Acute health effects common during graffiti removal

Objective: The aim of this study was to identify possible health effects caused by different cleaning agents used in graffiti removal. Methods: In 38 graffiti removers working 8-h shifts in the Stockholm underground system, the exposure to organic solvents was assessed by active air sampling, biological monitoring, and by interviews and a questionnaire. Health effects were registered, by physical examinations, porta7ble spirometers and self-administered questionnaires. The prevalence of symptoms was compared with 49 controls working at the underground depots, and with 177 population controls. Results: The 8-h time-weighted average exposures (TWA) were low, below 20% of the Swedish permissible exposure limit value (PEL) for all solvents. The short-term exposures occasionally exceeded the Swedish short-term exposure limit values (STEL), especially during work in poorly ventilated spaces, e.g. in elevators. The graffiti removers reported significantly higher prevalence of tiredness and upper airway symptoms compared with the depot controls, and significantly more tiredness, headaches and symptoms affecting airways, eyes and skin than the population controls. Among the graffiti removers, some of the symptoms increased during the working day. On a group basis, the lung function registrations showed normal values. However, seven workers displayed a clear reduction of peak expiratory flow (PEF) over the working shift. Conclusions: Though their average exposure to organic solvents was low, the graffiti removers reported significantly higher prevalence of unspecific symptoms such as fatigue and headache as well as irritative symptoms from the eyes and respiratory tract, compared with the controls. To prevent adverse health effects it is important to inform the workers about the health risks, and to restrict use of the most hazardous chemicals. Furthermore, it is important to develop good working practices and to encourage the use of personal protective equipment. Received: 23 June 2000 / Accepted: 01 November 2000     

Occupational chronic exposure to organic solvents

Summary Seventeen persons (2 women and 15 men), who were exposed to glycolethers in a varnish production plant, were examined according to their external and internal solvent exposure. The workers in the production plant (n =12) were exposed to average concentrations of ethoxyethanol, ethoxyethyl acetate, butoxyethanol, 1-methoxypropanol-2, 2-methoxypropyl-1-acetate and xylene of 2.8; 2.7; 1.1; 7.0; 2.8 and 1.7 ppm. In the air of the store (n = 3) and in the laboratory (n = 2) only minor concentrations of xylene respectively xylene and ethoxyethyl acetate could be measured. Internal exposure was estimated by measuring butoxyethanol (BE) in blood as well as ethoxyacetic acid (EAA) and butoxyacetic acid (BAA) in urine samples. Urine samples were taken pre- and post-shift. As expected, the highest values were found in the varnish production. The average post shift concentrations of BE, EAA and BAA were 121.3 g/l; 167.8 and 10.5 mg/l. The relatively high concentrations of EAA and BAA in pre-shift samples can be explained by the long half-lives of these metabolites. According to our findings most of the glycolethers were taken up through the skin. Comparing our results with those reported in the literature we think that a future tolerable limit value for the concentration of ethoxyacetic acid in urine should be in the order of 100 to 200 mg/l.     

Ambient monitoring and biomonitoring of workers exposed to N-methyl-2-pyrrolidone in an industrial facility

Objectives: The exposure of seven workers and three on-site study examiners to N-methyl-2-pyrrolidone (NMP) was studied in an adhesive bonding compound and glue production facility. Methods: Airborne NMP was analysed by personal and stationary sampling on activated charcoal tubes. NMP and its main metabolites, 5-hydroxy-N-methyl-2-pyrrolidone (5-HNMP) and 2-hydroxy-N-methylsuccinimide (2-HMSI), were analysed in pre-shift and post-shift spot urine samples by gas chromatography-mass spectrometry. The workers were examined with respect to irritation of the eyes, the mucous membranes and the skin, and health complaints before and after the work-shift were recorded. Results: The time-weighted average concentration of NMP in most work areas varied between 0.2 and 3.0 mg/m³. During the manual cleaning of stirring vessels, valves and tools, 8-h TWA exposures of up to 15.5 mg/m³ and single peak exposures of up to 85 mg/m³ were observed. NMP and its metabolites were detected in two pre-shift urine specimens. NMP and 5-HNMP concentrations in post-shift urine samples of five workers and three on-site study examiners were below 125 μg/g creatinine and 15 mg/g creatinine, respectively, while two vessel-cleaning workers showed significantly higher urinary NMP concentrations of 472 and 711 μg/g creatinine and 5-HNMP concentrations of 33.5 and 124 mg/g creatinine. 2-HMSI was detectable in four post-shift samples (range: 1.6–14.7 mg/g creatinine). The vessel cleaner with the highest NMP exposure reported irritation of the eyes, the upper respiratory tract and headaches. Conclusions: The results of this study indicate a relatively low overall exposure to NMP in the facility. An increased uptake of NMP occurred only during extensive manual vessel cleaning. Health complaints associated with NMP exposure were recorded in one case and might be related to an excessive dermal exposure due to infrequent and inadequate use of personal protective equipment.     

