Ten cities cross-sectional questionnaire survey of children asthma and other allergies in China

Asthma,rhinitis and eczema(allergic or non-allergic)have increased throughout the world during the last decades,especially among children.Changes in the indoor environment are suspected to be important causes.China has experienced a dramatic change in indoor environmental exposures during the past two decades.However,such changes and their associations with children’s asthma and other health aspects have not been thoroughly studied.China,Children,Homes,Health(CCHH),Phase I,was a cross-sectional questionnaire survey of 48219 children 1–8 years old in 10 Chinese cities during 2010–2012.The questionnaire includes the International Study of Asthma and Allergies in Childhood(ISAAC)core health questions and additional questions regarding housing,life habits and outdoor environment.In health analyses,children aged 3–6 years old were included.The prevalences of doctor diagnosed asthma varied from 1.7%to 9.8%(mean 6.8%),a large increase from 0.91%in 1999 and 1.50%in2000.The prevalence of wheeze,rhinitis and atopic eczema(last 12 months)varied from 13.9%to 23.7%,24.0%to 50.8%and4.8%to 15.8%,respectively.Taiyuan had the lowest prevalences of all illnesses and Shanghai the highest,except for wheezewhere the highest value was for Urumqi.We found(1)no obvious association between disease prevalences and ambient PM10concentrations and(2)higher prevalences of disease in humid climates with hot summers and cold winters,but with no centrally heated buildings.Associations between the diseases and economic status as indexed by Gross Domestic Product(GDP)requires further study.     

Prenatal and early life home environment exposure in relation to preschool children’s asthma, allergic rhinitis and eczema in Taiyuan, China

Prenatal and early life home environment might be related to children’s asthma or allergic diseases later in life.A cross-sectional epidemiological study was designed and a questionnaire survey was performed in 3700 preschool children in urban areas in Taiyuan,Shanxi Province,China.Questions on children’s asthma and allergic diseases from the International Study on Asthma and Allergies in Childhood(ISAAC)were integrated with questions on home environment from the Swedish Dampness in Buildings and Health(DBH)study,appropriately modified for Chinese life habits.By multivariate regression analyses controlling for age,gender,heredity,location in urban/suburban or rural areas,environmental tobacco smoke(ETS)and breastfeeding,we found that home new furniture(HNF)before birth(referring to 1 year before pregnancy and during pregnancy)was positively associated with wheezing ever(odds ratio(OR)1.23 with 95%CI of 1.03–1.48)and wheezing last 12 months(1.24,1.00–1.54),allergic rhinitis(AR)(1.26,1.06–1.51),and eczema(1.42,1.01–1.99).HNF between 0–1 years old was also positively associated with wheezing last 12 months.Home new decoration(HND)during 0–1 years old was positively associated with AR symptoms and eczema symptoms,more in the last 12 months.Stronger positive associations were found for signs of home mold and dampness with almost all children’s asthmatic and allergic symptoms(OR ranging from 1.23–1.85,P<0.05).By mutual adjustment between HNF before children’s birth and home mold or dampness,all the significance remained unchanged.Prenatal HNF and home mold or dampness was independently associated with children’s asthmatic and allergic diseases later in life.     

Dampness in dwellings and its associations with asthma and allergies among children in Chongqing: A cross-sectional study

The city of Chongqing has high outdoor temperatures and humidity throughout the year and consequently a high risk of dampness and mold problems in dwellings.As part of the China,Children,Homes,Health(CCHH),associations between home characteristics and children’s asthma,allergies,and related symptoms were investigated in Chongqing,China.A cross-sectional questionnaire survey on home characteristics including dampness and symptoms of asthma and allergies in 5299 children was performed.Data for 4754 children(3–6 years)and their homes were analyzed.Results showed that 35.1%of homes were reported to have"damp bedding",14.3%"condensation on window panes(higher than 5 cm)",11.6%"mouldy odor",9.3%"water leakage",8.3%"damp stains"and 5.3%"visible mould".Wheezing and rhinitis ever were reported for 27.0%and 51.1%children respectively,and rhinitis,wheezing,cough at night and eczema in the last 12 months were reported for 38.1%,20.5%,18.9%and 13.2%respectively.Doctor-diagnosed asthma was reported for 8.3%of children,and doctor-diagnosed rhinitis for 6.2%.Dampness in homes was generally strongly associated with asthma and allergies among Chongqing children.The strongest association was found between"visible mould"and doctor-diagnosed rhinitis,and the adjusted Odds Ratio(ORA)was 2.27(95%CI:1.48,3.49)."Damp bedding"was significantly associated with all asthma and allergic symptoms,but doctor-diagnosed asthma and rhinitis.The behavior of"putting bedding to sunshine"could effectively reduce the prevalence of asthma and allergic symptoms,and the risk of bedding affected with damp was reduced significantly when bedding was put to sunshine frequently.     

