Occurrence of antimicrobials in animal manure-amended soils around the breeding farms: The case of the Saigon River (southern Vietnam)

The excessive use of antimicrobials in animal rearing and the associated environmental hazards have become a pressing issue. Animal agriculture is often viewed as a significant contributor to environmental degradation due to the residues of antimicrobials. It is a common practice to use livestock waste as a soil enhancer in farming. Despite some research into antimicrobials, there is room for more comprehensive data regarding these pollutants in animal farming environments. A handful of earlier studies have identified antimicrobials in animal waste. This research undertook the task of examining and evaluating soils amended with animal waste (from chickens, cows, and pigs) for the presence of seven specific antimicrobials. The antimicrobials under scrutiny included trimethoprim (TRI), ormethoprim (ORM), ofloxacin (OFL), norfloxacin (NOR), tetracycline (TET), chlortetracycline (CTE), and tylosin (TLS). Soil samples were collected from areas surrounding breeding farms located upstream of the Sai Gon River. These samples were then subjected to laboratory analysis, which involved solid-phase extraction using ultrasonic waves and the application of high-performance liquid chromatography-tandem mass spectrometry (LCMS/MS) to identify the antimicrobials. TRI, which had the highest average concentration (2.603–91.304 μg/kg), and OFL, with the second highest average concentration (1.815–15.832 μg/kg), were detected in all soil samples amended with manure. CTE, with the third highest average concentration, was found in soils amended with cow and pig waste (1.625–15.486 μg/kg). ORM and TE, with lower average concentrations (0.595–1.318 μ and 11.537–13.569 μg/kg, respectively), were only detected in soils amended with chicken waste, while NOR was only found in soils amended with cow waste. These findings indicate that the use of antimicrobials in animal farming can negatively impact the soil ecosystem. Consequently, these results can contribute to the creation of guidelines for monitoring antimicrobial residues in agricultural ecosystems.     

Towards an integrated approach of disaster and environment management: A case study of Thua Thien Hue province, central Viet Nam

Objetivo: El objetivo de este estudio era examinar los problemas emocionales y comportamentales de niños refugiados no acompañados que fueron repatriados a Vietnam de los centros de refugiados de Hong-Kong y del Sudeste asiático. Los niños fueron comparados con una muestra emparejada de niños que nunca dejaron Vietnam.Método: La muestra estaba compuesta por un total de 455 niños vietnamitas de edades comprendidas entre los 10 y los 22 años. Un total de 238 niños habían residido previamente sin sus padres en campos de refugiados. Se recogieron datos aplicando la versión de autoinforme para jóvenes del Achenbach (Youth Self-Report), la Escala de Autoeficacia Percibida de Cowen, una escala de Soporte Social y una escala de Exposición al Trauma.Resultados: No se observaron diferencias significativas entre los grupos de niños en la puntuación total del YSR. Los niños previamente refugiados tuvieron puntuaciones más bajas que los niños del grupo control en la escala de “problemas de conducta externalizados”. Se observó una tendencia en los niños refugiados a presentar puntuaciones más altas que los niños del grupo control en la escala de “problemas de conducta internalizados”. No se observaron diferencias entre los dos grupos en la eficacia autopercibida, el número de fuentes de apoyo social y las experiencias de apoyo social. Otros análisis mostraron que una interacción significativa entre la condición de inmigrantes de los niños y su percepción subjetiva del actual nivel de vida explicó las diferencias en las puntuaciones en el YSR.Conclusión: Los resultados sugieren que la experiencia de vivir sin sus padres en un campo de refugiados no conduce a presentar más problemas emocionales y de conducta en los años posteriores inmediatos a la repatriación.

Concentrations,profiles, emission inventory,and risk assessment of chlorinated benzenes in bottom ash and fly ash of municipal and medical waste incinerators in northern Vietnam

Environmental Science and Pollution Research - Concentrations and congener profiles of seven di- to hexachlorinated benzenes (CBzs) were characterized in bottom ash and fly ash samples collected...     

Characteristics of polycyclic aromatic hydrocarbons in ambient air of a tropical mega-area,Ho Chi Minh City,Vietnam: concentration,distribution, gas/particle partitioning,potential sources and cancer risk assessment

Environmental Science and Pollution Research - This is the first investigation on overall characteristics of 25 polycyclic aromatic hydrocarbons (PAHs) (15 PAHs regulated by US-EPA (excluding...     

Calculating nuclear accident probabilities from empirical frequencies

Since there is no authoritative, comprehensive and public historical record of nuclear power plant accidents, we reconstructed a nuclear accident data set from peer-reviewed and other literature. We found that, in a sample of five random years, the worldwide historical frequency of a nuclear major accident, defined as an INES level 7 event, is 14 %. The probability of at least one nuclear accident rated at level ≥4 on the INES scale is 67 %. These numbers are subject to uncertainties because of the fuzziness of the definition of a nuclear accident.     