The use of experimental studies to reveal suspected neurotoxic chemicals as occupational hazards: acute and chronic exposures to organic solvents.

The nervous system differs from many other body organs by its central control of vital functions and its low regeneration capacity. Organic solvents have, as a group, been suspected to have neurotoxic effects. Because of their similar physical properties and the fact that in industrial uses, they are often present in various mixtures, organic solvents have also been regarded, unfortunately, to induce common neurotoxic effects. However, it is evident from experimental studies using specified exposure conditions that different organic solvents have very diverse neurotoxic effects and also that the toxic mechanism may differ between acute and chronic exposure. No specific method used to describe a neurotoxic effect or single toxic response can be used for the overall occupational risk assessment of all organic solvents. Each solvent has to be considered as having its own unique toxic effects.     

Occupational chronic exposure to organic solvents

Summary Two groups of workers occupationally exposed to glycol ethers in a varnish production plant or the ceramic industry were examined. For 19 persons the external and internal exposure was assessed on the Monday and Tuesday after an exposure-free weekend. In the varnish production area the concentrations of 2-ethoxy-ethanol (EE) 2-ethoxyethyl acetate (EEAc), and 2-butoxyethanol (BE) in air averaged 2.9, 0.5, and 0.5 ppm, respectively, on the Monday, and 2.1, 0.1, and 0.6 ppm, respectively, on the Tuesday. At the same workplaces the mean urinary 2-ethoxyacetic acid (EAA) and 2-butoxyacetic acid (BAA) concentrations were 53.2 and 0.2 mg/l on Monday preshift and 53.8 and 16.4 mg/l on Tuesday postshift. The results show that glycol ethers are very well absorbed through the skin. Therefore biological monitoring is indispensable. To study the kinetics of the toxic metabolite, 17 persons were examined for their excretion of EAA in urine during an exposure-free weekend. The median values of the calculated half-times were 57.4 and 63.4 h, respectively, which are longer than the values presented in literature until now. According to our calculations the limit value should not exceed 50 mg EAA per liter of urine, which is the current German biological tolerance value (BAT value) for EAA in urine. The maximum concentration value at the work place (MAK value) for EE and EEAc in air should be revised. Finally, the subjects from the varnish production plant as well as a group of reference persons were studied for cytogenetic effects of glycol ethers (sister chromatid exchange, micronucleus test). Such effects could not be detected.     

Adverse reproductive outcomes among male painters with occupational exposure to organic solvents

Objectives

To assess the risks of reproductive disorders and birth defects in offspring of male painters with exposure to organic solvents, and to determine the shape of the dose‐response relationship.

Methods

Random samples of painters and carpenters were drawn from workers affiliated with the Dutch Trade Union for Construction Workers, the Netherlands, 2001. Information on reproductive outcomes, occupational exposures, and lifestyle habits was retrospectively obtained through self‐administered questionnaires filled in by 398 painters exposed to organic solvents in paints, thinners, and cleansers in the period of three months before the last pregnancy, and 302 carpenters with little or no exposure to solvents. A statistical model was used to estimate quantitative exposure measures.

Results

Workers employed as painters at three months before pregnancy had an increased risk (odds ratio 6.2, 95% CI 1.4 to 27.9) of congenital malformations in offspring compared to carpenters. There was a positive exposure‐response trend with increasing exposure to organic solvents based on quantitative model predicted exposure estimates using toluene as a marker. There was some indication of an increased risk of functional developmental disorders in offspring among painters with intermediate and high model predicted exposure. The risk of low birth weight children seemed to be slightly increased among painters as well. Results for other reproductive outcomes (time to pregnancy, spontaneous abortion, and preterm birth) did not show increased risks.