China, Children, Homes, Health (CCHH)

Asthma and allergies have been increasing worldwide during the last 5 decades.Fifty years ago,prevalences of asthma and allergies were less than 1%;compared to today when up to 1/3 of children in some regions have been diagnosed with asthma.The burden on families and the health care system is great.The increase in asthma,rhinitis,and eczema(whether atopic or     

Effects of ambient air pollution on allergic rhinitis among preschool children in Changsha, China

Prevalence of allergic rhinitis has rapidly increased among Chinese children,but the reasons are unclear.Recent findings have suggested that exposure to outdoor air pollutants may increase the risk of allergic rhinitis,but the results were inconsistent.This study further investigated the effect of outdoor air pollutants on allergic rhinitis among preschool children.A standardized questionnaire on health,home and environmental factors was conducted for 4988 children aged 1–8 in the city of Changsha,and the concentrations of PM10(particle diameter 10 m),sulfur dioxide(SO2)and nitrogen dioxide(NO2)during 2006–2011 were acquired from the official web of Changsha Environmental Protection Agency.Results showed that the prevalence of children’s doctor diagnosed rhinitis was 8.4%(95%confidence interval[CI]7.0%–10.0%).It was found that the prevalence of rhinitis was not associated with site-specific background concentrations of air pollutants,but significantly positively correlated with age-related accumulative personal exposure of PM10,SO2and NO2.We conclude that age-related accumulative personal exposure to ambient air pollution may play an important role in the development of rhinitis.     

Sick building syndrome among parents of preschool children in relation to home environment in Chongqing, China

The prevalence and risk factors of sick building syndrome(SBS)symptoms in domestic environments were studied by a questionnaire survey on the home environment.Parents of 5299 3–6 years old children from randomly selected kindergartens in Chongqing,China returned completed questionnaires between December 2010 and April 2011.The prevalence of parents’SBS symptoms(often(every week)compared with never)were:11.4%for general symptoms,7.1%for mucosal symptoms and 4.4%for skin symptoms.Multiple logistic regressions were applied controlling for gender and asthma/allergic rhinitis/eczema.Living near a main road or highway was a strong risk factor for general symptoms(adjusted odds ratio,aOR=2.16,P<0.001),skin symptoms(aOR=2.69,P<0.001),and mucosal symptoms(aOR=1.63,P<0.01).Redecoration was a risk factor for general symptoms(aOR=2.00,P<0.001),skin symptoms(aOR=1.66,P<0.01),and mucosal symptoms(aOR=1.66,P<0.05).New furniture was a risk factor for general symptoms(aOR=2.16,P<0.001)and skin symptoms(aOR=1.67,P<0.01).Dampness related problems(mould spot,damp stain,water damage and condensation)were all risk factors for SBS symptoms,as was the presence of cockroaches,rats,and mosquitoes/flies and use of incense.Protective factors include cleaning the child’s bedroom every day and frequently exposing bedding to sunshine.In conclusion,adults’SBS symptoms were related to factors of the home environment.     

