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PubMed2001

[Outbreak of hemolytic reactions associated with chlorine and chloramine residuals in hemodialysis water].

OBJECTIVE: To investigate the process of water contamination and to assess the subsequent outbreak in the hemodialysis center. METHODS: In September 2000, sixteen patients undergoing chronic hemodialysis at a dialysis center in Minas Gerais, Brazil, experienced hemolytic reactions compatible with toxic symptoms due to chlorine and chloramine water contamination. Chlorine and chloramine concentrations in samples obtained from various sites of the dialysis center's water treatment and distribution system were measured. Case-patients were identified by reviewing medical records and nursing notes for all dialysis sessions carried out during the study period. Interviews with technicians, nursing and medical staff members were conducted. RESULTS: Reaction rate was significantly higher (p<0.028) during the outbreak period (September 25 to 27, 2000) than the pre-outbreak period (September 18 to 20, 2000). All patients with toxic symptoms had been under dialysis with water treated by reverse osmosis equipment and had used dialysers manually reprocessed. Chlorine and chloramine residuals concentrations found in the dialysis water as well as in the dialysers were at levels higher than regulations, </=0.5 mg/L for chlorine and </= 0.1 mg/L for chloramine. Individuals exposed to high chlorine and chloramine concentrations presented a relative risk of 2.58 (1.0-6.28) of having hemolytic reactions. CONCLUSION: There is a need to observe surveillance procedures to secure that the maximum allowable concentrations of regulated substances in the water used in the hemodialysis process are not exceeded.

Chloramines↗
PubMed1980

The effect of low-level ozone concentrations on the serum levels of immunoglobulins, alpha-1-antitrypsin and transferrin and on the activation of peripheral lymphocytes.

Long-term exposure (2--9 years) to ozone levels exceeding the Czechoslovak value of mean maximum allowable concentration (0.1 mg . m-3) turned out to induce changes in the exposed persons which can be characterized as initial immune disorders. Higher levels of IgG, IgA, IgM, alpha-1-antitrypsin and transferrin detected in comparison to the reference value in the group of ozone-exposed persons and significantly increased alpha-1-antitrypsin and transferrin levels in comparison to the control group of ore miners can be interpreted as a result of changed adaptation mechanisms in the organism. Analysis of the distribution pattern of the frequency of IgA and IgG changes exceeding the standard deviation shows that the group of ozone-exposed subjects exhibits a higher frequency of these changes than the control group of ore miners. However, the concurrently compared relative numbers of increases and decreases in both groups seem to indicate a considerable interindividual variability in the indicators studied.

Adult↗
PubMed1985

Cytogenetic analysis of peripheral blood lymphocytes in glass workers occupationally exposed to mineral oils.

Chromosome aberration tests were carried out in a group of 31 pressed glass makers operating an automatic line of press-and-blow machines known to release mineral oil mists containing relatively high concentrations of the mutagenic chemicals belonging to a class of polycyclic aromatic hydrocarbons (PAH). The workers were exposed to the mineral oil aerosol levels that did not exceed the Czechoslovak maximum allowable concentration limit of 5 mg . m-1 of air. The tests revealed that the frequency of aberrant cells (% AB.C.) and the value of breaks per cell (B/C) ratio found in mineral oil-exposed workers were increased significantly, accounting for 4.65 +/- 0.29% AB.C. (0.0532 B/C) vs. 1.13 +/- 0.19% AB.C. (0.0113 B/C) seen in matching controls. Also, a higher rate of dicentrics, reciprocal translocations and cells with pulverization was observed in this group of glass workers. These finding are considered as evidence suggesting that these workers might experience an increased risk of genetic injury due to exposure to mineral oil mists.

Adult↗
PubMed1997

Biological monitoring of experimental human exposure to trimethylbenzene.

