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PubMed2003

Nervous system effects of occupational manganese exposure on South African manganese mineworkers.

Occupational exposure to airborne manganese dust has been shown to produce adverse effects on the central nervous system. Four hundred and eighty-nine blue and white collar manganese mineworkers from South Africa were studied cross-sectionally to investigate the nervous system effects of medium to low occupational manganese exposures. The different facilities included underground mines, surface processing plants, and office locations. A job exposure matrix was constructed using routine occupational hygiene data. Exposure variables included years of service, a cumulative exposure index (CEI) and average intensity of exposure (AINT) across all jobs, and blood manganese. Endpoints included items from the Q16, WHO-NCTB, SPES, and Luria-Nebraska test batteries, and a brief clinical examination. Potential confounders and effect modifiers included age, level of education, past medical history including previous head injury, previous neurotoxic job exposures, tobacco use, alcohol use and home language. Associations were evaluated by multiple linear and logistic regression modeling. Average exposure intensity across all jobs was 0.21mg/m(3) manganese dust. Multivariate analyses showed that none of the symptom nor test results were associated with any measure of exposure including blood manganese, after adjustment for confounders. This relatively large null study indicates that manganese miners exposed on average across all jobs to MnO(2) at levels near the American Conference of Governmental Industrial Hygienists Threshold Limit Value (ACGIH TLV) are unlikely to have a subclinical neurotoxicity problem.

Adult↗
PubMed2003

The utility of biological monitoring for manganese in ferroalloy smelter workers in South Africa.

Five hundred and nine workers at a manganese (Mn) smelting works comprising eight production facilities and 67 external controls were studied cross-sectionally. Exposure measures from personal sampling included inhalable dust, cumulative exposure indices (CEI) and average intensity (INT = CEI/years exposed) calculated for the current job at the smelter and also across all jobs held by subjects. Biological exposure was measured by Mn in the blood (MnB) and urine (MnU) and biological effect was measured by serum prolactin. Average lifetime exposure intensity across all jobs ranged from near 0 (0.06 microg/m3) for unexposed external referents to 5 mg/m3. Atmospheric exposures and MnB and MnU distributions were consistent with published data for both unexposed and smelter workers. Associations between biological exposures and groups defined by atmospheric exposures in the current job were substantial for MnB, less so for MnU and absent for serum prolactin. Random sampling of MnB measurements representative of a group of workers with more than 1-2 years of service in the same job and notionally homogenous exposure conditions could serve as a cross-sectional predictor of atmospheric Mn exposure in the current job, as well as for surveillance of Mn exposure trends over time. Correlations at the individual level were only modest for MnB (33% of the variance in log atmospheric Mn intensity in the current job was explained by log MnB), much worse for MnU (only 7%). However, a receiver operating characteristic (ROC) analysis was performed which showed that it is possible to use a MnB cut-off of 10 microg/l (the 95th percentile in the unexposed) to good effect as a screening tool to discriminate between individual exposures exceeding and falling below a relatively strict atmospheric Mn exposure threshold at the ACGIH threshold limit value (TLV) of 0.2 mg/m3. MnU has no utility as a measure of biological exposure nor does serum prolactin as a measure of biological effect.

Alloys↗
PubMed2000

Increased airway responsiveness after skin sensitisation to 3-carene, studied in isolated guinea pig lungs.

Inhalation of 3-carene has been shown to induce bronchoconstriction in concentrations not far from the threshold limit value. In this study, one group of guinea-pigs were sensitised by dermal exposure to 3-carene according to the modified Cumulative Contact Enhancement Test protocol and another group of animals was used as controls. Lungs from the skin-sensitised and control guinea-pigs were perfused with diluted autologous blood (13 ml blood/87 ml buffer) and exposed to 3-carene at an air concentration of 3000 mg/m(3). In both groups there was a reduction in compliance and conductance but this reduction was significantly (P<0.05) more pronounced (2.5-3 times) in lungs obtained from sensitised animals than from control animals. In a previous study with similar design, but with plain buffer instead of diluted autologous blood as perfusate, we found no statistically significant difference in lung bronchoconstriction. Thus, it is concluded that skin sensitisation can increase lung reactivity to 3-carene and that important mediators of this effect seem to be present in the blood.