Oxidative damages to DNA by indoor PM10s: Their relationships with trace element compositions

Plasmid DNA assay and ICP-MS analysis were conducted in order to investigate the bioreactivity of inhalable particles (PM10) and the relationship between bioreactivity and trace element compositions of PM10 in Beijing air. A total of four PM10 samples were carefully selected to represent the indoor and corresponding outdoor environments: one from urban smoker's home, two from non-smoker's homes, and the other from the outdoor. In general, the oxidative damage by indoor PM10 was slightly higher than that of outdoor. Among the four sets of samples, the PM10 from the smoker's home had a lowest TD50 (toxic dose of PM10 causing 50% DNA to be damaged), being 100 μg·mL-1, suggesting the highest bioreactivity. The heavy metals are believed to be the main reason for oxidative damage to plasmid DNA. The ICP-MS analysis combined with the DNA assay showed that the water-soluble zinc levels had better relationship with TD50 values than other elements, implying that water-soluble zinc might play an important role in the damage of DNA. It is concluded that the PM10 in smoker's home had the highest level of water-soluble zinc as well as the lowest TD50 (highest bioreactivity). Iron is considered to be one of the most bioreactive elements, but it will cause little damage to plasmid DNA, probably because iron is mainly in water-insoluble state in Beijing PM10.     

Indoor decorating and refurbishing materials and furniture volatile organic compounds emission labeling systems: A review

The volatile organic compounds (VOC) emitted from indoor decorating and refurbishing materials and furniture is recognized as one of the main causes of bad indoor air quality,which has resulted in serious economic losses.In European countries and the U.S.,labeling systems for indoor decorating and refurbishing materials and furniture were established to address this issue with good effect.This paper is a review of these existing labeling systems.The basic principle of the labeling systems is introduced.The technical,policy and operational parts of the labeling systems are then discussed.The research concentrates on target pollutants,their threshold values and the testing methods employed.Some problems were uncovered in these labeling systems:too many VOCs were targeted;the method to determine the threshold values was not very rigorous;the testing time was too long (7-28 d).Some China’s special features in developing such system are stated.Therefore,as the world’s largest national producer and consumer of wood based panels and furniture,China should learn from foreign experience of establishing labeling systems as much as it can.However China should not simply copy the foreign approaches but develop its own scientific labeling system for indoor decorating and refurbishing materials and furniture.     

Facile synthesis of monodispersed copper oxalate flaky particles in the presence of EDTA

Monodispersed copper oxalate particles with flaky morphology were prepared via a simple one-pot synthesis method. Scanning electron microscope (SEM), X-ray diffraction (XRD), and fourier transform infrared (FTIR) spectra were used to characterize particle morphology, size, phase composition, and functional groups. It was found that the presence of ethylenediaminetetraacetic acid (EDTA) and the solution pH value had strong influence on the morphological and size evolution of the precipitated particles. On the basis of controlled release of copper ions from a Cu2+–EDTA complex and Weimarn’s law, a strategy for the controlled synthesis of monodispersed copper oxalate particles was designed by referring to the basic mode of the Stöber method. The inherent nature of crystallization to form the flaky solid in the early stage of precipitation as well as the driving force of the long-lasting low supersaturation in the growth stage was proposed to explain the size and morphological evolution of the copper oxalate precipitates. Thermodynamic equilibrium concentrations of copper(Ⅱ) species in the Cu(Ⅱ)–EDTA–oxalate–H₂O solution system were calculated to help explain the possible formation mechanism of copper oxalate precipitates.     

Dynamics of total culturable bacteria and its relationship with methylmercury in the soils of the water level fluctuation zone of the Three Gorges Reservoir

Field investigations were conducted to study the temporal and spatial distribution characteristics of total culturable bacteria(TCB)and its relationship with methylmercury(MeHg)in the soils of the water level fluctuation zone of the Three Gorges Reservoir.Different altitudes(170–180,170–175,165–170 and 160–165 m)in Zhenxi(Site 1),Shibaozhai(Site 2)and Tujing(Site 3),Chongqing,China were chosen as sampling sites.Results indicated that TCB did not have significant difference in the top(0–10 cm)and sub(10–20 cm)soil of the non-inundated area(175–180 m),but showing a significant difference in the water level fluctuation zone(\175 m,suggesting that water level fluctuation had an important effect on TCB.Moreover,TCB in soils of various altitudes of Site 1 and 2had significant difference,while for Site 3,this difference was not significant.And the difference of TCB in Site 2was much greater than that in Site 1.These results suggested that there were significant differences for TCB in soils of mainstream and tributaries.In addition,TCB in soils of 10–20 cm had significant or highly significant positive correlations with MeHg level(r C 0.762,P B 0.048),thus we assumed that there may be some aerobic microorganisms playing dominant roles in mercury methylation.     

