Asthma, allergies and respiratory symptoms in different activity groups of swimmers exercising in swimming halls

BACKGROUND

Respiratory symptoms are common in competitive swimmers. However, among these and in swimmers at other activity levels the swimming distance, the total spent time in swimming halls and their medical background varies. Our objectives were, first, to assess their medical histories and the associations with respiratory symptoms among swimmers in different activity groups and then second, to study the pulmonary function findings and related medications in competitive swimmers who exercise in swimming hall environments the most.

METHODS

First, 1118 participants consisting of 133 competitive-, 734 fitness- and 251 occasional swimmers answered questionnaires concerning their medical background, their respiratory symptoms in connection to swimming distance and their amount of time spent in swimming halls. Secondly, in 130 competitive swimmers, pulmonary function was tested by spirometry and a specific questionnaire was used to assess respiratory symptoms, medical histories and prescribed medication.

RESULTS

Respiratory symptoms were reported by 18% of the studied swimmers. Competitive swimmers had significantly more symptoms than fitness- and occasional swimmers. Naturally competitive swimmers swum more than 2000 m and stayed by the pool more than 90 min, longer than the other activity groups of swimmers. Spirometry testing showed airway obstruction in 15 swimmers, which was 12% of the 130 competitive swimmers. 21 of them, had physician-diagnosed asthma and 16 of these individuals had prescribed medication for it.

CONCLUSIONS

Competitive swimmers had the highest swimming hall exposure and reported significantly more respiratory symptoms. A high prevalence of airway obstruction findings in competitive swimmers with asthma and allergies suggests a need for future recommendations for regular testing and special medical care for competitive swimmers.

Positive impact on vitamin D related lifestyle of medical advice in pregnant Somali-born women and new mothers: a mixed method study in Swedish primary care

BACKGROUND

A previous study showed that pregnant women/new mothers especially Somali-born and some Swedish-born had extremely low vitamin D levels and poor physical performance. Our study aimed to examine vitamin D related lifestyle, attitudes and behaviour before and after brief information about vitamin D, with special long-term focus on Somali-born women.

METHODS

A cohort of 91 pregnant women/new mothers having serum hydroxyvitamin D (S-25-OHD) ≤ 50 nmol/L (n = 51 Somali-born with one third < 10 nmol/L of S-25-OHD) in primary health care in Sweden was targeted for intervention. Brief individual oral and visual information on vitamin D was given by doctors at baseline and after four and ten months. Questionnaires with ordinal scales on vitamin D related lifestyle of food, clothing, and outdoor activities were distributed on all occasions. Focus-group interviews with 15 women from the target-group were performed after two years. A Somali interpreter was available.

RESULTS

Veiled clothing, indoor living, and a low intake of milk, cheese, and fatty fish were common in the target group. Consumption pattern had increased significantly among the Somali-born women at the four-month follow-up but declined to non-significant levels at the ten-month follow-up. The focus-group interviews showed improved understanding of vitamin D deficiency, symptoms and attitudes, but varying applied behaviours related to sun exposure. Sun exposure for the children and increased fish consumption was the most evident positive results.

CONCLUSIONS

Vitamin D related lifestyle, attitudes and behaviour improved in a Somali-born group of pregnant women/new mothers with severe vitamin D deficiency. The preventive measures suggested in our study may have impact on public health in relation to bone and muscle strength and immunity especially in vitamin D deficiency risk groups.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02922803 . Date of registration: 28 September 2016.

The suitability of the IOM foam sampler for bioaerosol sampling in Occupational Environments

Concurrent samples were collected with Andersen and IOM foam samplers to determine whether if the IOM foam sampler can be applied to collect culturable microorganisms. Two different kinds of aerosols were studied: peat dust in a power plant and mist from coolant fluid aerosolized during grinding of blades and rollers in a paper mill. In the power plant, the concentrations of fungi were 2-3 times higher in the IOM samples than in the Andersen samples. However, more fungal genera were identified in the latter case. The methods yielded similar concentrations of bacteria and actinobacteria in the power plant. On the other hand, the performance of the IOM foam sampler was very poor in the paper mill, where stress-sensitive gram-negative bacteria dominated; low concentration of bacteria was detected in only one IOM sample even though the concentration of bacteria often exceeded even the upper detection limit in the Andersen impactor samples. It could be concluded that the IOM foam sampler performs quite well for collecting inhalable fungi and actinobacteria. However, the Andersen sampler provides better information on fungal genera and concentrations of gram-negative bacteria. Personal sampling with the IOM foam sampler provided an important benefit in the power plant, where the concentration ratio of personal to stationary samples was much higher for bacteria than for inhalable or respirable dust.

Laboratory and field testing of sampling methods for inhalable and respirable dust

The performance of four sampling devices for inhalable dust and three devices for respirable dust was tested with different kinds of dusts in the laboratory and in the field. The IOM sampler was chosen as the reference method for inhalable dust, and the IOM sampler provided with the porous plastic foam media was used as the reference method for respirable dust. The other tested instruments were the Button sampler, the optical Grimm aerosol monitor, and the Dekati two-stage cascade impactor with cutoff sizes of 10 and 4 mu m. The study confirmed the applicability of the IOM and Button samplers. The new foam product followed the respirable criteria well. However, the foam sampler was unstable for measuring inhalable dust, probably due to its moisture absorption. In addition, high dust loads should be avoided with the foam sampler due to increase in filtering efficiency. The concentrations of inhalable dust measured with the Button sampler, the Grimm monitor, and the impactor sampler were usually close to those measured with the reference sampler. On the other hand, impactor sampling yielded higher respirable dust concentrations than the reference method in the field, which may have been caused by particle bounce; high dust loads should be avoided while using the impactor. The results also showed that the Grimm monitor enables real-time dust concentration determinations that are accurate enough for routine monitoring of occupational exposure and for testing efficiency of control measures in workplaces.

