research and Development Program of Guangdong Province (No.2020B1111380003)the National Natural Science Foundation of China (Nos.42177377 and 31861133003)。
文摘Nano-enabled silicone-rubber articles for feeding or chewing could be a source of metallic nanoparticles(NPs)directly exposed to infants and young children.However,the impact of steam disinfection on release of NPs and the related potential risks to children's health are unknown.Here,we investigated contents and form of Ag and Zn in 57 nano-enabled silicone-rubber baby bottle teats,pacifiers,and teethers of seven countries and examined the impacts of steam disinfection on in vitro bioaccessibility(IVBA)of Ag and Zn in the articles.Nearly 89%articles had a mixture of Ag-and Zn-containing NPs and the teethers had relatively high Ag and Zn contents(up to 501 and 254μg/g,respectively).Steam disinfection caused rubber decomposition into micro(nano)plastics(0.54-15.7μm)and NP release from the interior of bulk rubber and micro-sized plastics,thus enhancing the IVBA of Ag and Zn by up to 5.5 times.The findings provide insights into mechanisms for NP release by steam disinfection.Though oral exposure risk assessment suggested low health concerns on individual metal release,our study points out the need to assess the potential health risks of child co-exposure to metallic NPs and micro(nano)plastics.
基金supported by the National Key Basic Research Program of China(No.2014CB441105)the National Natural Science Foundation of China(No.41671236)+1 种基金the“135”Plan and Frontiers Program of the Institute of Soil Science,Chinese Academy of Sciences(No.ISSASIP1614)the Outstanding Youth Fund of Natural Science Foundation of Jiangsu,China(No.BK20150050)
文摘The immobilization of co-contaminants of organic and inorganic pollutants by biochar is an efficient remediation strategy. However, the effect of biochar amendments on the bioaccessibility of the co-contaminants in dry versus flooded soils has rarely been compared. In batch experiments, bamboo-derived biochar（BB） had a higher sorption capacity for phenanthrene（Phe）/pyrene（Pyr）/zinc（Zn） than corn straw-derived biochar（CB）, while CB had a higher sorption capacity for lead（Pb） than BB. After 150 days of incubation, the amendments of 2% CB, 0.5% BB and 2% BB effectively suppressed the dissipation and reduced the bioaccessibility of Phe/Pyr by 15.65%/18.02%, 17.07%/18.31%and 25.43%/27.11%, respectively, in the aerobic soils. This effectiveness was more significant than that in the anaerobic soils. The accessible Zn/Pb concentrations were also significantly lower in the aerobic soils than in the anaerobic soils, regardless of treatments.The Gram-negative bacterial biomass and the Shannon–Weaver index in the aerobic soil amended with 2% CB were the highest. The soil microbial community structure was jointly affected by changes in the bioaccessibility of the co-contaminants and the soil physiochemical properties caused by biochar amendments under the two conditions. Therefore, dry land farming may be more reliable than paddy soil cultivation at reducing the bioaccessibility of Phe/Pyr/Zn/Pb and enhancing the soil microbial diversity in the short term.
