In order to study toxicological effects of perfluorononanoic acid (PFNA), perfluorooctane sulfonate (PFOS), and their mixtures (PFNA/ PFOS) on Daphnia magna (D. magna), a suite of comprehensive toxicity tests ...In order to study toxicological effects of perfluorononanoic acid (PFNA), perfluorooctane sulfonate (PFOS), and their mixtures (PFNA/ PFOS) on Daphnia magna (D. magna), a suite of comprehensive toxicity tests were conducted, including a 48-h acute toxicity test, a 21-day chronic test, a feeding experiment, and a biomarker assay. D. magna were exposed to aqueous solutions of PFNA and PFOS (alone and in combination) at concentrations ranging from 0.008 to 5 mg/L. The survival, growth, and reproduction of D. magna were monitored over a 21- day life cycle. The biomarkers, including acetylcholinesterase (ACHE), superoxide dismutase (SOD), and catalase (CAT) activities, were determined after seven days of exposure. PFOS was more toxic than PFNA based on the results of the acute toxicity test. Perfluorinated compounds (PFCs) inhibited both growth and reproduction of D. magna during the testing period. The ingestion rates and the biomarkers, including ACHE, SOD, and CAT activities, were significantly inhibited by PFCs in most cases. Moreover, the combined effects related to the growth and reproduction showed the antagonistic effects of PFCs.展开更多
Objective To understand the status of the forearm bone mineral density (BMD) in older adults, and to identify the potentialfactors influencing BMD. Methods A total of 1 214 older adults were examined, in Tianlin, Fe...Objective To understand the status of the forearm bone mineral density (BMD) in older adults, and to identify the potentialfactors influencing BMD. Methods A total of 1 214 older adults were examined, in Tianlin, Fenglin and Xietu sub-districts, of Xuhui district, Shanghai. BMD was tested at the left forearm, including distal radius and ulna 1/3 total, distal radius where the distance of radius and ulna is 8 mm, ultra-distal radius, by single energy X-ray densitometer. Results The BMD at all of the four sites decreased with the age increased. The average BMD was higher in male than in female for the same age and measured site. Distal radius 1/3 total had the highest BMD among the four sites. The incidence of low BMD and osteoporosis in distal forearm 1/3 radius total ascended with the age increased. Multiplied logistic regression showed that males had a lower risk to be low BMD (OR=0. 19) compared with female. Compared with the group aged from 50 to 54, the odds ratio in the group aged from 55 to 59, 60 to 64, and 65 to 70 were respectively 3.17, 5.13, 15.03. Compared with those whose monthly salary was less than 1 000, the odds ratio was O. 70 in those whose salary was more than 1 000. Conclusion The incidence of low BMD was high in older adults, and it is related with sex, age, monthly salary.展开更多
The stabilization of severely As-polluted soil has been a challenge, especially for the extremely toxic As(Ⅲ) contaminants. In this study, soil with a high As concentration(26084 mg/kg) was availably stabilized by a ...The stabilization of severely As-polluted soil has been a challenge, especially for the extremely toxic As(Ⅲ) contaminants. In this study, soil with a high As concentration(26084 mg/kg) was availably stabilized by a H2O2 pre-oxidation assisted TMT-15(Na3S3C3N3 solution with a mass fraction of 15%) and FeCl3·6 H2O stabilization method. The results showed that the combination of the two stabilizers(i.e., TMT-15 and FeCl3·6 H2O) presented a better stabilization behavior than either stabilizer used individually. The use of the H2O2 pre-oxidation assisted TMT-15 and FeCl3·6 H2O stabilization approach not only converted the As(Ⅲ) to As(Ⅴ) but also reduced the toxic leaching concentration of As to 1.61 mg/L, which is a safe level, when the additions of TMT-15 and FeCl3·6 H2O were 2 mL and 0.20 g, respectively. Thus, using only a simple H2O2 pre-oxidation to combine clean stabilization with non-toxic stabilizers TMT-15 and FeCl3·6 H2O could render the severely As-contaminated soil safe for disposal in a landfill.展开更多
Objective To measure the acute toxicity of halogenated benzenes to bacteria in natural waters and to study quantitative relationships between the structure and activity of chemicals. Methods The concentration values c...Objective To measure the acute toxicity of halogenated benzenes to bacteria in natural waters and to study quantitative relationships between the structure and activity of chemicals. Methods The concentration values causing 50% inhibition of bacteria growth (24h-IC50) were determined according to the bacterial growth inhibition test method. The energy of the lowest unoccupied molecular orbital and the net charge of carbon atom of 20 halogenated benzenes were calculated by the quantum chemical MOPAC program. Results The logl/IC50 values ranged from 4.79 for 2,4-dinitrochlorobenzene to 3.65 for chlorobenzene. A quantitative structure-activity relationship model was derived from the toxicity and structural parameters: logl/IC50 =-0.531(ELUMO)+1.693(Qc)+0.163(logP)+3.375. This equation was found to fit well (r^2=0.860, s=0.106), and the average percentage error was only 1.98%. Conclusion Halogenated benzenes and alkyl halogenated benzenes are non-polar narcotics, and have hydrophobicity-dependent toxicity. The halogenated phenols and anilines exhibit a higher toxic potency than their hydrophobicity, whereas 2,4-dinitrochlorobenzene is electrophile with the halogen acting as the leaving group.展开更多