Controlling occupational allergies in the workplace

OBJECTIVES

In recent years, the prevalence of work-related asthma has increased. Therefore, more attention needs to be paid to occupational allergens and their avoidance and control in workplaces. However, risk assessment of occupational allergen exposure is difficult because the relationship between exposure concentration, sensitization, and symptoms has not been fully established. This paper introduces a systematic and comprehensive approach to assessing and managing allergen risks at workplaces.

MATERIALS AND METHODS

This approach relies on the cooperation and active communication during the whole process between management, employees, and health care personnel, with the assistance of experts when needed. In addition to gathering background information, including allergic symptoms, through questionnaires addressed to the management and employees, hazard identification is also processed in the workplace through observations and measurements. The methods generally recommended to reduce allergen exposure are compared with those used in the workplace. The process is to be carefully planned and documented to allow later follow-up and re-evaluation.

RESULTS

The multi-faceted approach encompasses several risk assessment techniques, and reveals the prevalence of work-related allergic symptoms. The process effectively focuses on the potential means for controlling allergen exposure.

CONCLUSION

Based on this approach, the synopsis on the critical points that require implementation of effective control measures can be presented.

Exposure to Refractory Ceramic Fibres in the Metal Industry

Refractory ceramic fibres (RCF) are used in thermal isolation in the metal industry where high temperatures are regularly employed. Asbestos materials were earlier commonly used for these purposes. In this work, two Finnish steel plants, three foundries and a repair shop were studied for the ceramic fibre exposure of their workers under normal production and during the replacement of oven insulation. Personal and stationary sampling was used together with a novel nasal lavage sampling for the evaluation of personal exposure. Fibres were counted with optical and electron microscopy and they were identified using an energy-dispersive X-ray analyser. Ceramic fibres were found in most production phases [range <0.01-0.29 fibres per cubic centimetre (f cm(-3))]. Considerably higher fibre counts were obtained during the maintenance work (range <0.01-14.2 f cm(-3)). Nasal sampling was found to correlate with the airborne fibre concentrations at the group level. The mean fibre concentrations varied from 34 to 6680 f ml(-1) of lavage liquid. Use of personal respiratory protectors diminished the exposure on the average as analysed in the lavage specimens, but the effect of respirator use did not appear clearly in the results. Because of the heat conditions, the workers used the respirators for a strict minimum period. A considerable exposure to RCF occurs in the studied plants. Its risk should be evaluated and managed more closely in view that the material is carcinogenic. Use of personal respiratory protectors should be encouraged. Their effective use could be verified by the nasal sampling for fibres after the work shift.

A multi-faceted approach to risk assessment of laboratory animal allergens at two facilities

BACKGROUND

Risk assessment of exposure to allergens is difficult because the relationship between exposure, sensitization, and symptoms has not been fully established. Laboratory animal allergens (LAA) are an important occupational health risk factor; 10-32% of workers exposed to these allergens develop allergic diseases. This article introduces a versatile approach to assessing the risks posed by LAA at two laboratory animal facilities.

METHODS

The risk assessment approach that was used at the laboratory animal facilities included questionnaires for management and employees, a hazard identification visit and measurements in the workplaces, as well as the creation of a list of generally recommended procedures to reduce allergen exposure.

RESULTS

The prevalence of work-related allergic symptoms was 17%. Suggested countermeasures at the sites included changes in ventilation and work practices, reduction of unnecessary exposure, recommendations for more comprehensive use of personal protective equipment, and wider communication about LAA risks.

CONCLUSIONS

The approach managed to identify critical points and potential means for controlling LAA exposure.

Effects of moisture damage and renovation on microbial conditions and pupils' health in two schools--a longitudinal analysis of five years

Airborne microbes and pupils' symptoms were monitored in a moisture-damaged (index) school and a reference school for five consecutive years. These surveys were carried out in two separate years before the renovation of the index school, during the renovation, and one and two years after the renovation. Microbial concentrations were higher in the index school than those in the reference school before and during renovation, but afterwards, the levels decreased to the level of the reference school. The effect of remediation was seen as an altered mycobiota in the index school. Year-to-year variation of microbial concentrations, probably due to climatic factors, caused a peak in both schools but their difference remained. Several symptoms were more prevalent in the moisture-damaged school than in the reference school, but the differences disappeared during the renovations. These results emphasize the importance of using a reference building in assessing the microbial conditions of a moisture damaged building. Furthermore, microbial concentrations reflected well the technical condition of the construction, but the reported symptoms of the occupants did not strictly follow the timely fluctuation in microbial conditions.

Evaluation of the use of Low Flow Passive Sampling Technique in Offset Printing Plants

OBJECTIVES

The aim of this study was to evaluate the suitability and applicability of low-flow passive tubes for sampling of organic solvents in occupational environment.

MATERIALS AND METHODS

Laboratory and field studies were conducted to continue the evaluation of low-flow diffusive sampling combined with thermal desorption and gas chromatographic/mass spectrometric analysis in occupational hygiene surveys. Passive sampler tubes with Tenax GR adsorbent were employed to assess exposures to organic solvents in 10 small sheet-fed offset printing plants in Finland. The retention of the solvent compounds in the samplers was investigated using laboratory chamber studies. Active sampling with activated carbon tubes served as the control method.

RESULTS

The laboratory tests showed that passive tubes had good retention, stability and reproducibility for the solvent compounds. Parallel passive and active sampling in both breathing zone and area monitoring in the printing plants yielded similar measurements though passive sampling tended to give slightly higher concentrations (by 5 to 12%). The suitability of passive sampling to be done by workers was also confirmed. The study also shows that exposure to organic solvents can be effectively reduced by the use of vegetable oil-based cleaning fluids. Especially, since ventilation and other protective measures are often inadequate in small facilities, the use of toxic cleaning solutions should be avoided.

