Symptoms of nasal, pharyngeal and ocular discomfort have been reported among workers in the wood surface-coating industry. Symptoms were reported more often by workers using ultraviolet radiation-curable acrylate coatings (UV coatings), which contain potential chemical sensitizers, than by those using acid-curing coatings. Furthermore, increased levels of eosinophil cationic protein (ECP) and albumin, but not tryptase, in nasal lavage from workers exposed to UV coatings have been observed. To further examine whether air contaminants present in the UV-coating industry are causing the observed increase in symptoms, the inflammatory process in the nasal mucosa of workers exposed to UV coatings was investigated. Clinical and biochemical endpoints were selected to distinguish between specific and non-specific hypersensitivity and to test the hypothesis that the symptoms were consistent with Type IV hypersensitivity. The nasal lavage and nasal biopsy were performed under local anesthetic at the workplace during working hours after a minimum of 2 h of work in both the exposed and control groups. Albumin and ECP, and the cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-8 (IL-8), were used as inflammatory markers. A multi-probe ribonuclease protection assay was used to attempt to detect cytokine variation in human nasal biopsies. The cytokine genes analyzed were TNF-alpha, GM-CSF, interferon-gamma, IL-2, IL-4 and IL-5. L32 and GAPDH were used as control genes for mRNA expression levels. Mucosal inflammation symptoms correlated with increased levels of albumin, but not with increased levels of ECP, secreted proinflammatory cytokines or cytokine gene mRNA expression. We conclude that the symptoms are non-specific and do not correlate with occupational exposure to UV coatings under the conditions of this investigation.

Woodworkers exposed to wood dust have an increased frequency of rhinitis. We have previously reported such rhinitis in woodwork teachers. To test whether their nasal complaints are related to nasal hyper-reactivity, we selected 14 woodwork teachers with work-related rhinitis and 14 healthy and non-allergic control persons for nasal histamine challenge using symptom scores (0-3 scale) and acoustic rhinometry for effect evaluation. Intranasal saline followed by doubled concentrations of histamine phosphate (from 0.062 to 16 mg/ml) was given at five-minute intervals. There was no significant difference between the groups regarding symptom scores or acoustic rhinometry during the challenge. The results indicate that nasal hyperreactivity is not a prominent factor in wood-dust-related rhinitis. Other mechanisms probably prompt the nasal complaints.

Upper airway symptoms in workers employed in the manufacture of wood products using ultraviolet radiation curing or acid curing of surface coating have been reported. In this study, workers were divided into groups according to exposure: (1) UV-surface coating line, (2) acid curing surface coating line, (3) finishing processes of UV-cured acrylate coated products, (4) finishing processes of of both UV- and acid cured coated wood products, and (5) control group. The workers were examined with nasal lavage in order to investigate inflammatory signs (ECP, tryptase, albumin and microscopy with cell differential counting). UV-line workers and finishers had significantly increased levels of ECP in nasal lavage. There was a positive correlation between exposure time and ECP and albumin levels. Workers with general nasal complaints and atopics had increased levels of ECP. In this study there were findings indicating an inflammatory process in the nasal mucosa in workers exposed to UV radiation curing multifunctional acrylate coatings. The findings indicate an unspecific inflammation and, therefore, a correlation between occupational exposure to acrylate coatings and nasal inflammation seems probable.

Nasal complaints and impaired nasal physiology are common in various occupational environments. Saline lavage has been recommended as treatment but has not yet been sufficiently evaluated. In this cross-sectional study of 45 wood industry workers, a significant decrease in nasal symptoms (such as obstruction, posterior secretions, itching, irritation and sneezing) was seen after a 3-week treatment with Rhinomer, which contains de-ionized, sterilized, isotonic seawater. Nasal peak expiratory flow (NPEF), especially in workers with nasal complaints, and nasal mucociliary clearance also improved significantly. The treatment, according to participants, was simple to perform and there were only a few side effects.

