Food supplements and European regulation within a precautionary context: a critique and implications for nutritional, toxicological and regulatory consistency

In this paper, we review European legislation in the field of micronutrient food supplements and find it wanting. It is shown that the precautionary principle, embedded in European food legislation, pre-empts innovative developments in this field. In view of the scientific advances in micronutrients research, we subsequently critique the precautionary perspective and propose a novel outlook on micronutrients food supplements regulation. However, this requires a transition from the "survival" approach of the current deficiency-related RDAs to a "health-optimization" approach of a n(ew)-RDA. Genomic integrity is central in this envisioned transition.     

A novel analytical approach for visualizing and tracking organic chemicals in plants

Vegetation plays a key role in the environmental fate of many organic chemicals, from pesticides applied to plants, to the air-vegetation exchange and global cycling of atmospheric organic contaminants. Our ability to locate such compounds in plants has traditionally relied on inferences being made from destructive chemical extraction techniques or methods with potential artifacts. Here, for the first time, two-photon excitation microscopy (TPEM) is coupled with plant autofluorescence to visualize and track trace levels of an organic contaminant in living plant tissue, without any form of sample modification or manipulation. Anthracene-a polynuclear aromatic hydrocarbon (PAH)-was selected for study in living maize (Zea mays) leaves. Anthracene was tracked over 96 h, where amounts as low as approximately 0.1-10 pg were visible, as it moved through the epicuticular wax and plant cuticle, and was observed reaching the cytoplasm of the epidermal cells. By this stage, anthracene was identifiable in five separate locations within the leaf: (1) as a thin (approximately 5 microm) diffuse layer, in the upper surface of the epicuticular wax; (2) as thick (approximately 28 microm) diffuse bands extending from the epicuticular wax through the cuticle, to the cell walls of the epidermal cells; (3) on the external surface of epidermal cell walls; (4) on the internal surface of epidermal cell walls; and (5) within the cytoplasm of the epidermal cells. This technique provides a powerful nonintrusive tool for visualizing and tracking the movement, storage locations, and degradation of organic chemicals within vegetation using only plant and compound autofluorescence. Many other applications are envisaged for TPEM, in visualizing organic chemicals within different matrixes.     

A new approach to eliminate stress for two probiotics with chemicals in vitro

The effect of some chemicals to eliminate stress for two probiotics cultivation was studied. Lactobacillus acidophilus was incubated with sodium citrate or calcium carbonate at 37 °C for 19 h, or Bifidobacterium bifidum was incubated with sodium d-isoascorbate or sodium ascorbate at 37 °C for 24 h in an anaerobic chamber, aiming to eliminate acidic or oxidative stress produced during culture. Viable count of L. acidophilus or B. bifidum in culture was counted with standard plate counting technique. The result showed that the viable count of L. acidophilus or B. bifidum in culture had an increase about twofold compared with that of control. The mechanism involved was discussed preliminary. Chemical destressing effect of sodium citrate and calcium carbonate on L. acidophilus, or chemical destressing effect of sodium d-isoascorbate and sodium ascorbate on B. bifidum, might provide a potential approach for probiotic production.     

Metabolic footprinting: a new approach to identify physiological changes in complex microbial communities upon exposure to toxic chemicals

Metabolic footprinting coupled with statistical analysis was applied to multiple, chemically stressed activated sludge cultures to identify probable biomarkers that indicate community stress. The impact of cadmium (Cd), 2,4-dinitrophenol (DNP), and N-ethyl-maleimide (NEM) shock loads on the composition of the soluble fraction of activated sludge cultures was analyzed by gross biomolecular analyses and liquid chromatography-mass spectrometry (LC-MS). Fresh mixed liquor from four distinct treatment plants was each divided in four different batches and was subjected to no chemical addition (control) and spike additions of the stressors Cd, DNP, or NEM. The results indicate that chemical stress caused a significant release of proteins, carbohydrates, and humic acids from the floc structure into the bulk liquid. Using discriminant function analysis (DFA) with genetic algorithm variable selection (GA-DFA), the samples subjected to the different stress conditions plus control could be differentiated, thereby indicating that the footprints of the soluble phase generated by LC-MS were different for the four conditions tested and, therefore, were toxin-specific but community-independent. These footprints, thus, contain information about specific biomolecular differences between the stressed samples, and we found that only a limited number of m/z (mass to charge) ratios from the mass spectra were needed to differentiate between the control and each stressed sample. Since the experiments were conducted with mixed liquor from four distinct wastewater treatment plants, the discriminant m/z ratios may potentially be used as universal stress biomarkers in activated sludge systems.     