Trimethylbenzene (TMB) is a component of numerous commercial preparations of organic solvents (Farbasol, Solvesso, Shellsol) used in the chemical, plastics, printing and other industries. TMB is a mixture of three isomers (pseudocumene-1,2,4-TMB; mesitylene-1,3,5-TMB; hemimellitene-1,2,3-TMB). The proportion of individual isomers in the mixture differs. The aim of this study was to obtain toxicokinetic data on the absorption and elimination of trimethylbenzene and its metabolites in biological fluids and to investigate the relationship between the biological indices of exposure and the absorbed dose. Eight-hour inhalation tests were performed in a toxicological chamber, The subjects were eight volunteers aged 20-39 with no history of exposure to TMB. They were exposed to pseudocumene, mesitylene or hemimellitene at concentrations ranging from 5 to 150 mg/m3 air. Exhaled air, capillary blood and urine samples were collected before, during and after the exposure. The determinations of TMB or its metabolites were performed using gas chromatography (HP 5890 II Plus, MSD, FID). Pulmonary ventilation in the volunteers ranged from 0.56 to 1.0 m3/h. The retention of 1,2,4-TMB; 1,3,5-TMB; 1,2,3-TMB in the lungs was 68%, 67% and 71%, respectively. The elimination of TMB from capillary blood occurred in accordance with the open three-compartment model. Urinary excretion of dimethylbenzoic acids (DMBA) proceeded according to the open two-compartment model. Based on the toxicokinetic data, a simulation model of accretion and excretion of DMBA in urine during a 14-day period was developed. The highest rates of metabolite excretion and the highest quantities of DMBA in urine during 24-h intervals were observed on day 5 of exposure. The relationship between the levels of TMB or DMBA in biological material and TMB air concentration or absorbed dose were determined. To select the urine fraction suitable for determining occupational TMB exposure, linear regression analysis was performed. The biological exposure limit (BEL) for TMB has been proposed, with the current maximum allowable concentration (MAC) value of 100 mg/m3 (Polish standard) baseline value.

Absorption↗
PubMed1997

Trace elements in drinking and groundwater samples in southern Nigeria.

The levels of Al, Sn, Cs, Rb, Sr, Br, Cr, Mo, Co, Ba, Cu, Zn, Cd, Pb, Mn, Se, As, V and Ni were determined in drinking water supplies (public taps, domestic taps and treated water from public water sources) and groundwater supplies (boreholes and shallow wells) in some parts of Southern Nigeria. The water samples were analysed using inductively coupled plasma mass-spectrometry (ICP-MS). The mean levels (microgram/l) of all the elements ranged between 0.35 microgram/l for Cs and 87.3 micrograms/l for Zn in the drinking waters and between 0.54 microgram/l for Co and 420.3 micrograms/l for Ba in the groundwaters. A comparison of the elemental concentrations with WHO guidelines showed that with the exception of violations of Cd, Cr and Se limits in some of the drinking water samples, the levels of all the other elements investigated were below the WHO maximum allowable concentrations.

Environmental Monitoring↗
PubMed1984

Effects of molybdenum on the organism (a review).

Molybdenum belongs to a group of essential microelements and occurs in all components of the environment. Major Mo sources for man are foods, especially vegetable, to a lesser extent drinking water. Its metabolism is primarily influenced by interaction with other metals, specifically copper and iron. In the organism it is primarily accumulated in the liver, kidneys, skin and hard tissues. In the blood it binds specifically with alpha-2-macroglobulin, in the erythrocytic membrane with spectrin; it enhances the osmotic resistance of red blood cells. From the organism it is eliminated in the urine, bile and feces. The biochemical importance of molybdenum lies in that it catalyzes the oxidation of xanthine and purine bases and the reduction of nitrates and molecular nitrogen; it is also present in the prosthetic group of flavoprotein enzymes. As shown in both epidemiological and animal studies, molybdenum ions may prevent dental caries. Long-term overexposure to Mo may produce molybdenosis (teart) in cattle. Increased exposures of humans may be primarily encountered in the foundry industry, but the toxic manifestations are invariably nonspecific, similarly as in the case of other heavy metals. Molybdenum-exposed workers may also show elevated uric acid concentrations in their blood, simultaneously with clinical symptoms resembling gout (gout-like syndrome). A similar finding may also occur among individuals living in areas characterized by elevated molybdenum and decreased copper contents in soil. The maximum allowable concentration limits established for soluble and insoluble molybdenum compounds in the workplace air have been accepted in many countries, but their values vary in a wide range. No specific exposure test for molybdenum has been developed as yet.

