Objective Chlorination is often used to disinfect recreational water in large amusement parks;however,the health hazards of chlorination disinfection by-products(DBPs)to occupational populations are unknown.This study...Objective Chlorination is often used to disinfect recreational water in large amusement parks;however,the health hazards of chlorination disinfection by-products(DBPs)to occupational populations are unknown.This study aimed to assess the exposure status of chlorinated DBPs in recreational water and the health risks to employees of large amusement parks.Methods Exposure parameters of employees of three large amusement parks in Shanghai were investigated using a questionnaire.Seven typical chlorinated DBPs in recreational water and spray samples were quantified by gas chromatography,and the health risks to amusement park employees exposed to chlorinated DBPs were evaluated according to the WHO's risk assessment framework.Results Trichloroacetic acid,dibromochloromethane,bromodichloromethane,and dichloroacetic acid were detected predominantly in recreational water.The carcinogenic and non-carcinogenic risks of the five DBPs did not exceed the risk thresholds.In addition,the carcinogenic and non-carcinogenic risks of mixed exposure to DBPs were within the acceptable risk limits.Conclusion Typical DBPs were widely detected in recreational water collected from three large amusement parks in Shanghai;however,the health risks of DBPs and their mixtures were within acceptable limits.展开更多
Ensuring the health and safety of drinking water is crucial for both nations and their citizens.Since the 20th century,the disinfection of drinking water,effectively controlling pathogens in water sources,has become o...Ensuring the health and safety of drinking water is crucial for both nations and their citizens.Since the 20th century,the disinfection of drinking water,effectively controlling pathogens in water sources,has become one of the significant advances in public health.However,the disinfectants used in the process,such as chlorine and chlorine dioxide,react with natural organic matter in the water to produce disinfection by-products(DBPs).Most of these DBPs contain chlorine,and if the source water contains bromine or iodine,brominated or iodinated DBPs,collectively referred to as Halogenated disinfection byproducts(X-DBPs),are formed.Numerous studies have found that X-DBPs pose potential risks to human health and the environment,leading to widespread concern.Mass spectrometry has become an important means of discovering new types of X-DBPs.This paper focuses on the study of methods for analyzing X-DBPs in drinking water using mass spectrometry.展开更多
This experiment was conducted to study the effect of molasses on the fermentation characteristics of mixed silage ensiled rice straw and vegetable by-products with alfalfa.Mixture（202 g kg^-1 dry matter（DM））consis...This experiment was conducted to study the effect of molasses on the fermentation characteristics of mixed silage ensiled rice straw and vegetable by-products with alfalfa.Mixture（202 g kg^-1 dry matter（DM））consisting of rice straw,broccoli residue and alfalfa at the ratio of 5：4：1 was ensiled with three experimental treatments：（1）no additives（control）;（2）molasses at 2.5%（M1）;（3）molasses at 5%（M2）on a fresh matter basis of mixture,respectively.All treatments were packed into laboratory-scale silos,and three silos per treatment were sampled on days 1,3,5,14 and 30.The result showed that the p H value of all mixed silages decreased gradually with the time of ensiling except for the control silage,in which a significant increase（P〈0.05）on day 30 occurred.The lactic acid content increased gradually with the time of ensiling and reached the highest value on day 14,and a marked decrease（P〈0.05）was found in the control silage on day 30.The changes of acetic acid content showed similar pattern with lactic acid content.A trace amount of propionic and butyric acid contents were found in the three mixed silages during the fermentation period.Comparing to the control,M1 and M2 treatments improved the fermentation quality of mixed silages as indicated by higher（P〈0.05）lactic acid contents and lower（P〈0.05）p H and ammonia-N contents.The Flieg points also showed that M1 and M2 silages were well preserved,whereas the control silage had a bad quality.Overall,the findings of this study suggested that adding molasses could improve fermentation quality of mixed silage,and M1 was more suitable for practical application.展开更多
Objective To introduce a new sequential chlorination disinfection process in which short-term free chlorine and chloramine are sequentially added. Methods Pilot tests of this sequential chlorination were carried out i...Objective To introduce a new sequential chlorination disinfection process in which short-term free chlorine and chloramine are sequentially added. Methods Pilot tests of this sequential chlorination were carried out in a drinking water plant. Results The sequential chlorination disinfection process had the same or better efficiency on microbe （including virus） inactivation compared with the free chlorine disinfection process. There seemed to be some synergetic disinfection effect between free chlorine and monochloramine because they attacked different targets. The sequential chlorination disinfection process resulted in 35.7%-77.0% TTHM formation and 36.6%-54.8% THAA5 formation less than the free chlorination process. The poorer the water quality was, the more advantage the sequential chlorination disinfection had over the free chlorination. Conclusion This process takes advantages of free chlorine＇s quick inactivation of microorganisms and chloramine＇s low disinfection by-product （DBP） yield and long-term residual effect, allowing simultaneous control of microbes and DBPs in an effective and economic way.展开更多