Administration, Inhalation↗
PubMed1999

Reproductive toxicity of occupational mercury. A review of the literature.

OBJECTIVES: This paper aims to give the dental practitioner insight into the potential reproductive effects of handling dental silver amalgam, c.q. mercury. DATA SOURCES: Experimental studies on animals, case reports and epidemiologic studies. STUDY SELECTION: Experimental animal studies show high doses/concentrations of mercury to increase the risk of reproductive disorders, e.g. infertility, spontaneous abortion, stillbirth and congenital malformations. Some case reports suggest an association between the disorders in humans and high levels of mercury. Therefore, the present article reviews epidemiological studies on the relationship between occupational exposure to mercury, mainly as vapour in the dental practice, and females' procreative ability. Studies concerning the reproductive effects of males' occupational mercury body burden are scarce. The reproductive risk of patients' mercury uptake from silver amalgam fillings is assessed. CONCLUSIONS: It seems warranted to conclude that negative reproductive effects from exposure to mercury in the dental office are unproven, but safe levels have not been established. Seemingly problems are unlikely to occur, unless a poor hygiene causes the mercury concentration in the air to exceed females' time-weighted long-term Threshold Limit Value (TLV). Consequently, in view of the in general low amounts of mercury stemming from dental amalgam fillings, the population at large is at even less risk than dental staff. The effects of occupational elemental mercury concentrations lower than the TLV on the menstrual cycle, conception, male fertility and children's behaviour need, however, more research.

Animals↗
PubMed1998

Vapor emissions resulting from Nd:YAG laser interaction with tooth structure.

UNLABELLED: The Neodymium:yttrium aluminum garnet (Nd:YAG) dental laser has been cleared by the United States Food and Drug Administration (FDA) for marketing in intraoral soft tissue treatment. The efficacy and safety of the Nd:YAG laser in the treatment of hard dental tissue as well as the effects of dental irradiation on the pulp and periodontium have been investigated. Odors resulting from laser irradiation have been reported, but the nature and toxicity of associated decomposition vapors is unknown and the health consequences of their inhalation have not yet been studied. OBJECTIVES: The purpose of this in vitro study was to identify vapors emitted during interaction of the Nd:YAG laser with carious human enamel and dentin and sound enamel and dentin coated with organic ink. METHODS: Vapor emissions were collected from prepared sections of extracted human teeth receiving laser irradiation of 100 mJ and 10 Hz for a duration of 1, 10, or 60 s. Emissions were collected by means of charcoal absorption tubes, and subsequently analyzed using a Gas Chromatograph equipped with Mass Selective (GC/MS) and Flame Ionization Detectors to identify the chemical constituents of the vapors. RESULTS: No compounds were identified in Nd:YAG laser-treated caries, enamel and dentin. No volatile vapors were identified from samples of tooth materials exposed to the laser for 1 or 10 s. Camphor was positively identified in the test sample which consisted of India ink-coated dentin and the reference sample of India ink-coated glass beads, both exposed to the laser for 60 s. 2,5-norbornadiene was tentatively identified in these samples. The Threshold Limit Value (TLV) of camphor is 2 ppm with a Lethal Dose Level (LDLo) of 50 mg/kg (human oral), while the TLV and LDLo of 2,5-norbornadiene is unknown. SIGNIFICANCE: Occupational and public health safety measures are discussed in this article. Further research is needed to quantify the compounds produced and to determine their toxicity to patients and to dental care providers.

Air Pollution, Indoor↗
PubMed1998

Histopathological study in B6C3F1 mice chronically exposed by inhalation to glutaraldehyde.