The freshwater fish Carassius auratus was chosen as an experimental subject, and their hepatic biochemical responses to the medium-term exposure of Benzo(k)fluoranthene (BkF) alone and in combination with PCB 118 ...The freshwater fish Carassius auratus was chosen as an experimental subject, and their hepatic biochemical responses to the medium-term exposure of Benzo(k)fluoranthene (BkF) alone and in combination with PCB 118 and dichlorodiphenyltrichloroethane (DDT) were investigated by measuring the reduced glutathione (GSH), glutathione S-transferase (GST), and thiobarbituric acid reactive substances (TBARS), to assess sublethal effects. The hepatic GSH content was significantly inhibited by organic pollutants, alone and in mixtures, while the TBARS content was significantly induced after three days of exposure. Bell-shaped concentration-response charts of GST activities were obtained. Significant dose-response relationships were found for hepatic GSH and TBARS contents of all concentrations and for the GST activity, except at the highest concentration. The GSH content, GST activity, and TBARS content in Carassius auratus were confirmed as useful biomarkers of exposure to organic pollutions.展开更多
To study the correlation of toxicity with biodegradability (BODT) in order to promote QSBR development and understand the degradation mechanism. Methods Toxicity of substituted phenols to river bacteria was determin...To study the correlation of toxicity with biodegradability (BODT) in order to promote QSBR development and understand the degradation mechanism. Methods Toxicity of substituted phenols to river bacteria was determined by the turbidities that were measured using a spectrophotometer (UV-190) at 530 nm against a blank control. The biodegradability of substituted phenols was expressed as BODT and the DO concentrations were determined by the iodometric titration method. Results The BODT and toxicity(log 1/IC50) of 12 substituted phenols to bacteria from the Songhua River were determined respectively. The correlation of biodegradability with toxicity was developed: BODT=8.21 (±2.22) pKa -32.44 (±8.28) log 1/IC50 +89.04 (±38.20), n=12, R^2=0.791, R^2(adj)=0.745, SE=9.134, F=17.066, P=0.001. Conclusion The BODT of substituted phenols was influenced by their toxicity and the ionization constant pKa. The stronger the toxicity, the less readily the compound was degraded by river bacteria.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51279061)the Qing Lan Project of Jiangsu Province
文摘In order to study toxicological effects of perfluorononanoic acid (PFNA), perfluorooctane sulfonate (PFOS), and their mixtures (PFNA/ PFOS) on Daphnia magna (D. magna), a suite of comprehensive toxicity tests were conducted, including a 48-h acute toxicity test, a 21-day chronic test, a feeding experiment, and a biomarker assay. D. magna were exposed to aqueous solutions of PFNA and PFOS (alone and in combination) at concentrations ranging from 0.008 to 5 mg/L. The survival, growth, and reproduction of D. magna were monitored over a 21- day life cycle. The biomarkers, including acetylcholinesterase (ACHE), superoxide dismutase (SOD), and catalase (CAT) activities, were determined after seven days of exposure. PFOS was more toxic than PFNA based on the results of the acute toxicity test. Perfluorinated compounds (PFCs) inhibited both growth and reproduction of D. magna during the testing period. The ingestion rates and the biomarkers, including ACHE, SOD, and CAT activities, were significantly inhibited by PFCs in most cases. Moreover, the combined effects related to the growth and reproduction showed the antagonistic effects of PFCs.
文摘Objective To understand the status of the forearm bone mineral density (BMD) in older adults, and to identify the potentialfactors influencing BMD. Methods A total of 1 214 older adults were examined, in Tianlin, Fenglin and Xietu sub-districts, of Xuhui district, Shanghai. BMD was tested at the left forearm, including distal radius and ulna 1/3 total, distal radius where the distance of radius and ulna is 8 mm, ultra-distal radius, by single energy X-ray densitometer. Results The BMD at all of the four sites decreased with the age increased. The average BMD was higher in male than in female for the same age and measured site. Distal radius 1/3 total had the highest BMD among the four sites. The incidence of low BMD and osteoporosis in distal forearm 1/3 radius total ascended with the age increased. Multiplied logistic regression showed that males had a lower risk to be low BMD (OR=0. 19) compared with female. Compared with the group aged from 50 to 54, the odds ratio in the group aged from 55 to 59, 60 to 64, and 65 to 70 were respectively 3.17, 5.13, 15.03. Compared with those whose monthly salary was less than 1 000, the odds ratio was O. 70 in those whose salary was more than 1 000. Conclusion The incidence of low BMD was high in older adults, and it is related with sex, age, monthly salary.