Waste generation in traditional organized bazaars: a case study of organic waste sources in Da Nang City,Viet Nam

Journal of Material Cycles and Waste Management - Traditional organized bazaars are important retail venues in Viet Nam, but there are concerns about their waste management programs. This study...     

Influencing factors on sustainable development: a case study in Quang Tri province,Vietnam

Background Sustainable development (SD) is a common concept. Knowledge and attitudes are essential in the SD process. This study assesses the knowledge, attitudes, and practices (KAP) of local people about SD. Aim To study the factors that influence the understanding of the concept, contents, and indicators of different aspects affecting the health and environmental issues. Methods A cross-sectional study was carried out from June to July 2007 among 546 households in the Quang Tri province. Data were gathered on basis of socio-demographic variables, namely age, gender, education, occupation, income, and region. Chi square tests and multivariate analysis were performed on the obtained data. The data were cleaned and analysed using SPSS 15.0 for windows. Results Occupation is related to knowledge, attitude, or practice. Income is related to knowledge or practice. Gender related to only attitude. Lastly, region is related to attitude or practice. The proportion of wrong understanding about SD is 2.0 times (95% CI: 1.3; 3.1, p < 0.001) higher than that of the people who have good understanding about it. The rate of willingness to do any related SD programmes of the people who understanding is 2.1 times (95% CI: 1.4; 3.2, p < 0.001) higher than that of the people who have bad one. Conclusions This study shows that knowledge on sustainability of the local communities is low. Occupation and income influence understanding of SD more than region, age, gender, and education. Most of the local people who do not understand SD in general, do not want to participate or act in SD programmes.     

A socio-economic analysis of rice production systems in the uplands of northern Vietnam

Production of upland rice under shifting cultivation system is an important economic activity in the mountainous areas of northern Vietnam. A comparative study of two districts with differential market access and population pressure was conducted to highlight the effect of these variables on upland rice systems in northern Vietnam. Farmers in the district with a greater population pressure have a shorter cropping and a shorter fallowing cycle than in the district with lower population pressure. Farmers reported a high incidence of food shortage in both districts. Income from livestock and wages are important for food purchases, especially in the district with a better access to market. Even in these upland districts, access to lowland fields is a critical determinant of food security.     

VOCs in representative canadian residences

Stored extracts of passive samplers exposed in 757 randomly selected Canadian residences provided a unique opportunity for retrospective determination of the occurrence of airborne volatile organic compounds (VOCs). Aliquots of the individual extracts were pooled to form a composite exposure sample and a corresponding blank sample. To identify and quantitate potentially hazardous organics in the samples, GC-MS analyses were conducted by several approaches. The amounts of 52 target compounds in the the composite sample were estimated based on selected ion monitoring (SIM) results, extraction recoveries, average air volume sampled, and 3M OVM 3500 passive sampling rates. Forty of the organics were detected and were present in amounts equivalent to airborne concentrations ranging from <1 to 104 μg m⁻³. Several other compounds were also tentatively identified by full scan analysis. Many of the detected organics have been reported to be associated with activities such as tobacco smoking and the presence of consumer products and plastic materials indoors. The analytical results have been useful in risk assessments and establishment of a new Canadian priority substances list (PSL).     

Impact of minimum winter temperatures on the population dynamics of Dendroctonus frontalis.

Predicting population dynamics is a fundamental problem in applied ecology. Temperature is a potential driver of short-term population dynamics, and temperature data are widely available, but we generally lack validated models to predict dynamics based upon temperatures. A generalized approach involves estimating the temperatures experienced by a population, characterizing the demographic consequences of physiological responses to temperature, and testing for predicted effects on abundance. We employed this approach to test whether minimum winter temperatures are a meaningful driver of pestilence from Dendroctonus frontalis (the southern pine beetle) across the southeastern United States. A distance-weighted interpolation model provided good, spatially explicit, predictions of minimum winter air temperatures (a putative driver of beetle survival). A Newtonian heat transfer model with empirical cooling constants indicated that beetles within host trees are buffered from the lowest air temperatures by approximately 1-4 degrees C (depending on tree diameter and duration of cold bout). The life stage structure of beetles in the most northerly outbreak in recent times (New Jersey) were dominated by prepupae, which were more cold tolerant (by >3 degrees C) than other life stages. Analyses of beetle abundance data from 1987 to 2005 showed that minimum winter air temperature only explained 1.5% of the variance in interannual growth rates of beetle populations, indicating that it is but a weak driver of population dynamics in the southeastern United States as a whole. However, average population growth rate matched theoretical predictions of a process-based model of winter mortality from low temperatures; apparently our knowledge of population effects from winter temperatures is satisfactory, and may help to predict dynamics of northern populations, even while adding little to population predictions in southern forests. Recent episodes of D. frontalis outbreaks in northern forests may have been allowed by a warming trend from 1960 to 2004 of 3.3 degrees C in minimum winter air temperatures in the southeastern United States. Studies that combine climatic analyses, physiological experiments, and spatially replicated time series of population abundance can improve population predictions, contribute to a synthesis of population and physiological ecology, and aid in assessing the ecological consequences of climatic trends.