Conclusion

This study showed a positive association between paternal occupational exposure to organic solvents and congenital malformations in offspring. However, the small numbers of cases, especially when examining different exposure levels, as well as the self‐reported nature of exposure and outcome variables, may hamper interpretation of the results.     

Chronic occupational exposure to organic solvents

Summary Twenty-two persons (20 men and 2 women) were examined for their external and internal exposure to the glycol ether 1-methoxypropan-2-ol (PGME) during the production, leak testing and mounting of brake-hoses. For the measurement of external exposure, personal air monitoring was the method of choice. Average concentrations of PGME of 82.2 mg/m³ (22.3 ppm), 68.6 mg/m³ (18.6 ppm) and 11.3 mg/m³ (3.1 ppm) were found in the air of the brakehose production, leak test and mounting areas, respectively. For the estimation of internal exposure to PGME, this glycol ether was measured in both urine and blood. The biological samples were taken post-shift. The highest internal exposure levels were found in the brakehose production section and in the leak test area. The average post-shift concentrations for PGME in workers in the brakehose production section were 4.6 mg/l in urine and 13.5 mg/l in blood; the corresponding figures for workers in the leak test area were 4.2 mg/l in urine and 11.0 mg/l in blood. In blood and urine samples of workers engaged in the mounting area, PGME levels were below the detection limits. The elimination kinetics of PGME were also studied in three highly exposed persons, and mean excretion half-lives of PGME of approximately 4.4 h were found. On the basis of our results we made a rough calculation of a future biological tolerance value: we would except that concentrations of 38-109 mg per litre of blood and 10–31 mg per litre of urine would correspond to the German MAK value for PGME (375 mg/m³).     

The method of choice for the determination of 2,5-hexanedione as an indicator of occupational exposure to n-hexane

Summary To identify the method of choice for analysis of urine for 2,5-hexanedione (2,5-HD) as an indicator of occupational exposure to n-hexane, the end-of-shift urine samples of 36 n-hexane exposed male workers and 30 non-exposed male workers were analyzed for 2,5-HD under three conditions of hydrolysis, i.e. enzymic hydrolysis at pH 4.8, acid hydrolysis at pH 0.5, and without hydrolysis. The 2,5-HD concentrations thus determined were examined for correlation with 8-h, time-weighted average exposure concentrations of n-hexane measured by diffusive sampling. The regression analysis showed that the 2,5-HD concentrations without any hydrolysis correlated best with the intensity of exposure to n-hexane. No 2,5-HD was detected in the urine of the non-exposed subjects under the analytical conditions with no hydrolysis. Thus, the analysis without hydrolysis was considered to be the method of choice from the viewpoint of simplicity in analytical procedures, sensitive separation of the exposed from the non-exposed, and quantitative increase in the amount of 2,5-HD after n-hexane exposure.A part of this work was presented at the 63rd Annual Meeting of Japan Association of Industrial Health, held in Kumamoto, Japan, on 3rd–6th April, 1990     

Occupational exposure to organic solvents during paint stripping and painting operations in the aeronautical industry

