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PubMed1980

[Evaluation of the MPEL for SO2 and NO2 and the development of new MPELs for atmospheric pollutants based on modern epidemiological, ecological and toxicological studies].

Proceeding from modern experimental and natural observations on the effect of sulphur dioxide and nitrogen dioxide on live organism and environment, the now, operative in Bulgaria maximum allowable concentrations of these contaminants are reassessed. The maximal single and mean diurnal SO2 MAC are proposed to be reduced to 0.15 mg/m3 and 0.03 mg/m3, while those of NO2 remain the same. Based on data available in modern literature and equations proposed by the authors for express determination of MAC for some atmosphere contaminants, MAC for some nonstandardized contaminants in Bulgaria are suggested: ozone (maximal single - 0.06 mg/m3 and mean diurnal - 0.03 mg/m3 asbestos (mean dirnal - 0.25 fibers/cm3), zinc (mean diurnal - 0.05 mg/m3, copper (mean diurnal - 0.01 mg/m3. The use of mathematical equations for determination of MAC of differrent hydrocarbons is suggested.

Air Pollutants↗
PubMed2000

Biological monitoring of standardized exposure to ethylbenzene: evaluation of a biological tolerance (BAT) value.

The results of standardized 8 h lasting exposures of n = 18 volunteers to ethylbenzene (EthBz) at levels of 25 and 100% of the maximum allowable concentrations at the workplace (MAK) value of 100 ppm as well as the results of field studies are considered to evaluate a biological tolerance (BAT) value for EthBz. On the basis of the relationship between the external and internal exposure a BAT value of 1.5 mg/l has been set for the EthBz concentration in blood as the most sensitive and specific parameter of exposure to this aromatic hydrocarbon. The interpretation of EthBz blood values has to take into account the short half-life of t1/2 = 0.5 +/- 0.08 h in the first hour after the end of exposure in which this aromatic hydrocarbon is eliminated from the blood. The additional determination of the EthBz metabolites mandelic acid (MA) and phenylglyoxylic acid (PGA), respectively, excreted in post shift urine as well as in urine samples at the beginning of the next shift shows good correlations with the external exposure. The biological half-life of MA was calculated to t1/2 = 5.3 +/- 1.1 h. Because the time of sampling can vary the relationship between the levels of MA to PGA the total concentration of the excreted metabolites depends less on this influence and is therefore better suited for monitoring exposed persons. On the basis of the standardized experiments a BAT value has been proposed of 2 g MA plus PGA corrected per gram creatinine. Both BAT values are adjusted to data which result from earlier standardized exposures during 30 min to EthBz under physical activity of 50 watt on a bicycle ergometer.

Aged↗
PubMed2000

Human toxicokinetics of inhaled monochlorobenzene: latest experimental findings regarding re-evaluation of the biological tolerance value.

OBJECTIVE: The aim of this study was to obtain toxicokinetic data on the absorption and elimination of monochlorobenzene (MCB) in blood and its main metabolite 4-chlorocatechol (4-ClCat) as well as on the isomeric chlorophenols (o-ClPh, m-ClPh, and especially p-CIPh as the main ClPh metabolite) in urine for reevaluation of the biological tolerance (BAT) value of MCB. METHODS: Eight subjects performed 8-h inhalation tests daily over five successive days in an exposure chamber, at a maximum allowable concentration at the workplace (MAK) value of 10 ppm MCB. Five and two probands carried out the test series during physical activity levels of 75 and 50 W, respectively, for 10 min/h on a bicycle ergometer, and one subject was exposed continuously while at rest. MCB and its metabolites were analyzed by gas chromatography in combination with mass spectrometry. RESULTS: The mean MCB blood concentration of the five subjects exposed during physical activity of 75 W was 217 +/- 42 microg/l. The relationship of the mean blood concentration measured under the conditions of rest or 50 and 75 W activity levels was in a ratio of about 1:1.7:2.8. The half-life values in the first hour after ending the exposures were 53 min and 150 min for the ensuing period, with steady-state being reached after 45 min. The mean 4-ClCat concentration in urine at the end of the five days was 150 +/- 13 mg/g creatinine in the case of the subjects exposed at 75 W, which decreased to 25 mg/g creatinine at the beginning of the next exposure. The analogous p-ClPh concentrations were 25 +/- 2 and 9 +/- 2 mg/g creatinine. The elimination half-life values of the ClPh isomers ranged from 12.4 to 16.5 h, and the half-life of 4-ClCat was 6.4 h. There was no apparent tendency for MCB and its metabolites to accumulate in blood or urine. CONCLUSIONS: The results are in accordance with relevant field and laboratory studies. Taken into consideration with the 95th percentile, the evaluated BAT values should be set at levels of 300 microg MCB/l blood, 175 mg 4-ClCat/g creatinine or alternatively at 30 mg p-ClPh/g creatinine in urine after the end of a shift. At the beginning of the next shift, the BAT values of the metabolites should be 35 and 15 mg/g creatinine, respectively.

