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PubMed2000

Experimental exposure to methylformate and its neurobehavioral effects.

OBJECTIVES: The aim of the study was to investigate the acute effects of experimental methylformate exposure on the nervous system. METHODS: In an exposure chamber, 20 subjects were exposed to methylformate at 100 ppm [Swiss maximum allowable concentration (MAC)] for 8 h. The same number of subjects with the same ages (between 20 and 30 years), gender and education level (university) were examined by the same procedure as a control group. The subjects did not know if they were exposed or not. Three times (morning, noon, evening) during these 8 h, mood [Profile of Mood States (POMS)], neurobehavioral performance (reaction, Stroop, nonverbal learning, determination, tracking; Wiener Test System), vision (visual acuity, contrast sensitivity, color sensitivity) and postural sway were tested. During an undemanding test (POMS) and a demanding performance task (determination test), pulse, electromyography (EMG) of the forehead and of the neck were recorded. In the morning and evening spirometry [forced vital capacity (FVC), forced one-second expiration volume (FEV), medium expiration flow (MEF) and peak expiration flow (PEF)] and the odor perception threshold were measured. RESULTS: In the evening, in the exposed group, fatigue was significantly increased and the EMG of the forehead during a demanding task showed a different development during exposure. The other tests showed no significant solvent effect, but 16 of 43 test parameters showed a significant effect of time. CONCLUSIONS: The results of this study indicate a possible effect of methylformate exposure on the subjective feeling of fatigue after 8 h exposure at 100 ppm in young and healthy subjects, without measurable impairment of neurobehavioral performance. We assume that a similar effect in normal work, combined with a heavy workload and shift work, can lead to an impairment of productivity, and increase the risk of accidents.

Adult↗
PubMed2000

Neurobehavioural effects of experimental isopropanol exposure.

OBJECTIVES: The study investigated the acute effects of isopropanol exposure at the maximum allowable concentration (MAC) level on the performance of neurobehavioural functions. METHODS: In an exposure chamber 20 healthy subjects aged between 21 and 30 years were exposed to isopropanol at a concentration of 400 ppm (Swiss MAC value) for 8 h. A control group of another 20 subjects of the same age range, gender and education as used in a previous study with methylformate were subjected to the same test procedures without exposure. Mood was measured with the profile of mood states (POMS) in the morning, at noon and in the evening. Neurobehavioural performance tests were administered using the Wiener Test System (Wiener reaction test, Stroop, nonverbal learning, Wiener determination test, "Konturtracking" test), and the digit span test of the Neurobehavioural evaluation system (NES2). A test for postural sway was also conducted. During the POMS and the Wiener determination test the electromyography of the forehead and the left neck muscle as well as the pulse were registered. In the morning and evening spirometry (FVC, FEV, MEF and PEF) and odour threshold were measured. RESULTS: Only postural sway in bipedal standing at noon showed stronger deterioration in the exposed than in the control group when compared with the morning values. The evening values of monopedal standing were also more impaired in the exposed than the control group. In the other tests, no solvent effect could be established. CONCLUSIONS: It can be assumed, that, similar to other alcohols, isopropanol affects postural balance. Our results point to such a disturbance, but because it is the only study so far using the MAC value, any conclusions about safety risks would be premature.

2-Propanol↗
PubMed2006

The pollution load by nitrogen and phosphorus in the Jadro River.