Summary The exposure of workers to methylene chloride and phenol in an aeronautical workshop was measured during stripping of paint from a Boeing B 747. Methylene chloride exposure was measured during two work days by personal air sampling, while area sampling was used for phenol. During paint stripping operations, methylene chloride air concentrations ranged from 299.2 mg/m³ (83.1 ppm) to 1888.9 mg/m³ (524.7 ppm). The exposures to methylene chloride calculated for an 8-h work day ranged from 86 mg/m³ (23.9 ppm) to 1239.5 mg/m³ (344.3 ppm). In another aeronautical workshop, exposure to organic solvents, especially ethylene glycol monoethyl-ether acetate (EGEEA), was controlled during the painting of an Airbus A 320. The external exposure to solvents and EGEEA was measured by means of individual air sampling. The estimation of internal exposure to EGEEA was made by measuring its urinary metabolite, ethoxyacetic acid (EAA). Both measurements were made during the course of 3 days. The biological samples were taken pre-and post-shift. During painting operations, methyl ethyl ketone, ethyl acetate, n-butyl alcohol, methyl isobutyl ketone, toluene, n-butyl acetate, ethylbenzene, xylenes and EGEEA were detected in working atmospheres. For these solvents, air concentrations ranged from 0.1 ppm to 69.1 ppm. EGEEA concentrations ranged from 29.2 mg/m³ (5.4 ppm) to 150.1 mg/m³ (27.8 ppm). For biological samples, the average concentrations of EAA were 108.4 mg/g creatinine in pre-shift and 139.4 mg/g creatinine in post-shift samples. Despite the fact that workers wore protective respiratory equipment during paint spraying operations, EEA urinary concentrations are high and suggest that percutaneous uptake is the main route of exposure for EGEEA. The introduction of new paint stripping processes in the aeronautical industry could help to reduce future exposure to methylene chloride.     

Environmental monitoring of occupational exposure to <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dimethylformamide: comparison between active and diffusive sampling

Objectives The objective of this study is to optimize the evaluation of the exposure to N,N-dimethylformamide (DMF) in synthetic leather factories by diffusive samplers. The DMF exposure was monitored in synthetic leather factories by two sampler types: active and diffusive. Methods Air measurements were carried out using two different personal air samplers, a diffusive and an active one. The diffusive sampling method, TK200 with charcoal filters, was examined in comparison with pumping through NIOSH silica gel tubes workplace air as with the currently available “gold standard”. The evaluation was carried out, in two different years but in the same season, for all the duration of the shift, i.e. 8 h on workers employed in five different factories in the district of Florence and Prato (Italy). Results The statistical and graphical analysis of data show a good correlation between active and passive samplers (r = 0.96, P < 0.001, n = 91), a good linear regression (DMF_diffusive = 0.95 DMF_active + 0.15, R ² = 0.92), a not statistically significant difference between data (tested by paired t test and non-parametric Wilcoxon test). Moreover, all these results are confirmed for data lower and higher than TLV-TWA, in particular we found a significant Pearson correlation (r = 0.92, P < 0.001, n = 83; r = 0.92, P < 0.05, n = 8, respectively) and a significant linear regression (DMF_diffusive = 0.88 DMF_active + 0.73, R ² = 0.86; DMF_diffusive = 0.90 DMF_active + 3.76, R ² = 0.85). Besides, the analysis of graphical representations confirmed the previous evidences. Finally, we can not find a significant difference between different types of job. Conclusions Due to the good agreement between the two groups of data, the TK200 samplers can be considered as a simpler approach than the pump for screening worker exposures to DMF.     

Self-collected urine sampling to study the kinetics of urinary toluene (and <Emphasis Type="Italic">o</Emphasis>-cresol) and define the best sampling time for biomonitoring

Purpose  To study the excretion kinetics of urinary toluene, TOL-U, and o-cresol, o-C, following occupational exposure to toluene in order to define the best time for sample collection, to apply a non-invasive approach based on self-collected urine sampling. Methods  Five rotogravure printing workers exposed to uncontrolled levels of toluene collected spot urine samples over three consecutive working days and the following day of rest. In each sample TOL-U and o-C were measured and kinetics of excretion evaluated. Results  Toluene exposure ranged from 48.3 to 75.3 mg/m³; TOL-U and o-C ranged from 1.4 to 34.6 μg/L and from 0.013 to 1.012 mg/L. A time course trend was obtained: TOL-U and o-C increased during the shift and peaked at the end of exposure and up to 2 h later, respectively; afterwards they rapidly decreased following apparent first order kinetics. Considering TOL-U, the elimination half-life for the first fast phase was 79 (±35 standard error) min, and for the second slow phase was 1,320 (±1,162) min. For o-C the elimination half-life for the first fast phase was 231 (±48) min. Considering a toluene uptake of 86%, TOL-U and o-C excreted in urine were about 0.0067 and 0.18% of the up taken. Conclusion  Our results support the use of end shift TOL-U as a short term biomarker of occupational exposure to toluene and show the feasibility of self-collected urine sampling to investigate the elimination kinetics of industrial toxics in humans.     

