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Dien Bien Phu, Vietnam

Hong W.-J.,Dalian Maritime University | Jia H.,Dalian Maritime University | Ma W.-L.,Harbin Institute of Technology | Sinha R.K.,Patna University | And 9 more authors.
Environmental Science and Technology | Year: 2016

A large-scale monitoring program, the Asia Soil and Air Monitoring Program (Asia-SAMP), was conducted in five Asian countries, including China, Japan, South Korea, Vietnam, and India. Air samples were collected using passive air samplers with polyurethane foam disks over four consecutive 3-month periods from September 2012 to August 2013 to measure the seasonal concentrations of 47 polycyclic aromatic hydrocarbons (PAHs), including 21 parent and 26 alkylated PAHs, at 176 sites (11 background, 83 rural, and 82 urban). The annual concentrations of total 47 PAHs (47PAHs) at all sites ranged from 6.29 to 688 ng/m3 with median of 82.2 ng/m3. Air concentrations of PAHs in China, Vietnam, and India were greater than those in Japan and South Korea. As expected, the air concentrations (ng/m3) were highest at urban sites (143 ± 117) followed by rural (126 ± 147) and background sites (22.4 ± 11.4). Significant positive correlations were found between PAH concentrations and atmosphere aerosol optical depth. The average benzo(a)pyrene equivalent concentration (BaPeq) was 5.61 ng/m3. It was estimated that the annual BaPeq concentrations at 78.8% of the sampling sites exceeded the WHO guideline level. The mean population attributable fraction (PAF) for lung cancer due to inhalation exposure to outdoor PAHs was on the order 8.8‰ (0.056-52‰) for China, 0.38‰ (0.007-3.2‰) for Japan, 0.85‰ (0.042-4.5‰) for South Korea, 7.5‰ (0.26-27‰) for Vietnam, and 3.2‰ (0.047-20‰) for India. We estimated a number of lifetime excess lung cancer cases caused by exposure to PAHs, which the concentrations ranging from 27.8 to 2200, 1.36 to 108, 2.45 to 194, 21.8 to 1730, and 9.10 to 720 per million people for China, Japan, South Korea, Vietnam, and India, respectively. Overall, the lung cancer risk in China and Vietnam were higher than that in Japan, South Korea, and India. © 2016 American Chemical Society.

Van Thuong N.,Dioxin Laboratory Project | Hung N.X.,Dioxin Laboratory Project | Mo N.T.,Dioxin Laboratory Project | Thang N.M.,Dioxin Laboratory Project | And 6 more authors.
Environmental science and pollution research international | Year: 2015

The Bien Hoa airbase (south of Vietnam) is known as one of the Agent Orange hotspots which have been seriously contaminated by Agent Orange/dioxin during the Vietnam War. Hundreds of samples including soil, sediment and fish were collected at the Bien Hoa Agent Orange hotspot for assessment of the environmental contamination caused by dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). The toxicity equivalency quotient (TEQ) concentration of PCDD/Fs in soil and sediment varied from 7.6 to 962,000 and 17 to 4860 pg/g dry wt, respectively, implying very high contamination of PCDD/Fs in several areas. PCDD/F levels in fish ranged between 1.8 and 288 pg/g TEQ wet wt and was generally higher than advisory guidelines for food consumption. 2,3,7,8-Tetrachlorinated dibenzo-p-dioxins (2,3,7,8-TCDD) contributed 66-99 % of TEQ for most of the samples, suggesting 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) from Agent Orange as the major source of the contamination. The vertical transport of PCDD/Fs was observed in soil column with high TEQ levels above 1000 pg/g dry wt (Vietnamese limit for necessary remediation activities- TCVN 8183:2009 (2009)) even at a depth of 1.8 m. The vertical transport of PCDD/Fs has probably mainly taken place during the "Ranch Hand" defoliant spray activities due to the leaks and spills of phenoxy herbicides and solvents. The congener patterns suggest that transports of PCDD/Fs by weathering processes have led to their redistribution in the low-land areas. Also, an estimate for the total volume of contaminated soil requiring remediation to meet Vietnamese regulatory limits is provided.

Hettelingh J.-P.,Coordination Center for Effects at | Posch M.,Coordination Center for Effects at | Velders G.J.M.,Center for Environmental Monitoring | Ruyssenaars P.,European Topic Center on Air Quality and Climate Change Mitigation | And 6 more authors.
Atmospheric Environment | Year: 2013

The National Emission Ceilings Directive regulating European Union (EU) Member State emissions of acidifying and eutrophying pollutants as well as ozone precursors was adopted in 2001. Its interim environmental objectives, to be achieved in 2010, consist of a reduction of the exceedance of critical loads for acidification and eutrophication and of critical levels of ground-level ozone relative to 1990. Objectives for acidification and ground-level ozone were to be met in every single receptor grid cell in the European Union. For eutrophication, however, the target was to be met only for the EU area as a whole. Since 2001, reported emissions for 1990 and 2010 as well as knowledge and methodologies and for computing atmospheric dispersion and critical loads and levels have changed. In this paper, it is shown that acidification and eutrophication objectives are largely met when assessing them with the knowledge of 2001. However, with 2012 knowledge the interim objectives for acidification and eutrophication are not met in most of the EU. The objectives for ground-level ozone are met in most EU Member States with both 2001 and present (2012) knowledge, with the exception of the objective for forests, which was still not met in most Member States in 2010. Therefore, it seems prudent that science is employed also in the implementation phase of policy agreements. © 2013 Elsevier Ltd.

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