Objective To quantitatively assess the impact of ambient PM10 on hospital outpatient visits for respiratory diseases. Methods Daily hospital outpatient visit data in 2012 were collected from two hospitals in Shenzhen. Daily meteorological and air pollution data in the same duration were obtained from Shenzhen Meteorological Bureau and Shenzhen Environmental Protection Bureau, respectively. A time-series analysis using a generalized additive model (GAM) was applied to assess the association between ambient PM10 concentration and hospital outpatient visits for respiratory diseases after adjustment for long-term trend, day-of-week, meteorological factors and other air pollutants.Result The average PM10 concentration in Shenzhen in 2012 was 0.052 mg/m3, meeting the national second-level standard. The total outpatient visits of the two involved hospitals were 562 174 with an average of 1 535.99 persons per day. GAM models indicated a positive association between ambient PM10 concentration and hospital outpatient visits for respiratory diseases. In the single-pollutant models, the effect of PM10 was largest on lag 6 days（RR=1.004 7, 95%CI:1.003 6～1.005 8）. In multi-pollutant models adjustment for CO, O3, NO2 and SO2, the RRs for the increment of PM10 concentration varied, and the RRs in the models adjustment for SO2 (RR=1.005 9) and models adjustment for CO and SO2 (RR=1.006 7) were the largest two. Conclusion The ambient PM10 concentration was positively associated with hospital outpatient visits for respiratory diseases in Shenzhen, and a lag structure was found in these associations.

Objective To explore the relationship between meteorological factors and the incidence of mumps.Methods Based on the data of daily number of reported mumps cases and meteorological data including temperature, relative humidity, atmospheric pressure and wind velocity in Guangzhou during 2005-2012, the relationship between meteorological factors and mumps incidence was explored using a distributed lag non-linear time series model.Results There were 49 760 mumps cases reported in Guangzhou during 2005-2012. The medians of daily average maximum, mean, and minimum temperature were 28.3, 24.2, and 21.2 ℃, respectively. The medians of average relative humidity, average sunshine hours, average wind velocity, and average atmospheric pressure were 75.0%, 3.9 h, 1.5 m/s, and 1 007.1hPa. The Spearman rank correlation analysis and the constructed model showed that mean temperature, relative humidity and wind velocity were positively associated with the incidence of mumps, whereas atmospheric pressure was inversely associated with it. The risk was highest when daily mean temperature was 34.2℃ on lag 0 day as the relative risk (RR) was 1.05 (95% CI, 1.02-1.10); when relative humidity was 99% on lag 24 days, the RR was 1.39 (95% CI, 1.03-1.89) as the highest. Taking the median of each meteorological factor itself as the reference value, the RRs of the 99th percentile （31.7 ℃,95%）of daily mean temperature and relative humidity were 1.81(95%CI, 1.41-2.32),1.28(95% CI,1.02-1.59), respectively, in the total lag time of 30 and 24 days to the mumps incidence. Both hot and cold effects were larger in females than those in males, and the hot effect increased with age. Conclusion Mean temperature, relative humidity might be important predictors of the incidence of mumps in Guangzhou. More attention should be paid to the susceptible population during the summer.

Objective To examine the short-term effects of meteorological factors on occurrence of hand, foot, and mouth disease (HFMD) in children in Rizhao. Methods A generalized additive Poisson model was applied to estimate the effects of meteorological factors on occurrence of HFMD in children in 2009-2012. Results During the study period, there were 26 827 HFMD cases, among which 26 619 were children under 10 years old, and the sex ratio was 1.63∶1. A positive effect of temperature was observed on lag 4-8 days (Excess risk［ER］=1.54%, 95% CI: 0.69% to 2.40% for 1 ℃ increase on lag 6 days). A positive effect of relative humidity was found on lag 5-7 days with the ER being 0.19% (95% CI: 0.07%-0.31%) for 1% of increase in relative humidity on lag 7 days. An adverse effect was observed for sunshine on lag 4-7 days (ER=-0.53%, 95% CI: -0.93% to -0.13% on lag 4 days). Conclusion This study suggests that meteorological factors might be important predictor of HFMD occurrence in children in Rizhao and should be considered in future disease control and prevention.