Adult↗
PubMed2005

Metal contamination of soils and crops affected by the Chenzhou lead/zinc mine spill (Hunan, China).

In 1985, the collapse of the tailing dam in Chenzhou lead/zinc mine (Hunan, southern China) led to the spread of mining waste spills on the farmland along the Dong River. After the accident, an urgent soil cleaning up was carried out in some places. Seventeen years later, cereal (rice, maize, and sorghum), pulses (soybean, Adzuki bean, mung bean and peanut), vegetables (ipomoea, capsicum, taro and string bean) and the rooted soils were sampled at four sites: (1) the mining area (SZY), (2) the area still covered with the mining tailing spills (GYB), (3) the cleaned area from mining tailing spills (JTC), and (4) a background site (REF). Metal concentrations in the crops and soils were analyzed to evaluate the long-term effects of the spilled waste on the soil and the potential human exposure through food chains. The results showed that the physical-chemical properties of the soils obviously changed due to the different farming styles used by each individual farmer. Leaching effects and plant extraction of metals from some soils were quite weak. Certain soils were still heavily polluted with As, Cd, Zn, Pb and Cu. The contamination levels were in the order of GYB>SZY>JTC showing that the clean-up treatment was effective. The maximum allowable concentration (MAC) levels for Chinese agricultural soils were still highly exceeded, particularly for As and Cd (followed by Zn, Pb and Cu), with mean concentrations of 709 and 7.6 mg kg(-1), respectively. These concentrations exceed the MAC levels by 24 times for As and 13 times for Cd at GYB. Generally, the edible leaves or stems of crops were more heavily contaminated than seeds or fruits. Ipomoea was the most severely contaminated crop. The concentrations of Cd and Pb were 3.30 and 76.9 mg kg(-1) in ipomoea leaves at GYB, which exceeded the maximum permit levels (0.5 mg kg(-1) for Cd and 9 mg kg(-1) for Pb) by 6.6 and 8.5 times, respectively. Taro (+skin) could accumulate high concentrations of Zn and Cd in the edible stem, and rice and capsicum had high Cd concentration in the edible parts. However, the toxic element concentrations in maize, sorghum, Adzuki bean, soybean and mung bean remained lower than the threshold levels. The bio-accumulation factors (BAFs) of crops were in the order: Cd>Zn>Cu>Pb>As. BAF was typically lower in the edible seeds or fruits than in stems and leaves. The accumulation effect strongly depends on the crop's physiological properties, the mobility, of the metals, and the availability of metals in soils but not entirely on the total element concentrations in the soils. Even so, the estimated daily intake amount of Cu, Zn, Cd, and Pb from the crops grown in the affected three sites and arsenic at SZY and GYB exceeded the RDA (Recommended dietary allowance) levels. Subsequently, the crops grown in Chenzhou Pb/Zn mine waste affected area might have a hazardous effect on the consumer's health. This area still needs effective measures to cure the As, Cd, Pb, Zn and Cu contamination.

Accidents, Occupational↗
PubMed1988

Toxicity and character of the effect of some zinc compounds.

Investigation of the parameters of toxicity of 8 zinc compounds revealed some differences in the degree of their risk for persons working with them. The following TSELs (tentative safe exposure levels of harmful substances) have been determined: 0.5 mg/m3 for zinc nitrate and hydrogen and dihydrogen zinc phosphates, 2 mg/m3 for zinc carbonate and zinc selenide, as well as MAC (maximum allowable concentration) for zinc sulphide equal to 5 mg/m3. No TSEL have been set for zinc caprylate and zinc stearate, but intratracheal administration of 50 mg caprylate caused 100%, of stearate 50% death of experimental animals due to pulmonary edema. Maximum tolerable doses were 10 and 1 mg, respectively. Zinc nitrate shows an expressed irritative effect on the skin and a highly expressed effect on the conjunctiva. Zinc phosphates, zinc caprylate and zinc stearate are resorbed by the skin. In all cases, working persons must be protected from the effect of the compounds under study because even though the toxicity of a compound may be rather low, highly noxious compounds may develop in the course of the technological process, e.g., in mechanical treatment of zinc selenide and zinc sulphide monocrystals, hydrogen selenide and hydrogen sulphide, respectively, can be isolated.