Adult↗
PubMed2006

Chromosomal aberration frequencies determined by conventional methods: Parallel increases over time in the region of a petrochemical industry and throughout the Czech Republic.

The rationale for cytogenetic monitoring to determine if safe maximum allowable concentrations (MAC) of genotoxic chemicals are being maintained in a workplace is that exposure levels that do not increase chromosomal aberration frequencies are without harmful effects. Such monitoring, widely used in occupational health programs in the Czech Republic (CR), includes workers exposed to 1,3-butadiene (BD) or other chemicals. Studies of BD exposed workers in the years 1992, 1993, 1994, 1998, and 2004 compared mean frequencies of cells carrying chromosomal aberrations (frequency of aberrant cells=%AB.C.) in exposed workers with those in non-exposed matched controls in the same plant or in other individuals living in the region of the same petrochemical industry. Workers potentially exposed to acrylonitrile at this site were also evaluated in 2000, along with another unexposed matched control group. The %AB.C. values of exposed workers and their controls were also compared with reference values determined for normal individuals (ages 20-59 years) throughout the CR. Substantial discrepancies were noted between subjects in the region of the petrochemical industry (exposed workers and controls) for the years 2000 and 2004 and the reference CR-wide normal values that had been determined during an earlier time period. The matched non-exposed controls at the petrochemical industry site showed a mean %AB.C. value of 1.56+/-1.23% (N=25) in 1998; this rose to a mean of 2.65+/-2.29% (N=33) in 2000. In 2004, values for non-exposed matched controls at the industry site were 2.64+/-1.75% for males (N=25) and 2.38+/-1.74% (N=26) for females. However, the earlier determined CR-wide %AB.C. mean reference values for normal individuals were 1.77+/-1.16% (N=1305) for the interval 1977-1988 and 1.45+/-1.17% (N=2140) for the interval 1991-1999. As both reference values are substantially lower than those determined in 2000 and 2004 for the non-exposed matched controls at the petrochemical industry site, an analysis of the CR-wide mean normal individual reference values for this same 2000-2004 period was conducted. Unexpectedly, it was found that this reference value too had risen to 1.95+/-1.36% (N=1045) and was comparable to the concurrent matched control values at the petrochemical industry site where the monitoring studies were conducted. This substantial increase in %AB.C. values in 2000 and 2004, therefore, has occurred throughout the CR and is probably unrelated to chemicals uniquely present at the petrochemical industry site.

Acrylonitrile↗
PubMed2002

Leachability of elements from sub-bituminous coal fly ash from India.

Environmental concerns regarding the potential contamination of soil, surface and ground water due to the presence of soluble metal species in the ash pond leachate is of great importance. Serial batch leaching was carried out simulating the rainwater condition of the study area to understand the behaviour of elements during leaching. The leachates were analysed for the elements Al, Ca, K, Mg, Na, P, S, Si, As, Ba, Fe, Mn, Mo, Ti, V, Pb, Zn, Co, Cr, Cu, Ni and Cd by inductively coupled plasma optical emission spectrometer (ICP-OES). It was found that Cd, Co, Cr and Ni did not leach from the ash while Cu and Pb concentrations were insignificant in the leachate regardless of liquid to solid (L/S) ratio. Most of the elements showed maximum concentrations at lower L/S ratio and then decreased with increasing L/S. The total cumulative concentrations of As, Mn and Mo were found to be higher than the World Health Organization (WHO) recommended values for drinking water while the concentrations of Fe, Mn and As exceeded the maximum allowable concentrations prescribed by the United States Environmental Protection Agency (USEPA). The pre and the post leached ash samples were analysed for morphology, specific surface area and mineralogical changes. Analysis of post-leached fly ash indicated changes in the specific surface area and morphology but no change in mineralogy.