Objective To analyze the epidemiological characteristics of hand, foot, and mouth disease (HFMD) and its correlation with meteorological factors in Qingcheng District, Qingyuan, so as to provide scientific evidences for control and prevention measures. Methods Epidemic surveillance data from 2009 to 2013 in Qingcheng District were obtained from China Information System for Disease Prevention and Control, and corresponding meteorological data, from Qingyuan Climate Monitoring System. Descriptive epidemiological method was conducted to analyze epidemiological characteristics of HFMD and multiple regressions were adopted to test the correlation between the number of HFMD cases and meteorological factors. Results A total of 17 768 HFMD cases were reported from 2009 to 2013, with an average annual incidence of 517.55/100 thousand. The incidence was increased year by year from 2009 to 2011, while decreased dramatically from 2012 to 2013. Cases were reported in every street (town) around the district. The annual incidence was the highest in Dongcheng street, the combination zone between urban and rural area (724.840/100 thousand).Most cases were mainly distributed from April to July (56.60%,10 056/17 768), 95.04% (16 886/17 768) of them was children aged 5 years or younger, and 83.29% (14 800/17 768) was scattered children. There were 11 531 male cases and 6 237 female cases, and their average annual incidence rates were 651.25/100 thousand and 375.50/100 thousand, respectively. The ratio of male to female incidences was 1.73∶1. EV 71 was the predominant strain of HFMD in this district (62.50%, 75/120). The increase in HFMD cases showed a positive correlation with the daily average temperature, precipitation, and daily average wind speed, respectively（β=0.264, 0.079, and 0.064, P<0.05 or P<0.01）, but a negative one with the daily average air pressure (β=-0.166, P<0.01). Conclusion The occurrence of HFMD varied in area, season, age, gender, and occupation, and indicated a close correlation with the meteorological factors. Main actions should be taken to the focus groups and key locations to prevent and control HFMD before the epidemic season.

Objective To investigate the impacts of the heat wave on the emergency department (ED) visits among different ages, gender, illness groups in Beijing in 2010. Methods Daily maximum and mean temperatures in Beijing were obtained from the U.S. National Climatic Data Center website. The ED visit data were collected from a tertiary general hospital in Beijing. The heat wave period was defined from July 22 to 30, 2010 when the daily maximum temperature was higher than 35 ℃ for three or more consecutive days. The control period from July 23 to 31, 2009 was selected according to the same number of days in the same season and weeks without high temperature. The rate ratios (RRs) of ED visits during the heat wave and control period were calculated to determine the impact of heat wave on ED visits in different groups. Results The total ED visits in the study hospital during the heat wave were 1 567, increased 9.4% compared with those in the control period (1 433). An increased risk was observed for ED visits during the heat wave period compared with those in the control (RR=1.09, 95% CI: 1.05-1.13). The ED visits for children during the heat wave period were 434, increased 61.3% compared with those in the control period (269) (RR=1.61,95% CI：1.49-1.74). The ED visits for the elderly during the heat wave were 243, increased 25.9% compared with those in the control period (193) (RR=1.26,95% CI：1.14-1.39). The ED visits for respiratory diseases during the heat wave period were 497, increased 14.5% compared with those in the control period (434) (RR=1.15,95% CI：1.07-1.22). During the heat wave, the RR was 1.08 (95% CI：1.03-1.14) for males and 1.11 (95% CI：1.05-1.16) for females, increased for both gender groups compared with those in the control period. Conclusion The heat wave could increase the risk of ED visits and the sensitive groups might be the elderly, children and patients with respiratory diseases.