Administration, Cutaneous↗
PubMed2001

[Assessment of exposure to bioaerosols in workplace ambient air during municipal waste collection and disposal].

The assessment of the exposure to bioaerosols among workers engaged in the collection and disposal of municipal waste is presented. The workers were divided into the following groups, depending on the job performed: waste collectors (loaders, drivers), composting plant workers (heavy equipment operators, waste site workers), sorters (heavy equipment operators, waste sorters) and landfill site workers (heavy equipment operators, weighers). Air samples were also collected on the city streets and in flats. They were reference points to the results obtained. Air samples were collected at the breathing zone. The concentrations of dust, viable microorganisms (mesophilic and thermophilic bacteria, and fungi), endotoxins and the total number of microbiol cells were determined. The highest, individual exposure to dust was found in composting plant workers and waste collectors. The values exceeded considerably maximum allowable concentrations (by ten times at composting plant). The mean values for the above listed groups also exceeded the concentration of 4 mg/m3. Dust concentrations at other workposts were substantially lower. The concentrations in the city streets and in flats maintained at the level of 0.1 mg/m3. Endotoxin concentration at a protecting upper airway inflammation level (10 ng/m3) was exceeded in the majority (above 50%) of samples. That is why the average concentration in individual groups was also higher than 10 ng/m3. Street and flat samples included endotoxins at the level of 1 ng/m3. Taking as a criterion the obligatory total dust and endotoxin MAC value of 10 ng/m3 for assessing work hygiene conditions, it should be stated that waste collectors and composting plant workers were employed in conditions of poor hygiene.

Adult↗
PubMed2000

Smell impairment in workers occupationally exposed to cadmium.

ENT and olfactometric examinations were carried out on 73 workers at an electrochemical plant involved in the production of cadmium-nickel batteries, where cadmium fumes were emitted into the workplace. Exposure levels exceeded the maximum allowable concentrations by about 1-2 times. The controls included 43 non-exposed, age- and cigarette-smoking-matched people. The olfactometric tests were carried out by the blast injection method, using natural coffee, aniseed, lemon and mint oils; two threshold measurements were assessed: maximum perceptible odour (MPO) and minimum identifiable odour (MIO). In addition, blood chemistries and urinalysis were carried out. The study revealed the smell lesion in 45.2% of the exposed group vs 4.6% of the controls. A statistically significant correlation between olfactory dysfunction and cadmium concentrations in the blood and urine was found; however, no correlation with the duration of employment was observed. It seems most likely that cigarette smoking, which is a considerable source of cadmium, may intensify this dysfunction, hence heavy smokers should not work in conditions of cadmium exposure.

Adult↗
PubMed2002

Phthalates in underground waters of the Zagreb area.

AIM: To determine whether and in what concentrations the underground waters, stream waters, spring water, and tap water from the Zagreb area contain phthalates -- compounds used as plastic softeners, which have recently been ascribed carcinogenic, mutagenic, and teratogenic effects. METHOD: The presence of dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), benzylbutyl phthalate (BBP), diethylhexyl phthalate (DEHP), and dioctyl phthalate (DOP) was determined in a total of 96 samples of underground waters, stream waters, and tap water from the Zagreb area between February and June 1998. Identification and quantification of phthalates were performed by the method of gas chromatography (GC-ECD), with a detection limit of 0.005 microg/L. RESULTS: The presence of one or more phthalates was demonstrated in 93 out of 96 (97%) water samples. The measured values ranged from 0.005 to 18.157 microg/L. Phthalates were detected in 76 out of 77 (98%) underground water samples. The mean level of all phthalates present in the water samples was 4.879 microg/L. Median test yielded a significantly increased level of phthalates in the underground waters from Jakusevac (sampled in February 1998) and Trebe , which are Zagreb and Samobor city waste dumps, as compared with other sites in the study (overall median=3.785; chi-square=22.682; p<0.001). Phthalates were found at a mean concentration of 3.363 microg/L in all 10 water samples from the Sava river, the major source of the Zagreb alluvium underground waters. In case of drinking water, phthalates were detected in 7 out of 9 (78%) samples, at a mean concentration of 0.887 microg/L. As expected, DEHP was the most commonly detected phthalate, found in 78 (81%) water samples. CONCLUSION: The highest phthalate concentrations were recorded in underground waters directly related to the proximity of a waste dump. The levels of phthalates recorded in this study were lower than those reported from other countries and did not present a threat to human health. Environmental phthalate monitoring should be continued and their maximum allowed concentrations should be prescribed by regulations.