Coal↗
PubMedDate not supplied

Chromosome aberrations induced by occupational exposure to mercury.

The incidence of chromosome aberrations was studied by peripheral blood incubation (52 hr, the last 4 hr in the presence of Colcemid) using a modification of the Evans' technique in twenty-two men exposed to either vapors of metallic mercury (Group I) or organic mercury (Group II). Mercury concentrations of the work areas frequently exceeded the Maximum Allowable Concentrations in the past. During the year proceding the investigation, mercury values ranged between 0.15 and 0.44 mg/m3. None of the investigated men were poisoned, but all had had repeated increased mercury absorption with urinary eliminations reaching 890 microgram/l and 896 microgram/l for subjects in Groups I and II, respectively. The incidence of chromosome aberrations was significantly higher (P less than .001) in subjects exposed to mercury as compared with a control group (ten subjects) of a similar mean age. There was no statistical difference in the incidence of chromosome aberrations between men belonging to Groups I and II. Although an increase of both chromatid gaps and breaks was noticed in exposed men, the incidence did not significantly differ from controls. No chromatid interchanges were recorded and no difference between exposed and control subjects was noticed concerning the frequency of aneuploid or polyploid cells.

Adult↗
PubMed2002

[Exposure to selected aldehydes among municipal transport bus drivers].

The objective of the study was to determine occupational exposure of municipal transport bus drovers to selected aldehydes: formaldehyde, acetaldehyde and acrolein. Ten drivers serving 5 bus lines were selected for the study. Air samples were collected in the driver's breathing zone and in bus cabins. The test air (about 10 l) was drawn through columns filled with silicagel coated by dinitrophenylhydrazine (DNPH). The products of DNPH reaction with aldehydes were extracted with acetonitrile and analyzed by HPLC with a spectrophotometric detector (lambda = 360 nm). The analytical procedure enabled to determine the selected aldehydes in the concentration range equivalent to 0.1-2.0 of the Polish maximum allowable concentrations (MAC). In the quantitative analysis, the concentrations of selected aldehydes were found to be much lower than MAC values, regardless of the bus type. The concentrations of formaldehyde and acrolein ranged from 0.025 to 0.090 mg/m3 and from 0.010 to 0.035 mg/m3, respectively. In all samples, acetaldehyde concentrations were well below the limit of detection of the analytical method. The combined exposure to aldehydes was also below the limit value for mixtures.

Aldehydes↗
PubMed2002

Effect of acrylate chemistry on human health.

OBJECTIVES: The prospective cohort study of 1992-1999 describes the effect of occupational exposure to chemical substances in the production of acrylic acid, acrylic acid esters and acrylate dispersions at the various workplaces of one chemical plant. METHODS: Exposure to selected chemicals (acrylonitrile, n-butanol, butyl acrylate, ethyl acrylate, methyl acrylate, methyl methacrylate, toluene, and styrene) was determined by personal passive dosimetry (GC/MS method). The annual examinations included general health, by guided interview, a general medical examination, hematological and biochemical examinations, examination of the parameters of serum immunity and selected tumor markers, and spirometry. The authors also repeatedly performed cytogenetic analysis of human peripheral lymphocytes. RESULTS: The authors followed a group of 120 employees (60 exposed, 60 controls), mean age 40+/-8 years in both groups, with average period of exposure to chemicals (exposed group) 13+/-5 years. The measured concentrations of chemicals in the working atmosphere were generally low; maximum allowable concentrations (MAC) values or suggested limits of certain chemicals were occasionally exceeded (most frequently for butyl acrylate). The results of the examination of the workers over the 8 years have not revealed any marked differences between the exposed and control groups that could be attributable solely to the acrylate exposure. CONCLUSIONS: Exposure to chemical substances at the workplace was relatively low, the limits being exceeded only sporadically (each such case was investigated at the workplace), and the level of exposure continues to decrease gradually over the years. Considering the fact that the exposed individuals are expected to work for 23 additional years on average, we feel that long-term monitoring of selected health-related parameters, not including tumor markers, appears desirable. The examination of tumor markers has not contributed to the problem evaluation for a number of false-positive results.

