This study reports on the dietary exposure of people in Yaounde, Cameroon to heavy metals： lead （Pb）, cadmium （Cd）, mercury （Hg）, copper （Cu） and zinc （Zn）. One hundred and fifty table-ready food, water and...This study reports on the dietary exposure of people in Yaounde, Cameroon to heavy metals： lead （Pb）, cadmium （Cd）, mercury （Hg）, copper （Cu） and zinc （Zn）. One hundred and fifty table-ready food, water and soft drink samples were collected from households and street restaurants in Yaounde and analyzed for heavy metals contents using atomic absorption spectrophotometer. Lead （93%, range 0.019-1.77 ppm）, Cd （70%, range 0.01-4.68 ppm）, Hg （81%, range 0.03-10.56 ppm）, Cu （90%, range 0.004-40.32 ppm） and Zn （87%, range 0.014-2,447.04 ppm） were detected in studied samples. Maximum level of each metal exceeded its corresponding European Commissions legislative limits. Samples from street restaurants were most tainted with heavy metals. The highest average daily intakes （ADIs） of Pb （0.96 mg/day） and Hg （1.84 mg/day） were through tap water, while Cd （1.15 mg/day）, Cu （5.42 mg/day） and Zn （601.6 mg/day） were through rice/peanut sauce mixed food. The ADI for Cd and Hg was each higher than its respective PTDI （provisional tolerable daily intake） as defined by JECFA （Joint FAO/WHO Expert Committee on Food Additives） and EVM （Expert Group on Vitamins and Minerals）. The estimated average daily exposure dose of each detected metal significantly （p = 0.001） exceeded its corresponding PTDI. However, the health risk index was 〈 1 for all studied samples and it was found to be safe, indicating there is a relative absence of health risks associated with the ingestion of contaminated foods, water and soft drinks. Notwithstanding, the detected levels and ADI being higher than legislative limits and PTDI respectively speculates need for awareness raising towards reducing exposure levels to heavy metals in Cameroon.展开更多
Objective： To assess whether these characteristics of less misclassification and greater area under receiver operator characteristic （ROC） curve of the new injury severity score （NISS） are better than the injury ...Objective： To assess whether these characteristics of less misclassification and greater area under receiver operator characteristic （ROC） curve of the new injury severity score （NISS） are better than the injury severity score （ISS） as applying it to our multiple trauma patients registered into the emergency intensive care unit （EICU）. Methods： This was a retrospective review of registry data from 2 286 multiple trauma patients consecutively registered into the EICU from January 1,1997 to December 31, 2006 in the Second Affiliated Hospital, Medical School of Zhejiang University in China. Comparisons between ISS and NISS were made using misclassification rates, ROC curve analysis, and the H-L statistics by univariate and multivariate logistic progression model. Results： Among the 2 286 patients, 176 （7.7%） were excluded because of deaths on arrival or patients less than 16 years of age. The study population therefore comprised 2 1 10 patients. Mean EICU length of stay （LOS） was 7.8 days ± 2.4 days. Compared with the blunt injury group, the penetrating injury group had a higher percentage of male, lower mean EICU LOS and age. The most frequently injured body regions were extremities and head/neck, followed by thorax, face and abdomen in the blunt injury group; whereas, thorax and abdomen were more frequently seen in the penetrating injury group. The minimum misclassification rate for NISS was slightly less than ISS in all groups （4.01% versus 4.49%）. However, NISS had more tendency to misclassify in the penetrating injury group. This, we noted, was attributed mainly to a higher false-positive rate （21.04% versus 15.55% for IS S, t=-3.310, P〈0.001）, resulting in an overall misclassification rate of 23.57% for NISS versus 18.79% for ISS （t=3.290, P〈0.001）. In the whole sample, NISS presented equivalent discrimination （area under ROC curve： NISS=0.938 versus ISS=0.943）. The H-L statistics showed poorer calibration （48.64 versus 32.11, t=3.305, P〈0.001） in the penetrating injury group. Conclusions： NISS should not replace ISS because Lhey share similar accuracy and calibration in predicting multiple blunt trauma patients. NISS may be more sensitive but less specific than ISS in predicting mortality in certain penetrating injury patients.展开更多
Concentrations of heavy metals in 74 sediment samples from the Fenghe River, which originates from the north of the Qinling Mountains and flows through Xi'an, Shaanxi Province, China, were characterized by employi...Concentrations of heavy metals in 74 sediment samples from the Fenghe River, which originates from the north of the Qinling Mountains and flows through Xi'an, Shaanxi Province, China, were characterized by employing geographic information system(GIS)mapping, fuzzy synthetic assessment, and multivariate statistical analysis to determine the enrichment characteristics of heavy metals as well as their potential risks of pollution to sediments. Al, Cd, and Co were the major pollutants, with a high enrichment factor(EF) value. Heavy metal concentrations from samples near the paper plant were maintained at a high level. Significant enrichment of Al, Ba, Cr, Ni, Pb, and Co was found in the midstream and downstream, while high concentration of Cu occurred in the headwater stream. Based on the cluster and principal component analyses, sediment metals mainly came from the paper plants, agronomic practices, natural sources, and tourism, with a contribution of 51.59%, 23.01%, 14.21%, and 9.88%, respectively. Sediment pollution assessment explored using fuzzy theory based on the entropy method and toxicity coefficient showed that 26, 32, and 11 sites fell into Class III(slightly polluted), Class IV(moderately polluted), and Class V(heavily polluted), respectively, and their scores of membership degree in the polluted level were on the rise, suggesting a relatively high degree of sediment metal pollution in the study area. Closely related to the excessive industrial and agricultural applications, metal pollution in sediment is necessary to be addressed in the Fenghe River.展开更多