CONCLUSIONS

Passive sampling tubes with capillary orifice analyzed with thermal desorption GC-MS are well suited for measuring occupational solvent exposure. Method is well suited for sampling done by workers.

Dermal Exposure to Polycyclic Aromatic Hydrocarbons among Road Pavers

OBJECTIVES

Dermal exposure to polycyclic aromatic hydrocarbons (PAHs) and the role of an industrial by-product, coal fly ash, on workers' PAH exposure were investigated during stone mastic asphalt (SMA) paving and remixing.

METHODS

PAH exposure was measured at eight sites during the laying of SMA containing coal fly ash or limestone (conventional SMA) as the filler. Six of the surveys were carried out during SMA paving and two during remixing of SMA (hot recycling at the paving site). Dermal PAH exposure was measured by hand washing (using sunflower oil and wiping with Kleenex tissues) before and after the work shift, and by placing exposure pads on the workers' wrists during the work shift. The analyses included 15 native PAHs from the hand-washing samples determined using high-performance liquid chromatography equipped with a two-channel fluorescence detector and 16 native PAHs and four methylated PAHs from the exposure pads using gas chromatography with mass-selective detection.

RESULTS

The PAH results obtained using the pad and hand-washing methods (concentrations after the work shift) were equivalent and showed a strong correlation (r = 0.757, P < 0.001, N = 23 for total PAHs). There was a statistically significant difference between pre- and post-shift samples as measured by hand washing. The skin contamination by PAHs was significantly higher (P < 0.01) during remixing than during SMA paving. The variation in PAH contamination on the skin explained more of the variation in the excretion of urinary 1-hydroxypyrene and phenanthrols than the variation in the respiratory PAH concentrations.

CONCLUSIONS

The industrial by-product investigated in asphalt, coal fly ash, had no statistically significant effect on the workers' dermal PAH exposure. The dermal exposure of paving workers to PAHs was higher during remixing than during SMA paving.

Microbial exposure, symptoms and inflammatory mediators in nasal lavage fluid of kitchen and clerical personnel in schools

OBJECTIVES

The aim of this study was to investigate how the microbial conditions of kitchen facilities differ from those in other school facilities. The health status of the personnel was also studied.

MATERIALS AND METHODS

The microbial investigations were conducted in six moisture-damaged schools and two reference schools. The symptoms of the kitchen personnel were surveyed with questionnaires and inflammatory responses in nasal lavage (NAL) fluid were measured.

RESULTS

The total concentrations of airborne microbes were lower in kitchens than in other facilities of the schools. However, the occurrence of moisture damage increased the airborne microbial concentrations both in kitchens, and in other facilities. Bacterial concentrations were high on surfaces in the damaged kitchens. Gram-negative bacteria predominated, but also thermophilic bacteria and mycobacteria were detected. Respiratory and general symptoms were prevalent both among kitchen workers and clerical personnel in the moisture-damaged environments. Reported allergies and repeated respiratory infections were connected with high IL-4 concentrations in NAL fluid. Median concentrations of studied inflammatory mediators (NO, IL-4, IL-6 and TNF-alpha) were slightly higher in NAL samples of kitchen workers than among the clerical personnel.

CONCLUSIONS

Kitchen facilites differ from other facilities of the school building for their moisture conditions and microbial contamination. Thus, they represent a specific type of environment that may affect the health status of the personnel.

Detection of mouse and rat urinary aeroallergens with an improved ELISA

BACKGROUND

Risk analysis of laboratory animal work presupposes allergen monitoring with sensitive methods. Commercial ELISA kits have recently become available for the detection of mouse (Mus m 1) and rat (Rat n 1) urinary allergen from settled dust samples and air samples with high allergen levels.

OBJECTIVE

Our aims were to enhance the sensitivities of the commercial ELISA kits for low aeroallergen levels (less than 1 ng/m(3)) and to test these methods with air samples collected from an animal facility.

METHODS

Personal and stationary air samples were collected from an animal facility during various tasks of laboratory animal work and from various premises of the animal facility.

RESULTS

The sensitivities of the ELISA assays were improved with a careful choice of analysis parameters and reagents. The detection limits of 0.1 ng/m(3) for Mus m 1 and 0.8 ng/m(3) for Rat n 1 were established. The sensitized assays enabled detection of mouse and rat aeroallergens also from premises in which animals or dirty cages were not present during sampling.

CONCLUSION

These sensitive assays will help to perform risk assessment in laboratory animal work. However, there remains a lack of standardized analytic procedures and occupational exposure limits for laboratory animal allergens.

Evaluation of exposure to man-made vitreous fibers by nasal lavage

The objectives of this study were to develop a biomonitoring method for the assessment of exposure to man-made vitreous fibers (MMVF), to examine the level of exposure to MMVF in the prefabricated house industry, and to study nasal inflammatory reactions and respiratory symptoms associated with MMVF among workers. Nasal lavage was performed on workers from two factories, and concentrations of MMVF were measured by electron microscopy. Cytokines (IL-6, IL-8, TNF-alpha, and IFN-gamma) were also assayed and inflammatory cells (lymphocytes, eosinophils, neutrophils, and macrophages) were counted microscopically. Concentrations of airborne fibers (longer than 5 microm) were measured for comparison. Moreover, the exposure to MMVF and the related symptoms were studied with a structured questionnaire. In nasal lavage samples, the mean concentration of MMVF (length >1.5 microm) was 3260 f/ mL in Factory 1, 1680 f/mL in Factory 2, and below 500 f/mL in the control group. About 52% of the retained fibers were longer than 100 microm. The group-specific mean concentrations of MMVF in nasal lavage samples correlated with production rates and airborne fiber levels in both plants. The airborne concentrations of MMVF both in the breathing zone and fixed-point samples were low (below 0.1 f/cm(3)). No significant differences in the biological response (inflammatory cells, cytokines) were found between the groups exposed and the control group. The workers complained of some irritation of the skin, eyes, and upper respiratory tract, which could be reduced by appropriate protective equipment. It is concluded that nasal lavage can be used as a biomonitoring method in the assessment of MMVF exposure.