Acrylates↗
PubMed1987

Blood lead and carboxyhemoglobin levels in chainsaw operators.

Fallers in the British Columbia west coast lumber industry often work in climatic and local conditions where little ventilation in their immediate environment is possible. Under these conditions carbon monoxide (CO) and lead fumes from exhaust gases could build up and become a serious occupational hazard. This study monitored the environmental exposure of six fallers to carbon monoxide, nitrogen oxides, and lead under conditions where buildup of these agents would be expected. At the same time blood samples were taken to correlate these environmental concentrations to carboxyhemoglobin (COHb) and blood lead levels. Although there was a highly significant difference between the fallers and the controls regarding the exposure to CO and lead as well as their corresponding COHb and blood lead levels, the environmental and blood concentration of the agents in question did not exceed the maximum allowable concentrations. Temporary short fluctuations in carboxyhemoglobin levels were not monitored in this study and cannot be ruled out as a potential occupational hazard.

Adult↗
PubMed1993

Relation between various chromium compounds and some other elements in fumes from manual metal arc stainless steel welding.

For the years 1987-1990 160 individual samples of manual metal arc stainless steel (MMA/SS) welding fumes from the breathing zone of welders in four industrial plants were collected. Concentrations of soluble and insoluble chromium (Cr) III and Cr VI compounds as well as of some other welding fume elements (Fe, Mn, Ni, F) were determined. Concentration of welding fumes in the breathing zone ranged from 0.2 to 23.4 mg/m3. Total Cr amounted to 0.005-0.991 mg/m3 (including 0.005-0.842 mg/m3 Cr VI). Total Cr content of fumes varied from 0.1 to 7.4%. The distribution of particular Cr compounds was: 52.6% soluble Cr (including 50.7% Cr VI), 65.5% total Cr VI, and 11.4% insoluble Cr VI. The results obtained indicate that MMA/SS welding is a process that could be highly hazardous to human health. Evaluation of occupational exposure has shown that MMA/SS welders may exceed the admissible concentrations of soluble and insoluble Cr VI forms as well as of Mn and Ni. In the plants investigated the sum of the ratios of concentrations of particular welding fumes in the breathing zone of welders exceeded corresponding maximum allowable concentration values by 24 times (including 17 times for total Cr VI). Due to the variety and changeability of particular parameters occurring in the working environment, the composition of MMA/SS welding fumes (in the welder's breathing zone) is so variable that it is not possible to assess the exposure by means of one universal exposure indicator (maximum additive hygienic limit value). The evaluation should be based on the results of measurements of concentrations of particular elements in welding fumes.

Air↗
PubMed1995

Long-term effects of metals in sewage sludge on soils, microorganisms and plants.

This paper reviews the evidence for impacts of metals on the growth of selected plants and on the effects of metals on soil microbial activity and soil fertility in the long-term. Less is known about adverse long-term effects of metals on soil microorganisms than on crop yields and metal uptake. This is not surprising, since the effects of metals added to soils in sewage sludge are difficult to assess, and few long-term experiments exist. Controlled field experiments with sewage sludges exist in the UK, Sweden, Germany and the USA and the data presented here are from these long-term field experiments only. Microbial activity and populations of cyanobacteria, Rhizobium leguminosarum bv. trifolii, mycorrhizae and the total microbial biomass have been adversely affected by metal concentrations which, in some cases, are below the European Community's maximum allowable concentration limits for metals in sludge-treated soils. For example, N2-fixation by free living heterotrophic bacteria was found to be inhibited at soil metal concentrations of (mg kg-1): 127 Zn, 37 Cu, 21 Ni, 3.4 Cd, 52 Cr and 71 Pb. N2-fixation by free-living cyanobacteria was reduced by 50% at metal concentrations of (mg kg-1): 114 Zn, 33 Cu, 17 Ni, 2.9 Cd, 80 Cr and 40 Pb. Rhizobium leguminosarum bv. trifolii numbers decreased by several orders of magnitude at soil metal concentrations of (mg kg-1): 130-200 Zn, 27-48 Cu, 11-15 Ni, and 0.8-1.0 Cd. Soil texture and pH were found to influence the concentrations at which toxicity occurred to both microorganisms and plants. Higher pH, and increased contents of clay and organic carbon reduced metal toxicity considerably. The evidence suggests that adverse effects on soil microbial parameters were generally found at surprizingly modest concentrations of metals in soils. It is concluded that prevention of adverse effects on soil microbial processes and ultimately soil fertility, should be a factor which influences soil protection legislation.

