Residual congener pattern of dioxins in human breast milk in southern Vietnam

This study evaluated residual congener patterns of dioxin/furan (=PCDD/DF) related to tactical herbicides aerially sprayed over the regions of southern Vietnam through Operation Ranch Hand. The study focused on Cam Chinh (CC) commune, Quang Tri province (an area sprayed with tactical herbicides), and the Cam Phuc (CP) commune, Ha Tinh province (a non-sprayed area). Breast milk samples for analysis were collected in September 2002 and July 2003 from lactating primiparous and multiparous mothers born after the war (<31 years old). We found the levels of each congener in the CC commune were higher than in the CP commune, and determined specificity in the PCDD/DF congener pattern in CC commune samples by cluster analysis. The congener pattern is characterized by higher (the hexa-, the hepta-, and the octa-) chlorinated PCDD/DFs; this appears to be the same profile as that presented by pentachlorophenol (PCP), rather than 2,4,5-trichlorophenoxy acid (2,4,5-T) contaminated with 2,3,7,8-TCDD. A GC/MS study in the 1970s detected the chlorophenols 2,4-di and 2,4,6-trichlorophenol in some Agent Orange samples, which contained, like PCP, a wide variety of PCDD/DF congeners. In this context, it may be expected that certain tactical herbicides contaminated with various chlorophenol impurities, have a unique congener pattern when compared with pure 2,4,5-T formulations.     

Activated carbon/Fe(3)O(4) nanoparticle composite: fabrication, methyl orange removal and regeneration by hydrogen peroxide

In the water treatment field, activated carbons (ACs) have wide applications in adsorptions. However, the applications are limited by difficulties encountered in separation and regeneration processes. Here, activated carbon/Fe₃O₄ nanoparticle composites, which combine the adsorption features of powdered activated carbon (PAC) with the magnetic and excellent catalytic properties of Fe₃O₄ nanoparticles, were fabricated by a modified impregnation method using HNO₃ as the carbon modifying agent. The obtained composites were characterized by X-ray diffraction, scanning and transmission electron microscopy, nitrogen adsorption isotherms and vibrating sample magnetometer. Their performance for methyl orange (MO) removal by adsorption was evaluated. The regeneration of the composite and PAC-HNO₃ (powdered activated carbon modified by HNO₃) adsorbed MO by hydrogen peroxide was investigated. The composites had a high specific surface area and porosity and a superparamagnetic property that shows they can be manipulated by an external magnetic field. Adsorption experiments showed that the MO sorption process on the composites followed pseudo-second order kinetic model and the adsorption isotherm date could be simulated with both the Freundlich and Langmuir models. The regeneration indicated that the presence of the Fe₃O₄ nanoparticles is important for a achieving high regeneration efficiency by hydrogen peroxide.     

Development of an analytical strategy based on liquid chromatography-high resolution mass spectrometry for measuring perfluorinated compounds in human breast milk: application to the generation of preliminary data regarding perinatal exposure in France

Perfluorinated compounds (PFCs) are man-made chemicals for which endocrine disrupting properties and related possible side effects on human health have been reported, particularly in the case of an exposure during the early stages of development, (notably the perinatal period). Existing analytical methods dedicated to PFCs monitoring in food and/or human fluids are currently based on liquid chromatography coupled to tandem mass spectrometry, and were recently demonstrated to present some limitations in terms of sensitivity and/or specificity. An alternative strategy dedicated to the analysis of fourteen PFCs in human breast milk was proposed, based on an effective sample preparation followed by a liquid chromatography coupled to high resolution mass spectrometry measurement (LC-HRMS). This methodology confirmed the high interest for HRMS after negative ionization for such halogenated substances, and finally permitted to reach detection limits around the pg mL(-1) range with an outstanding signal specificity compared to LC-MS/MS. The proposed method was applied to a first set of 30 breast milk samples from French women. The main PFCs detected in all these samples were PFOS and PFOA with respective median values of 74 (range from 24 to 171) and 57 (range from 18 to 102) pg mL(-1), respectively. These exposure data appeared in the same range as other reported values for European countries.     

A follow up of the decrease of non exchangeable organically bound tritium levels in the surroundings of a nuclear research center

In the past decades limited amounts of tritium were handled on the CEA site of Bruyères le Châtel with authorised atmospheric releases. A small fraction of the tritium released entered into environmental samples under three forms: (i) as part of free water (TFWT - Tissue Free Water Tritium), or associated with organic matter in two ways; either (ii) bound to the oxygen and nitrogen atoms of the material as exchangeable organically bound tritium (E-OBT), or (iii) bound to carbon atoms as non exchangeable organically bound tritium (NE-OBT). The first two components provide only a picture of atmospheric tritium concentrations at the sampling time as they are in equilibrium with atmospheric moisture and soil humidity. Unlike these exchangeable forms, however, NE-OBT is tightly bound to the organic matter and provides an integrated record of atmospheric tritium during the growing phase of the vegetation. We mapped NE-OBT in tree leaf samples in an area of about 25 × 30 km² around the centre of the CEA site and compared the results with those obtained during a previous sampling exercise in 1989. At this time, the activity levels were almost ten times higher than those observed presently in a similar area almost 20 years later which is consistent with the decrease of atmospheric releases issued from the centre. As the activity levels are now close to environmental background specific attention was also paid to the analytical procedure to ensure reliable low level NE-OBT detection.     

