The review of publications evaluating the effectiveness of personal respiratory protection (RPE) as means of reducing morbidity (occupational and morbidity with temporary loss of ability to work) and indicators of the degree of purification of the inhaled air is presented. It is revealed that with a high degree of probability, systematic studies in this field were not carried out and that in some cases the effectiveness was overestimated by incorrect justification.

Keywords: RPE, efficiency, protection factor, occupational diseases

The relationship between the platinum electrode open circuit potential (OCP) in the blood plasma as an integral indicator of the balance of oxidation-reduction processes in the body with an oxidative stress coefficient (K) reflecting the balance of the lipid peroxidation and state of antioxidant system (LPO/AOS) in patients with acute poisoning by cauterant agents was investigated. The platinum electrode OCP in the blood plasma was measured using an original electrochemical technique. The oxidative stress coefficient was determined from the ratio of the malondialdehyde level to the total antioxidant activity of blood serum. The shift of the value of the platinum electrode OCP in blood plasma during the first 5-7 days towards the positive potential region coincided with the intensification of LPO processes and the decrease in total antioxidant activity of the blood serum. Sharp shift in the value of the platinum electrode OCP to the region of positive values (more than 25 mV) in patients with acute poisoning with cauterant agents coincides with the worsening of their condition. The data obtained during the monitoring of the platinum electrode OCP in blood plasma in patients with acute poisoning by cauterant agents allow to make a conclusion about the diagnostic capabilities of this technique for assessing the patient’s severity and correcting his treatment.

Keywords: open circuit potential, oxidative stress, electrode, blood plasma, malondialdehyde, total antioxidant activity, acute poisoning, cauterant agents

The indexes of external respiration of white rats exposed by inhalation to a substance of the CS type were estimated. Increase in the respiratory volume and respiratory minute volume as well as the absence of changes in respiratory rate when exposed to the formulation at the level of effective inhalation toxodosis has been found. It has been established that substance of the CS type causes a significant change in motor activity.

Keywords: aerosol, inhalation toxicity, irritants, lacrimators, substances of the CS type

Stable suspensions of metal/metalloid oxide nanoparticles (MeO-NPs) obtained by laser ablation of 99.99% pure elemental aluminum, titanium or silicon under a layer of deionized water were used separately or in different combinations to induce subchronic intoxications in rats. To this end, MeO-NPs had been repeatedly injected intraperitoneally (i.p.) 18 times during 6 weeks before a large number of functional, biochemical and morphometric indexes for the organism’s status were measured. It was found that, in many respects, the Al2O3-NPs were the most toxic as such and the most dangerous component of the studied combinations. Mathematical modeling with the help of the Response Surface Methodology has shown that the response of the organism to a simultaneous exposure to any two of the MeO-NPs under study is characterized by all possible types of combined toxicity (additivity, subadditivity or superadditivity of unidirectional action and different variants of opposite effects) depending on which outcome this type is estimated for as well as on the levels of the effect and dose. With any third MeO-NP species acting in the background, the type of combined toxicity displayed by the other two can change significantly. Many adverse effects produced by the [Al2O3-NP+TiO2-NP+SiO2-NP]-combination, including its genotoxicity, were substantially attenuated by giving to rats per os during the entire exposure period complex of innocuous bioprotective substances.

Keywords: nanoparticles, subchronic effects, comparative and combined toxicity, bioprotectors

Safety in the use of GMO for food purposes and public opinion on the problem are discussed. It is shown that the awareness of respondents on GMO has increased since 2011 to 2016. However, middle-aged and elderly respondents treat with care their contents in food.