The objective of the investigations of the Jadro River, located in Croatia, was to estimate the nitrogen and phosphorus loads in the Jadro River spring and its streamflow by calculating the load in kg/day or tons/year and to compare this with the load for the maximum allowed concentrations (MAC) for drinking water (Official Bulletin, No 46/94) expressed in kg/day or tons/year. Daily pollution loads at the Jadro River spring for total N ranged from 0 to 304 kg, for NH3-N from 0 to 38 kg, for NO3-N from 0-1321 kg and for PO4-P from 0-92 kg in the period from September 1993 to September 2003. When compared with MAC loads the results prove that the Jadro River spring is not polluted by nitrogen compounds and phosphorus. The average annual load for total N ranged from 10 to 33 t, for NH3-N from 0.25 to 5.15 t, for NO3-N from 40 to 190 t, and for PO4-P from 0.3 to 11.5 t. The nitrogen compounds and phosphorus loads vary from one year to another without any constant decreasing or increasing trends. The annual average loads compared with the average annual MAC loads (especially for NH3-N and PO4-P) show that there were no threats of constant pollution of the spring. The loads for total N and PO4-P along the Jadro River flow from the spring to the fishpond entrance were monitored over a five year period from September 1999 to September 2004. The results show no regularities. The highest annual total nitrogen load of 45 t was recorded at the entrance to the fishpond during the 2002/2003 period. The highest annual PO4-P load of 10 t was measured at the Vidović Bridge during the 2003/2004 period; however, the concentrations of N and P did not exceed the MAC concentrations which are prescribed for drinking water. According to the investigation results of the daily and average annual loads compared with MAC loads for drinking water, it can be concluded that the Jadro River spring and its streamflow are not polluted by nitrogen and phosphorus.

Croatia↗
PubMed1995

High-performance liquid chromatographic profiles of aloe constituents and determination of aloin in beverages, with reference to the EEC regulation for flavouring substances.

Characteristic HPLC profiles of fresh and aged aloe solutions, detected at 360 and 220 nm, are presented and compared. Several aloe constituents (aloesin, aloeresin A, hydroxyaloin, aloin A and B and aloinoside A and B) were simultaneously separated and identified. The determination of aloin is described (detection limit 0.15 ppm) and discussed. In aloe-based alcoholic beverages, the aloins could not be detected, owing to their instability and degradation in solution; this is discussed in relation to the EEC Council Directive 88/388, which fixed the values of maximum allowable concentrations for aloin in food and beverages. Instead of aloin, other aloe compounds (e.g., aloeresin A or aloesin) should perhaps be used as an index of the presence of aloe in alcoholic beverages.

Alcoholic Beverages↗
PubMed1991

A study of occupational exposure to isopropylbiphenyls (Sure Sol-250).

Environmental and medical examinations in workers exposed to the isopropylbiphenyl (IPBs) mixture, Sure Sol-250, in a capacitor-manufacturing plant were carried out once a year for three years. Levels of the total IPBs ranged from 0.03 to 36.6 mg/m3 with a mean of 5.6 mg/m3. The time-weighted average (TWA) exposures varied between 0.3 and 1.8 mg/m3. Physical and laboratory examinations (blood cell count, liver and kidney function tests and also antipyrine metabolism were normal) revealed no adverse effects of IPBs. Based on these observations as well as on the results of our six-month oral toxicity studies in rats, not presented in this paper, we recommend a TWA-MAC (maximum allowable concentration) of 10 mg/m3 for IPBs.

Acetylglucosaminidase↗
PubMed1984

Industrial lead poisoning in China over the past 33 years.

This paper is a review of the 48 articles in scientific journals and special reports of investigations emanating from the author's department involving 2504 subjects. During the past 33 years, as a result of the establishment of health and antiepidemic stations throughout the country, the enactment of hygienic standards, and the setting up of the reporting system for industrial poisoning and occupational diseases, the air lead level has been reduced from 10 mg/m3 in the years soon after liberation (1949) to below 0.03 mg/m3 at present. Severe plumbism has disappeared. Some mild cases, however, could still be found among workers in lead smelters and electric battery plants. Great advances have been made in techniques for early diagnosis of lead poisoning. Blood lead, urine lead, aminolevulinic dehydrase, free erythrocyte protoporphyrin, and zinc protoporphyrin (ZnPP) have been used as criteria for lead exposure. For the purpose of preventive monitoring, ZnPP as a screening index is the first choice. Behavioral function and sensory and motor nerve conduction velocity measurements of median nerve might also be used for the investigation of lead exposure. The maximum allowable concentration of 0.03 mg/m3 for air lead level in the workshop, in agreement with the results of a nationwide lead industry investigation, has been proven safe. There is also the need to monitor the air lead level and blood lead level in the general population and children living adjacent to a lead industry.

