Larysa Darchuk

Infrared investigation of hard human teeth tissues exposed to various doses of ionizing radiation from the 1986 Chernobyl accident

Infrared spectroscopy (IR) was applied to study changes in solid teeth tissues of persons exposed to low (0.12–0.20 Gy) and high (0.5–1.7 Gy) doses of ionizing radiation during their work in the Chernobyl zone after the accident. Changes in the inorganic and organic matrix of teeth were noted for both high and low radiation doses. The obtained results demonstrated that high doses of radiation lead to imbalance between phosphate–carbonate phases level (because of increasing of CO32− content) and accumulation of soluble phosphates in the mineral part of the teeth. These changes have an effect on dental matrix strength. Low doses of radiation do not induce appreciable negative changes in the mineral part of all tooth tissues but lead to changes in organic matrix of teeth (in collagen).

Particle deposition in airways of chronic respiratory patients exposed to an urban aerosol

Urban atmospheres in modern cities carry characteristic mixtures of particulate pollution which are potentially aggravating for chronic respiratory patients (CRP). Although air quality surveys can be detailed, the obtained information is not always useful to evaluate human health effects. This paper presents a novel approach to estimate particle deposition rates in airways of CRP, based on real air pollution data. By combining computational fluid dynamics with physical-chemical characteristics of particulate pollution, deposition rates are estimated for particles of different toxicological relevance, that is, minerals, iron oxides, sea salts, ammonium salts, and carbonaceous particles. Also, it enables some qualitative evaluation of the spatial, temporal, and patient specific effects on the particle dose upon exposure to the urban atmosphere. Results show how heavy traffic conditions increases the deposition of anthropogenic particles in the trachea and lungs of respiratory patients (here, +0.28 and +1.5 μg·h(-1), respectively). In addition, local and synoptic meteorological conditions were found to have a strong effect on the overall dose. However, the pathology and age of the patient was found to be more crucial, with highest deposition rates for toxic particles in adults with a mild anomaly, followed by mild asthmatic children and adults with severe respiratory dysfunctions (7, 5, and 3 μg·h(-1), respectively).

Composition of prehistoric rock-painting pigments from Egypt (Gilf Kébir area)

The composition of rock-painting pigments from Egypt (Gilf Kebia area) has been analyzed by means of molecular spectroscopy such as Fourier transform infrared and micro-Raman spectroscopy and scanning electron microscopy coupled to an energy dispersive X-ray spectrometer and X-ray fluorescence analysis. Red and yellow pigments were recognized as red and yellow ochre with additional rutile.

Molecular Spectroscopy Study of Human Tooth Tissues Affected by High Dose of External Ionizing Radiation (Caused by Nuclear Catastrophe of Chernobyl Plant)

Ionizing radiation remains the most significant environmental factor, causing severe impacts on human health on the vast territory of Ukraine for 25 years. Medical monitoring of the dental health of more than 1500 people who participated in cleaning work at the Chernobyl power station territory after the catastrophe has demonstrated an increasing of specific dental problems occurred after several years of participating at these works (Leus et al., 1998). The high level of hyperstenzy of hard dental tissues, the increase of enamel abrasion (first and second degrees) and the noncarious dental disease (cuneiform defects, pitting) are typical for around 63%, 36% and 47% of examined patients, respectively (Darchuk et al., 2008). Pathological dental abrasion, cuneiform defects, enamel erosion and enamel scissuras have been shown in Fig.1. Significant damages of parodontium (level II-III) by generalized severe periodontitis were detected for men with an acute radiation syndrome (Revenok, 1998). The main pathology was an intensified degeneration process while carious changes occurred, although these last were not directly related to irradiation.