Potentially pathogenic, slow-growing mycobacteria released into workplace air during the remediation of buildings

Construction workers' exposure to airborne viable mycobacteria was studied during the remediation of three moldy and two nonmoldy buildings. Furthermore, the concentrations of airborne fungal and actinobacterial spores were determined. The samples for the microbial analyses were collected using a six-stage impactor and an all-glass impinger sampler, and by filter sampling. Specific mycobacteria media and nonselective media were used for the cultures. The samples were cultured for the total numbers of rapidly growing and slow-growing mycobacteria, and the isolates obtained were identified to the genus or species level. Mycobacteria were recovered from the air during the remediation of two of the moldy buildings and one nondamaged building. Concentrations of mycobacteria up to 160 cfu/m3 were detected. A total of 43 mycobacterial isolates was recovered. Most of the isolates were slow-growers, only two rapid-growing strains being detected. The 38 identified isolates belonged to potentially pathogenic species, including Mycobacterium avium complex, M. scrofulaceum, and M. fortuitum, and to saprophytic species, including M. nonchromogenicum and M. terrae. Mycobacteria were the most often detected in samples taken with a six-stage impactor. They were found in buildings with both high and low concentrations of fungi. In conclusion, mycobacteria, both potentially pathogenic and saprophytic species, may be released into the indoor air during the remediation of buildings.

Laboratory and field testing of particle size-selective sampling methods for mineral dusts

The performances of eight sampling devices were tested with mineral dusts in the laboratory and in a talc production plant. The IOM sampler was chosen as the reference method for inhalable dust, and the IOM samplers provided with the porous plastic foam media were used as the reference methods for both the thoracic and respirable aerosols. The other size-selective instruments tested included the Respicon virtual impactor, the optical GRIMM aerosol monitor, and a two-stage cascade impactor with cut points of 10 and 4 microm. The 37-mm cassettes were also included both as open- and closed-face versions. The study confirmed the usability of the IOM samplers for mineral dust, not only in its original version for the inhalable fraction but also its modified versions for the thoracic and respirable fractions. A high correlation with the two-stage impactor results is an indication of good reproducibility. The results increased the evidence that the 37-mm cassette is a poor indicator of inhalable aerosol. The concentrations obtained with both cassette methods were not only systematically too low but also showed large collection efficiency variability. Therefore, the results cannot be corrected by using correction factors. The concentrations of inhalable aerosol measured with the Respicon were generally low, but its performances for the thoracic and respirable fractions were closer to those for the reference samplers. The results also indicate that the GRIMM monitor is well-suited for such mineral dust determinations when very good accuracy is not required, but the immediate availability of the result is more important.

Diffusive uptake in passive and active adsorbent sampling using thermal desorption tubes

Low flow active sampling techniques collecting vapors and gases using thermally desorbable adsorbents are now feasible and desirable in many applications as they permit long integration times, the potential for miniaturized sampling configurations, and other advantages. At very low air flow rates (< 1 ml min(-1)), diffusive uptake on adsorbents in conventional sorbent tubes may equal or exceed the active (pumped) uptake rate, and even at low flow rates (1-4 ml min(-1)), diffusive uptake may significantly bias measurements. Thus, corrections to account for the diffusive flux or means to limit the diffusive uptake are needed in low flow applications. This paper presents (1) a theoretical analysis of the role of diffusive and advective uptake for several sampling geometries of tube-type samplers; (2) experimental confirmation using both laboratory and field studies; (3) estimates of the tortuosity and porosity of the glass wool packing used to retain the adsorbent, parameters needed to estimate diffusive fluxes in passive and active sampling; (4) a demonstration that orifice-equipped low flow active samplers can reduce diffusive uptake and improve precision, and (5) a model predicting the saturated adsorbent layer that helps to account for the gradual decline in uptake rates seen in passive sampling. Diffusive uptake will depend on the tube configuration and diffusion coefficient of the substance of interest, but for conventional sampling tubes (0.4-0.5 cm id, 1.5 cm air gap), sample flow rates should be maintained above 1 to 4 ml min(-1) to keep errors below 5%. Laboratory experiments showed close agreement with theoretical calculations, and the field study using 1 to 4 d sampling periods and 0.3 ml min(-1) flows demonstrated that the orifice-equipped samplers essentially eliminated diffusive uptake. No significant practical difficulties are encountered using orifices, e.g., pressure drop is minimal. Experimental estimates of tortuosity (0.79 +/- 0.02) and porosity (0.92 +/- 0.10) of the glass wool packing (0.3 cm length) represent relatively little resistance to diffusion; however, variation in the packing and adsorbent placement can degrade the precision achievable by passive samplers. Diffusion barriers, consisting most simply of an orifice, may be used to lower the diffusive uptake. A needle-type orifice permits flows below 0.1 ml min(-1) and is suitable for sampling periods as long as several weeks, and it provided greater precision than conventional open-ended sampling tubes (8% compared to 13%). Finally, the gradual decrease in diffusive fluxes often seen in passive sampling is attributed to additional resistance posed by a saturated adsorbent layer, in agreement with a simple model based on total VOCs and specific adsorptivity of the adsorbent.