Bacteria↗
PubMedDate not supplied

[Use of complex indices of environmental air pollution for sanitary ranging of the territory of the South Administrative District of Moscow].

Whether complex indices of ambient air pollution can be used for sanitary ranging of primary facilities of the district was studied. The indices were calculated by using single air samples. The impact of "zero samples" on the results of calculation of the significance of differences in the single concentrations of individual chemical air pollutants was examined. The average annual concentrations of pollutants were calculated on the basis of average daily maximum allowable concentrations and the a-coefficient recommended by M. A. Pinigin. The database contains 20,000 definitions of the most hazardous chemical pollutants in the ambient air. Significant and insignificant values of chemical pollutants in single ambient air samples may be used in calculating complex indices as the rate of result coincidence was 80%, the suitability of insignificant values for ranging was confirmed in 81.25% of cases.

Air Pollution↗
PubMed1993

Air pollution in a city street. 1965.

Measurements of the concentrations of smoke, lead, and five polycyclic hydrocarbons in the air have been made in the City of London in the middle of a busy street and at two control sites. Samples were taken only throughout the daytime hours on weekdays to enable us to assess the maximum contribution made by traffic to the pollution in the street. The results showed that during these periods the air in the middle of the street contained three times as much smoke, four times as much lead, and 1.7 times as much 3:4-benzpyrene as were present in the general atmosphere as the City of London as estimated from samples taken at the control sites. One of these sites was chosen because it was only 150 feet away from the street; analyses yielded no evidence that the traffic contributed to the pollution sampled there. Sulphur dioxide concentrations were determined in the early part of the study and the results showed that traffic appeared to add little to the background level. The concentrations of lead found were below those held to be safe by many authorities. Carbon monoxide concentrations, reported in greater detail elsewhere, sometimes reached the accepted industrial maximum allowable concentration of 100 p.p.m.

Air Pollutants↗
PubMed2000

Metal Contamination in the Republic of Armenia.

/ Air, soil, and water samples were collected throughout the Republic of Armenia both before and after its independence from the Soviet Union in 1991. Reported analyses of those samples indicated that levels of several trace metal concentrations (Ag, Cd, Cr, Cu, Mo, Ni, Pb, Ti, and Zn) exceeded the maximum allowable concentrations established by the former Soviet Union (FSU) and subsequently adopted by Armenia. Although industrial production has declined by more than 80% since the 1980s, the economy is improving and there is potential for a significant increase in the generation of industrial metal emissions. These include automobile emissions, which are now considered to be the primary source of atmospheric lead. Historically, the Soviet Union did not strictly enforce environmental standards, and Armenia is now faced with the resulting environmental problems and the associated risks to public health. Since some trace metal concentrations may be at or near potentially toxic levels, there is a need to accurately assess the extent of metal contamination in order to devise cleanup plans and develop long-term environmental protection and public health strategies in Armenia.

Journal Article↗
PubMed2006

Determination of Pb(II), Cu(II) and Fe(III) with capillary electrophoresis using ethylenediaminetetraacetic acid as a complexing agent and vancomycin as a complex selector.

