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Results for “Maximum Allowable Concentration”

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PubMedDate not supplied

[Characterization of the ecological and geochemical state of soils in the Orenburg Region].

The data reflecting the state-of-the-art of studies into soil pollution with heavy metals and radionuclides in the context of hygienic evaluation of the environment are presented. Soil pollution with heavy metals was shown to be characterized by natural heterogeneity, a wide range of elements, such as technogenic pollutants, and by the local (mosaic) distribution. The degree of pollution was generally not 2-3 times higher than the maximum allowable concentrations. Soil pollution with radionuclide elements is associated with human activities and confined to the western areas of the region, and also noted for patchiness.

Catchment Area, Health↗
PubMedDate not supplied

[Alternative methodologies for standardization of deleterious environmental factors].

Some ecologists propose in recent papers to replace the ideology of the maximum allowable concentrations (MAC) by a new biotic concept of regional environmental monitoring by the method of ecologically allowable levels (EAL). By comparing the basic provisions of MAC and EAL methodologies, by taking into account their advantages and disadvantages, the authors conclude that there is no alternative to the hygienic MAC concept. The principles of EAL substantiation have no well-grounded scientific-and-practical methodology. New concepts of the common control of environmental quality, the health status of man, animals, plants, and the microworld should be sought by using the existing regulations.

Air Pollutants↗
PubMed1992

[Project for amending regulations regarding jobs prohibited to women].

Considering that the current legal regulations on jobs prohibited to women lack consistency, especially in relation to the criteria for including specific jobs into the prohibited category, and because the regulations fail to protect women satisfactorily from the harmful effects of occupational and environmental loads and exposures, preparation of new legal regulations on those matters has been attempted. Special stress has been put on specifying parameters which, when measured and compared with the suggested allowable values, should provide a basis for deciding whether a woman can be employed at a specified post. Separate criteria have been specified to determine jobs prohibited to women: a) irrespective of age, b) at reproductive age, c) during pregnancy and lactation. The irrespective-of-age restrictions result from lower average physical efficiency of women in relation to men, lower muscular strength and different psychical or biological characteristics. Lower allowable physical loads and lower maximum allowable weights of objects to be carried or moved by women have been specified. In specifying the restrictions for women at the reproductive age it has been assumed that, when determining the maximum allowable concentrations of chemicals at workplaces, effects of those chemicals on the reproducibility and health state of the off spring were taken into consideration. However, for chemicals which, according to the present knowledge, show genotoxic, teratogenic, or reproduction-disturbing effects, employers will be obliged to inform the reproductive-age female employees about the risk involved, as well as to take steps to reduce, as far as possible, below MAC the concentrations of those chemicals in the ambient air at workplaces. The restrictions in the employment of the pregnant and lactating women are intended to ensure conditions enabling correct development of pregnancy and safe growth of the fetus and, subsequently, of the neonate. The restrictions relate to: physical effort--as this has been proved to affect the course and the outcome of pregnancy (increased abortion risk, reduced duration of pregnancy, reduced neonate weight); exposure to carcinogens--as there is evidence that carcinogens display genotoxic properties and are capable of permeating the placenta: exposure to agents which can disturb the course of pregnancy and damage the fetus or unfavourably affect health condition of the offspring even if the MAC and MAI values are not exceeded; exposure to biologic agents, evidently harmful to the fetus and to the condition of health of the progeny.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed2003

[Heavy metals in the soil of allotment gardens in industrialized post-flooded areas in the Opole region]].

The results of studies concerning the levels of heavy metals (chromium, zinc, cadmium, nickel and lead) in soils of allotment gardens in post-flooded industrialized areas of the Opole Region, conducted during the period 2000-2001 was presented. Spectrophotometric method was applied for the determination of heavy metals in soils. The results of the study show that the levels of chromium, zinc and cadmium in the soils examined are constantly decreasing. However, an opposite phenomenon is observed with respect to copper and lead, where an increase was noted in the number of samples exceeding the maximum allowable, concentration of these metals during the second year of the study. This suggests that there exist local sources of contamination with the above-mentioned elements.

Cadmium↗
PubMed2003

[Effect of technological process in bottled water production on its redox properties].

