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PubMed1997

[Workplace contamination from sevoflurane. Concentration measurement during bronchosopy in children].

UNLABELLED: General anaesthetic agents are frequently used for paediatric bronchoscopy. A disadvantage of open-system anaesthesia is the contamination of the working environment. The aim of this study was to determine the exposure of the anaesthesiologist and endoscopist during paediatric bronchoscopy under general anaesthesia in different working environments and to compare these measurements to the currently valid international threshold limits. MATERIALS AND METHODS: Twenty-five children (ASA I-III) scheduled for diagnostic bronchoscopy were included in the study. After inhalational induction, all patients were intubated with a nonflexible bronchoscope and manually ventilated through a side-arm of the bronchoscope. Maintenance of anaesthesia was achieved with sevoflurane (2-3 vol.%) in pure oxygen. Trace concentrations were measured every 90 s in the breathing zones of the operating theatre (OT) personnel by means of a highly sensitive direct-reading instrument (Brüel & Kjaer 1302). The lower detection limit was 0.02 ppm. The investigation was done in an OT with and without air-conditioning and a scavenging system. RESULTS: The mean age of the children was 50.3 months (range: 3-109 months). Ventilation and oxygenation were stable throughout the bronchoscopic procedure. Mean exposure to sevoflurane in the OT without air-conditioning and a scavenging system was over 40 ppm for the anaesthetist and 50 ppm for the endoscopist. All international threshold limit values were exceeded. Peak concentrations higher than 100 ppm could be detected during 40% of the anaesthetics. CONCLUSION: The main finding of the present study is that under inhalation anaesthesia with sevoflurane for paediatric bronchoscopy, occupational exposure is higher than all known health regulation guidelines permit. Therefore, the use of total intravenous anaesthesia is advocated even in very small infants.

Anesthesia, Inhalation↗
PubMed2002

A meta-analysis for neurobehavioural results due to occupational mercury exposure.

A meta-analysis for neurobehavioural test results of subjects occupationally exposed to mercury was carried out in order to find general tendencies and express possible deficits numerically. Out of 44 studies investigating neurobehavioural functions of occupationally exposed individuals, 12 studies provided the data required and were included in the analysis. In all, 14 neuropsychological tests with 20 different tasks were analysed. The results related to 686 exposed and 579 control subjects. Nine significant performance effects were shown for mean urinary concentrations between 18 and 34 microg Hg/g creatinine. The effects sizes (D(W+)) referred to attention (D(W+)=-0.40 and -0.46), memory (D(W+)=-0.38 and -0.40), construction (D(W+)=-0.20) and motor performance (D(W+)=-0.24, -0.40, -0.44 and -0.47). Additionally there was evidence for a dose-response relationship of effect sizes, if all test results were taken into account. Whether the effect sizes could be subject to overestimation was discussed, but there were no reasons for such an assumption. The results can be used as suggestions for new discussions about threshold limit values.

Cognition↗
PubMed2001

A quartz crystal microbalance sensor for the detection of formic acid vapors.

A new quartz crystal microbalance sensor is developed to determine formic acid at low concentrations. Four previously selected polymers with acid-base characteristics were tested as possible coatings. Polyoxyethylene bis [amine] presented the best results. The sensor is rapid, sensitive [0.67 Hz/(mg/m3)], and reversible at low concentrations. The detection limit for formic acid (7.2 mg/m3) is comparable with the short term exposure limit and the threshold limit values. It presents a fast mechanical response to pressure changes, so that it can be quickly used in different environments and situations. The sensor also shows a good stability in a temperature range typical of work atmospheres (16-36 degrees C). It has a wide linear range (7.2-911.2 mg/m3) and a long useful time. It is also applicable to other low molecular mass carboxylic acids such as acetic acid.

Calibration↗
PubMed1996

[An example for stepwise reduction of work site-induced formaldehyde exposure in pathology].

Occupational formaldehyde exposure in pathology depends on the efficiency of the ventilation system in use and may reach concentrations considerably above the current threshold limit values. The reduction of formaldehyde exposure by stepwise improvement of the ventilation system at a pathologist's workplace is presented as an example in this paper. Assessment of formaldehyde concentration by personal air sampling at a workplace originally equipped with a hood ventilation system resulted in values of up to 4 ml/m3 in the pathologist's breathing zone. Lowering the ventilation inlet to the working level by connecting the hood to a suction unit via a flexible hose resulted in an effective reduction of formaldehyde exposure to values of about 0.5 ml/m3. This simple and low-cost technical improvement had some uncomfortable side effects, such as current noise and wind chill, which could only be overcome by installing ventilated work tables according to modern technical standards.