Glutaraldehyde vapors are irritating for the skin, eyes, nose and lungs; respiratory symptoms and headaches have been described among workers exposed to low concentrations of glutaraldehyde far below to 190 ppb. This study was initiated to determine the chronic effects in mice of inhaled glutaraldehyde vapors. B6C3F1 mice were exposed using whole-body inhalation chambers, 6 h/day, 5 days/week, for 52 and 78 weeks to 100 ppb, or to filtered air (controls). In nasal passages at the level of the vestibule, hyperplasia of the squamous epithelium lining of the dorsal wall and lateral aspect of the atrioturbinate was observed in a greater number of exposed females than in controls. Epidermal erosion and ulceration as well as squamous and inflammatory exfoliation were also seen in the nasal lumens. All these changes were dependent on the length of glutaraldehyde exposure. The present data suggest that glutaraldehyde long term exposure only led to changes in nasal passages of female mice but did not induce mortality and/or tumors in nasal passages, in all mice. These results, along with the previous subchronic inhalation study of Gross et al., 1994, demonstrates that in a long term study, chronic glutaraldehyde exposure close to the current threshold limit values induced lesions at the more anterior part of the nasal passages in mice and that they likely result from an irritation mechanism (antero-posterior gradient).

Animals↗
PubMedDate not supplied

Color vision and occupational toluene exposure.

We examined the relationship between acquired color vision loss and exposure to toluene and total hydrocarbons among 125 male workers. Seventy-two toluene-exposed printers were compared with 34 workers from the same photogravure plant with ambient background exposure, and with 19 workers from a bookbinding plant located in the same town (nonexposed). Environmental mean toluene exposure level at workstation was estimated from individual 8-h sampling. Historic exposure data from the last 30 years were used to construct two cumulative exposure indices, one for toluene and one for total hydrocarbons. Airborne toluene levels were overall lower than the current Threshold Limit Value (TLV) of 50 ppm. Color vision was assessed by the Lanthony D-15 desaturated panel. Color vision loss was quantitatively established by the Color Confusion Index (CCI) and classified by type of acquired dyschromatopsia according to Verriest's classification. CCI was positively related to current airborne toluene levels, and cumulative exposure indices for toluene and total hydrocarbons (.18< or =r< or =.35). Odds ratios of acquired dyschromatopsia were significant for current airborne toluene, toluene, and total hydrocarbon past exposure (1.27 [1.02-1.58], 1.21 [1.04-1.39], 1.15 [1.02-1.31], respectively). In conclusion, this study suggests that the Lanthony D-15 desaturated panel detects early neurotoxic effects among workers exposed to toluene.

Adult↗
PubMed2001

Cell and molecular biology of chemical allergy.

OBJECTIVE: The objective of this review is to provide current approaches to gain increased understanding of the molecular basis of chemical allergenicity. Chemical allergy refers to an allergic reaction to a low molecular weight agent (ie, <1 kD). The symptoms and pathology of chemical asthma resemble those of allergy to larger sized agents, such as pollens, weeds, and danders. The differences relate to mechanisms of disease. To stimulate an immune response, low molecular weight chemicals function as haptens and bind to carrier macromolecules. This article focuses on the chemical reactions and physicochemical characteristics of chemical allergens. DATA SOURCES: Data were obtained from published clinical reports and from the Documentation of Threshold Limit Values (1998) published by the American Congress of Governmental Industrial Hygienists. RESULTS: In vitro studies indicate the stoichiometric reaction of some chemical allergens with glutathione and the subsequent transfer of the allergen from glutathione to other nucleophiles. Computer-generated structure-activity relationship models have been developed for chemicals that induce respiratory allergy. The models, based on physicochemical properties of the agents, have high sensitivity and specificity. CONCLUSIONS: The structure-activity relationship model suggests that chemical binding is the essential feature of chemical allergens. Their in vivo reactions with thiols may result in glutathione deficiency with consequent alteration in cellular reduction-oxidation (redox) status, release of cytokines, and promotion of the T helper cell 2 phenotype. Prevention of permanent disease is dependent on periodic medical surveillance of affected workers. When detected early, the disease can frequently be reversed.

Allergens↗
PubMed1999

Toxicologic considerations in the diagnosis of occupational asthma.

