Concentrations of lead(Pb) were determined in leaf samples of \%Chromolaena adorata\% from a rural road and an urban road in Akwa Ibom State of Nigeria in relation to vehicular traffic density. Mixed results were obt...Concentrations of lead(Pb) were determined in leaf samples of \%Chromolaena adorata\% from a rural road and an urban road in Akwa Ibom State of Nigeria in relation to vehicular traffic density. Mixed results were obtained wich no trend to indict automobile exhaust fumes. Lead was not detected in rain water from these areas and leaf lead levels seemed to relate more to soil lead concentrations. There was no significant difference in mean leaf lead levels between rural and urban leaf samples and between washed and unwashed leaf samples. It was suggested that the lack of concordance between vehicular traffic density and lead levels in leaves along the highways indicates either a low level use of tetraethyl leaded petrol or, a relatively low vehicular traffic density with lead from exhaust fumes not reaching a threshold to affect levels in plants or be detected in the atmosphere. Implications of concentrations obtained in leaves to consumers when compared with international standards were discussed.展开更多
Samples of roadside dust were collected from 30 sites in Hong Kong.The total concentrations of 10 metals in the samples were analyzed,and the correlation coefficients among the metal contents and the annual average da...Samples of roadside dust were collected from 30 sites in Hong Kong.The total concentrations of 10 metals in the samples were analyzed,and the correlation coefficients among the metal contents and the annual average daily traffic(AADT)in 1986 were determined.Pb was found to have a significant correlation(P<0.01)with AADT.No correlation was found between Al, Ba,Cd,Cr,Cu,Fe,Mn,Ni,and Zn with respect to AADT.A general decrease in the level of Pb in roadside dust in the past few years has been observed since the reduction in the level of lead in petrol.1989 Academic Press,Inc.展开更多
This study was designed to determine the cord blood lead (BPb) levels of babies born in one urban area of Shanghai, and to preliminarily identify the demographic, social environment and prenatal factors which have an ...This study was designed to determine the cord blood lead (BPb) levels of babies born in one urban area of Shanghai, and to preliminarily identify the demographic, social environment and prenatal factors which have an effect on the cord BPb concentrations. From August to November 1993, umbilical cord blood samples were obtained from 605 live newborns in the Yangpu Maternal and Child Hospital. 257 samples were excluded from measurement because of clotting. In 348 cord samples, the geometric mean of cord BPb levels was 9. 2μg/dl, with a 95 % confidence interval of the mean 8. 86-9. 54 (μg/dl). 142 babies (40. 8 % ) had cord BPb levels of 10μg/dl or greater. As a result of this high percentage of newborns with BPb levels equal to or greater than 10 μg/dl, we estimate that each year in the Shanghal City about 60,000 newborns are at risk for developing neuropsychological deficiencies caused by maternal lead exposure during pregnancy. To investigate the factors affecting cord blood levels, the subjects with levels greater than the 70th percentile (10. 7μg/dl) (n = 104) and less than the 3oth percentile (7. 4μg/dl) (n = 104) were selected to compare the demographic, environ ment and prenatal medical history. Increased BPb levels at birth were associated with maternal passive smoking, a family member being occupationally exposed to lead, proximity to major traffic way, household coal combustion, neighborhood coal combustion, low level of meternal occupations, and the increasing occurrence of having the high lead foodstuff pidan (preserved duck egg) during pregnancy. We conclude that prenatal lead exposure has become an impor tant health issue for young children in Shanghai展开更多
Lead,a heavy metal,which is nonessential but may be harmful to the human body,has been widely used to manufacture many products for use in the modern world.Lead-acid batteries have the advantages of low price,high saf...Lead,a heavy metal,which is nonessential but may be harmful to the human body,has been widely used to manufacture many products for use in the modern world.Lead-acid batteries have the advantages of low price,high safety,and advanced technology.展开更多
In this study, we searched multiple databases for all relevant original articles (1996-2013). To investigate blood lead levels (BLL) and possible risk factors for lead exposure among children in China A total of 388 a...In this study, we searched multiple databases for all relevant original articles (1996-2013). To investigate blood lead levels (BLL) and possible risk factors for lead exposure among children in China A total of 388 articles met our inclusion criteria. The overall geometric mean (GM) BLL was 71 μg/L, and the prevalence of elevated BLL (EBLL, defined as BLL ≥100 μg/L) was 18.48% among children. The prevalence of EBLL remained significantly higher among boys. In children less than 6 years of age, there were significantly increasing trends in both BLL and prevalence of EBLL in an age-dependent manner. The ban on leaded gasoline significantly reduced the BLL as well as EBLL prevalence; however, children whose parents had lower educational levels or were exposed to lead in the workplace had a higher EBLL prevalence. Despite its decline over time, the average BLL among children in China remains higher than the average level most recently reported in the United States. Childhood lead poisoning remains a public health problem in China.展开更多