Air Pollutants, Occupational↗
PubMed2002

Urinary determination of N-acetyl- S-( N-methylcarbamoyl)cysteine and N-methylformamide in workers exposed to N, N-dimethylformamide.

OBJECTIVES: We conducted this biomonitoring study with the aim of evaluating the correlation between the excretion of N-methylformamide (NMF) (mainly from N-hydroxy- N-methylformamide) and N-acetyl- S-( N-methylcarbamoyl)cysteine (AMCC), and levels of exposure to N, N-dimethylformamide (DMF) among occupationally exposed subjects. METHODS: Exposure levels were determined by personal sampling: breathing zone air samples were collected by means of passive samplers. DMF collected by the charcoal in personal samplers was analysed after extraction with methanol by a gas chromatograph. For the purpose of biological monitoring the levels of NMF and AMCC were measured in pre-shift and post-shift samples. Determinations were carried out by, respectively, gas chromatography and high performance liquid chromatography (HPLC). RESULTS AND CONCLUSIONS: The mean time-weighted average (TWA) exposure was approximately half (13.5 mg/m(3)) of the current threshold limit value, the range of the values was from 0.4 to 75.2 mg/m(3). Environmental DMF concentrations exhibited a significant correlation with the specific mercapturic acid (AMCC) collected at the end of the working week (AMCC Friday morning mg/l=1.384xDMF (mg/m(3))+8.708; r(2)=0.47; P<0.008]; hence urinary AMCC represents an index of the average exposure during several preceding working days, making it possible to calculate the approximate relationship between DMF uptake and excretion of this metabolite. A significant correlation was found also between the daily excretion of NMF and the corresponding levels of DMF in air. The equation of the regression line was: NMF (mg/g creatinine)=0.936xDMF (mg/m(3))+7.306; r(2)=0.522 ( P<0.0001).

Acetylcysteine↗
PubMed2003

Intermittent extremely low frequency electromagnetic fields cause DNA damage in a dose-dependent way.

OBJECTIVES: Epidemiological studies have reported an association between exposure to extremely low frequency electromagnetic fields (ELF-EMFs) and increased risk of cancerous diseases, albeit without dose-effect relationships. The validity of such findings can be corroborated only by demonstration of dose-dependent DNA-damaging effects of ELF-EMFs in cells of human origin in vitro. METHODS: Cultured human diploid fibroblasts were exposed to intermittent ELF electromagnetic fields. DNA damage was determined by alkaline and neutral comet assay. RESULTS: ELF-EMF exposure (50 Hz, sinusoidal, 1-24 h, 20-1,000 mu T, 5 min on/10 min off) induced dose-dependent and time-dependent DNA single-strand and double-strand breaks. Effects occurred at a magnetic flux density as low as 35 mu T, being well below proposed International Commission of Non-Ionising Radiation Protection (ICNIRP) guidelines. After termination of exposure the induced comet tail factors returned to normal within 9 h. CONCLUSION: The induced DNA damage is not based on thermal effects and arouses concern about environmental threshold limit values for ELF exposure.

Adult↗
PubMed2004

Gases and organic solvents in urine as biomarkers of occupational exposure: a review.

A brief review of urine analysis in studies of occupational exposure to volatile organic compounds and gases is provided. Analysis of exhaled breath for volatile compounds does not have a long history in occupational medicine. A number of studies has been undertaken since the 1980s, and the methods are well enough accepted to be put forward as biological equivalents of threshold limit values (TLVs) for some volatile organic compounds (VOCs) such as acetone; methanol; methyl ethyl ketone (MEK); methyl isobutyl ketone (MIBK); tetrahydrofurane; dichloromethane. In the last 20 years many scientific articles have shown that the urinary concentrations of unchanged solvents are correlated with environmental exposure and could be used for biological monitoring. The use of urine analysis of unchanged solvents in occupational applications is not yet widespread. Nonetheless, in the short time since its application, a number of important discoveries has been made, and the future appears bright for this branch of analysis. In this paper, the basic concepts and methodology of urine analysis are briefly presented with a critical revision of the literature on this matter. The excretion mechanisms of organic solvents in urine are discussed, with regard to biological variability, and the future directions of research are described.