Objective To assess the impact of heat wave on non-accidental mortality in Jinan. Methods Mortality data, meteorological data and air pollution index data were collected during the period from June to August of 2009, 2010, and 2012 in Jinan. A time-stratified case-crossover study was used to assess the effects of heat wave on non-accidental death and deaths due to the main cause-specific circulatory diseases and their subtypes of acute myocardial infarction, cerebrovascular diseases, respiratory disease, and tumors of residents on different lag days in the city. Results A total of 16 427 non-accidental deaths were recorded during the 276 study days, of which 14 121 deaths were in 242 non-heat wave days and 2 306 deaths were in 34 heat wave days. Significant impacts of heat wave on non-accidental mortality, mortalities of circulatory diseases ,respiratory diseases, cerebrovascular disease, and acute myocardial infarction were observed among the local residents and significant delayed effects were observed on day 2, day 2, day 1, day 2 and day 4 for non-accidental deaths and other deaths, respectively. No significant effect was found for mortality from tumors. After controlling for the holidays, atmospheric pressure, relative humidity and average pollution index, the factor analysis OR values of heat wave and non-accidental mortality, mortality of circulatory diseases, respiratory diseases, cerebrovascular disease, and acute myocardial infarction were 1.44,1.70,1.87,1.56 and 1.60. Conclusion This study suggests that heat wave may be a risk factor for the health of residents in Jinan. Heat wave had large impact on respiratory disease, followed by circulatory diseases. Relevant authorities should take corresponding measures to reduce health hazard in accordance with meteorological characteristics in Jinan.

Objective To investigate human internal exposure levels and composition of polycyclic aromatic hydrocarbons (PAHs) in urine of residents living around a petrochemical enterprise. Methods According to continuous random variables sampling method, urine samples from residents living around a petrochemical enterprise in South China were collected in July 2012. The hydroxyl-PAHs (OH-PAHs) in the urine samples were detected by the rapid liquid chromatography coupled to triple quadrupole tandem mass spectrometry. Results A total of 165 residents (81 males and 84 females) aged 45 and over were investigated. Among the residents, 102 (62.82%) were aged 45 to 64 years. Their occupation was mainly farmer (49.09%, 81/165). Ten OH-PAHs detected in the urinary samples and their median concentrations of the metabolites were 2-hydroxy naphthalene (1.83μmol/mol creatinine),1-hydroxy naphthalene (1.34),2-+3-hydroxy fluorine (0.51),2-hydroxy phenanthrene (0.14),3-hydroxy phenanthrene (0.21),4-hydroxy phenanthrene (0.07), 1-+9-hydroxy phenanthrene (0.69) and 1-hydroxy pyrene (0.25)．Except 2-OHN and 1-+9-OHPhe, the other OH-PAHs were positively correlated (P<0.05 or P<0.01) and the correlation coefficients ranged from 0.20 to 0.76. Conclusion OH-PAHs in urine samples of residents living around the petrochemical enterprise were dominated by total hydroxyl naphthalene (1-OHN and 2-OHN), which was consistent with the fact that the main pollutants of the petrochemical factory were low ring OH-PAHs.

Objective To investigate the effects of smoking on pulmonary function and urinary concentrations of polycyclic aromatic hydrocarbon (PAH) metabolites among male adults in Guangzhou.Methods A systematic sampling method was employed to select male adults in Huangpu District and Zengcheng during July 2012. All subjects were aged 45 years and over, lived in the location more than half year, and interviewed with the questionnaire. Ten OH-PAHs in urine and pulmonary functions were tested. Covariance and multiple linear regression analyses were employed to test relationships between smoking, pulmonary functions and OH-PAH concentrations.Results A total of 142 male adults were recruited whose average age was (61.30±9.73) years. Ninety four of them were smokers (66.20%). The covariance analyses revealed that the FEV1/FVC (F=6.84), FEF25-75 (F=5.52) and MVV (F=4.54) were lower in smokers than those in none-smokers (P<0.05 for all). Smokers had higher concentrations of urinary 1-OHNa (F=10.21), 2-OHNa(F=8.74）and 2-+3-OHFlu (F=4.11) than none-smokers (P<0.05 or P<0.01). Furthermore, 2-OHPhe (β=-6.34), 3-OHPhe (β=-6.39), 4-OHPhe (β=-5.44), and 1-OHP (β=-5.03) had negative relationships with PEF (P<0.05 for all); 2-OHNa had negative relationship with FEF25-75 (β=-5.91, P<0.05); 1-OHNa (β=-2.85) and 2-OHNa (β=-3.11) had significantly negative relationships with MVV (P<0.05 for all). Conclusion Smoking could reduce pulmonary functions of male adults in Guangzhou and increase their internal exposure to PAHs. The internal increase in PAHs was related to the declined pulmonary functions.