The simultaneous determination of metal ions using ethylenediaminetetraacetic acid (EDTA) as a complexing agent and vancomycin as a complex selector was successfully studied by capillary electrophoresis with the U-shaped cell. The partial filling method (counter current mode) was used in order to gain selectivity of the separation, and also to increase the detection sensitivity. The effect of the vancomycin concentration on the separation behavior of free EDTA and metal products, and the effect of the EDTA concentration on the stability of metal-EDTA products were considered. Under the optimal condition, the reproducibilities (RSD) of the migration time and the peak area were less than 3.39% and 9.61%, respectively. With the high sensitivity of the method, Pb(II), Cu(II) and Fe(III) in tap water were successfully determined, and the recoveries were 99 - 105%. The concentrations of these metal ions found in tap water did not exceed the maximum allowed concentrations regulated by the U.S. Environmental Protection Agency.

Anti-Bacterial Agents↗
PubMed1992

Environmental hazard evaluation of amalgam scrap.

Amalgam scrap was subjected to two different Environmental Protection Agency (EPA) extraction procedures to determine if it presents an environmental hazard. The results indicate that concentrations of mercury and silver in the extracts do not exceed the EPA's maximum allowable concentrations. It was concluded that amalgam scrap is not a hazardous solid waste. Proper handling of amalgam scrap disposal by recycling is, however, highly recommended.

Copper↗
PubMed2026

A quantitative microbial risk assessment of activated carbon point-of-use filters and the risk of Legionella pneumophila.

Activated carbon point-of-use (POU) filters have become increasingly popular. Often certified to remove lead and improve water taste, these filters are not certified to remove bacteria. In this study, we examined the effects of using POU filters on the risk posed by Legionella pneumophila (L. pneumophila) in a quantitative microbial risk assessment model. Release rates of L. pneumophila were measured for new and artificially aged (ripened) POU filters. Additionally, we measured aerosol concentrations produced by water fixtures that might have a POU filter (e.g., drinking fountain bubbler, faucet). We modeled scenarios without filters (with and without residual chlorine) and with filters (new and ripe filters), four water usage activities (drinking from a drinking fountain, handwashing, dishwashing, and showering), and three age groups (children, adults, and elderly). Systems with the highest to lowest risk were those without filters and without chlorine, those with ripe filters, those without filters and with chlorine, and finally, those with new filters. The risk of illness decreased for activities with shorter exposure times, such as drinking and handwashing. The L. pneumophila concentrations, aerosol concentrations, and exposure time had the largest impacts on the risk of illness. The maximum allowable concentration of L. pneumophila needed to achieve a 10-4 target annual risk of illness was 0.02 copies/mL. This study showed that POU filters may reduce L. pneumophila risk but only if the filter is new (≤ 1 week old before the filter ripens significantly), and other strategies for reducing L. pneumophila concentrations or decreasing exposure time may be needed to further decrease the risk of illness.

Legionella pneumophila↗
PubMed2006

Accumulation of some metals in muscles of five fish species from lower Nitra river.

This paper reports the results of accumulated selected metals concentrations (Fe, Mn, Zn, Cu, Ni, Co, Cr, Pb, Cd, Hg and meHg) in the muscle of five common Slovak fish species (Chub-Leuciscus cephalus, Common carp-Cyprinus carpio, Prussian carp-Carassius gibelio, Roach-Rutilus rutilus, and Wels catfish-Silurus glanis). Furthermore, correlations among the selected metals and order of metal accumulation in the fish muscle were determined. The concentrations of metals (mg/kg wet weight basis) ranged as follows: Fe 3.70-21.10; Mn 0.27-1.50; Zn 3.72-42.82; Cu 0.26-1.82; Ni 0.02-0.29; Co 0.06-0.28; Cr 0.09-0.28; Pb 0.08-34.59; Cd 0.06-2.76, Hg 0.34-3.64 and meHg 0.08-1.20. The level of lead and mercury exceeded the maximum allowed concentration in Slovakia by the Codex Alimentarius for safe human consumption (0.2 and 0.5 mg/kg, respectively) in the majority of samples (94.6 and 82.1%, respectively). Content of Cd (0.88 +/- 0.76 mg/kg wet weight) in the fish muscle exceeded maximum allowed levels (0.05 mg/kg) in all samples. An average, the order of metal concentrations in the fish muscle was: Fe > Zn > Pb > Cd > Hg > Cu > Mn > meHg > Ni > Cr > Co.

Animals↗