Biomarkers↗
PubMed2001

Occupational exposure to low concentrations of carbon disulfide as a risk factor for hypercholesterolaemia.

OBJECTIVE: The objective of this study was to investigate the effect of occupational exposure to carbon disulfide (CS2) concentrations below threshold limit value (TLV)-time-weighted average (TWA) (31 mg/m3) on total cholesterol, blood pressure and the prevalence of coronary heart disease (CHD). METHODS: A cross-sectional study involving 141 viscose rayon workers (64 men), and 141 age- and gender-matched controls without occupational contact with noxious chemicals, was carried out. The probability for CHD was determined by means of the WHO questionnaire and was 12-lead electrocardiography-coded using Minnesota criteria. Blood pressure was measured by the standardized method of the WHO and blood was examined for total cholesterol. A cumulative exposure index (CS2 index) was calculated for each worker by multiplying the number of years held in a particular job, by the CS2 concentrations in that job-environment. According to the CS2 index, the exposed workers were distributed into two groups: group 1 (CS2 index < 100) and group 2 (CS2 index > or = 100). RESULTS: Depending on the job and specific work place the CS2 concentrations were between 1 and 30 mg/m3. Cholesterol levels were significantly higher in the exposed group (4.9 +/- 0.7) compared with the controls (4.6 +/- 0.7). Adjustment for age, smoking, body-mass index (BMI) and gender showed the significant effect of the CS2 index on the total cholesterol (P < 0.001). The prevalence of hypercholesterolaemia was significantly higher in the exposed group (42.6%), compared with the controls (26.2%); odds ratio (OR) (adjusted for potential confounders) was 2.56, 95% CI 1.47-4.46. Logistic regression showed a significantly increased risk for elevated cholesterol in group 2 (OR 5.52; 95% CI 2.81-10.83). No significant effect of CS2 index on blood pressure and CHD prevalence was found. CONCLUSIONS: The results of our study show that occupational exposure to CS2 concentrations below 31 mg/m3 and a CS2 index > 100 may increase total cholesterol. Our results imply that even the CS2 concentrations below TLV-TWA may produce morbid changes, and suggest the mechanism of the effect of CS2, leading to lipid metabolism disturbances and acceleration of atherosclerosis.

Bulgaria↗
PubMed2001

Occupational exposure to airborne mercury during gold mining operations near El Callao, Venezuela.

OBJECTIVE: The National Institute for Occupational Safety and Health (NIOSH) recently conducted a cross-sectional study during gold mining operations near El Callao, Venezuela. The purpose of the study was to assess mercury exposures and mercury-related microdamage to the kidneys. The study consisted of concurrent occupational hygiene and biological monitoring, and an examination of the processing techniques employed at the different mining facilities. Mercury was used in these facilities to remove gold by forming a mercury-gold amalgam. The gold was purified either by heating the amalgam in the open with a propane torch or by using a small retort. METHODS: Thirty-eight workers participated in this study. Some participants were employed by a large mining company, while others were considered "informal miners" (self-employed). Mercury exposure was monitored by sampling air from the workers' breathing zones. These full-shift air samples were used to calculate time-weighted average (TWA) mercury exposure concentrations. A questionnaire was administered and a spot urine sample was collected. Each urine sample was analyzed for mercury, creatinine, and N-acetyl-beta-D-glucosaminidase (NAG). RESULTS: The range for the 8-h TWA airborne mercury exposure concentrations was 0.1 to 6,315 micrograms/m3, with a mean of 183 micrograms/m3. Twenty percent of the TWA airborne mercury exposure measurements were above the NIOSH recommended exposure limit (REL) of 50 micrograms/m3, and 26% exceeded the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) of 25 micrograms/m3. The mean urine mercury concentration was 101 micrograms/g creatinine (microgram/g-Cr), and the data ranged from 2.5 to 912 micrograms/g-Cr. Forty-two percent of the study participants had urine mercury concentrations that exceeded the ACGIH biological exposure index (BEI) of 35 micrograms/g-Cr. Urinary NAG excretion is considered a biological marker of preclinical, nonspecific microdamage to the kidney's proximal tubule cells. The mean urine NAG concentration was 3.6 International Units/g-Cr (IU/g-Cr) with a range of 0.5 to 11.5 IU/g-Cr. Three workers had urine NAG levels in excess of the reference values. Correlation analyses found statistically significant correlations between airborne mercury exposure and urine mercury level (P = 0.01), and between urine mercury level and urine NAG excretion (P = 0.01). In addition, the airborne mercury exposure data and urine mercury data were segregated by job tasks. A Wilcoxon rank sum test revealed significant correlations between tasks and mercury exposure (P = 0.03), and between tasks and urine mercury level (P = 0.02). CONCLUSIONS: The tasks with the highest mean airborne mercury exposures were "burning the mercury-gold amalgam" and "gold refining/smelting". Recommendations were provided for improving the retort design to better contain mercury, for ventilation in the gold shops, and for medical surveillance and educational programs.