Low-flow active and passive sampling of VOCs using thermal desorption tubes: theory and application at an offset printing facility

While air sampling techniques using adsorbent-based collection, thermal desorption and chromatographic analysis have found a niche in ambient air sampling, occupational applications have been more limited. This paper evaluates the use of thermal desorption techniques for low flow active and passive sampling configurations which allow conveniently long duration sampling in occupational settings and other high concentration environments. The use of an orifice enables flows as low as 0.5 ml min(-1) and sampling periods up to several days without significant biases. A model is used to predict sampling rates of a passive sampler encompassing an orifice, a void space, glass wool, and the adsorbent. Laboratory and field tests conducted at a commercial offset printing facility, which contained a variety of volatile organic compounds (primarily aromatic but also a few chlorinated and terpene compounds at levels from 1 to 67,000 microg m(-3)), are used to evaluate the approach. Tenax GR and Carbosieve SIII, both singly and together, were employed as adsorbents. Side-by-side tests comparing high flow, low flow and passive samplers show excellent agreement and high linearity (r = 0.95) for concentrations spanning nearly five orders of magnitude. Active samplers were tested at flows as low as 0.5 ml min(-1), compared to typical flows up to 40 ml min(-1). Passive samplers demonstrated a linear range and agreement with predictions for adsorbate loadings from approximately 1 ng to nearly 10 microg. Using a chemical mass balance receptor model, concentrations in the facility were apportioned to solvents, inks and other indoor and outdoor sources. Overall, the use of low flow active and passive sampling approaches employing thermal desorption techniques provides good performance and tremendous flexibility that facilitates use in many applications, including workplace settings.

Indoor radon concentrations caused by construction materials in 23 workplaces

The aim of this study was to compare the measured and the calculated concentrations of indoor radon caused by building materials at 23 workplaces. The measured concentrations of radon were clearly higher than the calculated radon concentrations from the building materials, which indicated that the main source of indoor radon was the soil under and around the buildings. The highest means of continuously (933 Bq m(-3)) and integrated (169 Bq m(-3)) measured and calculated (from 70 to 169 Bq m(-3)) concentrations of radon were found in hillside locations. On the other hand, the median (27 and 43 Bq m(-3)) and maximum (626 and 1002 Bq m(-3)) values of calculated indoor radon concentrations exhaled from construction materials were the highest at the ground level places. On average, only 7-19% of the radon seemed to originate from the construction materials.

Applicability of homogeneous exposure groups for exposure assessment in the chemical industry

The purpose of the study was to assess occupational exposure to chemicals, by taking the aspects presented in European standard EN 689 into account, especially with respect to homogeneous exposure groups and their suitability as the basis for exposure assessment. In addition, dermal exposure to chemicals was assessed when appropriate. The industries studied included a plywood factory, a paint factory and a sewage treatment plant of an oil refinery. The workers were classified into homogeneous exposure groups by the persons in charge of occupational health issues in the respective workplaces. The concentrations of the contaminants were measured in workplace air by breathing-zone and stationary sampling, and these approaches were compared. Dermal exposure was measured when applicable. The homogeneity of the grouping was tested with analysis of variance whenever possible. The tasks studied in plywood manufacturing fulfilled the criteria of homogeneous exposure groups for both respiratory and dermal exposure. The group of operators in the sewage treatment plant was highly homogeneous. The complicated organization of the tasks made the use of homogeneous exposure groups (HEG) unsuitable at the paint factory. These findings show that reliable exposure assessment cannot be achieved with a formal standard; instead, comprehensive occupational hygiene evaluation is needed. It should also have a great importance when exposure models are developed.

The relationship between measured moisture conditions and fungal concentrations in water-damaged building materials

We determined the moisture levels, relative humidity (RH) or moisture content (MC) of materials, and concentrations of culturable fungi, actinomycetes and total spores as well as a composition of fungal flora in 122 building material samples collected from 18 moisture problem buildings. The purpose of this work was to clarify if the is any correlation between the moisture parameters and microbial levels or generic composition depending on the type of materials and the time passed after a water damage. The results showed an agreement between the concentrations of total spores and culturable fungi for the wood, wood-based and gypsum board samples (r > 0.47). The concentrations of total spores and/or culturable fungi correlated with RH of materials particularly among the wood and insulation materials (r > 0.79), but not usually with MC (r < 0.45). For the samples collected from ongoing damage, there was a correlation between RH of materials and the concentrations of total spores and culturable fungi (r > 0.51), while such a relationship could not be observed for the samples taken from dry damage. A wide range of fungal species were found in the samples from ongoing damage, whereas Penicillia and in some cases yeasts dominated the fungal flora in the dry samples. This study indicates that fungal contamination can be evaluated on the basis of moisture measurements of constructions in ongoing damage, but the measurements are not solely adequate for estimation of possible microbial growth in dry damage.

Assessment of total exposure to phenol-formaldehyde resin glue in plywood manufacturing

OBJECTIVE

Respiratory and dermal exposure to phenol-formaldehyde resin-glue components used in plywood manufacturing were assessed.

METHODS

Formaldehyde and phenol were monitored in the workplace air. Formaldehyde was measured both in the breathing zones of the workers and at stationary sampling sites. Phenol was used as a marker agent for dermal exposure due to its near-nonvolatility at the temperatures occurring during the present study and to its ready absorption through the skin, causing systemic exposure in addition to local skin rashes. Sampling and analytical methods were developed to measure the dermal exposure to phenol. Sampling was accomplished with whole-body dosimetry using Tyvek coveralls and cotton gloves. In addition, a liquid chromatography method was developed for the analysis of phenol from dermal exposure samples.

RESULTS

As expected, formaldehyde was noted to be the major compound causing respiratory exposure. When exposure assessment was done on the basis of air samples collected both at stationary sampling sites and in the breathing zones of the workers the agreement between the results obtained was good. The dermal sampling revealed that the workers were exposed to phenol, but the risk for toxic effects was slight due to the low concentrations of urinary phenol.

CONCLUSIONS

We conclude that it is possible to use the stationary sampling method for the assessment of respiratory exposure in a plywood factory instead of the usually more complicated breathing-zone sampling. This study also demonstrates the importance of taking dermal exposure into account, at least due to the ability of the resins to cause skin rashes, in assessment of the exposure to chemicals in plywood manufacturing.