Keywords: GMO, safety assessment, public opinion

The structure of the laboratory population of green microalgae Scenedesmus quadricauda (Turp.) Breb (=Desmodesmus communis E. Hegew.) was studied at different stages of its growth (lag-phase, log-phase and stationary phase) at low concentrations of copper chloride and silver nitrate by the method microculture, allowing to monitor the state and development of single cells having different physiological status. The response of the culture of S. quadricauda - the change in the number of cells and the fractional composition (the fraction of dividing, «dormant» and dying cells) depended not only on the concentration of the toxicant in the medium, but also on the physiological state of the culture: the level of synchronization and the growth phase. Silver ions at low concentrations had a more pronounced toxic effect on the culture than copper ions at different phases of its development, especially at a concentration of 0.001 mg/l (10-9 M). The main mechanism of the toxic effect of metals is to inhibit the process of cell division. At low concentrations of toxicants, especially at a concentration of 0.001 mg/l, a «paradoxical» effect expressed in the predominance of the fraction of «dormant» cells was revealed. The temporary inhibition of the process of cell division can be regarded as a protective mechanism that allows preserving the integrity of the population and its ability to survive in a changing environment. The obtained data explain the effect of action of low concentrations of substances due to their inclusion in the cell, the subsequent accumulation in the cell and their low excretion.

Keywords: Scenedesmus quadricauda, silver nitrate, copper chloride, low concentrations, heterogeneity of population

The toxicity of the Ag/AgCl nanocomposite was evaluated at different concentrations in chronic experiments for 41 days using standard freshwater and marine plant test organisms of Scenedesmus quadricauda (0.05, 0.1, 0.5 and 1.0 mg/l) and Phaeodactylum tricornutum (0.25, 0.5, 1.0, and 2.0 mg/L). Comparative sensitivity of test organisms in acute experiments (72 hours) in terms of LC50 was carried out. It was established that the green alga of S. quadricauda is more sensitive to the Ag/AgCl nanocomposite (LC50 = 0.02 mg/l) than the marine diatomea P. tricornutum (LC50 = 0.3 mg/l). The greatest algicidal effect on the growth of S. quadricauda culture was provided by the nanocomposite in concentrations of 1 and 0.5 mg/l, at which the culture did not grow during the experiment. And at concentrations of 0.1 and 0.05 mg/l the algostatic effect was observed for 10 and 1 days, respectively, after which the culture resumed growth. In the culture of P. tricornutum at concentrations of 1.0 and 2.0 mg/l there was a prolonged inhibition of growth, but after 25 days at 1.0 mg/l the number of cells began to increase. In the presence of 0.5 mg/l the culture resumed growth after 4 days of lag phase and overtook the number of control. At the concentration of 0.25 mg/l the growth of P. tricornutum was either at or above the control level. The difference in the response of the two species of algae can be explained both by the individual feature of the species and by the more complex composition of the marine nutrient medium, which reduces the toxicity of the nanocomposite. According to analytical electron microscopy silver from Ag/AgCl nanocomposites within a day falls inside the cells of S. quadricauda and P. tricornutum algae, passing unimpeded both through the cell wall and the cell membrane.

Keywords: Scenedesmus quadricauda, Phaeodactylum tricornutum, nanocomposite Ag/AgCl, toxicity

The preparation “Phytase” is low-toxic, does not have an irritant and sensitizing effect. The threshold of acute inhalation of the preparation is set at the level of 28.0 mg/m3 (on phytase) according to the change in the function of the nervous system and kidneys. Indicative safe exposure level of the preparation “Phytase” in the air of the working area is recommended to be 1.0 mg/m3 (according to phytase), in the atmospheric air of populated areas - 0.02 mg/m3, the aggregate state is aerosol.

Keywords: phytase, toxicity, hygienic standards

The experiment on the study of food behavior and the dynamics of weight gain in experimental animals (rats) after single oral intake of the mixed oxide of depleted uranium (U3O8 + UO2) with water is given. It is shown that when depleted uranium enters the body, rodent eating behavior increases possibly due to direct neurotoxicity of uranium compounds, as well as impaired metabolism of neurotransmitters in a brain. At the same time, the toxic effect of uranium compounds on the organs of the gastrointestinal tract is probably the cause of malabsorption syndrome, which causes a decrease in weight gain in animals.

Keywords: depleted uranium, food behavior, brain, incorporation