Acetylglucosaminidase↗
PubMed2001

Internal exposure to PAHs of children and adults living in homes with parquet flooring containing high levels of PAHs in the parquet glue.

UNLABELLED: PAHs form during the incomplete combustion of organic substances and hence they are distributed ubiquitously in the environment. PAHs in the diet are the main source of exposure in man. In 1997 a new source of potential PAH exposure was discovered: very high levels of polycyclic aromatic hydrocarbons (PAHs) and benzo-a-pyrene (BaP) were detected in household dust from former American Forces housing in Frankfurt am Main, Germany, built in 1955/1956. This contamination was caused by a parquet glue containing coal tar, the use of which was formerly standard building practice in Germany. Because the inhabitants of these flats were very concerned about the effects on their health, they were offered the opportunity to take part in biomonitoring examinations to assess individual internal PAH exposure. PARTICIPANTS AND METHODS: 1213 inhabitants from 511 flats/houses took part in the investigation; this corresponds to 12.7% of the total inhabitants of the former US housing estates in Frankfurt am Main. Spot urine samples were collected and frozen until analysis for 1-, 2-, 3- and 4-hydroxyphenanthrene and 1-hydroxypyrene, which was carried out using a very sensitive and practical high performance liquid chromatographic method with fluorescence detection, approved by the Deutsche Forschungsgemeinschaft. RESULTS: The level of internal exposure to PAHs in study participants living in homes where parquet glue containing PAHs had been used did not differ from the levels found in participants in whose homes PAH-containing parquet glue was not used. This was true for the whole group as well as subgroups divided according to age and smoking behaviour. Internal exposure was not influenced by different levels of external exposure (BaP in parquet glue and in household dust). Spearman rank correlations between the level of BaP in parquet glue and in household dust were low and insignificant. CONCLUSION: An increase in internal PAH exposure due to high levels of PAHs in parquet glue and household dust could not be detected. This confirms earlier results with small collectives, where only low and insignificant trends were found towards higher internal PAH exposure caused by contaminated homes. Therefore, the ad-hoc working group of the Commission for Indoor Air Quality of the German Federal Environmental Agency stated that a definitive threshold limit value cannot be defined for PAH contamination in parquet glue and household dust. For reasons of disease prevention, however, BaP contamination in household dust exceeding 10 mg/kg should be minimised.

Adhesives↗
PubMed1997

Biological monitoring of vehicle mechanics and other workers exposed to low concentrations of benzene.

It has been suggested that the threshold limit value (TLV) for the time-weighted average (TWA), of benzene be lowered because of its possible leukemogenic effect at low exposure concentrations. This requires the development of new methods of biological monitoring. In this cross-sectional study the diagnostic power of blood and breath benzene and of urinary phenol, catechol, hydroquinone, S-phenylmercapturic acid, and muconic acid were compared in a population of 410 male workers exposed to benzene in garages, in two coke plants, and in a by-product plant. Benzene exposure was assessed by personal air sampling (charcoal tube and passive dosimeter). In all, 95% of the workers were exposed to less than 0.5 ppm benzene. According to the multiple regression equation, the muconic acid and S-phenylmercapturic acid concentrations detected in nonsmokers exposed to 0.5 ppm benzene were 0.3 mg/g and 6 micrograms/g, respectively (range 0.2-0.6 mg/g and 1.2-8.5 micrograms/g, respectively). With muconic acid very few false-positive test results were found, and this determination remained reliable even around a cutoff level of 0.1 ppm benzene. Moreover, the diagnostic power of this test proved to be good even when diluted or concentrated urine samples were not excluded. S-Phenylmercapturic acid (S-PMA) also performed fairly well. Blood and breath benzene as well as urinary phenol (PH) and hydroquinone (HQ) were clearly less suitable biomarkers than muconic acid (MA). Catechol (CA) was not associated with occupational benzene exposure. According to the results of biological monitoring, the skin resorption of benzene from gasoline or other fuels seems negligible. Correlation, multiple regression, and likelihood ratios consistently showed that MA and S-PMA concentrations were fairly good indicators of benzene exposure in the 0.1- to 1-ppm range, even in a population comprising both smokers and nonsmokers. PH, HQ, CA, and blood and breath benzene were less suitable, if at all, in the same exposure range.