Objective To study the relationship between household biomass fuels use and lower respiratory tract symptoms in rural area of Guangzhou City.Methods A systematic sampling survey was performed in residents aged over 6 years in rural area in Zengcheng District of Guangzhou, to obtain the information of indoor biomass fuels use and human lower respiratory tract symptoms. A multiple factor logistic analysis was carried out to test the relationship. Status factors of age, gender, smoke, indoor ventilation and kitchens ventilating devices were controlled in the analysis.Results A total of 266 households were investigated and 645 subjects were included in the study. Among the subjects, 478（74.1%）used biomass fuels and 167（25.9%）used clean energy. The prevalence of lower respiratory tract symptoms (containing any one of the symptoms of dry cough, expectoration, asthma, chest tightness or dyspnea) in past half year in biomass fuels group and clean energy group were 51.5%（246/478） and 41.3%（69/167）, respectively. In the multiple logistic regression model, the risks of expectoration（OR=1.90, 95% CI: 1.23-2.93）, asthma (OR=6.71, 95% CI: 1.74-25.85), chest congestion (OR=2.41, 95% CI: 1.02-5.72) and dyspnea (OR=5.99, 95% CI: 1.23-29.28) in biomass fuels group were all higher than those in clean energy group.The risk of lower respiratory tract symptoms was significantly associated with the frequency of biomass fuels use for symptoms experienced (OR=1.72, 95% CI: 1.14-2.59) and often appearing symptoms (OR=4.10, 95% CI: 1.40-12.04) in the group of using biomass fuels every day.Conclusion Indoor biomass fuels use may be an important risk factor for respiratory tract symptoms in rural area in Guangzhou. 【Key words】 Biofuel; Indoor air pollution; Respiratory tract disease

Objective To analyze the association between the low level occupational and environmental exposures to benzene and concentrations of trans, trans-muconic acid (t, t-MA) and s-phenilmercapturic acid (S-PMA) in urine collected from exposed individuals.Methods Persons who worked with a shoe-lasting machine and were continuously exposed to glue in shoe factories in Guangzhou City were selected as occupational exposure group, and those who lived in newly decorated houses for more than six months were defined as environmental exposure group.Contents of t,t-MA and S-PMA in urine were detected by ultra-performance liquid chromatography tandem mass spectrometry.Airborne benzene was detected by gas chromatography method.Results The concentrations of airborne benzene were (0.16±0.06) mg/m3 (x±s) in occupational exposure group and 0.01（0.02）mg/m3 (M［ITQ］) in environmental exposure group.The concentrations of t,t-MA and S-PMA were (42.7±39.2) μg/g Cr and (0.28±0.19) μg/g Cr in occupational exposure group and 20.5 (16.2) and 0.03（0.04）μg/g Cr in environmental exposure group, respectively.Mann-Whitney U-test revealed that the concentrations of airborne benzene and t,t-MA, S-PMA were all higher in occupational exposure group than those in environmental exposure group (P<0.01 for all). Moreover, t,t-MA and S-PMA in urine were correlated with airborne benzene when the airborne benzene concentration was 0.16 mg/m3 (r=0.499,0.715).Conclusion t,t-M and S-PMA could be taken as biomarkers to apply in monitoring low level occupational and environmental exposures to benzene.