Adult↗
PubMed2006

Dimethyl sulfoxide is a potent modulator of estrogen receptor isoforms and xenoestrogen biomarker responses in primary culture of salmon hepatocytes.

Dimethyl sulfoxide (DMSO) has been frequently used as carrier solvent in toxicological experiments where the most compelling DMSO attributes are its exceptionally low toxicity and environmental impact. We were inspired by recent and consistent observations that ethanol and DMSO modulate endocrine-disruptor biomarker responses in both in vitro and in vivo studies in our laboratory, to take a critical evaluation of these effects. Quantitative (real-time) polymerase chain reaction (PCR) method with specific primer pairs was used in this study to measure DMSO-induced time-dependent modulation of estrogen receptor (ER) isoforms, vitellogenin (Vtg) and zona radiata-protein (Zr-protein) gene expression patterns in primary culture of salmon hepatocytes. In addition, immunochemical analysis, using indirect enzyme linked immunosorbent assay (ELISA) with monoclonal (Vtg) and polyclonal (Zr-proteins) antibodies was used to detect and measure Vtg and Zr-proteins secreted in culture media. Salmon hepatocytes were isolated by a two-step collagenase perfusion method and exposed to 0.1% or 10 microL/L of DMSO after 48 h pre-culture. Cells were harvested at 12, 24, 48 and 72 h after exposure and analysed for ERalpha, ERbeta, Vtg and Zr-protein gene expression using real-time PCR method. Media samples were collected at similar time-intervals for protein analysis. Our data show that DMSO-induced significant increase in ERalpha, ERbeta, Vtg and Zr-protein genes in a time-dependent manner. Indirect ELISA analysis showed a time-specific effect of DMSO. The use of DMSO as carrier solvent in fish endocrine disruption studies should be re-evaluated. We recommend more investigation, using other endocrine-disruptor biomarkers in order to validate the suitability of common carrier solvents used in toxicology with the aim of setting new maximum allowable concentrations. In particular, given the high sensitivity of genomic approaches in toxicology, these results may have serious consequences for the interpretation of biomarker responses.

Animals↗
PubMed2005

Monitoring phthalate exposure in humans.

The dialkyl- or alkyl/aryl esters of 1,2-benzenedicarboxylic acid, commonly known as phthalates, are high-production-volume synthetic chemicals and ubiquitous environmental contaminants because of their use in plastics and other common consumer products. Di-(2-ethylhexyl) phthalate (DEHP) is the most abundant phthalate in the environment. Humans are exposed to these compounds through ingestion, inhalation, and dermal exposure for their whole lifetime, since the intrauterine life. Public and scientific concern has increased in recent years about the potential health risks associated with exposure to phthalates. The main focus has moved away from the hepatotoxic effects to the endocrine disrupting potency of these chemicals. To date, although the consistent toxicologic data on phthalates is suggestive, information on sources and pathways of human exposure to phthalates is limited. Recently, exposure to phthalates has been assessed by analyzing urine for their metabolites. This approach is contrary to the determination of the parent phthalates in air, water and foodstuff and not subject to contamination. Furthermore, these metabolites and the parent phthalates are considered the toxic species. However, accurate methods and models for measuring the amount of phthalates absorbed by the various pathways of exposure have to be developed. In fact, a frequent biological monitoring of phthalates in body fluids and tissues would be highly advisable, both in helping physicians to perform health risk assessments for exposure in the general population and in guiding governments to provide regulations concerning the maximum allowed concentrations in the environment, plasticized products, medications and medical equipment.

Animals↗
PubMed2004

Effect of season of application on the adhesion, retention and recontamination of herbage by potentially toxic metals and sewage sludge.