Objective To investigate the blood lead levels (BLLs) in the duration of pregnancy and 6-12 weeks after delivery,and analyze the influencing factors of BLLs in healthy pregnant women.Methods Pregnant women were recrui...Objective To investigate the blood lead levels (BLLs) in the duration of pregnancy and 6-12 weeks after delivery,and analyze the influencing factors of BLLs in healthy pregnant women.Methods Pregnant women were recruited from September 2009 to February 2010 at the prenatal clinic in Nanjing Maternity and Child Health Care Hospital.Altogether 174 healthy pregnant women without pregnant or obstetric complications or abnormal pregnancy outcomes were enrolled as the gravida group,and 120 healthy non-pregnant women as the control group.BLLs during pregnancy were determined by flame atomic absorption spectroscopy.Results BLLs in all the three pregnancy trimesters and postpartum were 59.8±24.3,55.4±20.1,55.9±19.7,and 67.6±17.4 μg/L,respectively,and the mean BLL in control group was 67.5±21.3 μg/L.BLLs during all the three trimesters were lower in the gravida group than in the control group (P=0.043,0.021,and 0.028).Furthermore,occupations,nutrients supplementation,and time of house/apartment painted were associated with BLLs in pregnant women.Lead-related occupations,cosmetics use,and living in a house painted less than 1 year before are risk factors of high BLLs among pregnant women,while calcium,iron,zinc,and milk supplements are protective factors.Conclusion Supplementing calcium,iron,zinc,and milk,or avoiding contact with risk factors may help people,especially pregnant women,to reduce lead exposure.展开更多
The decision-making and optimization of two-echelon inventory coordination were analyzed with service level constraint and controllable lead time sensitive to order quantity.First,the basic model of this problem was e...The decision-making and optimization of two-echelon inventory coordination were analyzed with service level constraint and controllable lead time sensitive to order quantity.First,the basic model of this problem was established and based on relevant analysis,the original model could be transformed by minimax method.Then,the optimal order quantity and production quantity influenced by service level constraint were analyzed and the boundary of optimal order quantity and production quantity was given.According to this boundary,the effective method and tactics were put forward to solve the transformed model.In case analysis,the optimal expected total cost of two-echelon inventory can be obtained and it was analyzed how service level constraint and safety factor influence the optimal expected total cost of two-echelon inventory.The results show that the optimal expected total cost of two-echelon inventory is constrained by the higher constraint between service level constraint and safety factor.展开更多
Economic responsibility audit is an important part of the socialist audit supervision system with Chinese characteristics.It is an important responsibility of audit institutions at all levels to carry out economic res...Economic responsibility audit is an important part of the socialist audit supervision system with Chinese characteristics.It is an important responsibility of audit institutions at all levels to carry out economic responsibility audit.This article conducts a comprehensive and profound analysis of the problems existing in the current grassroots economic responsibility audit work.In addition,countermeasures and suggestions are proposed in this article,which are of positive significance to promote the economic responsibility audit work of leading cadres.展开更多
文摘Concentrations of lead(Pb) were determined in leaf samples of \%Chromolaena adorata\% from a rural road and an urban road in Akwa Ibom State of Nigeria in relation to vehicular traffic density. Mixed results were obtained wich no trend to indict automobile exhaust fumes. Lead was not detected in rain water from these areas and leaf lead levels seemed to relate more to soil lead concentrations. There was no significant difference in mean leaf lead levels between rural and urban leaf samples and between washed and unwashed leaf samples. It was suggested that the lack of concordance between vehicular traffic density and lead levels in leaves along the highways indicates either a low level use of tetraethyl leaded petrol or, a relatively low vehicular traffic density with lead from exhaust fumes not reaching a threshold to affect levels in plants or be detected in the atmosphere. Implications of concentrations obtained in leaves to consumers when compared with international standards were discussed.
文摘Samples of roadside dust were collected from 30 sites in Hong Kong.The total concentrations of 10 metals in the samples were analyzed,and the correlation coefficients among the metal contents and the annual average daily traffic(AADT)in 1986 were determined.Pb was found to have a significant correlation(P<0.01)with AADT.No correlation was found between Al, Ba,Cd,Cr,Cu,Fe,Mn,Ni,and Zn with respect to AADT.A general decrease in the level of Pb in roadside dust in the past few years has been observed since the reduction in the level of lead in petrol.1989 Academic Press,Inc.