Serum IgG antibodies against Wallemia sebi and Fusarium species in Finnish farmers

BACKGROUND

Wallemia sebi and Fusarium species are common fungi in agricultural environments. Because Fusarium species are difficult to culture, and W. sebi has only recently been found in an agricultural environment with the use of a new culture medium, immunochemical methods may be important for evaluating exposure to these fungi.

OBJECTIVE

Immunoglobulin (Ig) G antibodies against W. sebi and two Fusarium species were measured in the sera of Finnish farmers to estimate exposure to fungi.

METHODS

Serum-specific IgG antibody levels against the fungi were determined in farmers with farmer's lung disease and asthma, as well as in asymptomatic farmers with low and high IgG antibody levels against other agricultural microorganisms, and in control persons (printing and office workers). Both enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunofiltration assay (ELIFA) techniques were used.

RESULTS

Significantly higher IgG antibody levels against the fungi studied were observed in farmer's lung patients and asymptomatic farmers with high IgG levels against other agricultural fungi, than in the control group. On the other hand, the development of IgG antibodies to the fungi in asthmatic farmers remained unclear because of a discrepancy between the ELISA and ELIFA results. Cross-reactivity between Fusarium species was detected.

CONCLUSIONS

The results indicate that Finnish farmers are exposed to W. sebi and Fusarium species in their work environment to a greater extent than has earlier been evaluated with air sampling and microbiologic methods.

Control of exposure to airborne viable microorganisms during remediation of moldy buildings; report of three case studies

Three different techniques for reducing exposure to microorganisms were tested during remediation of moldy buildings. Concentrations of spores (fungi and actinomycetes) were determined by filter sampling before, during, and after remediation. The local exhaust method used for asbestos dismantling was the most effective control method. In the construction zone, concentrations of microorganisms were 4-25 times higher during remediation than before it. In the adjacent area no increase in concentrations was seen. When the construction zone was placed under negative pressure with a fan and isolated with a plastic barrier, concentrations of microorganisms were about 100 times higher there during remediation work. Nevertheless, levels remained low in the adjacent area. The use of a portable exhaust fan with a side-draft hood decreased concentrations of fungi to one-tenth compared with demolition without the control technology. Furthermore, this method prevented the migration of fungal spores from the construction zone to the adjacent area, although it was less effective in prevention of actinomycete spore migration. It also decreased the levels of microorganisms in the construction zone below the preconstruction level within 2 hours. This study showed that levels of airborne microorganisms, including from the working area to adjacent area, can be reduced with commonly used dust control methods during demolition work. However, microorganism levels in the construction zone remained elevated. Therefore, personal protection of construction workers is needed even with control techniques.

Dissolution of short and long rockwool and glasswool fibers by macrophages in flowthrough cell culture

Dissolution of MMVF (man-made vitreous fibers) by macrophages has previously been studied utilizing cell cultures in wells. A new, more dynamic method has been developed to explore the effects of macrophages on MMVF dissolution. In this method, the culture medium flows through a membrane on which the macrophages and fibers are placed. The dissolution of short and long rockwool and glasswool fibers was investigated in the present study by macrophages by assessing the dissolution of Si (silicon), Fe (iron), and Al (aluminium) from the fibers. Dissolution of these elements usually increased as a function of time. Generally, the dissolution of elements from the fibers in the flowthrough culture exceeded that observed with the culture in wells system. The dissolution of glasswool fibers was greater in medium than in cell culture, whereas the opposite was true for rockwool fibers. Dissolution of Si was greater from glasswool than from rockwool fibers, while the opposite was true for Fe and Al. Macrophages that had phagocytized fibers in flowthrough culture contained Si, and there were also precipitations with Si in the samples. The fibers in the flowthrough culture also exhibited surface changes such as breakings, pittings, etching, and peeling. The short rockwool fibers tended to fracture more than short glasswool fibers, while long glasswool fibers were more extensively broken than short glasswool fibers. The results with this new, dynamic, flowthrough culture method with macrophages demonstrate that this method provides valuable information on the abilities of macrophages to dissolve MMVF leading to subsequent morphological changes of fibers.

Identification of environmental hazards of gasoline oxygenate tert-amyl methyl ether (TAME)

The physico-chemical and environmental properties of a new gasoline component tert-amyl methyl ether (TAME, 2-methoxy-2-methylbutane) were determined experimentally and environmental hazards of the new component were thereafter identified. The methodology was based on the chemical regulations of the European Union (EU). On the basis of the experimental results, TAME is a volatile, non-hydrophobic and water-soluble liquid, which is not expected to be adsorbed onto organic matter in soil or sediment. It is not readily biodegradable. TAME has very low acute toxicity to aquatic organisms and is not expected to bioaccumulate.

Exposure to airborne microbes during the repair of moldy buildings

Concentrations of airborne microbes, studied during the repair of seven moldy buildings, showed that concentrations of airborne fungi increased during the repair work. This was especially true during the demolition of moldy building materials, even though the total dust levels remained low. Concentrations of viable fungi sampled with a six-stage cascade impactor were 10(3) - > 1.9 x 10(5) cfu/m3, and the total concentrations of fungal propagules, as determined by the Camnea method (i.e., air filtration method with epifluorescence microscopic counting of acridine-stained organisms) showed 10(5)-10(6) counts/m3 during the demolition. Penicillium was the main genus throughout. Concentrations of viable total bacteria also increased, but this change proved less noticeable than that of the fungi. However, rather high concentrations of viable actinomycetes up to 10(4) cfu/m3 were detected during the demolition. Results show that construction workers are exposed to high concentrations of microbes, perhaps causing health problems. Thus, personal protection of both the respiratory system and eyes is strongly recommended for workers as they repair moldy buildings. In addition, the repair room should be isolated from other areas to protect occupants or any other people present.

