Evaluation of organic contamination in urban groundwater surrounding a municipal landfill, Zhoukou, China.

This paper investigates the organic pollution status of shallow aquifer sediments and groundwater around Zhoukou landfill. Chlorinated aliphatic hydrocarbons, monocylic aromatic hydrocarbons, halogenated aromatic hydrocarbons, organochlorine pesticides and other pesticides, and polycyclic aromatic hydrocarbons (PAHs) have been detected in some water samples. Among the detected eleven PAHs, phenanthrene, fluorine, and fluoranthene are the three dominant in most of the groundwater samples. Analysis of groundwater samples around the landfill revealed concentrations of PAHs ranging from not detected to 2.19 µg/L. The results show that sediments below the waste dump were low in pollution, and the shallow aquifer, at a depth of 18-30 m, was heavily contaminated, particularly during the wet season. An oval-shaped pollution halo has formed, spanning 3 km from west to east and 2 km from south to north, and mainly occurs in groundwater depths of 2-4 m. For PAH source identification, both diagnostic ratios of selected PAHs and principal component analysis were studied, suggesting mixed sources of pyro- and petrogenic derived PAHs in the Zhoukou landfill. Groundwater table fluctuations play an important role in the distribution of organic pollutants within the shallow aquifer. A conceptual model of leachate migration in the Quaternary aquifers surrounding the Zhoukou landfill has been developed to describe the contamination processes based on the major contaminant (PAHs). The groundwater zone contaminated by leachate has been identified surrounding the landfill.

[Study on prevalence of physical activity in rural residents in four counties (districts) of Shanxi and Chongqing].

Objective: To investigate the prevalence of physical activity and its influencing factors in rural residents in Shanxi and Chongqing. Methods: In four counties (districts) of Shanxi and Chongqing, local residents aged ≥18 who lived there for more than one year and had no plan to migrate to other areas in 2 years were surveyed through face to face questionnaire interviews to collect the information about their daily physical activity time, sedentary time, related knowledge and attitude, and others. Results: The physical inactivity rate of the residents was 14.9%, and 88.7% of residents never took daily physical activity. The average sedentary time was (3.91±2.06) hours. The results of multivariate analysis showed that education level, per capita monthly income and activity degree were the factors influencing physical inactivity. Conclusion: The proportion of people who never took daily physical activity in the survey area was higher than the average level in rural areas in China, so measures should be taken to improve the overall rate of physical activity. For people who have exercise willingness, but have no practice, and those who have already increased their physical activities, targeted guidance is needed on the basis of strengthened health education.

[Influence of extreme weather on years of life lost due to diabetes death in Chongqing and Harbin, China].

Objective: To understand the associations between extremely low and high air temperature and the years of life lost (YLL) due to diabetes deaths in Chongqing and Harbin with different climatic characteristics in China. Methods: A double threshold B-spline distributed lag non-linear model (DLNM) was used to investigate the lag and cumulative effects of extremely low and high air temperature on YLL due to diabetes for lag 0-30 days by using the urban meteorological and diabetes mortality data of Chongqing (2011-2013) and Harbin (2008-2010). The effects were expressed as relative risk (RR). Results: In Chongqing, the cold effects on YLL due to diabetes were delayed by four days and lasted for three days (lag4-6) with the highest RR of 1.304 (95%CI:1.033-1.647) at lag5. The hot effects were delayed by one day (lag1) with RR of 1.321 (95%CI:1.061-1.646). In Harbin, the extreme cold effects on YLL were delayed by four days and lasted for seven days (lag4-10) with the highest RR of 1.309 (95%CI: 1.088-1.575) at lag6. The hot effects were delayed by one day and lasted for four days (lag1-4) with the highest RR of 1.460 (95%CI:1.114-1.915) at lag2. The unit risk for cold and hot effects was 43.7% (P=0.005 5) and 18.0% (P=0.000 2) in Chongqing and 15.0% (P=0.000 8) and 29.5% (P=0.001 2) in Harbin, respectively. Conclusions: Both extremely low air temperature and extremely high air temperature might increase the years of life lost due to diabetes in cities with different climate characteristics. Health education about diabetes prevention should provide information about the effects of extreme weather events.

Intramolecular charge transfer at reverse micelle-water pool interface: p-N,N-dimethylaminobenzoic acid in AOT/cyclohexane/water reverse micelle.

Photoinduced intramolecular charge transfer (ICT) of p-N,N-dimethylaminobenzoic acid (DMABOA) in AOT/cyclohexane/H2O reverse micelle was investigated and compared with that in CTAB/1-heptanol/H2O reverse micelle. It is proposed that the DMABOA molecule exists at the AOT reverse micelle water pool interface with its carboxylic group heading toward the water pool while the dimethylaminophenyl moiety buried in the micellar phase. Dual fluorescence of DMABOA that is indicative of the ICT reaction in the excited state was observed over the investigated water pool size, W of 3-17, in the AOT reverse micelle. The ICT emission of DMABOA in the AOT reverse micelle-water pool interface was found to be much weaker than that in the CTAB reverse micelle-water pool interface, and was attributed to the parallel direction of the electric field at the AOT reverse micelle-water pool interface to the charge transfer.