Effect of lead exposure on the immune function of lymphocytes and erythrocytes in preschool children

Objective: To investigate the influence of lead exposure on the immune function of lymphocytes and erythrocytes in preschool children. Materials and methods: A group of 217 children three to six years of age from a rural area were given a thorough physical examination and the concentration of lead in blood samples taken from each subject was determined. The indices of lymphocyte immunity (CD^ 3CD^ 4, CD^ 3CD^ 8, CD^ 4CD^ 8, CDˉ3CD^ 19) and erythrocyte immunity (RBC-C3b, RBC-IC, RFER, RFIR, CD35 and its average fluorescence intensity) of 40 children with blood lead levels above 0.483 μmol/L were measured and compared with a control group. Results: The blood lead levels of the 217 children ranged from 0.11 μmol/L to 2.11 μmol/L. The CD^ 3CD^ 4and CD^ 4CD^ 8 cells were lower (P＜0.01) and the CD^ 3CD^ 8 cells were higher in the lead-poisoned subjects than those in the control group (P＜0.05). CD^ 3 and CDˉ3CD^ 19 did not show significant differences. Although the RBC-C3b rosette forming rate was lower and the RBC-IC rosette forming rate was higher in the lead-poisoned group, this difference could not be shown to be statistically significant (P＞0.05). RFIR was found to be lower in the lead-poisoned group (P＜0.01). Compared with the control group, the positive rate of CD35 was not found to be significantly different in a group of 25 lead-poisoned children (P＞0.05), while the average fluorescence intensity was lower in the lead-poisoned group (P＜0.05). Conclusion: Lead exposure can result in impaired immune function oft lymphocytes and erythrocytes in preschool children.     

Sick building syndrome,perceived odors,sensation of air dryness and indoor environment in Urumqi,China

In order to evaluate the perceived home indoor air quality, as well as sick building syndrome （SBS） in areas with typical arid continental climate such as Urumqi, northwest of China, a cross-sectional study including 4,260 parents of children （1-8 years） was performed by a ques- tionnaire survey in winter season in 2011. The sensation of air dryness （weekly/sometimes） in the last 3 months had the highest proportion of reports by more than half of the parents （57.4 %）, followed by perceived stuffy odor （40.6 %）, unpleasant odor （27.0 %）, tobacco smoke odor （25.5 %）, sensation of humid air （17.9 %）, pungent odor （11.7 %） and moldy odor （9.5 %）, respectively. The prevalence of SBS symptoms in the same time period was 40.4 % for general symptom, 47.7 % for mucosal symptom and 9.5 % for skin symptom, respectively. There were significant associations between perceived odors/sensation of air dryness and SBS symptoms （ORs range 1.39-1.42）. Additionally, the OR values increased with an increase of the OH score （P 〈 0.05）. Dampness, the presence of cockroaches and mosquitoes/flies, prenatal exposure to decoration and close to traffic were all risk factors of SBS symptoms. However, frequently putting bedding to sun- shine was potentially a protective factor. In conclusion, adults＇ perceptions of odors and sensation of air dryness are related to SBS symptoms and home environmental factors in Urumqi, China.     

Effect of TiO_2 nanoparticles on hydrogen evolution reaction activity of Ni coatings

The electrocatalytic activity of electrodeposited Ni and Ni–TiO_2 coatings with regard to the alkaline hydrogen evolution reaction(HER) was investigated. The Ni coatings were electrodeposited from an acid chloride bath at different current densities, and their HER activities were examined in a 1.0-mol·L~(-1) KOH medium. The variations in the HER activity of the Ni coatings with changes in surface morphology and composition were examined via the electrochemical dissolution and incorporation of nanoparticles. Electrochemical analysis methods were used to monitor the HER activity of the test electrodes; this activity was confirmed via the quantification of gases that evolved during the analysis. The obtained results demonstrated that the Ni–TiO_2 nanocomposite test electrode exhibited maximum activity toward the alkaline HER. The surface appearance, composition, and the phase structure of all developed coatings were analyzed using scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS), and X-ray diffraction(XRD), respectively. The improvement in the electrocatalytic activity of Ni–TiO_2 nanocomposite coating toward HER was attributed to the variation in surface morphology and increased number of active sites.     