A feeding trial was conducted for 75 d to evaluate the nutritive value of a mixture of animal by-products （MAB） as a possible protein source in diets for juvenile mangrove red snapper, Lutjanus argentimaculatus （me...A feeding trial was conducted for 75 d to evaluate the nutritive value of a mixture of animal by-products （MAB） as a possible protein source in diets for juvenile mangrove red snapper, Lutjanus argentimaculatus （mean initial body weight, 30 g）. Fish were fed one of five isonitrogenous diets （40% crude protein） replacing 0, 25% （MAB25）, 50% （MAB50）, 75% （MAB75） and 100% （MAB100） of fish meal protein with similar percentages of MAB. The MAB consisted of 25% cow liver meal, 20% leather meal, 20% meat and bone meal, 15% blood meal, 10% APC （poultry feather meal）, 8% poultry manure dried, 1.5% choline and 0.5% chromic oxide. After 75 d of feeding, fish fed with diets MAB50, MAB75 and MABI00 exhibited significantly lower growth performance than that of fish fed with control and MAB25 diets. The optimum level of MAB was estimated to be 23%. Replacement of fish meal by MAB23% showed the following performance： maximum weight gain, 510%; SGR, 2.39% and FCE, 2.83%. The MAB substitution up to 75% of fish meal protein in diets did not show differences in apparent protein digestibility （83.6% for MAB25, 79.2% for MAB50, 78.7% for MAB75） compared with control （83.4%）, whereas in MABI00 group digestibility （65.3%） was significantly lower than in other groups. The apparent phosphorus absorption of test diet groups was significantly higher （37.1% for MAB25, 28.5% for MABS0, 55.6% for MAB75 and 54.5% for MABI00） than that of control （1 1.2%）. The levels of protein and ash in the whole body, carcass and viscera increased as MAB substitution in diets increased, whereas lipids and moisture remained consistent among all treatment groups. These results showed that approximately 23% of fish meal protein could be replaced by a mixture of animal by-products for juvenile snapper growing from 30 g to 167 g in 75 d without compromising growth performance and feed efficiency.展开更多
基金funded by the Foundation of State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants(Grant No.SEPKL-EHIAEC-202210)the Foundation of Shanghai Municipal Health Commission(Grant No.202240327)the Key Discipline Project of the Three-year Action Plan for Strengthening Public Health System Construction in Shanghai(2023-2025)(Grant No.GWVI-11.1-38)。
文摘Objective Chlorination is often used to disinfect recreational water in large amusement parks;however,the health hazards of chlorination disinfection by-products(DBPs)to occupational populations are unknown.This study aimed to assess the exposure status of chlorinated DBPs in recreational water and the health risks to employees of large amusement parks.Methods Exposure parameters of employees of three large amusement parks in Shanghai were investigated using a questionnaire.Seven typical chlorinated DBPs in recreational water and spray samples were quantified by gas chromatography,and the health risks to amusement park employees exposed to chlorinated DBPs were evaluated according to the WHO's risk assessment framework.Results Trichloroacetic acid,dibromochloromethane,bromodichloromethane,and dichloroacetic acid were detected predominantly in recreational water.The carcinogenic and non-carcinogenic risks of the five DBPs did not exceed the risk thresholds.In addition,the carcinogenic and non-carcinogenic risks of mixed exposure to DBPs were within the acceptable risk limits.Conclusion Typical DBPs were widely detected in recreational water collected from three large amusement parks in Shanghai;however,the health risks of DBPs and their mixtures were within acceptable limits.
文摘Ensuring the health and safety of drinking water is crucial for both nations and their citizens.Since the 20th century,the disinfection of drinking water,effectively controlling pathogens in water sources,has become one of the significant advances in public health.However,the disinfectants used in the process,such as chlorine and chlorine dioxide,react with natural organic matter in the water to produce disinfection by-products(DBPs).Most of these DBPs contain chlorine,and if the source water contains bromine or iodine,brominated or iodinated DBPs,collectively referred to as Halogenated disinfection byproducts(X-DBPs),are formed.Numerous studies have found that X-DBPs pose potential risks to human health and the environment,leading to widespread concern.Mass spectrometry has become an important means of discovering new types of X-DBPs.This paper focuses on the study of methods for analyzing X-DBPs in drinking water using mass spectrometry.
