Microplastics’ (particles size ≤5 mm) sources and fate in marine bottom and beach sediments of the brackish are strongly polluted Baltic Sea have been investigated. Microplastics were extracted using sodium chloride (1.2 g cm−3). Their qualitative identification was conducted using micro-Fourier-transform infrared spectroscopy (μFT-IR). Concentration of microplastics varied from 25 particles kg−1 d.w. at the open sea beach to 53 particles kg−1 d.w. at beaches of strongly urbanized bay. In bottom sediments, microplastics concentration was visibly lower compared to beach sediments (0–27 particles kg−1 d.w.) and decreased from the shore to the open, deep-sea regions. The most frequent microplastics dimensions ranged from 0.1 to 2.0 mm, and transparent fibers were predominant. Polyester, which is a popular fabrics component, was the most common type of microplastic in both marine bottom (50%) and beach sediments (27%). Additionally, poly(vinyl acetate) used in shipbuilding as well as poly(ethylene-propylene) used for packaging were numerous in marine bottom (25% of all polymers) and beach sediments (18% of all polymers). Polymer density seems to be an important factor influencing microplastics circulation. Low density plastic debris probably recirculates between beach sediments and seawater in a greater extent than higher density debris. Therefore, their deposition is potentially limited and physical degradation is favored. Consequently, low density microplastics concentration may be underestimated using current methods due to too small size of the debris. This influences also the findings of qualitative research of microplastics which provide the basis for conclusions about the sources of microplastics in the marine environment.

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Sample thickness considerations for quantitative X-ray fluorescence analysis of the soft and skeletal tissues of the human bodytheoretical evaluation and experimental validation Magdalena Szczerbowska-Boruchowska* A good estimation of the matrix composition and the areal mass of the sample is critical for quantitative X-ray fluorescence (XRF) analysis. Integrated aspects of the XRF quantitative analysis of various human body organs are presented. Special emphasis is placed on the determination of the sample thicknesses at which the specimen can be regarded as thin, thick, or intermediate thickness depending on the element under consideration. Moreover, a method for a fully quantitative analysis allowing the determination of the masses per unit area of chemical elements in thin, thick, and intermediate thickness samples is discussed. It was found that for an incident beam of 17 keV energy, a 15 mm thick sample is of intermediate thickness for all elements between P and Ca and becomes thin from Fe for most human body tissues in a natural form. Dried samples of soft tissues excluding these of low water content can be regarded as thin for all elements from phosphorus to strontium. The use of thin sample approach in quantification of intermediate thickness specimen may result in about 30-45% discrepancy in areal mass (weight fraction) of phosphorus, 20-35% of sulfur, 15-25% of chlorine, 8-15% of potassium, and 5-10% of calcium. Theoretical evaluations presented in the work are verified experimentally. The analysis of human brain samples (white and gray matter) and bovine liver (National Institute of Standards and Technology standard reference materials 1577b) confirms high accuracy of the XRF quantification on the basis of the described procedures.

Amyotrophic Lateral Sclerosis (ALS) is an untreatable, neurodegenerative disease of motor neurons characterized by progressive muscle atrophy, limb paralysis, dysarthria, dysphagia, dyspnae and finally death. Large motor neurons in ventral horns of spinal cord and motor nuclei in brainstem, large pyramidal neurons of motor cortex and/or large myelinated axons of corticospinal tracts are affected. In recent synchrotron Fourier Transform Infrared microspectroscopy (sFTIR) studies of ALS CNS autopsy tissue, we discovered a small deposit of crystalline creatine, which has a crucial role in energy metabolism. We have now examined unfixed, snap frozen, post-autopsy tissue sections of motor cortex, brain stem, spinal cord, hippocampus and substantia nigra from six ALS and three non-degenerated cases with FTIR and micro-X-ray fluorescence (XRF). Heterogeneous pigmented deposits were discovered in spinal cord, brain stem and motor neuron cortex of two ALS cases. The FTIR signature of creatine has been identified in these deposits and in numerous large, non-pigmented deposits in four of the ALS cases. Comparable pigmentation and creatine deposits were not found in controls or in ALS hippocampus and substantia nigra. Ca, K, Fe, Cu and Zn, as determined by XRF, were not correlated with the pigmented deposits; however, there was a higher incidence of hot spots (Ca, Zn, Fe and Cu) in the ALS cases. The identity of the pigmented deposits remains unknown, although the absence of Fe argues against both erythrocytes and neuromelanin. We conclude that elevated creatine deposits may be indicators of dysfunctional oxidative processes in some ALS cases.