The redox potential was measured in selected natural mineral and spring waters of different origin and chemical composition. To analyse the effect of the technological process the samples to be studied were collected at different stages of the bottling process: directly at the intake, at the beginning of the pipeline, after the deironing and/or demanganisation, after filtration, at the end of the pipeline and at the end of the process from the freshly filled bottles. Along with the redox potential measurements, some physico-chemical parameters of the samples studied were determined: colour, turbidity, conductivity, pH value, susceptibility to oxidation, contents of iron, manganese, antimony and arsenic. The potentiometric method applied to measure the redox potential was found suitable for the purpose of the study.

Consumer Product Safety↗
PubMed2004

[Comparative studies of the hydrogen ion exponent (rH) level in a natural spring carbonated water and unsaturated spring water in course of the water preservation in single packaging].

Redox properties of the low mineralized unsaturated and saturated natural spring water determined with the aid of hydrogen ion exponent (rH). There was marked: redox potential, hydrogen ion activity (pH), electrical conductivity, and also consument oxygen (ChZT) for the bottled water in the glass or plastic containers of various sizes during preservation of the water, taking into consideration the utility limits as well as after the limited utility period. The sort of packing, it size and the water preservation period in the packing essentially influence the values of the hydrogen index in the examined water. Statistically important changes of pH values and Eh appeared in most of examined samples. The essential changes were confirmed in unsaturated especially in the PET type containers. The conclusion was: the determination of hydrogen ion exponent (rH) of the water may be applied to the water quality control during the preservation in a single packing.

Consumer Product Safety↗
PubMed1977

[Simplified liquid nutrient media for controlling antibiotic activity, the spectrum of their antibacterial action and the sensitivity of microorganisms].

Beaf-peptone broth and some of its modifications, one of which is a simple and in expensive one to a leser extent binding to antibiotics, such as penicillin, oxytetracycline and streptomycin and providing sufficient growth of the test microbes were used to determine the antibiotic activity with the methods of serial dilutions. The simple modification was recommended for practical use. The MIC of the antibiotics in the above simple medium was less than that in the control. The results of the antibiotic activity determination on both media coincided.

Anti-Bacterial Agents↗
PubMed2004

Integration of chemical and biological oxidation in a SBBR for tannery wastewater treatment.

This paper reports the results of an investigation aimed at evaluating the laboratory-scale performance of an innovative process for treating tannery wastewater. In this process, biological degradation, carried out in a sequencing batch biofilm reactor (SBBR), is combined with chemical oxidation by ozone. Tannery wastewater treatment was carried out, at laboratory scale, on a real primary effluent coming from a centralised plant treating wastewater produced by a large tannery district in Northern Italy. SBBR performance both without and with ozonation, was assessed with very satisfactory results. In particular, in the latter instance the recorded COD, TKN and TSS average removals, (96%), (92%) and (98%) respectively, allowed the maximum allowable concentration values fixed by the Italian regulation in force to be achieved without any additional polishing step. During the investigation biofilm properties (biofilm concentration and biofilm density) and flow dynamics aspects (head loss, shear stress, bed porosity) were also studied. A major feature of the process is that, with or without ozonation, it was characterised by very low specific sludge production (0.05 kgVSS/kgCODremoved) and high biofilm density (i.e. 87-122 gVSS/Lsludge) both contributing to a rather high biofilm concentration (i.e. 31-44 gTSS/Lfilter).

Ammonia↗
PubMedDate not supplied

[Optimization of analytical methods for assay of ochratoxin A in the foodstuffs].

Ochratoxin A is a mycotoxin produced by widespread mold fungi of the genera Aspergillius and Penicillium. It is a common contaminant of cereals, coffee, wine, dried fruits, and spicery. There is evidence that ochratoxin A has nephrotoxic, immunosuppressive, embryotoxic, teratogenic, and carcinogenic effects on many species of mammals. Its maximum allowable concentration established by the Alimentarius Code and the European Union is 5 microg/kg for cereals and 3 microg/kg for ready-made cereals. Two optimized techniques (silica gel column chromatography (CC) or immunoaffinity CC for extract purification and high performance liquid chromatography with fluorescence detection) are proposed for the detection, identification, and assay of ochratoxin A in food commodities. The detection limit was 0.05 and 0.5 microg/kg, respectively. The developed techniques were used to assay the content of ochratoxin A in 46 samples of the grain gathered in different regions of Russia. Nine samples were contaminated by ochratoxin A at concentrations of 0.05 to 5 microg/kg.

Chromatography, Affinity↗
PubMed2006

[Cardiovascular risk factors in the main professional groups in a machine-building plant].