Exposure to airborne metals in the manufacture and maintenance of hard metal and stellite blades

This study evaluated the exposure of Finnish workers to airborne metals. It was conducted in 16 workplaces; 8 tool manufacturing companies (3 of which specialize in the maintenance of hard metal blades) and 8 blade repair shops in the mechanical wood-processing industry. The main emphasis of the study was on exposure in servicing (resharpening), especially involving wet-tip grinding processes. The results show that workers grinding hard metal blades may be exposed to high levels of airborne cobalt even when airborne total dust concentrations are low. The respirable proportion of the total dust was found to be high, and the total dust concentrations correlated well with the cobalt concentrations. Most of the airborne cobalt was water soluble (ionized), but there was also solid particles containing cobalt and other materials in the air of the workplaces. The mean concentration of cobalt in the grinding coolants was high, though it varied considerably. Concentrations of all the other metals measured in the air (tungsten, chromium, cadmium, silver, and nickel) and in the coolants (tungsten and chromium) were low. To reduce workers' exposure to cobalt, it is recommended that grinding machines should be enclosed and equipped with local exhausts. Use of coolants that dissolve less cobalt is also recommended, and the coolants should be changed more often. Brazing should be done in a well-ventilated place, and only cadmium-free materials should be used.

The effect of fiber length on the dissolution by macrophages of rockwool and glasswool fibers

The effect of fiber length on the dissolution of experimental rockwool and commercial glasswood fibers in rat alveolar macrophage (AM) culture and in mere culture medium was studied. The ultrastructure of macrophages after their exposure to fibers and the suitability of macrophage-type cell line P388D1 culture in dissolution studies were also explored. The fiber samples included short (ground) and long (untreated) rockwool and glasswool fibers. The fibers were incubated in rat AM cultures, in P388D1 culture, or in mere culture medium for 4 or 8 days. The dissolution of the fibers was determined by measuring the amounts of silicon (Si), iron (Fe), and aluminum (Al) in the medium. There were no differences in the diameter of the fibers, but a clear difference existed in the length of the short and long fibers. The dissolution of Si, Fe, and Al was more pronounced from experimental rockwool than from commercial glasswool fibers. The dissolution of Si was always greater in mere culture medium than in rat AM culture. Moreover, the dissolution of Si was greater from the long fibers than from the short ones. On the contrary, the dissolution of Fe and Al in AM culture exceeded that in mere culture medium. The dissolution of Si, Fe, and Al from both fibers in P388D1 culture was similar to their dissolution in rat AM culture. The fibers were also effectively phagocytized by the macrophages. The present results together suggest that the intracellular and the extracellular dissolutions of man-made vitreous fibers differ from each other.

Microbial growth on respirator filters from improper storage

Microbiological contamination and particle penetration were studied in two respirator filters with high efficiency. Microbial growth in filter materials during storage under conditions and the passing of microorganisms through the filters were particularly examined. Filters with different fiberglass and cellulose proportions were loaded in environments containing high microbial levels and incubated at a relative humidity of 98%. Particle penetration through loaded and incubated filters and carbon, nitrogen and microbial content were measured. After incubation, considerable particle penetration and the passing of fungal spores were observed for filters composed mainly of cellulose, probably because of humid conditions, which stimulated fungi to grow and extend mycelia and spores through the filter. Microbial activity, microorganism concentrations, and the chemical properties of the filter materials also supported this hypothesis. Storing used respirators in humid environments may result in heavy microbial contamination of the filters, especially if the filter material is biodegradable by microorganisms.

Chromosome aberrations in peripheral lymphocytes of workers employed in the plywood industry

Workers employed in sawmills and in the manufacture of plywood are exposed to potentially mutagenic chemical aromatic emissions from wood. However, very little is known about the exposure to these natural wood components. In an attempt to determine whether such exposure could have clastogenic effects, a group of 13 male nonsmoking employees mainly from the beginning of the wood-processing line of three plywood mills and 15 matched nonsmoking referents were studied for chromosome aberrations in blood lymphocytes. A statistically significant elevation of the frequency of cells with chromatid-type breaks (mean 2.1%), as compared with the corresponding frequency of the referents (mean 1.0%), was observed for the lymphocytes of the wood workers. These results lend support to previous studies which suggested that wood-drying fumes may be carcinogenic.

Mutagenic compounds in wood-chip drying fumes

The mutagenicity of fumes from the heating of freshly cut spruce and birch chips was measured with Salmonella typhimurium strains TA98, TA100 and TA102. The bacteria were exposed directly and indirectly to the fumes. Wood chips were also extracted with solvents. No mutagenicity was found in wood extracts or the fume samples measured indirectly. The results from the direct exposure experiments indicate, however, that drying spruce and birch at 170 degrees C emits mutagenic compounds, which are short-lived and/or volatile. One of the mutagenic compounds of the fumes is probably 3-carene. These results are consistent with previous epidemiological findings, which suggest that these fumes are carcinogenic.

Concentrations of specific dusts in swineries and the humoral response of swinery workers

The concentrations of swine epithelial antigen (SEA), swine urinary antigen (SUA) and swine feed antigen (SFA) were measured in swineries. SEA seems to be the most prevalent of the constituents measured. In the serum samples of the subjects studied, specific IgG antibodies against the antigens were frequently encountered. However, a difference was seen in the distribution of anti-SUA-IgG antibodies between swinery workers and a control group of students. The influence of the level of specific dust concentrations on specific antibody titers was studied statistically. Positive correlations were observed between stationary site SUA concentrations and anti-SUA-IgG and anti-SEA-IgG titers, respectively, pointing to an association between exposure and humoral response in swinery work. Consequently, our results suggest that the measurement of antibodies against SUA or its components could offer a basis for the estimation of the level of swinery work-related respiratory exposure and for monitoring the quality of the working environment in swineries.