Grassland in the United Kingdom can accept sewage sludge when, as a result of cropping restrictions, arable land cannot. However, one of the uncertainties associated with the application of sewage sludge to grassland is the potential exposure of the grazing ruminant to sewage sludge particulates adhered to the grass or deposited on the soil surface. The implications of elevated levels of sludge particulates and associated potentially toxic metals (PTMs) are the potential accumulation of PTMs into edible tissues of the grazing animal. Two experiments were performed to investigate the effect of season of application on the adhesion, retention and recontamination of herbage by sewage sludge and PTMs. In each experiment, three treatments were installed, an untreated control, application of sludge in the autumn and application of sludge in the spring. Sewage sludge particulates and PTMs were eluted sequentially 21 days after the application of sludge using water and detergent and the residual (tissue) concentrations were monitored. Total concentrations in each fraction and adhesion indices were calculated. Soil samples taken from the sward treatments after each application showed no elevated concentrations of PTMs or concentrations that approached the maximum concentrations allowed for soils amended with sewage sludge. The amounts of sludge adhered to herbage ranged from 114 to 360 g sludge DM/kg herbage DM. There was evidence of preferential retention of PTMs to herbage. However, during the 21-day no grazing period there was a general decline in concentration of all PTMs. Copper was retained on the herbage for greater periods of time compared to Zn, CD, Pb and Fe (P < 0.01). The proportion of Pb recovered from the water phase increased during the 21-day no grazing period in comparison to Cu, Zn and Fe (P < 0.001). It is concluded that the concentrations of PTMs adhered and integral to herbage as a result of surface application of sewage sludge are likely to fall to acceptable levels in well-managed permanent grassland.

Adsorption↗
PubMedDate not supplied

Embryotoxicity of butyltin compounds to the sea urchin Paracentrotus lividus.

Tributyltin (TBT) has been widely employed in marine anti-fouling paints as a biocide, although it represents a serious risk, particularly in estuarine and coastal water/sediment ecosystems. In this study, the embryotoxic effects of TBT and its degradation products, dibutyltin (DBT) and monobutyltin (MBT), were analyzed during the development of the sea urchin Paracentrotus lividus from post-fertilization to the pluteus stage, to better clarify ecotoxicological impact. The embryotoxicity of butyltins is concentration-dependent and increases proportionally with number of butyl groups. Significant growth reduction was observed at TBT concentrations as low as 0.01 microgram l-1; 1 microgram l-1 was the maximum concentration allowing embryos to reach the pluteus stage at 48 h post-fertilization. Development was blocked at the morula or blastula stage with higher TBT concentrations. DBT and MBT are less toxic: slowed development and a decrease in pluteus size occurred at 10 micrograms l-1 DBT and 0.5 mg l-1 MBT. Effects on both skeletal deposition and blocked embryonic development are suggested to be due to the interference of organotin compounds with intracellular calcium homeostasis.

Animals↗
PubMed1995

Microbiological and endotoxin assays of hemodialysis fluids.

The potential for exposure of dialysis patients to greater levels of microbial and endotoxin contamination has increased dramatically during the last decade with the increase in reuse of hemodialyzers, and the use of bicarbonate dialysate and high flux dialysis. To help prevent pyrogenic reactions and bacteremia in hemodialysis patients caused by microbial and endotoxin contamination of hemodialysis fluids, the Association for the Advancement of Medical Instrumentation (AAMI) has promulgated standards for maximum allowable concentrations of bacteria and endotoxin in these fluids. Each dialysis center should develop microbiological and endotoxin surveillance policies and procedures for the types of hemodialysis fluids to assay, frequency and manner of sample collection, assay techniques, and methods for recording and interpreting results to ensure compliance with the AAMI standards. These necessary components of a comprehensive surveillance program are discussed in depth in this article. A safer environment will be provided for each dialysis patient if appropriate microbiological assay procedures are followed and the results are consistently within the AAMI microbiological and endotoxin standards.

Bacteremia↗
PubMedDate not supplied

Quantification and characterization of volatiles evolved during extrusion of rice and soy flours.