BACKGROUND: The consideration of dose for chemicals inducing occupational asthma is examined from the point of view of a toxicologist. Two widely used chemicals in industry, toluene diisocyanate (TDI) and formaldehyde, are used as examples of agents that are formally recognized by OSHA to cause occupational asthma. The Permissible Exposure Limit (PEL) of OSHA and the Threshold Limit Value (TLV) of ACGIH for TDI are identical and are in the range of values for which occupational asthma has been reported in some workers. The narrow range of exposure values for TDI in studies of workers with and without asthma is discussed and correlated with the background concentration of TDI in the ambient atmosphere. For formaldehyde, the PEL and TLV, in contrast, offer a wide margin of safety for the inducement of occupational asthma. CONCLUSION: From this disparity in exposure limits for TDI and formaldehyde, it is concluded that occupational exposure limits by agencies for specific chemicals do not provide a reliable indication of the concentration of a chemical that is necessary to produce occupational asthma. The need for a better appreciation of dose response, particularly relative to background, ambient levels, in the evaluation of occupational asthma is emphasized.

Asthma↗
PubMed2002

Inhalation of ozone induces DNA strand breaks and inflammation in mice.

Ozone (O3) is a well-known oxidant pollutant present in photochemical smog. Although ozone is suspected to be a respiratory carcinogen it is not regulated as a carcinogen in most countries. The genotoxic and inflammatory effects of ozone were investigated in female mice exposed to ozone for 90 min. The tail moment in bronchoalveolar lavage (BAL) cells from BALB/c mice was determined by the comet assay as a measure of DNA strand breaks. Within the first 200 min after exposure, the BAL cells from the mice exposed to 1 or 2 ppm ozone had 1.6- and 2.6-fold greater tail moments than unexposed mice. After 200 min there was no effect. It could be ruled out that the effect during the first 200 min was due to major infiltration of lymphocytes or neutrophils. Unexpectedly, ozone had no effect on the content of 8-oxo-deoxyguanosine (8-oxo-dG) in nuclear DNA or on oxidised amino acids in the lung tissue. The mRNA level of the repair enzyme ERCC1 was not increased in the lung tissue. Inflammation was measured by the cytokine mRNA level in lung homogenates. An up to 150-fold induction of interleukin-6 (IL-6) mRNA was detected in the animals exposed to 2 ppm ozone compared to the air-exposed control mice. Also at 1 ppm ozone, the IL-6 mRNA was induced. The large induction of IL-6 mRNA in the lung took place after DNA strand breaks were induced in BAL. This does not support the notion that inflammatory reactions are the cause of DNA damage. To determine whether these exposures were mutagenic, Muta Mice were exposed to 2 ppm ozone, 90 min per day for 5 days. No treatment-related mutations could be detected in the cII transgene. These results indicate that a short episode of ozone exposure at five times the threshold limit value (TLV) in US induces lung inflammatory mediators and DNA damage in the cells in the lumen of the lung. This was not reflected by an induction of mutations in the lung of Muta Mice.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2002

Quality assurance of biological monitoring in occupational and environmental medicine.

Biological monitoring of chemical exposure in the workplace has become increasingly important in the assessment of health risk as an integral part of the overall occupational health and safety strategy. In environmental medicine biological monitoring plays also an important role in the assessment of excessive, acute or chronic exposure to chemical agents. To guarantee that the results obtained in biological monitoring are comparable with threshold limit values and results from other laboratories, the analysis must be carried out with tested and reliable analytical methods and accompanied by a quality assurance scheme. Confounding influences and interferences during the pre-analytical phase can be minimised by recommendations from experienced laboratories. For internal quality control commercially available control samples with an assigned concentration are used. External quality control programs for biological monitoring are offered by several institutions. The external quality control program of the German Society of Occupational and Environmental Medicine has been organised since 1982. In the meantime the 27th program has been carried out offering 96 analytes in urine, blood and plasma for 47 substances. This program covers most of the parameters relevant to occupational and environmental medicine. About 350 laboratories take part in these intercomparison programs. At present, ten German and 14 international laboratories are commissioned to determine the assigned values. The data evaluated from the results of the intercomparison programs give a good overview of the current quality of the determination of analytes assessed in occupational and environmental toxicological laboratories. For the analysis of inorganic substances in blood and urine the tolerable variation ranges from 7.5 to 43.5%. For organic substances in urine the tolerable variation ranges from 12 to 48%. The highest variations (36-60%) were found for the analysis of organochlorine compounds in plasma. The tolerable variations for the determination of solvents in blood by head space gas chromatography range from 26 to 57%. If the recommendations for the pre-analytical phase, the selection of reliable analytical methods by the laboratory and the carrying out of adequate quality control are observed, the pre-requisites for reliable findings during biological monitoring are fulfilled

Chromatography↗
PubMed2001

Determination of morpholine in air by derivatisation with 1-naphthylisothiocyanate and HPLC analysis.