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.     

In vivo assessment of plant extracts for control of plant diseases: A sesquiterpene ketolactone isolated from Curcuma zedoaria suppresses wheat leaf rust

As an alternative to synthetic pesticides, natural materials such as plant extracts and microbes have been considered to control plant diseases. In this study, methanol extracts of 120 plants were explored for in vivo antifungal activity against Rhizoctonia solani, Botrytis cinerea, Phytophthora infestans, Puccinia triticina, and Blumeria graminis f. sp. hordei. Of the 120 plant extracts, eight plant extracts exhibited a disease control efficacy of more than 90% against at least one of five plant diseases. In particular, a methanol extract of Curcuma zedoaria rhizomes exhibited strong activity against wheat leaf rust caused by P. triticina. When the C. zedoaria methanol extracts were partitioned with various solvents, the layers of n-hexane, methylene chloride, and ethyl acetate showed disease control values of 100, 80, and 43%, respectively, against wheat leaf rust. From the C. zedoaria rhizome extracts, an antifungal substance was isolated and identified as a sesquiterpene ketolactone based on the mass and nuclear magnetic resonance spectral data. The active compound controlled the development of rice sheath blight, wheat leaf rust, and tomato late blight. Considering the in vivo antifungal activities of the sesquiterpene ketolactone and the C. zedoaria extracts, these results suggest that C. zedoaria can be used as a potent fungicide in organic agriculture.     

The implementation of PAYT system under the condition of financial balance in France

Since 2005, France has been facing a reform of the financial regulation of the management of municipal solid waste, by tax or flat fees. Nevertheless, the application of unit pricing is limited to about 15 local authorities, but interest is expanding. The French examples confirm the efficiency of this PAYT system. The prevention and the sorting of packaging waste are increasing and the quantity of residual waste falling. But, we have highlighted the difficulty for the local authorities to balance their budgets during the years of PAYT system implementation. After a short review of the situation in France of the financing of waste services, and in particular of PAYT system, the paper presents, firstly the financial model and then, the results of its application in two communities. The cost model takes into account the expenditure of management on various waste flows and the revenues for the sale of by-products. A financial balance is ensured by the payments from households. Consequently, the unit pricing and the effect of the behaviour of the inhabitants are introduced into the simulation model. The application on two local authorities showed that the increase of sorting waste did not restore the balance. From the analysis, three reasons explain this situation: Thus, the development of the tariff must be carried out according to an economic approach. In the end, after the presentation of the financial modelling and its application, we make recommendations to aid the implementation of the PAYT system and the development of the pricing structures by local authorities.     

Dynamis CO2 quality recommendations

In the carbon capture and storage (CCS) chain, transport and storage set different requirements for the composition of the gas stream mainly containing carbon dioxide (CO₂). Currently, there is a lack of standards to define the required quality for CO₂ pipelines. This study investigates and recommends likely maximum allowable concentrations of impurities in the CO₂ for safe transportation in pipelines. The focus is on CO₂ streams from pre-combustion processes. Among the issues addressed are safety and toxicity limits, compression work, hydrate formation, corrosion and free water formation, including the cross-effect of H₂S and H₂O and of H₂O and CH₄.     

A biome-scale assessment of the impact of invasive alien plants on ecosystem services in South Africa

This paper reports an assessment of the current and potential impacts of invasive alien plants on selected ecosystem services in South Africa. We used data on the current and potential future distribution of 56 invasive alien plant species to estimate their impact on four services (surface water runoff, groundwater recharge, livestock production and biodiversity) in five terrestrial biomes. The estimated reductions in surface water runoff as a result of current invasions were >3000 million m³ (about 7% of the national total), most of which is from the fynbos (shrubland) and grassland biomes; the potential reductions would be more than eight times greater if invasive alien plants were to occupy the full extent of their potential range. Impacts on groundwater recharge would be less severe, potentially amounting to approximately 1.5% of the estimated maximum reductions in surface water runoff. Reductions in grazing capacity as a result of current levels of invasion amounted to just over 1% of the potential number of livestock that could be supported. However, future impacts could increase to 71%. A ‘biodiversity intactness index’ (the remaining proportion of pre-modern populations) ranged from 89% to 71% for the five biomes. With the exception of the fynbos biome, current invasions have almost no impact on biodiversity intactness. Under future levels of invasion, however, these intactness values decrease to around 30% for the savanna, fynbos and grassland biomes, but to even lower values (13% and 4%) for the two karoo biomes. Thus, while the current impacts of invasive alien plants are relatively low (with the exception of those on surface water runoff), the future impacts could be very high. While the errors in these estimates are likely to be substantial, the predicted impacts are sufficiently large to suggest that there is serious cause for concern.