NASA-Johnson Space Center is designing and building a habitat (Bioregenerative Planetary Life Support Systems Test Complex, BIO-Plex) intended for evaluating advanced life support systems developed for long-duration missions to the Moon or Mars where all consumables will be recycled and reused. A food system based on raw products obtained from higher plants (such as soybeans, rice, and wheat) may be a central feature of a biologically based Advanced Life Support System. To convert raw crops to edible ingredients or food items, multipurpose processing equipment such as an extruder is ideal. Volatile compounds evolved during the manufacturing of these food products may accumulate and reach toxic levels. Additionally, off-odors often dissipated in open-air environments without consequence may cause significant discomfort in the BIO-Plex. Rice and defatted soy flours were adjusted to 16% moisture, and triplicate samples were extruded using a tabletop single-screw extruder. The extrudate was collected in specially designed Tedlar bags from which air samples could be extracted. The samples were analyzed by GC-MS with special emphasis on compounds with Spacecraft Maximum Allowable Concentrations (SMACs). Results showed a combination of alcohols, aldehydes, ketones, and carbonyl compounds in the different flours. Each compound and its SMAC value, as well as its impact on the air revitalization system, was discussed.

Acetaldehyde↗
PubMed2003

The use of rice hulls for sustainable control of NOx emissions in deep space missions.

The use of the activated carbon produced from rice hulls to control NOx emissions for future deep space missions has been demonstrated. The optimal carbonization temperature range was found to be between 600 and 750 degrees C. A burnoff of 61.8% was found at 700 degrees C in pyrolysis and 750 degrees C in activation. The BET surface area of the activated carbon from rice hulls was determined to be 172 m2/g when prepared at 700 degrees C. The presence of oxygen in flue gas is essential for effective adsorption of NO by activated carbon. On the contrary, water vapor inhibits the adsorption efficiency of NO. Consequently, water vapor in flue gas should be removed by drying agents before adsorption to ensure high NO adsorption efficiency. All of the NO in the flue gas was removed for more than 1.5 h when 10% oxygen was present and the ratio of the carbon weight to the flue gas flow rate (W/F) was 15.4 g min/L. Reduction of the adsorbed NO to form N2 could be effectively accomplished under anaerobic conditions at 550 degrees C. The adsorption capacity of NO on the activated carbon was found to be 5.02 mg of NO/g of carbon. The loss of carbon mass was determined to be about 0.16% of the activated carbon per cycle of regeneration if the regeneration occurred when the NO in the flue gas after the carbon bed reached 4.8 ppm, the space maximum allowable concentration. The reduction of the adsorbed NO also regenerated the activated carbon, and the regenerated activated carbon exhibited an improved NO adsorption efficiency.

Adsorption↗
PubMed2002

UV filters in sunscreen products--a survey.

The contents of 18 permitted chemical UV filters in 75 sunscreen products have been determined to check the compliance of these products with the EU Cosmetic Directive, as well as to generate data for quantitative exposure assessments. 81% of the products were found to contain 14 of the target chemical UV filters. The remaining products contained only the physical UV-filters titanium oxide and zinc oxide, which were not determined in the present study. Maximum content (29.3%) of chemical UV filters was found in a product that contained 6 of the target UV filters. Octyl methoxycinnamate (1.4-4.7%) and butyl methoxydibenzoylmethane (0.4-4.8%) were the most frequently used UV filters, present, respectively, in 49% and 44% of the investigated products. Correlation between declared sun protection factor (SPF) and the contents of chemical UV filters in the respective products was not significant (correlation coefficient 0.5362). The content of UV filters in all products complied with the maximum allowed concentration of these according to EU Cosmetic Directive.

Chromatography, High Pressure Liquid↗
PubMed2000

Organic dust and gaseous contaminants at wood working shops.