Biological monitoring of exposure to solvents using the chemical itself in urine: application to toluene

Objective Biomonitoring of solvents using the unchanged substance in urine as exposure indicator is still relatively scarce due to some discrepancies between the results reported in the literature. Based on the assessment of toluene exposure, the aim of this work was to evaluate the effects of some steps likely to bias the results and to measure urinary toluene both in volunteers experimentally exposed and in workers of rotogravure factories. Methods Static headspace was used for toluene analysis. o-Cresol was also measured for comparison. Urine collection, storage and conservation conditions were studied to evaluate possible loss or contamination of toluene in controlled situations applied to six volunteers in an exposure chamber according to four scenarios with exposure at stable levels from 10 to 50 ppm. Kinetics of elimination of toluene were determined over 24 h. A field study was then carried out in a total of 29 workers from two rotogravure printing facilities. Results Potential contamination during urine collection in the field is confirmed to be a real problem but technical precautions for sampling, storage and analysis can be easily followed to control the situation. In the volunteers at rest, urinary toluene showed a rapid increase after 2 h with a steady level after about 3 h. At 47.1 ppm the mean cumulated excretion was about 0.005% of the amount of the toluene ventilated. Correlation between the toluene levels in air and in end of exposure urinary sample was excellent (r = 0.965). In the field study, the median personal exposure to toluene was 32 ppm (range 3.6–148). According to the correlations between environmental and biological monitoring data, the post-shift urinary toluene (r = 0.921) and o-cresol (r = 0.873) concentrations were, respectively, 75.6 μg/l and 0.76 mg/g creatinine for 50 ppm toluene personal exposure. The corresponding urinary toluene concentration before the next shift was 11 μg/l (r = 0.883). Conclusion Urinary toluene was shown once more time a very interesting surrogate to o-cresol and could be recommended as a biomarker of choice for solvent exposure.     

Biological monitoring of workers exposed to<Emphasis Type="Italic"> N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dimethylformamide in synthetic leather manufacturing factories in Korea

Objectives To investigate the relationship between N,N-dimethylformamide (DMF) exposure and excretion of urinary N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC) and N-methylformamide (NMF) in workers at synthetic leather manufacturing factories in Korea, for the first time.Methods One-hundred forty-four male workers at nine synthetic leather manufacturing factories were surveyed. Exposure to DMF was evaluated through breathing zone air sampling followed by analysis via a gas chromatograph equipped with a flame ionization detector (GC-FID). The levels of NMF and AMCC were determined by a GC with a flame thermionic detector (GC-FTD). Urine samples were collected at the end of the workshift.Results and Conclusions Geometric mean of workplace air DMF and urinary NMF was 8.8 ppm and 47.5 mg/l, respectively, and the level of DMF and NMF was significantly correlated. The biological exposure limit for NMF (15 mg/ml) was exceeded in 89.5% of urine samples, and 37.9% of air samples exceeded the environmental DMF exposure limit (10 ppm), indicating a serious health risk to the employees of the synthetic leather industry in Korea. Exposure to 10 ppm DMF in the workplace air corresponded to a urinary NMF concentration of 53.4 mg/l. Alcohol intake the day before urine was sampled influenced NMF excretion into urine (40.5 mg/l NMF for the no-alcohol group and 94.6 mg/l for the group consuming more than 63.0 g alcohol/day). We could not find a significant relationship between air DMF and urinary AMCC concentration. Exposure to 10 ppm DMF corresponded to an AMCC concentration of 8.0 mg/l in the urine samples collected on the same day as the air was sampled.     

Comparative evaluation of urinalysis and blood analysis as means of detecting exposure to organic solvents at low concentrations

Summary One hundred and forty-three workers exposed to one or more of toluene, xylene, ethylbenzene, styrene, n-hexane, and methanol at sub-occupational exposure limits were examined for the time-weighted average intensity of exposure by diffusive sampling, and for biological exposure indicators by means of analysis of shift-end blood for the solvent and analysis of shift-end urine for the corresponding metabolite(s). Urinalysis was also performed in 20 nonexposed control men to establish the background level. Both solvent concentrations in blood and metabolite concentrations in urine correlated significantly with solvent concentrations in air. Comparison of blood analysis and urinalysis as regards sensitivity in identifying low solvent exposure showed that blood analysis is generally superior to urinalysis. It was also noted that estimation of exposure intensity on an individual basis is scarcely possible even with blood analysis. Solvent concentration in whole blood was the same as that in serum in the case of the aromatics, except for styrene. It was higher in blood than in serum in the case of n-hexane, and lower in the cases of styrene and methanol.     