文摘目的探讨大鼠孕期暴露DBP对子代睾丸mRNA差异表达的影响。方法选取清洁级SD成年鼠,雌雄比例12交配,确定怀孕后行DBP染毒,试验组灌胃剂量为500 mg/kg,同时设置对照组,每组8只;试验组老鼠染毒至哺乳期结束,饲养子代雄鼠60 d,解剖取睾丸组织,采用二代高通量测序技术对睾丸样本进行基因差异表达分析及筛选,对差异表达基因进行GO富集分析和KEGG富集分析。结果差异表达的基因共有1421个,其中,上调基因722个,下调基因699个。筛选出的差异表达基因GO功能富集分析显示,生物过程(Biological Process BP)中,差异表达基因与老化、细胞增殖、炎症反应等密切相关;细胞成分(Cellular Component CC)中,差异表达基因主要富集在内质网膜、细胞膜等部分;分子功能(Molecular Function MF)中,差异表达基因主要与钙离子结合、趋化因子活性等密切相关。KEGG富集结果显示,孕期暴露DBP对子代雄鼠的影响集中分布在TNF信号传导途径、类固醇生成、细胞黏附分子(CAMs)、醛固酮合成和分泌等通路。结论大鼠孕期DBP暴露可致雄性子代睾丸mRNA差异表达,影响生殖系统的通路主要有TNF信号传导途径、类固醇生成、细胞黏附分子(CAMs)、醛固酮合成和分泌等。
基金supported by the project of Jiangsu Independent Innovation, China (CX(15)1003-3)the Key Technologies R&D Program of China during the 13th Five Year Plan period (2016YFC0502005)the special project of grass of Tibetan Autonomous Region for the “13th FiveYear” Plan, China
文摘This experiment was conducted to study the effect of molasses on the fermentation characteristics of mixed silage ensiled rice straw and vegetable by-products with alfalfa.Mixture（202 g kg^-1 dry matter（DM））consisting of rice straw,broccoli residue and alfalfa at the ratio of 5：4：1 was ensiled with three experimental treatments：（1）no additives（control）;（2）molasses at 2.5%（M1）;（3）molasses at 5%（M2）on a fresh matter basis of mixture,respectively.All treatments were packed into laboratory-scale silos,and three silos per treatment were sampled on days 1,3,5,14 and 30.The result showed that the p H value of all mixed silages decreased gradually with the time of ensiling except for the control silage,in which a significant increase（P〈0.05）on day 30 occurred.The lactic acid content increased gradually with the time of ensiling and reached the highest value on day 14,and a marked decrease（P〈0.05）was found in the control silage on day 30.The changes of acetic acid content showed similar pattern with lactic acid content.A trace amount of propionic and butyric acid contents were found in the three mixed silages during the fermentation period.Comparing to the control,M1 and M2 treatments improved the fermentation quality of mixed silages as indicated by higher（P〈0.05）lactic acid contents and lower（P〈0.05）p H and ammonia-N contents.The Flieg points also showed that M1 and M2 silages were well preserved,whereas the control silage had a bad quality.Overall,the findings of this study suggested that adding molasses could improve fermentation quality of mixed silage,and M1 was more suitable for practical application.
基金This work was sponsored by National Natural Science Fundation Committee (No. 50238020).
文摘Objective To introduce a new sequential chlorination disinfection process in which short-term free chlorine and chloramine are sequentially added. Methods Pilot tests of this sequential chlorination were carried out in a drinking water plant. Results The sequential chlorination disinfection process had the same or better efficiency on microbe （including virus） inactivation compared with the free chlorine disinfection process. There seemed to be some synergetic disinfection effect between free chlorine and monochloramine because they attacked different targets. The sequential chlorination disinfection process resulted in 35.7%-77.0% TTHM formation and 36.6%-54.8% THAA5 formation less than the free chlorination process. The poorer the water quality was, the more advantage the sequential chlorination disinfection had over the free chlorination. Conclusion This process takes advantages of free chlorine＇s quick inactivation of microorganisms and chloramine＇s low disinfection by-product （DBP） yield and long-term residual effect, allowing simultaneous control of microbes and DBPs in an effective and economic way.
文摘A feeding trial was conducted for 75 d to evaluate the nutritive value of a mixture of animal by-products （MAB） as a possible protein source in diets for juvenile mangrove red snapper, Lutjanus argentimaculatus （mean initial body weight, 30 g）. Fish were fed one of five isonitrogenous diets （40% crude protein） replacing 0, 25% （MAB25）, 50% （MAB50）, 75% （MAB75） and 100% （MAB100） of fish meal protein with similar percentages of MAB. The MAB consisted of 25% cow liver meal, 20% leather meal, 20% meat and bone meal, 15% blood meal, 10% APC （poultry feather meal）, 8% poultry manure dried, 1.5% choline and 0.5% chromic oxide. After 75 d of feeding, fish fed with diets MAB50, MAB75 and MABI00 exhibited significantly lower growth performance than that of fish fed with control and MAB25 diets. The optimum level of MAB was estimated to be 23%. Replacement of fish meal by MAB23% showed the following performance： maximum weight gain, 510%; SGR, 2.39% and FCE, 2.83%. The MAB substitution up to 75% of fish meal protein in diets did not show differences in apparent protein digestibility （83.6% for MAB25, 79.2% for MAB50, 78.7% for MAB75） compared with control （83.4%）, whereas in MABI00 group digestibility （65.3%） was significantly lower than in other groups. The apparent phosphorus absorption of test diet groups was significantly higher （37.1% for MAB25, 28.5% for MABS0, 55.6% for MAB75 and 54.5% for MABI00） than that of control （1 1.2%）. The levels of protein and ash in the whole body, carcass and viscera increased as MAB substitution in diets increased, whereas lipids and moisture remained consistent among all treatment groups. These results showed that approximately 23% of fish meal protein could be replaced by a mixture of animal by-products for juvenile snapper growing from 30 g to 167 g in 75 d without compromising growth performance and feed efficiency.