Polarization behavior of microbial fuel cells under stack operation

The polarization behavior of microbial fuel cells(MFCs)was evaluated under different stack operation modes,including series,parallel,series–parallel,and parallel–series.During the stack operation,voltages of individual MFCs,subunit stacks,and overall stacks were recorded as a function of the current.Meanwhile,the potentials of individual MFCs’anode and cathode were also determined via Ag/AgCl electrodes to study the change in potentials under stack operations.The results demonstrated that the MFCs with relatively low ability to generate current were easier to suffer polarity reversal in the series stack,which was confirmed in the series subunit of the series–parallel stack.MFCs with high electroactivity would be enhanced to generate larger maximum power;however,MFCs with low electroactivity outputted smaller maximum power in a parallel stack.The changes in individual MFCs’behavior under stack operation mode were determined primarily caused by the influences on the behavior of the anode.Results of the present study provide valuable information for optimization of stack operation of MFCs.     

Spatiotemporal pattern and regional characteristics of visibility in China during 1976–2010

Degradation in visibility occurs extensively across China,creating the urgent need to better understand visibility patterns and characteristics in China.Using daily observation data from the U.S.National Climatic Data Center(NCDC)during 1976–2010,the spatial distribution and temporal trends of visibility in China,as well as seasonal and regional characteristics,were determined.The distribution of visibility was characterized by a longitudinal gradient between west and east China.The northwest of China generally experienced consistent high visibility of[20 km,while central and eastern China experienced visibility degradation and increase in haziness.The 133stations with significant downward trends in visibility were clustered around central-east China and the average reduction rate was-1.65 km/decade(from 18.5 km).The96 stations with increasing trends of visibility were mostly on the Qinghai–Tibet Plateau and Xinjiang and were closely related to a reduction in local sand storms.The average visibility in 12 key regions in China varied between9.9–17.8 km(except for 23.9 km in Urumqi),which was lower than the national average of 18.7 km.The Taiyuan–Hohhot,Guanzhong,Yangtze River Delta,Pearl River Delta and Fuzhou–Xiamen areas all encountered significant decreases in visibility,while minor increases were observed in Beijing–Tianjin–Hebei and the Cheng-Yu region.At most stations,the worst visibility was measured in winter,but the season with best visibility varied between regions.A comparison of visibility trends with the emission trends of various pollutants revealed that SO2emissions dominated the visibility degradation in eastern Chinawith NOxand volatile organic compounds playing ascending roles during the 2000s.     

皮秒Nd:YAG激光对生物金属纯Ti和Ti–13Nb–13Zr合金的表面改性

The effects of picosecond Nd:YAG laser irradiation on chemical and morphological surface characteristics of the commercially pure titanium and Ti–13Nb–13Zr alloy in air and argon atmospheres were studied under different laser output energy values. During the interaction of laser irradiation with the investigated materials, a part of the energy was absorbed on the target surface, influencing surface modifications. Laser beam interaction with the target surface resulted in various morphological alterations, resulting in crater formation and the presence of microcracks and hydrodynamic structures. Moreover, different chemical changes were induced on the target materials’ surfaces, resulting in the titanium oxide formation in the irradiation-affected area and consequently increasing the irradiation energy absorption. Given the high energy absorption at the site of interaction, the dimensions of the surface damaged area increased. Consequently, surface roughness increased. The appearance of surface oxides also led to the increased material hardness in the surface-modified area. Observed chemical and morphological changes were pronounced after laser irradiation of the Ti–13Nb–13Zr alloy surface.     

Effect of lower bainite/martensite/retained austenite triplex microstructure on the mechanical properties of a low-carbon steel with quenching and partitioning process

We present a study concerning Fe–0.176C–1.31Si–1.58Mn–0.26Al–0.3Cr (wt%) steel subjected to a quenching and partitioning (Q&P) process. The results of scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and tensile tests demonstrate that the microstructures primarily consist of lath martensite, retained austenite, lower bainite (LB), and a small amount of tempered martensite; moreover, few twin austenite grains were observed. In the microstructure, three types of retained austenite with different sizes and morphologies were observed: blocky retained austenite (~300 nm in width), film-like retained austenite (80–120 nm in width), and ultra- fine film-like retained austenite (30–40 nm in width). Because of the effect of the retained austenite/martensite/LB triplex microstructure, the specimens prepared using different quenching temperatures exhibit high ultimate tensile strength and yield strength. Furthermore, the strength effect of LB can partially counteract the decreasing strength effect of martensite. The formation of LB substantially reduces the amount of retained austenite. Analyses of the retained austenite and the amount of blocky retained austenite indicated that the carbon content is critical to the total elongation of Q&P steel.     