Chromatography, Gas↗
PubMed1991

Dose-response relationship between urinary cadmium and metallothionein in a Japanese population environmentally exposed to cadmium.

The dose-response relationship between cadmium (Cd) exposure and renal dysfunction, as measured by urinary Cd and metallothoinein (MT), was evaluated in a population living in the Kakehashi River basin, a Cd-polluted area in Japan. Morning urine specimens were collected from 1397 men and 1713 women who were 50 years or older. In addition, urine specimens were collected from a control population consisting of 110 men and 130 women. The 97.5% upper limits for MT in the control population were used to determine the prevalence rates for MT-uria at various urinary Cd concentrations. Probit linear regression analysis showed significant dose-response relationships between MT and Cd. In the control population, prevalence rates of MT-uria for men and women were 1.8 and 3.1%, respectively. Based on the prevalence rates of MT-uria in the control population, the upper limits for the urinary Cd concentrations were calculated from the slopes of the regression lines to be 4.2 and 4.8 micrograms/g creatinine for men and women, respectively. These values, which are similar to those reported previously using urinary beta 2-microglobulin as the indicator, may be of use in establishing the biological threshold, i.e. maximum allowable concentration, for urinary Cd in the environmentally exposed Japanese population.

Age Factors↗
PubMed1998

Olfactory disorders induced by cadmium exposure: a clinical study.

The evaluation of olfaction is not only widely applied and undeniably valuable in clinical diagnostics but it is also of interest to industrial medicine. It should be borne in mind that in certain workplaces, particularly in the chemical industry, the olfactory receptor has to act as an organ which warns the worker against threatening intoxication, and this is possible only when it functions properly. Cadmium, as a highly toxic metal, found widely in industry and in the environment, is frequently included in the list of chemicals known to cause olfactory impairment. The purpose of this study was to evaluate olfaction in workers occupationally exposed to cadmium. The correlation between olfaction and concentrations of cadmium in urine, blood and in the workplace air as well as employment duration was examined in workers of the "CENTRA" S.A., an electrochemical plant in Poznań. In this plant cadmium-nickel batteries are produced, and there is chronic occupational exposure to cadmium in quantities exceeding maximum allowable concentration (MAC). A group of 73 workers aged 20 to 60 years (42.0 +/- 18.0), employed from 4 to 24 years (12.5 +/- 8.5) were examined. Of the 73 workers who completed the evaluation, 53 people (72.7%) were smokers (10-40 cigarettes per day). In addition to medical history, medical and ENT examinations, blood and urine tests were taken and olfactometry performed. Olfactometry was performed according to Elsberg and Levy's method, modified by Pruszewicz, in which natural coffee as well as aniseed, lemon and mint oils were used. The quantitative and qualitative olfactory disorders were evaluated on the basis of the established odor detection threshold (ODT) and odor identification threshold (OIT). The examinations revealed numerous cases of hyposmia (26.0%) and parosmia (17.8%) and one case of anosmia (1.4%). In the majority of people with olfactory disorders, hypertrophic changes in the nasal mucosa, dependent on the duration of employment, were identified. Statistically significant relationship between olfactory impairment and cadmium concentration in blood, urine and the workplace air was observed. However, such a relationship was not found in regard to the duration of employment. The study indicated the need to carry out routine olfactometries. The results of these examinations could be the ground to perform certain preventive and therapeutic procedures.

Adult↗
PubMed1997

Dynamic compartmentation of vacuolar amino acids in Penicillium cyclopium. Cytosolic adenylates act as a control signal for efflux into the cytosol.