GIS-based system for surface water risk assessment of agricultural chemicals. 1. Methodological approach

A methodology to develop a GIS-based system for the surface water risk assessment of agricultural chemicals is described. It is based on the integration of relational and spatial databases, GIS incorporating raster and vector, mass balance models, and pesticide risks indicators. Surface water pollution was modeled by taking into account two main processes: the load due to drift and the load due to a rainfall-runoff event. The former is immediately consequent to pesticide application; the second occurs a short period afterward. Thus two distinct PEC (predicted environmental concentration) values were estimated, differing in time. A pilot approach was applied to the herbicide alachlor on corn in Lombardia region (northern Italy) and represents the first stage of a wider project. Although the resultant alachlor PEC and risk maps represent a static image of a worst-case simulation, the main objective was to provide information for the territory with respect to relative risks at the watershed level, which is important in managing risks to the aquatic environment. The driving forces and spatial variability of the above-mentioned processes were investigated to improve knowledge about the territory and to indicate the need for more detailed site-specific studies.     

A hierarchical modeling approach for estimating national distributions of chemicals in public drinking water systems

Water quality studies often include the analytical challenge of incorporating censored data and quantifying error of estimation. Many analytical methods exist for estimating distribution parameters when censored data are present. This paper presents a Bayesian-based hierarchical model for estimating the national distribution of the mean concentrations of chemicals occurring in U.S. public drinking water systems using fluoride and thallium as examples. The data used are Safe Drinking Water Act compliance monitoring data (with a significant proportion of left-censored data). The model, which assumes log-normality, was evaluated using simulated data sets generated from a series of Weibull distributions to illustrate the robustness of the model. The hierarchical model is easily implemented using the Markov chain Monte Carlo simulation method. In addition, the Bayesian method is able to quantify the uncertainty in the estimated cumulative density function. The estimated fluoride and thallium national distributions are presented. Results from this study can be used to develop prior distributions for future U.S. drinking water regulatory studies of contaminant occurrence.     

News: New reporting rules for endocrine-modulating chemicals considered

Government.     

一种酿酒酵母多倍体系列菌株的构建及快速筛选方法

介绍了一种酿酒酵母多倍体系列菌株的构建和快速筛选的方法,即利用HO基因表达使酿酒酵母菌株交配型发生转变,通过相应菌株间的杂交构建酿酒酵母多倍体系列菌株,与已知交配型的酿酒酵母菌株杂交,显微镜观察杂合子,快速筛选得到多倍体菌株。PCR分析及DNA含量测定结果进一步表明得到的多倍体菌株是正确的。研究所采用的构建多倍体及快速筛选的方法快捷、可靠。     

Food contact substances and chemicals of concern: a comparison of inventories

Food contact materials (FCMs) are intended to be in contact with food during production, handling or storage. They are one possible source of food contamination, because chemicals may migrate from the material into the food. More than 6000 FCM substances appear on regulatory or non-regulatory lists. Some of these substances have been linked to chronic diseases, whilst many others lack (sufficient) toxicological evaluation. The aim of this study was the identification of known FCM substances that are also considered to be chemicals of concern (COCs). The investigation was based on the following three FCM lists: (1) the 2013 Pew Charitable Trusts database of direct and indirect food additives legally used in the United States (or Pew for short), (2) the current European Union-wide positive list for plastic FCMs (or Union for short), and (3) the 2011 non-plastics FCM substances database published by EFSA (or ESCO for short). These three lists of food contact substances (Pew, Union, ESCO lists) were compared with the Substitute It Now! (SIN) list 2.1, which includes chemicals fulfilling the criteria listed in article 57 of Regulation (EC) No. 1907/2006 (REACH), and the TEDX database on endocrine-disrupting chemicals. A total of 175 chemicals used in FCMs were identified as COCs. Fifty-four substances present on the SIN list 2.1 were also found on the Union and/or ESCO lists. Twenty-one of those 54 substances are candidates for Substances of Very High Concern (SVHC), and six of these 21 are listed on Annex XIV and intended for phase-out under REACH. In conclusion, COCs used in FCMs were identified and information about their applications, regulatory status and potential hazards was included.