The subjects of the study were members of the main professional groups in a machine-building plant, who had long been exposed to a complex of low-intensive harmful industrial factors, not exceeding maximum allowable concentrations and levels (vibration, noise, organic solvents, neuroemotional and physical tension). The study revealed a significantly higher incidence of arterial hypertension in the members of the main professional groups and its dependence on industrial and non-industrial risk factors.

Adult↗
PubMed1991

[The experimental transplacental passage of dimethylformamide and toluene].

The author presents data on the transplacental passage of dimethylformamide (DMFA) and toluene in combined exposure at the level of the maximum allowable concentrations. A new method for measurements of chemicals in animal biomedia is suggested. The permeability index for DMFA has made up 37.1%, that for toluene 90.2%. The results recommend the new method for experimental and clinical measurements of chemicals.

Administration, Inhalation↗
PubMed1990

[A study of hazard of methylmercury pollution in no. 2 Songhua River to fishermen's health].

In the present paper the methyl mercury pollution in no. 2 Songhua river is reported. After ten years of continuous investigation, it was found that the health of fishermen who had eaten mercury polluted fish as a dietary for a long time was affected. There was an accumulation of methyl mercury in the fishermen's body and symptoms and pathologic changes related to toxication by methyl mercury. The average value of mercury content in fish (0.44-0.89 ppm) was shown to be above the maximum allowable concentration by one to three times. The intake of methyl mercury by the fishermen was in the range of 0.17-0.34 mg/per day and 90% of the mercury in the fishermen's body was from the polluted fish. The average mercury content in hair was 13-58 times higher than that of normal. The mercury concentration in urine after therapy was higher than that before by 10.6 to 33.3 times. There was a close correlation between mercury content in hair and in blood and the ratio was shown to be 250:1. The hazard of methyl mercury to fishermen was discussed.

Adult↗
PubMed1989

[Assessment of the degree of carcinogenicity of small doses of nitrites].

Chronic experiments on CBA and C57B1 mice and acute experiments on CBA mice established: (a) carcinogenic effect of sodium nitrite given continuously with drinking water (0.1; 1.0 and 10.0 maximum allowable concentration) in combination with morpholine fed with bread, and (b) endogenous synthesis of nitrosomorpholine as a result of simultaneous intragastric administration of same doses of sodium nitrite and morpholine. Also, nitrosomorpholine and N-nitrosodimethylamine synthesis was observed in vitro following addition of low-dose sodium nitrite, morpholine and amidopyrine to human gastric juice. Carcinogenic hazard associated with low-dose nitrite consumption in humans is discussed.

Aminopyrine↗
PubMed1985

Chronic allyl chloride poisoning. An epidemiology, clinical, toxicological and neuropathological study.

It was previously reported that chronic exposure to allyl chloride resulted in liver and kidney damage. No neurotoxic effect of allyl chloride had been noticed until two outbreaks of polyneuropathy without liver and kidney dysfunction due to exposure to allyl chloride in China in the early 1970's. Epidemiological and clinical studies done within 1973-1982 revealed that the main risk of industrial exposure to allyl chloride is damage to the peripheral nervous system. Polyneuropathy is thought to be the main clinical manifestation of chronic allyl chloride poisoning. Electroneuromyography is essential and valuable for early diagnosis and biological monitoring. Toxicological and neuropathological studies in rabbits and mice have given the evidence of a pattern of central-peripheral distal axonopathy in peripheral nervous system which has further confirmed the neurotoxicity of allyl chloride found in man. Based on the above results, the maximum allowable concentration of allyl chloride and diagnostic criteria for chronic allyl chloride poisoning are proposed.

Adenosine Triphosphate↗
PubMed1984

[Characteristics of aniline, lead nitrate, carbon tetrachloride and formaldehyde as modifiers of chemical carcinogenesis].

The modifying effect of aniline, lead nitrate, carbon tetrachloride and formaldehyde on nitrosodimethylamine-induced blastogenesis was studied in chronic experiments on 750 CBA X C57 / Bl6 female mice. A mixture of carcinogen with aniline or formaldehyde given in drinking water for 39 weeks produced a significantly higher tumor incidence. A similar, though statistically insignificant, effect was registered for a mixture of carcinogen and lead citrate or carbon tetrachloride. It is emphasized that aniline and formaldehyde are capable of modifying effect at levels 10 times maximum allowable concentrations.

Aniline Compounds↗