基金financially supported by the National Key R&D Program of China (No. 2018YFC1802400)the National Natural Science Foundation of China (No. 51604310)+1 种基金the Major Project of Central Research Institute of Building and Construction (No. XAC2017Ky03)the Opening Foundation of State Key Laboratory for Environmental Protection of Iron and Steel Industry (No. 2016YZC02)
文摘The stabilization of severely As-polluted soil has been a challenge, especially for the extremely toxic As(Ⅲ) contaminants. In this study, soil with a high As concentration(26084 mg/kg) was availably stabilized by a H2O2 pre-oxidation assisted TMT-15(Na3S3C3N3 solution with a mass fraction of 15%) and FeCl3·6 H2O stabilization method. The results showed that the combination of the two stabilizers(i.e., TMT-15 and FeCl3·6 H2O) presented a better stabilization behavior than either stabilizer used individually. The use of the H2O2 pre-oxidation assisted TMT-15 and FeCl3·6 H2O stabilization approach not only converted the As(Ⅲ) to As(Ⅴ) but also reduced the toxic leaching concentration of As to 1.61 mg/L, which is a safe level, when the additions of TMT-15 and FeCl3·6 H2O were 2 mL and 0.20 g, respectively. Thus, using only a simple H2O2 pre-oxidation to combine clean stabilization with non-toxic stabilizers TMT-15 and FeCl3·6 H2O could render the severely As-contaminated soil safe for disposal in a landfill.
基金This work was supported by the National 973 Great Foundation Research Item of China (2002CB412303) and the National Natural Science Foundation of Jiangsu Province (BK2004118).
文摘Objective To measure the acute toxicity of halogenated benzenes to bacteria in natural waters and to study quantitative relationships between the structure and activity of chemicals. Methods The concentration values causing 50% inhibition of bacteria growth (24h-IC50) were determined according to the bacterial growth inhibition test method. The energy of the lowest unoccupied molecular orbital and the net charge of carbon atom of 20 halogenated benzenes were calculated by the quantum chemical MOPAC program. Results The logl/IC50 values ranged from 4.79 for 2,4-dinitrochlorobenzene to 3.65 for chlorobenzene. A quantitative structure-activity relationship model was derived from the toxicity and structural parameters: logl/IC50 =-0.531(ELUMO)+1.693(Qc)+0.163(logP)+3.375. This equation was found to fit well (r^2=0.860, s=0.106), and the average percentage error was only 1.98%. Conclusion Halogenated benzenes and alkyl halogenated benzenes are non-polar narcotics, and have hydrophobicity-dependent toxicity. The halogenated phenols and anilines exhibit a higher toxic potency than their hydrophobicity, whereas 2,4-dinitrochlorobenzene is electrophile with the halogen acting as the leaving group.
基金supported by the Special Fund for Public Welfare Industry of Ministry of Water Resources of China(Grant No201001056)the Project of Jiangxi Provincial Department of Science and Technology (Grant No2010BSA20300)the Project of Jiangxi Provincial Department of Education(Grants No GJJ11246 and GJJ11636)
文摘The freshwater fish Carassius auratus was chosen as an experimental subject, and their hepatic biochemical responses to the medium-term exposure of Benzo(k)fluoranthene (BkF) alone and in combination with PCB 118 and dichlorodiphenyltrichloroethane (DDT) were investigated by measuring the reduced glutathione (GSH), glutathione S-transferase (GST), and thiobarbituric acid reactive substances (TBARS), to assess sublethal effects. The hepatic GSH content was significantly inhibited by organic pollutants, alone and in mixtures, while the TBARS content was significantly induced after three days of exposure. Bell-shaped concentration-response charts of GST activities were obtained. Significant dose-response relationships were found for hepatic GSH and TBARS contents of all concentrations and for the GST activity, except at the highest concentration. The GSH content, GST activity, and TBARS content in Carassius auratus were confirmed as useful biomarkers of exposure to organic pollutions.
基金This research was supported by the Science Foundation of Education Ministry of China (No. 03058) and Science Foundation for YoungTeachers of Northeast Normal University (No. 20050503).
文摘To study the correlation of toxicity with biodegradability (BODT) in order to promote QSBR development and understand the degradation mechanism. Methods Toxicity of substituted phenols to river bacteria was determined by the turbidities that were measured using a spectrophotometer (UV-190) at 530 nm against a blank control. The biodegradability of substituted phenols was expressed as BODT and the DO concentrations were determined by the iodometric titration method. Results The BODT and toxicity(log 1/IC50) of 12 substituted phenols to bacteria from the Songhua River were determined respectively. The correlation of biodegradability with toxicity was developed: BODT=8.21 (±2.22) pKa -32.44 (±8.28) log 1/IC50 +89.04 (±38.20), n=12, R^2=0.791, R^2(adj)=0.745, SE=9.134, F=17.066, P=0.001. Conclusion The BODT of substituted phenols was influenced by their toxicity and the ionization constant pKa. The stronger the toxicity, the less readily the compound was degraded by river bacteria.