Airborne dust bioaerosols, ammonia and formaldehyde levels were determined inside two different (ventilated and unventilated) wood working shops. Airborne dust was found at mean values of 4.3 and 3.01 mg m(-3). These levels were higher than that recommended by Egyptian environmental law [1 mg m(-3) indoor maximum allowable concentration (MAC) for hard wood]. The highest frequency of aerodynamic size distribution of airborne wood dust was detected at a diametre of 4.9 microm which was recorded during a machining operation. Total viable bacteria were recorded at a mean value of 10(4) colony-forming units (cfu) m(-3), whereas Gram-negative bacteria were found at very low counts (10(1) cfu m(-3)). Fungi levels were recorded at mean values of 10(3) and 10(2) cfu m(-3) in ventilated and unventilated shops, respectively. Penicillium, Aspergillus, Cladosporium and yeast species were dominant isolates. Moreover, actinomycetes were found at a mean value of 10(3) cfu m(-3) at both workshops. Ammonia was detected in relatively low concentrations (mean values of 457 and 623 microg m(-3)), whereas formaldehyde was found in relatively moderate concentrations (mean values of 0.42 and 0.64 ppm).

Aerosols↗
PubMed1996

Analytical performance testing of an atrazine immunoassay system.

A rigorous performance evaluation of an enzyme immunoassay (EIA) kit for the determination of atrazine in water samples was undertaken. Eleven individual batches of samples containing standards and spiked drinking waters were analysed and precision, bias and limit of detection were measured using statistical analysis. The technique was shown to be capable of achieving performance criteria (a total standard deviation of less than 5% or 2.5 ng, whichever is the greater) demanded of modern analytical systems and achieved a limit of detection of 9.2 ng l-1. There was no statistically significant bias measured for drinking water samples. Interference tests showed that the atrazine immunoassay was not significantly affected in the pH range 4.0-8.0 or by drinking water matrix components (anions, cations and chlorination by-products), even at their maximum allowable concentrations. There was a small extent of cross-reaction with simazine and atrazine degradation products, but given the persistence of atrazine, through its resistance to hydrolysis, breakdown products are likely to be present at much lower concentrations than the parent compound in drinking water. Simazine may potentially be more problematic, so it would be prudent to monitor a proportion of samples for simazine to determine the extent to which this may be contributing to the 'atrazine' measured in drinking water samples using the EIA kit.

Atrazine↗
PubMed1998

Preservatives in moisturizers on the Swedish market.

The presence of 9 common preservatives was investigated in 100 moisturizers by high-performance liquid chromatography. According to the manufacturers/suppliers 88 of the 100 moisturizers contained at least one of the 9 preservatives. This information was erroneous in 9 cases (10.2%). When the moisturizers were investigated for the presence of the 9 preservatives which should not be present in the moisturizers according to the manufacturers/suppliers, at least one of the preservatives was detected in 17 moisturizers (17.0%). Parabens were the most common preservatives. The concentrations of the 9 preservatives did not exceed the maximum concentrations allowed in cosmetics. When a patient with suspected allergic contact dermatitis tests positively to a preservative, the assessment of present clinical relevance requires demonstration of exposure to the sensitizer. This demonstration cannot rely solely on information on the packages or from the manufacturers/suppliers but has often to be supplemented by chemical analysis.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

Cadmium in the environment of three Russian cities and in human hair and urine.

Daily cadmium intake was assessed in three Russian cities as were deviations in health of the working population and children who resided near the sources of contamination. In the surveyed workers of a storage battery factory (n = 27), the urinary cadmium content exceeded the threshold of 14 micrograms/l and averaged 53.8 micrograms/l; the average hair cadmium was 99.3 micrograms/g. Workers employed in metallurgic cadmium production (n = 16) had an average urinary cadmium level of 40.9 micrograms/l and a hair cadmium level of 92.0 micrograms/g. Workers in a cadmium-containing dyes plant had an average urinary cadmium level of 9.04 micrograms/l and a hair cadmium level of 25.1 micrograms/g. Increased urinary excretion of beta-2-microglobulin was found only in workers aged 31 y or older. The general population that resided in the vicinity of the cadmium emissions showed increased urine and hair cadmium levels; levels were greatest near the metallurgic plant and the storage battery factory. Air cadmium content and beta-2-microglobulin excretion were correlated (r = 0.96). The findings confirm results of other epidemiologic studies and underscore the necessity of reducing the maximum allowable concentration of cadmium in the atmospheric air because of excessive intake from other sources.

Adult↗