The main directions of activity of the Toxicology Service in the Sanitary and Epidemiological Surveillance network of Moscow over 50 year period are highlighted.

Keywords: toxicity, hazard

The study was designed to evaluate the influence of nitric oxide precursors (NO) on the state of the main regulatory systems оf the organism. It was shown that the administration of sodium nitrate at sub-toxic doses resulted in authentic increase (p <0.05) in blood methemoglobin content, with more pronounced growth rate observed against the blockade of NO products arginine-dependent pathway. Increasing in the amount of arginine (the main NO precursor) in the diet of the animals permitted to significantly reduce the production of methemoglobin. Those changes closely correlated with nitrate and nitrite levels in blood plasma of experimental animals (r= 0.74 and r= 0.77 respectively). It was found out that at inhibition of NOsynthase, disturbances in tissue respiration, emergence of uncompensated metabolic acidosis, acceleration of free-radical processes are observed. The feasibility of revising existing hygiene standards for without-sponge-dough-consumption of nitrates and nitrites with food and drinking water was examined.

Keywords: nitrates, nitric oxide, hygiene, toxicology

7-hydroxycoumarin is suggested as a perspective luminescent dye for low-alcohol beverages. In this connection a type of combination acute oral action of 7-hydroxycoumarin(7-HOC) a nd ethanol on the rat organism was studied in doses of 5000 mg/kg and 6000 mg/kg respectively with divisive method. Based on the majority of indicators investigated, a n independent type of combination action was determined ( =0.05). Antagonism of 7-HOC and ethanol toxic effect was identified based on glycosuria (24 h),reduced concentration of urinary urea nitrogen and cholesterol in blood serum (3 days) potentiation based on the content of blood serum urea, urea clearance (24 h), activity of alkaline phosphatase in blood serum (24 h, 3 days).

Keywords: 7-hydroxycoumarin, ethanol, acute toxicity, combination action

It is established that by LD50 values, fluoxetine belongs to a moderately hazardous substances. It has strong irritant effect on the skin and eye mucous membranes. It has an expressed cumulation ability. The threshold of acute inhalation actions is 11.1 mg/m3. The tentative safe exposure level of fluoxetine in occupational air is 0.1 mg/ m3.

Keywords: fluoxetine, toxicological evaluation, tentative safe exposure levels (TSELs) in occupational air

Pre-clinic investigations were conducted into vaccine Ad5-H5N2 within the study of biological safety of against type A flu candidate genetic vaccine based on fifth-serotype human adenovirus expressing hemagglutinin gene of avian flu H5N2 virus. While performing a single intraperitoneal, intravenous and intranasal administration of vaccine Ad5-H3N2 to mice and rats in doses exceedinga 10-and 100 -fold suggested immunizing dose for humans, the general condition of animals was satisfactory. While administrated multifold intra-abdominally («chronic toxicity»), the candidate vaccine did not exert an apparent toxic effect on rodents peripheral blood, liver, kidneys and CNS.A histological investigation into internal organs of rats receiving abdominally the vaccine during 5 days showed that the vaccine induced slightly expressed inflammatory and destructive inflammatory alterations in liver, myocard and lungs. Activating effect of the vaccine on proliferative cells in liver, spleen, adrenals, bile capillaries epithelium was identified. A vaccine dose characterized as a high toxic dose was found out. The outcome of investigations of acute and chronic toxicity of vaccine AdH5N2 in rodents showed in terms of «acute» toxic effect, vaccine AdH5N2 can be allocated to low hazardous medical drugs and in terms of «chronic toxic effect to moderately hazardous ones.

Keywords: general toxic effect, «acute» toxicity, «chronic» toxicity, vaccine against flu A

The differences in effects on the organism of toxic and radiotoxic substances as well as in the approaches to their norms setting are discussed. The main difference lies in the fact that the central principle of hygienic norms setting for chemical substances is the liminality principle, that is defining the minimum amount of substance intaken in various ways when no signs of its harmful effect are present. Radiotoxicologists define norms for radiation exposure according to nonthreshold effects. The differences found are probably connected with a limiting (determinant) attribute of harm used in determining maximum permissible concentration of chemicals. It is pointed out that the risk from the maximum dose of some radiation exposure is within the acceptable ranges risks recommended by WHO, while the risks of a maximum concentration of some nonradioactive substances exceed them.

Keywords: liminality principle, nonthreshold principle, norms setting, radiotoxicity, toxicity

Alternative methods for use in investigations is still one of the key issues in assessment of products chemical safety. The use of different alternative methods is analyzed.

Keywords: alternative methods of investigations, initegral toxicity, toxicity sign

Toxicity of corrosion inhibitors «Azol 5030», «Azol 5031» and demulsifier «Azol 6001» was assessed for hydrobionts: phytoplanktonic organisms –Scenedesmus quadricauda (Turp) Breb; zooplanktonic organisms Daphnia magna Straus and fishes, one-day old fishes (baby fishes)-Poecillia reticulate Peters. To assess toxic effects of test-objects, , were used indicators of median lethal concentrations (EC50 and LC50) characterizing changes in living parameters of phytoplanktonic organisms by 50% for a determined period of time- (EC50 /72h) and changes by 50% in survival( death) of zooplanktonic organisms for a certain period of time (LC50 /96h). Based on the assessment results, it was found out that the corrosion inhibitor and fishes «Azol 5030» is a low toxic substance (group 2), «Azol 5031» is moderately toxic (group 3) and demulsifier «Azol 6001»(group 1) is very slightly toxic.

Keywords: preparations, phytoplankton, zooplankton, fish, toxicity

While developing oilfield, drilling- holes process produces a great amount of refuses –drill cutting consisting of drilled out rock, chemical reagents, used -up drilling mud fluid. The question about toxicity or safety of drill cuttings remains a debating point so far. To assess ecotoxicology of drill cuttings, complex chemico-analytical and experimental biological investigations were conducted. Biological control was performed with substrate and eluate biotesting. Hydrobionts, higher plants, microorganisms and mammalians were used as test-organisms. Drill cuttings were assessed in compliance with approved regulatory documents. Based on the investigations outcome, it was laid down that the majority of refuses do not produce toxicity and therefore do not present a threat to the environment. In other words, drilling cuttings appear ecologically safe.

Keywords: drill cuttings, biotesting, ecotoxicological evaluation, test-organisms, hazard class