A method for the determination of morpholine in air was developed. Samples were collected with adsorbent tubes containing XAD-2 resin coated with 1-naphthylisothiocyanate (NIT). The thiourea derivative formed was subsequently desorbed with acetonitrile and analysed by HPLC with UV detection. The recovery after gas phase spiking with morpholine (2.2-1570 micrograms) was 91% (86-100%) with a relative standard deviation of 5.5%. No effect on recovery from relative humidity or amount of morpholine was seen. The lowest level tested corresponded to 7 mg m-3 (1/10 threshold limit value) for a 15 min sampling period with a sampling rate of 20 ml min-1. Exposed NIT-coated XAD-2 tubes were stable at room temperature for at least 2 weeks.

1-Naphthylisothiocyanate↗
PubMed2001

Particle size and chemical species 'fingerprinting' of aerosols in primary nickel production industry workplaces.

A field study was conducted at a range of worksites at a number of plants, for two companies, in the primary nickel production industry. The aim of the field study was to provide direct measurements of the distributions of both particle size and relevant nickel species groups (soluble, sulfidic, metallic and oxidic). and to use the data to characterize health-relevant aerosol exposures of workers at the worksites in question. Since there was no commercially-available sampler that could provide samples of sufficient quantity to enable chemical speciation for the species fractions of interest, as well as particle size distribution information, new instrumentation was developed, based on a modified version of the Andersen cascade impactor, incorporating a porous foam media top stage that produced particle classification over the upper end of the inhalable range (Kerr, Vincent and Ramachandran, Annals of Occupational Hygiene, 2001, in the press). This modified-Andersen sampler was used in extensive field studies, along with other sampling instruments, including, in particular, the IOM personal inhalable aerosol sampler. The results of the field study provided results that could be represented succinctly in terms of the distributions of the four nickel species groups and the three health-related particle-size fractions: inhalable, thoracic and respirable. They showed that, for practical purposes, the distributions of the four nickel species groups were consistently uniform across the full range of particle-size distribution. For the purpose of characterizing the distribution of nickel species for each worksite, this finding enabled incorporation of additional data taken at those same sites using the IOM personal inhalable aerosol sampler. This yielded a data set sufficient to permit the development of exposure 'fingerprints' for each worksite. Such 'fingerprints' make it possible for the occupational hygienists at the plants in question to estimate workers' exposure to individual nickel species fractions based on measurement only of overall inhalable nickel. In addition, by reference to the differing threshold limit values (TLV) for the various nickel species, the 'fingerprints' also allow the individual worksites to be characterized by hazard indices (in the form of 'equivalent sulfidic fractions', or ESFs) that reflect the weightings of the risks experienced by workers at each worksite.

Aerosols↗
PubMed2002

An evaluation of total and inhalable samplers for the collection of wood dust in three wood products industries.