Adult↗
PubMed1997

Biological monitoring of triethylamine among cold-box core makers in foundries.

OBJECTIVES: The objectives of the study were to assess triethylamine (TEA) exposure in cold-box core making and to study the applicability of urinary TEA measurement in exposure evaluation. METHODS: Air samples were collected by pumping of air through activated-charcoal-filled glass tubes, and pre- and postshift urine samples were collected. The TEA concentrations were determined by gas chromatography. DESIGN: Tea was measured in air and urine samples from the same shift. Breathing-zone measurements of 19 workers in 3 foundries were included in the study, and stationary and continuous air measurements were also made in the same foundries. Pre- and postshift urine samples were analyzed for their TEA and triethylamine-N-oxide (TEAO) concentrations. RESULTS: The TEA concentration range was 0.3-23 mg/m3 in the breathing zone of the core makers. The mean 8-h time-weighted average exposure levels were 1.3, 4.0, and 13 mg/m3 for the three foundries. Most of the preshift urinary TEA concentrations were under the detection limit, whereas the postshift urinary TEA concentrations ranged between 5.6 and 171 mmol/mol creatinine. The TEAO concentrations were 4-34% (mean 19%) of the summed TEA + TEAO concentrations. The correlation between air and urine measurements was high (r = 0.96, P < 0.001). A TEA air concentration of 4.1 mg/m3 (the current ACGIH 8-h time-weighted average threshold limit value) corresponded to a urinary concentration of 36 mmol/mol creatinine. CONCLUSIONS: The TEA exposure levels of foundries and their core makers vary greatly. Stationary air measurements in factories are not sufficient to assess TEA exposure; instead, personal sampling is needed. The biological monitoring of TEA in postshift urine samples provides a practical and accurate method for assessing exposure.

Adult↗
PubMed1999

Skin absorption in vitro of glycol ethers.

OBJECTIVES: The increased use of glycol ethers (GEs) for water-based paints and cleaning products, combined with a lack of information about many of these products, particularly with regard to the effects of percutaneous exposure, led us to evaluate the skin absorption rates of a group of glycol ethers in vitro. METHODS: Skin permeation was calculated using the Franz cell method with human skin. A physiological solution was used as the receiving phase. The amount of solvent passing through the skin was analysed with a gas chromatographic technique employing flame ionization detection. A permeation profile was obtained and steady state, lag time and permeation constant flux was calculated for each of the following solvents: ethylene glycol monoethyl ether (EGMEE), propylene glycol mono-methyl ether (PGMME); propylene glycol mono-methyl ether acetate (PGMMEac); 2-propylene glycol 1-butyl ether (2PG1BE), ethylene glycol dimethyl ether (EGDME), ethylene glycol diethyl ether (EGDEE) and diethylene glycol dimethyl ether (DEGDME). All solvents were tested in their pure form and with 70% acetone. RESULTS: For all solvents tested the lag time was less than 2 h, and for the majority of them was about 60 min. Flux at steady state ranged between 0.017 +/- 0.005 and 3.435 +/- 1.897 mg/cm(2)/h and permeation rate was from 0.0192 to 1.02 x 10(-3) cm/h. The presence of acetone in the solution caused a reduction in lag time and an increase in permeation rate, higher for EGMEE, lower for EGDEE, indicating the enhancing effect of this mixture of solvents. CONCLUSIONS: Our results confirm the high percutaneous absorption of the GEs tested. The Franz method might be helpful for obtaining a grading of skin notation for hydrophilic substances: in the case of glycol ethers, it can give us precise information about permeation risk, particularly important in the evaluation of exposure. In the case of solvents with high dermal absorption, the air concentration is no longer a sufficient measure of the total exposure to workers, and therefore merely respecting threshold limit values (TLVs) in the air is not necessarily enough to protect them.

Adult↗
PubMed2005

Air pollution and heat exposure study in the workplace in a glass manufacturing unit in India.