The regulation of amino acid transport from the vacuolar reservoir into the cytoplasm has been studied in hyphal cells of Penicillium cyclopium. To avoid artifacts caused by the isolation of vacuoles, efflux was examined "in situ," i.e. in cells whose plasma membranes were permeabilized for micromolecules by a treatment with nystatin. The ATP-dependent proton gradient and amino acid transport activities at the vacuolar membrane remained intact under these conditions. Accumulation of amino acids in the vacuole proved to be the result of a dynamic equilibrium of active, ATP-dependent uptake and energy-independent efflux. The latter was strongly accelerated after the vacuolar amino acid content had surpassed a threshold level. Efflux of vacuolar amino acids was specifically controlled by extravacuolar adenylates: ATP, 5'-adenylyl imidodiphosphate (an ATPase-resistant ATP-analogue), ADP, or AMP caused a strong inhibition in the concentration range around 200 micromol/liter, whereas both lower and higher concentrations allowed significant efflux rates. Estimates of the cytosolic adenylates (which consisted mainly of ATP) were close to 2 mmol/liter in glucose-metabolizing cells, which concentration allowed maximum rates of both vacuolar uptake and efflux. During 24 h of carbon and nitrogen starvation, the adenylate level decreased toward the efflux-inhibiting region around 200 micromol/liter, whereas 3-4 d of carbon and nitrogen starvation caused a further decline of the adenylate content, leading again to efflux-permitting concentrations. Thus, the cytosolic adenylate pool appears to effectively control the availability of vacuolar amino acids for the cellular metabolism.

Adenine Nucleotides↗
PubMed2001

A new flux-orientated concept to derive critical levels for ozone to protect vegetation.

The current European critical levels for ozone (O3) to protect crops, natural and semi-natural vegetation and forest trees are based on a relative small number of open-top chamber experiments with a very limited number of plant species. Therefore, the working group "Effects of Ozone on Plants" of the Commission on Air Pollution Prevention of the Association of German Engineers and the German Institute of Standardization reanalysed the literature on O3 effects on European plant species published between 1989 and 1999. An exposure-response relationship for wild plant species and agricultural crops could be derived from 30 experiments with more than 30 species and 90 data points; the relationship for conifer and deciduous trees is based on 20 experiments with nine species and 50 data points. From these relationships maximum O3 concentrations for different risk stages are deduced, below which the vegetation type is protected on the basis of the respective criteria. Because it is assumed that the fumigation concentrations reflect the O3 concentrations at the top of the canopy, i.e. the upper surface boundary of the quasi-laminar layer if the micrometeorological big-leaf approach is applied, the application of these maximum O3 concentrations requires the transformation of O3 concentrations measured at a reference height above the canopy to the effective phytotoxic concentrations at the top of the canopy. Thus, the approach described in this paper is a synthesis of the classical concept of toxicology of air pollutants (critical concentrations) and the more toxicological relevant dose concept.

Crops, Agricultural↗
PubMedDate not supplied

[Sanitary-toxicological assessment of petroleum slimers undergone biological purification].

Pilot production and production studies using a biological method for treating and neutralizing toxic waste polluted with petroleum products at high concentrations (up to 30%) were conducted. The results have indicated that the use of oil degrading microorganisms is highly promising. Within the first vegetative period as high as 80% of petroleum products withdrew from waste and over 95% of those migrated into the aqueous medium. Purification decreased the content of mobile phases of metals to the values below the maximum allowable concentrations. The waste that is highly toxic for protozoa and the test crop wheat shall be considered to be nontoxic.

Hazardous Substances↗
PubMed1983

[Respiratory pathology of isocyanates].

Isocyanates are chemical compounds used in making polyurethane (for flexible or rigid foam, paint, varnish, glue and textiles). In strong concentrations isocyanates are powerful irritants producing chemical bronchopulmonary lesions. In weak doses they are responsible for occupational asthma and more rarely allergic alveolitis. Long term exposure to isocyanates may produce a deterioration in pulmonary function in asymptomatic patients. The pathophysiology of isocyanate asthma remains uncertain: immunological data remains contradictory while isocyanates have been shown to have a Betablocking effect. The maximum allowable concentration in the working environment, at present proposed in the U.S.A. is 0.005 ppm.

Alveolitis, Extrinsic Allergic↗