In 1998 the American Conference for Governmental Industrial Hygienists (ACGIH) proposed size selective sampling for wood dust based on the inhalable fraction. Thus the proposed threshold limit values (TLVs) require the use of a sampler whose performance matches the inhalable convention. The Institute of Occupational Medicine (IOM) sampler has shown good agreement with the inhalable convention under controlled conditions, and the Button sampler, developed by the University of Cincinnati, has shown reasonable agreement in at least one laboratory study. The Button sampler has not been previously evaluated under wood working conditions, and the IOM has been shown to sample more mass than expected when compared to the standard closed-face cassette, which may be due to the collection of very large particles in wood working environments. Some projectile particles may be > 100 microm aerodynamic diameter and thus outside the range of the convention. Such particles, if present, can bias the estimates of concentration considerably. This study is part of an on-going research focus into selecting the most appropriate inhalable sampler for use in these industries, and to examine the impact of TLV changes. This study compared gravimetric analyses (National Institute of Occupational Safety and Health Method 0500) of side-by-side personal samples using the Button, IOM, and 37 mm closed-face cassette (CFC) under field-use conditions. A total of 51 good sample pairs were collected from three wood products industries involved in the manufacturing of cabinets, furniture, and shutters. Paired t-tests were run on each sample pair using Statistical Package for the Social Sciences (SPSS) version 10. The IOM and the CFC measured statistically different concentrations (p < 0.0005, n = 16). The IOM and Button measured statistically different concentrations (p = 0.020, n = 12). The Button and CFC did not measure statistically different concentrations of wood dust (p = 0.098, n = 23). Sampler ratios for IOM/CFC pairs ranged from 1.19-19 (median 3.35). Sampler ratios for IOM/Button pairs ranged from 0.49-163 (median 3.15). Sampler ratios for CFC/Button pairs ranged from 0.36-27 (median 1.2). In all cases, higher ratios were associated with higher concentrations. The median relative difference between the IOM's and CFC's is in accord with prior field studies in woodworking environments, and, taken together, the data imply a conversion factor greater than the 2.5 normally applied to CFC results to approximate inhalable values, as measured by the IOM. Raising the limit values by approximately 50% appears warranted for this particular situation of inhalable wood dust measured by the IOM. The IOM/Button and CFC/Button ratios were unexpectedly low, which may be due to the exclusion of very large particles, collected by the IOM and CFC samplers. Further work is required to explain these results.

Dust↗
PubMed2004

Total versus inhalable sampler comparison study for the determination of asphalt fume exposures within the road paving industry.

Exposure to asphalt fumes has a threshold limit value (TLV of 0.5 mg m(-3) (benzene extractable inhalable particulate) as recommended by the American Conference of Governmental Industrial Hygienists (ACGIH). This reflects a recent change (2000) whereby two variables are different from the previous recommendation. First is a 10-fold reduction in quantity from 5 mg m(-3) to 0.5 mg m(-3). Secondly, the new TLV specifies the "inhalable" fraction as compared to what is presumed to be total particulate. To assess the impact of these changes, this study compares the differences between measurements of paving asphalt fume exposure in the field using an "inhalable" instrument versus the historically used 'total' sampler. Particle size is also examined to assist in the understanding of the aerodynamic collection differences as related to asphalt fumes and confounders. Results show that when exposures are limited to asphalt fumes, a 1:1 relationship exists between samplers, showing no statistically significant differences in benzene soluble matter (BSM). This means that for the asphalt fume ACGIH TLV, the 'total' 37-mm sampler is an equivalent method to the "inhalable" method, referred to as IOM (Institute of Occupational Medicine), and should be acceptable for use against the TLV. However, the study found that when confounders (dust or old asphalt millings) are present in the workplace, there can be significant differences between the two samplers' reported exposure. The ratio of IOM/Total was 1.37 for milling asphalt sites, 1.41 for asphalt paving over granular base, and 1.02 for asphalt over asphalt pavements.

Air Pollutants, Occupational↗
PubMed2006

A series of metal-organic polymers assembled from MCl2 (M = Zn, Cd, Co, Cu): structures, third-order nonlinear optical and fluorescent properties.