Dose-dependent increase in 2,5-hexanedione in the urine of workers exposed to n-hexane

Summary The concentrations of 2,5-hexanedione (2,5-HD), an n-hexane metabolite, and 2-acetylfuran (2-AF) were measured in urine samples from 123 workers who had predominantly been exposed to n-hexane vapor and 53 workers who had experienced no exposure to solvents. The time-weighted average intensity of exposure to n-hexane vapor was determined by a diffusive sampling method. For biological monitoring of exposure, urine samples were collected late in the afternoon during the second half of a working week and were analyzed in the presence and absence of acid hydrolysis (at pH < 0.5) for 2,5-HD and 2-AF by gas chromatography on a non-polar capillary DB-1 column. The urinary 2,5-HD concentration increased as a linear function of the intensity of exposure to n-hexane, showing a correlation coefficient of 0.64–0.77 after acid hydrolysis and that of 0.730–0.83 in the absence of hydrolysis, depending on the correction for urinary density (P < 0.01 in all cases, with no improvement in the coefficient occurring after the corrections). In contrast, 2-AF levels were independent of n-hexane exposure. The geometric mean 2,5-HD concentration in urine samples from 53 nonexposed men was 0.26 mg/l as observed (i.e., with no correction), 0.19 mg/l after correction for a urinary specific gravity of 1.016, and 0.23 mg/g creatinine after correction for creatinine concentration, and the geometric standard deviation was approximately 2.     

Percutaneous absorption of N,N-dimethylformamide in humans

Summary Skin penetration fo N,N-dimethylformamide (DMF) liquid or vapour was studied in volunteers. Exposure to liquid DMF was performed in two ways: in a dipping experiment, one hand was dipped up to the wrist in DMF for 2–20 min, while in a patch experiment, 2 mmol DMF was applied to the skin and allowed to be absorbed completely. The period of exposure to DMF vapour (50 mg · m^–3) was 4 h. The DMF metabolites N-hydroxymethyl-N-methylformamide (MF), N-hydroxymethylformamide (F), and N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC) were monitored in the urine. Liquid DMF was absorbed through the skin at a rate of 9.4 mg · cm^–2 · h^–1. Percutaneous absorption of DMF vapour depended strongly on ambient temperature and humidity and accounted for 13%–36% of totally excreted MF. The results suggest that skin absorption of liquid DMF is likely to contribute to occupational exposure substantially more than penetration of DMF vapour. The yield of metabolites after transdermal DMF absorption was only half of that seen after pulmonary absorption. Elimination of MF and F but not that of AMCC was delayed, which supports the contention that AMCC should be used instead of MF as the most suitable biomarker of DMF in cases where percutaneous intake can occur.     

Biological monitoring of workers exposed toN,N-dimethylformamide by determination of the urinary metabolites,N-methylformamide andN-acetyl-S-(N-methylcarbamoyl) cysteine

Biological monitoring of workers exposed toN,N-dimethylformamide (DMF) was carried out by determination of the urinary metabolites,N-methylformamide (MF, mainly fromN-hydroxymethylformamide) andN-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC), which were derived from two different routes of metabolism of the solvent. The urinary levels of MF increased rapidly at the start of the work shift, and decreased almost to zero within 24 h after the beginning of the last exposure. The highest level was found between the end of the afternoon shift and bedtime. AMCC levels remained constant over the consecutive work days and increased after the cessation of exposure, with the peak concentration being observed at 16–40 h after the cessation of exposure. AMCC levels at the beginning of the next morning shift were closely correlated with personal exposure levels of DMF in air, although the correlation of MF and DMF in air was highest in the urine at the end of the shift. Hence urinary AMCC represents an index of the average exposure during several preceding work days and may indicate the internal dose. By contrast, MF represents an index of daily exposure.