Estimating long-term exposure levels in process-type industries using production rates

Exposure to toluene in two publication rotogravure plants was investigated to examine how accurately long-term exposure can be estimated on the basis of production rate. Toluene consumption was used as the measure of production rate. Continuous area monitoring was used to find a correlation between production rate and airborne level of toluene. Workers' exposure levels were first estimated by combining data on toluene concentrations in various monitoring sites with data supplied by the workers on the time spent in these areas. These calculated exposure levels were found to correlate well with the actual exposure levels obtained by breathing zone sampling. There was also a fairly high correlation between the concentration of toluene in front of the press and the consumption of toluene if the process conditions remained stable. It was, however, necessary to investigate this association separately for the situations where the degree of enclosure of the press or number of emission sources were unusual or when the workers stayed in the control rooms, which were separated from the other pressroom areas. A reasonably high correlation between the variables of the main interest, that is, the calculated toluene exposures and the consumption of toluene, was found in one of the plants investigated, whereas this correlation was low in the other plant. Even though this kind of estimation procedure does not always lead to accurate exposure levels, it helps in understanding how those are affected by the process parameters.

Fungi carried from farmers' work into farm homes

Airborne fungal spore concentrations and main fungal genera were compared in rural and urban living environments in Finland during the winter. In addition to conventional viable fungal spore counts (based on the six-stage impactor sampling and cultivation), total spore concentrations were obtained by scanning electron microscope (SEM) investigation of filter samples. The viable spore counts were only 0.2%-25% of the number of total spore aggregates. A high correlation between these two methods was noted, however, at the recommended measuring ranges of the methods. In the farm houses, viable and total spore levels were 10(3) to 10(4) colony forming units/m3 (cfu/m3) and 10(4) to 10(5), spores/m3, respectively. These counts were 10-10(3)-fold higher than the concentrations in an urban apartment. The spore levels of farmers' homes, however, were somewhat lower than those observed in their cow barns. Aspergillus, Cladosporium, and Penicillium spores were present in both urban and rural environments. Actinomycetes and some fungal genera--such as Acremonium, Alternaria, Botrytis, and Chrysosporium--which were detected in cow barns and in farm houses, were not present in urban environment. The results indicated that airborne fungal spores may be carried from cow barns to farmers' homes.

Solvent exposure in construction and maintenance painting

Exposure to solvents in interior house painting was determined by industrial hygiene surveys and questionnaires on work history. Painting work was observed in 92 work situations at 18 sites, mainly during maintenance work. The effects of the size of the work area, the volume of air, the type of paint, the amount used, the method of application, and the use of ventilation on the solvent concentrations were also studied. In small, poorly ventilated rooms the concentration of solvent naphtha averaged 275 ppm when alkyd paints were used. Wall and ceiling painting with alkyd paints yielded an average solvent naphtha concentration of 210 ppm, and window and door painting 80 ppm. The presence of a strong draft reduced the solvent concentrations by two-thirds. The painters' average lifetime dose of solvent naphtha was 12.2 kg, the average annual dose 0.54 kg. These levels decreased over the study period. The mean 8-h concentration of solvent naphtha in the breathing zone averaged 40 ppm over the painters' total worklife.

Influence of fly ash and charcoal on the inducer activity of benzo[a]pyrene and smoke condensate in the gut mucosa of the rat

Fly ash from either peat- or coal-fired power plants is unable to block the inducer activity of benzo[a]pyrene in the gastrointestinal tract. Activated charcoal retains adsorbed polycyclic aromatic hydrocarbons during passage through the gut so that no induction of polysubstrate monooxygenase occurs in the mucosa.

The tracer gas technique--a useful tool for industrial hygiene

The tracer gas technique was applied in industrial hygiene surveys. Carbon dioxide, nitrous oxide, and sulfur hexafluoride were used to elicit ventilation rates and determine spreading routes of dilution air in the work environment. The continuous monitoring of nitrous oxide with an infrared spectrophotometer was found to be the most practicable choice for ventilation testing, whereas plastic bag sampling of nitrous oxide or sulfur hexafluoride with subsequent analysis by gas chromatography appeared to be a good method for emission spreading studies. The local flow rates of dilution air and the percentages of make-up air present were the most important information gained in the ventilation studies.

Urinary mandelic acid concentration after occupational exposure to styrene and its use as a biological exposure test

Excretion of mandelic acid from workers in the reinforced polyester plastic industry was studied with the determination of urinary mandelic acid concentrations. The styrene exposure level at the workplaces was evaluated with measurements of the styrene concentration in the ambient air. Three different groups (I, II and III) were studied. In group I [n=9, median of the time-weighted average (TWA) of exposure = 23 ppmof styrene, postexposure observation period = 64 h] two excretion slopes were observed, the first with a median half-time of 9.4 h (postexposure period 0--18 h) and a second with a median half-time of 16.6 h (postexposure period 19--64 h). For group II (n=9, median TWA exposure = 248 ppm, postexposure observation period = 15 h) a half-time of 6.4 h was found. These results suggest that the excretion rate of mandelic acid is dependent on the styrene exposure level. In addition the mandelic acid concentrations of 29 workers (group III) before and after the work shift were analyzed. The urinary mandelic acid concentrations of groups I, II and III, sampled immediately after the 8-h work shift, correlated with the 8-h TWA of styrene exposure (n=47, r=0.93). Accordingly about 2,300 mg of mandelic acid per gram of creatinine corresponded to 100 ppm of styrene.

Charcoal sampling method for determining the concentration of styrene in air

The vapors of styrene (vinylbenzene) were trapped on charcoal in a glass tube. Air from the worker's breathing zone was sucked through the tube by a battery-operated, modified, MSA personal sampling pump. The sampler and pumping system were worn by the worker. The styrene were eluted with dimethyl formamide and estimated by gas chromatography. The range and sensitivity of the method when sampling with a flow rate of 0.2 1/min during 1 h were 5 to 1,500 ppm, and during 4 h they were 2 to 400 ppm. The recovery (accuracy) was over 90%. The precision for the method, in terms of relative standard deviation, was 8.4%.