In this paper four metal-organic polymers {[Zn(fcz)Cl2].CH3OH}n 1, {[Cd(fcz)2Cl2].CH3OH.2H2O}n 2, {[Co(fcz)2Cl2].2CH3OH}n 3 and {[Cu(fcz)2Cl2].2CH3OH}n 4 (fcz = fluconazole: alpha-(2,4-difluorophenyl)-alpha-(1H-1,2,4-triazol-l-ylmethyl)-1H-1,2,4-triazole-l-ethanol) were synthesized and characterized by X-ray single crystal diffraction. Polymer consists of 1-D infinite chains arranged along the b-axis. All of polymers 2-4 exhibit a 2-D rhombohedral grid structure. We study the third-order nonlinear optical properties of fcz and polymers 1-4 in DMF solution by using 8 ns laser pulses at 532 nm, and find that 1 and 4 exhibit different NLO properties from fcz and both 2 and 3 show similar NLO properties to fcz. 1 possesses strong NLO refractive effects and large NLO absorptive behaviors. 2, 3 and fcz exhibit strong refractive effects, but their NLO absorptive behaviors are weaker than that of 1. The NLO effects of 4 are very weak. The study of optical limiting (OL) effects by using 40 ps laser pulses at 532 nm shows that fcz and polymer 3 possess a strong OL effect. The optical limiting threshold values of 0.15 J cm(-2) for fcz and 0.16 J cm(-2) for are comparable to those of many heterothiometallate clusters. Polymers 1, 2 and 4 show a weak OL effect. The fluorescent spectra in DMF solution (concentration: 1 x 10(-4) mol dm(-3)) show that polymers 1-4 exhibit different luminescence properties from fcz. The maximum wavelength of polymers 1-3 are blue shifted gradually by 2-12 nm while polymer 4 exhibits a fluorescent self-quenching phenomenon. These results demonstrate that metal ions play an important part in the NLO and fluorescent properties of coordination polymers.

Journal Article↗
PubMed1998

Diethanolamine-induced occupational asthma, a case report.

BACKGROUND: Amino alcohols are low molecular weight chemicals used widely in industrial processes, often as minor constituents. They have been found to cause allergic contact dermatitis. Marked exposure through airways is uncommon in other than occupational settings where chemicals containing amino alcohols may be heated or vaporized, liberating free amino alcohols into the ambient air. A few cases of asthma and allergic rhinitis have been reported, but the amounts inducing the airway reactions have not been defined. OBJECTIVE: To further characterize ethanolamine-induced asthma and define the concentration inducing the asthmatic reaction, a case of diethanolamine-induced occupational asthma in a patient handling diethanolamine containing cutting fluid is reported. METHODS: Suspicion of work related asthma was raised by symptoms and peak expiratory flow monitorings at work and at home. Specific bronchial provocation tests with the cutting fluid containing DEA and with DEA aerosol at two different concentration below the American Conference of Governmental Industrial Hygienists threshold limit value of DEA (2.0 mg/m3) were done. RESULTS: DEA caused asthmatic airway obstruction at two different concentrations below the ACGIH TLV. A slight dose-response relationship was observed. Specific IgE-antibodies against DEA could not be found. CONCLUSIONS: DEA is able to induce occupational asthma by a sensitization mechanism, the exact pathophysiological mechanism of which is not known.

Adult↗
PubMed2000

[Air pollution by volatile organic compounds (VOC) and health complaints].

BACKGROUND AND OBJECTIVE: Complaints of well-being and health after moving in a new or redeveloped building occur quite frequently. If these complaints persist for several months and are indicated by the majority of occupants, an examination of the air quality is required. However, the interpretation of these data can be difficult since different recommendations but no threshold limit values for the indoor contamination with volatile organic compounds (VOC's) exist. PATIENTS AND METHODS: This report presents a case with serious health complaints (14 males, average age 40.4 years; 44 females, average age 37.9 years) after moving in a completely redeveloped building. Complaints of well-being and health were investigated by a standardised questionnaire and compared with a control group (11 males, average age 41.4 years; 12 females, average age 33.3 years). The VOC-contamination was analysed by various measurements. RESULTS: Two months after moving into the building a total VOC-concentration of 2000-3000 micrograms/m3 was registered, after 10 months the concentration decreased to 900-1300 micrograms/m3 due to intense airing. The following symptoms showed the clearest differences between exposed persons and the control group: soreness of throat (odds ratio: 10.72; 95%-confidence interval: 1.46-465.2), irritations of mucous membranes (OR: 10.45; 95%-CI: 1.43-453.8), headache (OR: 9.9; 95%-CI: 1.35-430.9) and increased weariness (OR: 7.55; 95%-CI: 1.55-71.2). As a consequence extensive redevelopment measures were initiated. CONCLUSION: Contamination of the indoor air with 900 micrograms/m3 VOC's (total value) can induce serious complaints of well-being and health. Rooms with VOC-concentrations > 1200-1500 micrograms/m3 are not suited for regular stay of unprotected people.

Adult↗