Evaluation of the microstructure,secondary dendrite arm spacing,and mechanical properties of Al–Si alloy castings made in sand and Fe–Cr slag molds

The microstructure and mechanical properties of as-cast A356(Al–Si) alloy castings were investigated. A356 alloy was cast into three different molds composed of sand, ferrochrome(Fe–Cr) slag, and a mixture of sand and Fe–Cr. A sodium silicate–CO_2 process was used to make the necessary molds. Cylindrical-shaped castings were prepared. Cast products with no porosity and a good surface finish were achieved in all of the molds. These castings were evaluated for their metallography, secondary dendrite arm spacing(SDAS), and mechanical properties, including hardness, compression, tensile, and impact properties. Furthermore, the tensile and impact samples were analyzed by fractography. The results show that faster heat transfer in the Fe–Cr slag molds than in either the silica sand or mixed molds led to lower SDAS values with a refined microstructure in the products cast in Fe–Cr slag molds. Consistent and enhanced mechanical properties were observed in the slag mold products than in the castings obtained from either sand or mixed molds. The fracture surface of the slag mold castings shows a dimple fracture morphology with a transgranular fracture nature. However, the fracture surfaces of the sand mold castings display brittle fracture. In conclusion, products cast in Fe–Cr slag molds exhibit an improved surface finish and enhanced mechanical properties compared to those of products cast in sand and mixed molds.     

Highly active brookite TiO2-assisted photocatalytic degradation of dyes under the simulated solar−UVA radiation

Brookite TiO_2 nanoparticles were synthesized by hydrothermal method and characterized by X-ray powder diffraction(XRD), diffuse reflectance UV–Visible spectroscopy(DRUV), and scanning electron microscopy(SEM). The obtained particles were spherical in shape with the diameter of about ～10 nm under the hydrothermal temperature of 175 °C. The photocatalytic performance of brookite was investigated in the photodegradation of dyes(rhodamine B and rose bengal) under UV-A radiation by low-power lamp. The activity of brookite and the photodegradation efficiency of dyes were estimated using a UV–Visible spectrophotometer and a total organic carbon(TOC) analyzer. Compared to anatase and rutile prepared by the similar synthesis procedure, brookite is highly active in terms of decolourization, aromatic ring opening, and mineralization.     

Testing reintroduction as a conservation strategy for the critically endangered Chinese alligator: Movements and home range of released captive individuals

The Chinese alligator (Alligator sinensis) is considered the most critically endangered crocodilian as a result of the near total loss of its habitat and its extremely small and fragmented wild populations. Plans for population recovery lie mostly with wetland res- toration and the reintroduction of captive-reared animals. We carried out a first-trial release of 3 adult Chinese alligators (1♂, 2♀) into a pond at the Hongxing conservation site, Xuancheng, southern Anhui Province; the animals were radio-tracked from May to October in 2003. We hypothesized that after a period of adaptation, the alligators would establish definable home ranges. Two (1♂, 1♀) of the 3 alligators were monitored for the whole of the tracking period. The male had an annual home-range size of 7.61 hm2, and the female 4.00 hm2. Water temperature and pond water level were two important factors influencing the alligators’ distributions, and daily movements. The radio-tracked alligators had overlapping home ranges, which notably included the one substantial island in the pond; that island is the only known nesting site of the local native wild alligators. Aggressive interactions between the released alligators and native wild alligators were observed during the breeding season around this island. All the three reintroduced alligators survived the winter of 2003 and were alive in the same pond in 2008. We concluded that the Hongxing conservation site provided a suitable habitat for the reintroduced alligators. However, the low water level in the pond resulting from farmland irrigation in August and September can be a substantial threat to the alligators’ survival. Therefore, regu- lations on irrigation in summer and autumn are needed to balance the water needs of the alligators and agriculture.