文摘This study reports on the dietary exposure of people in Yaounde, Cameroon to heavy metals： lead （Pb）, cadmium （Cd）, mercury （Hg）, copper （Cu） and zinc （Zn）. One hundred and fifty table-ready food, water and soft drink samples were collected from households and street restaurants in Yaounde and analyzed for heavy metals contents using atomic absorption spectrophotometer. Lead （93%, range 0.019-1.77 ppm）, Cd （70%, range 0.01-4.68 ppm）, Hg （81%, range 0.03-10.56 ppm）, Cu （90%, range 0.004-40.32 ppm） and Zn （87%, range 0.014-2,447.04 ppm） were detected in studied samples. Maximum level of each metal exceeded its corresponding European Commissions legislative limits. Samples from street restaurants were most tainted with heavy metals. The highest average daily intakes （ADIs） of Pb （0.96 mg/day） and Hg （1.84 mg/day） were through tap water, while Cd （1.15 mg/day）, Cu （5.42 mg/day） and Zn （601.6 mg/day） were through rice/peanut sauce mixed food. The ADI for Cd and Hg was each higher than its respective PTDI （provisional tolerable daily intake） as defined by JECFA （Joint FAO/WHO Expert Committee on Food Additives） and EVM （Expert Group on Vitamins and Minerals）. The estimated average daily exposure dose of each detected metal significantly （p = 0.001） exceeded its corresponding PTDI. However, the health risk index was 〈 1 for all studied samples and it was found to be safe, indicating there is a relative absence of health risks associated with the ingestion of contaminated foods, water and soft drinks. Notwithstanding, the detected levels and ADI being higher than legislative limits and PTDI respectively speculates need for awareness raising towards reducing exposure levels to heavy metals in Cameroon.
文摘Objective： To assess whether these characteristics of less misclassification and greater area under receiver operator characteristic （ROC） curve of the new injury severity score （NISS） are better than the injury severity score （ISS） as applying it to our multiple trauma patients registered into the emergency intensive care unit （EICU）. Methods： This was a retrospective review of registry data from 2 286 multiple trauma patients consecutively registered into the EICU from January 1,1997 to December 31, 2006 in the Second Affiliated Hospital, Medical School of Zhejiang University in China. Comparisons between ISS and NISS were made using misclassification rates, ROC curve analysis, and the H-L statistics by univariate and multivariate logistic progression model. Results： Among the 2 286 patients, 176 （7.7%） were excluded because of deaths on arrival or patients less than 16 years of age. The study population therefore comprised 2 1 10 patients. Mean EICU length of stay （LOS） was 7.8 days ± 2.4 days. Compared with the blunt injury group, the penetrating injury group had a higher percentage of male, lower mean EICU LOS and age. The most frequently injured body regions were extremities and head/neck, followed by thorax, face and abdomen in the blunt injury group; whereas, thorax and abdomen were more frequently seen in the penetrating injury group. The minimum misclassification rate for NISS was slightly less than ISS in all groups （4.01% versus 4.49%）. However, NISS had more tendency to misclassify in the penetrating injury group. This, we noted, was attributed mainly to a higher false-positive rate （21.04% versus 15.55% for IS S, t=-3.310, P〈0.001）, resulting in an overall misclassification rate of 23.57% for NISS versus 18.79% for ISS （t=3.290, P〈0.001）. In the whole sample, NISS presented equivalent discrimination （area under ROC curve： NISS=0.938 versus ISS=0.943）. The H-L statistics showed poorer calibration （48.64 versus 32.11, t=3.305, P〈0.001） in the penetrating injury group. Conclusions： NISS should not replace ISS because Lhey share similar accuracy and calibration in predicting multiple blunt trauma patients. NISS may be more sensitive but less specific than ISS in predicting mortality in certain penetrating injury patients.
基金supported by the National Natural Science Foundation of China(Nos.41030744 and 41173123)
文摘Concentrations of heavy metals in 74 sediment samples from the Fenghe River, which originates from the north of the Qinling Mountains and flows through Xi'an, Shaanxi Province, China, were characterized by employing geographic information system(GIS)mapping, fuzzy synthetic assessment, and multivariate statistical analysis to determine the enrichment characteristics of heavy metals as well as their potential risks of pollution to sediments. Al, Cd, and Co were the major pollutants, with a high enrichment factor(EF) value. Heavy metal concentrations from samples near the paper plant were maintained at a high level. Significant enrichment of Al, Ba, Cr, Ni, Pb, and Co was found in the midstream and downstream, while high concentration of Cu occurred in the headwater stream. Based on the cluster and principal component analyses, sediment metals mainly came from the paper plants, agronomic practices, natural sources, and tourism, with a contribution of 51.59%, 23.01%, 14.21%, and 9.88%, respectively. Sediment pollution assessment explored using fuzzy theory based on the entropy method and toxicity coefficient showed that 26, 32, and 11 sites fell into Class III(slightly polluted), Class IV(moderately polluted), and Class V(heavily polluted), respectively, and their scores of membership degree in the polluted level were on the rise, suggesting a relatively high degree of sediment metal pollution in the study area. Closely related to the excessive industrial and agricultural applications, metal pollution in sediment is necessary to be addressed in the Fenghe River.