Air pollution in the workplace environment due to industrial operation have been found to cause serious occupational health hazard. Similarly, heat stress is still most neglected occupational hazard in the tropical and subtropical countries like India. The hot climate augments the heat exposure close to sources like furnaces. In this study an attempt is made to assess air pollution and heat exposure levels to workers in the workplace environment in glass manufacturing unit located in the State of Gujarat, India. Samples for workplace air quality were collected for SPM, SO(2), NO(2) and CO(2) at eight locations. Results of workplace air quality showed 8-hourly average concentrations of SPM: 165-9118 microg/m(3), SO(2): 6-9 microg/m(3) and NO(2): 5-42 microg/m(3), which were below the threshold limit values of workplace environment. The level of CO(2) in workplace air of the plant was found to be in the range 827-2886 microg/m(3), which was below TLV but much higher than the normal concentration for CO(2) in the air (585 mg/m(3)). Indoor heat exposure was studied near the furnace and at various locations in an industrial complex for glass manufacturing. The heat exposure parameters including the air temperature, the wet bulb temperature, and the globe parameters were measured. The Wet Bulb Globe Temperature (WBGT), an indicator of heat, exceeded ACGIH TLVs limits most of the time at all the locations in workplace areas. The recommended duration of work and rest have also been estimated.

Air Pollutants, Occupational↗
PubMed2005

A longitudinal study of industrial and clerical workers: incidence of carpal tunnel syndrome and assessment of risk factors.

This study followed workers over an extended period of time to identify factors which may influence the onset of Carpal Tunnel Syndrome (CTS). The purpose was to evaluate incidence of CTS and to create a predictive model of factors that play a role in the development of CTS. This prospective study followed 432 industrial and clerical workers over 5.4 years. Incident cases were defined as workers who had no prior history of CTS at baseline testing and were diagnosed with CTS during the follow-up period or at the follow-up screening. On the basis of logistic regression, significant predictors for CTS include baseline median-ulnar peak latency difference, a history of wrist/hand/finger tendonitis, a history of numbness, tingling, burning, and/or pain in the hand, and work above the action level of the peak force and hand activity level threshold limit value. This longitudinal study supports findings from previous cross-sectional studies identifying both work related ergonomic stressors and physical factors as independent risk factors for CTS.

Adult↗
PubMed1985

Production and quality control of 15O2 and C15O2 for medical use.

The remotely controlled on-line production with a cyclotron of 15O2 and C15O2 for routine medical use is described. The radiochemical purities have been determined and compared with literature data. The impurities formed during irradiation can be removed with appropriate traps. The toxic gases ozone, nitrogen dioxide and carbon monoxide are formed in the target at concentration levels above the "Threshold Limit Value". Therefore a chemical quality control procedure has been developed. A copper oxide-iron oxide trap was found to improve the radiochemical and chemical purity of the C15O2.

Carbon Dioxide↗
PubMed1980

Dust in dental laboratories. Part II: Measurement of particle size distributions.

It has been demonstrated in a previous study that threshold limit values of various elements or compounds could be considerably exceeded in various work operations in the dental laboratories when appropriate ventilation systems were not used. This refers to working with chromium-cobalt alloys, amalgam dies, porcelain, and gypsum. In the present study, size distributions of particles arising from cutting, grinding, or polishing of alloys, gypsum, porcelain, or denture base material in dental laboratories have been measured. The particle size distributions were evaluated by means of light and electron microscopy as well as by coulter-counting techniques. The measurements revealed the occurrence of a high proportion of respirable dust associated with these operations. consequently, the use of efficient ventilation systems is strictly necessary to ensure industrial safety with respect to air pollution in the working environment of dental laboratories.

Air Pollutants↗
PubMed1984

Immobilized cholinesterase to detect airborne concentrations of hexamethylene diisocyanate (HDI).

A sensitive personal passive dosimeter, based on an enzymatic reaction, was developed to monitor exposure to airborne concentrations of hexamethylene diisocyanate (HDI), used in the production of polyurethanes. Dosimeters were prepared by adsorption of butyryl- or acetylcholinesterase on sheets of polystyrene. Exposure of enzyme-coated strips to vapors of isocyanates demonstrated their great sensitivity to HDI. Dosimeters detected workplace exposure levels of 5 ppb (NIOSH recommended threshold limit value) within 12 min. Dosimeters responded to higher concentrations of toluene diisocyanate (TDI). Interference by TDI and other anticholinesterase agents is unlikely as they would not be expected to be present in the same industrial workplace.

Air Pollutants, Occupational↗