Air pollution has become an alarming issue in Vietnam recently; however, there was only one study so far on the effects of ambient air pollution on population health. Our study aimed to investigate the short-term effects of air pollutants including PM10, NO2, SO2, and O3 on respiratory and cardiovascular hospitalizations in Ho Chi Minh City (HCMC), the largest city in Vietnam. Data on hospitalization from the two largest hospitals in HCMC and daily records of PM10, NO2, SO2, O3 and meteorological data were collected from February 2004 to December 2007. A time-series regression analysis with distributed lag model was applied for data analysis. Changes in levels of NO2 and PM10 were strongly associated with hospital admissions for both respiratory and cardiovascular diseases (CVD); whereas levels of SO2 were only moderately associated with respiratory and CVD hospital admissions and O3 concentration was not associated with any of them. For a 10μg/m(3) increase of each air pollutant, the risk of respiratory admissions increased from 0.7% to 8% while the risk of CVD admissions increased from 0.5% to 4%. Females were found to be more sensitive than males to exposure to air pollutants in regard to respiratory diseases. In regard to CVD, females (RR, 1.04, 95% CI, 1.01-1.07) had a slightly higher risk of admissions than males (RR, 1.03, 95% CI, 1-1.06) to exposure to NO2. In contrast, males (RR, 1.007, 95%CI, 1-1.01) had a higher risk of admission than females (RR, 1.004, 95%CI, 1.001-1.007) to exposure to PM10. People in the age group of 5-65year-olds had a slightly higher risk of admissions caused by air pollutants than the elderly (65+years old) except for a significant effect of PM10 on the risk of cardiovascular admissions was found for the elderly only.

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Introduction:Leachate is a noticeable pollution problem because it contains a considerable amount of persistent organic pollutants (POPs). If leachate isn't treated thoroughly, its leak will negatively affect the environment. Therefore, appropriate treatment technologies are required to remove them. Bio-Electro-Fenton (BEF) is a new method using microorganisms such as electrolytes to convert chemical energy into electricity to help create H 2 O 2 support advanced oxidation process (AOPs). Realizing the potentials that BEF brings, this study applies BEF to assess the effectiveness of leachate treatment at Da Phuoc landfill (operation period > 12 years), Ho Chi Minh City, which to save costs and energy for Fenton process. Methods: The BEF pilot scale model (30 x 10 x 10 cm) is divided by a proton exchange membrane (PEM) (Nafion ® 112) into two chambers (anode and cathode). Cathode chamber used a graphite electrode, the anode chamber used a carbon fabric electrode. The experiments aimed to determine the optimal conditions of parameters affecting the BEF system by determining the efficiency of COD removal and BOD 5 /COD ratio in leachate. Results: At optimal conditions of the model including pH 3, [Fe 2+ ] = 4g/L, current intensity = 1A, reaction time 60 minutes and airflow = 12 L/min, as a result COD was reduced by 68.2 ± 1.04 % from 4950 ±14 mgO 2 /L to 1574.1 ± 51.4 mgO 2 /L, the ratio of BOD 5 /COD = 0.1 Conclusion: The study result showed thatBio-electro-Fenton process is effective for wastewater with high concentrations of pollutant and difficult to treat as leachate suggesting that the appropriate method for pre-treatment processes support the thorough elimination of pollutants.

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