文摘This study was designed to determine the cord blood lead (BPb) levels of babies born in one urban area of Shanghai, and to preliminarily identify the demographic, social environment and prenatal factors which have an effect on the cord BPb concentrations. From August to November 1993, umbilical cord blood samples were obtained from 605 live newborns in the Yangpu Maternal and Child Hospital. 257 samples were excluded from measurement because of clotting. In 348 cord samples, the geometric mean of cord BPb levels was 9. 2μg/dl, with a 95 % confidence interval of the mean 8. 86-9. 54 (μg/dl). 142 babies (40. 8 % ) had cord BPb levels of 10μg/dl or greater. As a result of this high percentage of newborns with BPb levels equal to or greater than 10 μg/dl, we estimate that each year in the Shanghal City about 60,000 newborns are at risk for developing neuropsychological deficiencies caused by maternal lead exposure during pregnancy. To investigate the factors affecting cord blood levels, the subjects with levels greater than the 70th percentile (10. 7μg/dl) (n = 104) and less than the 3oth percentile (7. 4μg/dl) (n = 104) were selected to compare the demographic, environ ment and prenatal medical history. Increased BPb levels at birth were associated with maternal passive smoking, a family member being occupationally exposed to lead, proximity to major traffic way, household coal combustion, neighborhood coal combustion, low level of meternal occupations, and the increasing occurrence of having the high lead foodstuff pidan (preserved duck egg) during pregnancy. We conclude that prenatal lead exposure has become an impor tant health issue for young children in Shanghai
基金financially supported by the Jiangsu Province Special Project of Clinical Science and Technology[Grant No.BL2014082]the Jiangsu Provincial Medical Innovation Team[CXTDA2017029]the Jiangsu Provincial Medical Youth Talent[QNRC2016548]
文摘Lead,a heavy metal,which is nonessential but may be harmful to the human body,has been widely used to manufacture many products for use in the modern world.Lead-acid batteries have the advantages of low price,high safety,and advanced technology.
基金supported by The National Natural Science Foundation of China(No.81172628)the Fundamental Research Funds for the Central Universities(No.2014305020201)
文摘In this study, we searched multiple databases for all relevant original articles (1996-2013). To investigate blood lead levels (BLL) and possible risk factors for lead exposure among children in China A total of 388 articles met our inclusion criteria. The overall geometric mean (GM) BLL was 71 μg/L, and the prevalence of elevated BLL (EBLL, defined as BLL ≥100 μg/L) was 18.48% among children. The prevalence of EBLL remained significantly higher among boys. In children less than 6 years of age, there were significantly increasing trends in both BLL and prevalence of EBLL in an age-dependent manner. The ban on leaded gasoline significantly reduced the BLL as well as EBLL prevalence; however, children whose parents had lower educational levels or were exposed to lead in the workplace had a higher EBLL prevalence. Despite its decline over time, the average BLL among children in China remains higher than the average level most recently reported in the United States. Childhood lead poisoning remains a public health problem in China.
基金supported by Nanjing Maternity and Child Health Care Hospital
文摘Objective To investigate the blood lead levels (BLLs) in the duration of pregnancy and 6-12 weeks after delivery,and analyze the influencing factors of BLLs in healthy pregnant women.Methods Pregnant women were recruited from September 2009 to February 2010 at the prenatal clinic in Nanjing Maternity and Child Health Care Hospital.Altogether 174 healthy pregnant women without pregnant or obstetric complications or abnormal pregnancy outcomes were enrolled as the gravida group,and 120 healthy non-pregnant women as the control group.BLLs during pregnancy were determined by flame atomic absorption spectroscopy.Results BLLs in all the three pregnancy trimesters and postpartum were 59.8±24.3,55.4±20.1,55.9±19.7,and 67.6±17.4 μg/L,respectively,and the mean BLL in control group was 67.5±21.3 μg/L.BLLs during all the three trimesters were lower in the gravida group than in the control group (P=0.043,0.021,and 0.028).Furthermore,occupations,nutrients supplementation,and time of house/apartment painted were associated with BLLs in pregnant women.Lead-related occupations,cosmetics use,and living in a house painted less than 1 year before are risk factors of high BLLs among pregnant women,while calcium,iron,zinc,and milk supplements are protective factors.Conclusion Supplementing calcium,iron,zinc,and milk,or avoiding contact with risk factors may help people,especially pregnant women,to reduce lead exposure.
基金Project(71102174,71372019)supported by the National Natural Science Foundation of ChinaProject(9123028)supported by the Beijing Natural Science Foundation of China+3 种基金Project(20111101120019)supported by the Specialized Research Fund for Doctoral Program of Higher Education of ChinaProject(11JGC106)supported by the Beijing Philosophy&Social Science Foundation of ChinaProjects(NCET-10-0048,NCET-10-0043)supported by the Program for New Century Excellent Talents in University of ChinaProject(2010YC1307)supported by Excellent Young Teacher in Beijing Institute of Technology of China
文摘The decision-making and optimization of two-echelon inventory coordination were analyzed with service level constraint and controllable lead time sensitive to order quantity.First,the basic model of this problem was established and based on relevant analysis,the original model could be transformed by minimax method.Then,the optimal order quantity and production quantity influenced by service level constraint were analyzed and the boundary of optimal order quantity and production quantity was given.According to this boundary,the effective method and tactics were put forward to solve the transformed model.In case analysis,the optimal expected total cost of two-echelon inventory can be obtained and it was analyzed how service level constraint and safety factor influence the optimal expected total cost of two-echelon inventory.The results show that the optimal expected total cost of two-echelon inventory is constrained by the higher constraint between service level constraint and safety factor.
文摘Economic responsibility audit is an important part of the socialist audit supervision system with Chinese characteristics.It is an important responsibility of audit institutions at all levels to carry out economic responsibility audit.This article conducts a comprehensive and profound analysis of the problems existing in the current grassroots economic responsibility audit work.In addition,countermeasures and suggestions are proposed in this article,which are of positive significance to promote the economic responsibility audit work of leading cadres.