OBJECTIVE: To study the relation between exposure and nasal function in woodwork teachers. METHODS: 39 selected woodwork teachers employed full time and 32 control subjects (other school personnel) were examined at the beginning and at the end of a working week with symptom rating, nose and throat inspection, rhinomanometry, nasal mucociliary clearance test, and a smell identification test. During one working day of the same week climate, dust and terpene concentrations were measured in all 39 schools. RESULTS: The ventilation rate was highest in rooms with mechanical ventilation. Range of total dust (personally sampled) was 0.12-1.18 mg/m3, respirable dust 0.02-0.21 mg/m3, and terpenes (area sampled) 0.02-6.8 mg/m3. In contrast to the control subjects, the woodwork teachers had more nasal symptoms on the Thursday afternoon than on the Monday morning, especially those working in rooms without mechanical ventilation. Their mucociliary clearance worsened during the week (mean increase 4 min, P < 0.001). A small impairment of olfactory function was also found, but their rhinomanometric values did not change significantly. Nasal symptoms correlated weakly with the percentage of respirable dust in the total dust. Otherwise there were no significant dose-effect relations between measured dust or terpene concentrations and nasal tests. CONCLUSIONS: The woodwork teachers had mainly reversible nasal complaints, impaired nasal mucociliary clearance and olfactory function related to the work environment, with dust concentrations below the Swedish threshold limit value of 2 mg/m3.

Respiratory and ocular effects from exposure to airborne contaminants in workers employed in the manufacture of wood products using ultraviolet radiation curing (UV) or acid curing (AC) of surface coating were investigated. Surface coating line or finishing workers exclusively employed in one or both processes were compared to a control group. Symptoms of exposure were investigated by questionnaire and medical examination. Nasal, pharyngeal, and ocular symptoms of discomfort, but not lower airway, were common among all exposed groups. These symptoms were most frequent in UV line workers and finishers of UV surface-coated wood products. Mucociliary clearance was significantly slower in UV line workers. Significantly higher olfaction thresholds were observed in UV line and AC line workers and finishers of UV/AC surface-coated wood products. Low levels of organic solvents and coating dusts (composed in part of wood dust, chemical composition unknown) were measured in the workers' breathing zones. Although remarkable improvements have been made in both AC and UV surface coating, additional control measures to eliminate airborne contaminants and improved work practices are required.

Exposure to wood dust can cause allergic and nonallergic rhinitis. Inflammatory markers [cells, albumin, tryptase, and eosinophil cationic protein (ECP)] were examined in nasal lavage fluid (NAL) sampled from 24 Industrial Arts (IA) teachers exposed to wood dust and other irritants and from 24 control subjects. The IA teachers had more nasal complaints but they did not differ significantly from the controls regarding ECP concentration (median 4.1 and 4.7 micrograms/L, respectively), albumin concentration (median 30.7 and 20.7 g/L), and percentage of neutrophils (median 56 and 34) in NAL. Tryptase was not detected. No marked inflammation was thus found, but the albumin concentration was higher in subjects reporting nasal stuffiness. In the IA teachers, a relationship between the percentage of neutrophils and the number of classes during the working week was found (Spearman's rank correlation coefficient 0.53, p < 0.01) indicating a possibility of wood-dust-related inflammatory effects on the nasal mucosa.

Occupational exposure to formaldehyde often causes nasal discomfort. The objective of this study was to determine whether chronic exposure to formaldehyde causes annoying symptoms by direct irritation and whether it affects all exposed people (through hyperreactivity in atopic persons, through formaldehyde-induced hyperreactivity also in nonatopic persons, or through an immunologically mediated, immediate type 1 reaction to formaldehyde itself). It was found that about 50% of the studied population of 66 workers occupationally exposed to formaldehyde during formaldehyde production experienced nasal discomfort through hyperreactivity. Atopics were not significantly overrepresented among the persons with occupational nasal symptoms. Two workers with isolated occupational nasal discomfort, and sensitized by long-term inhalation, had a positive radioallergosorbent test for formaldehyde. The conclusion was reached that exposure to formaldehyde should be minimized as much as possible for all people, not only for atopic persons.

Medium-density fiber (MDF) board was recently introduced in the furniture industry. In this pilot study health complaints, physiology, and histology of the upper airways were evaluated for two groups of workers, one handling MDF board for at least one-third of their work week (MDF group) and another handling traditional fiber board. Civil servants served as a reference group. The frequency of health complaints concerning the airways was higher, the sense of smell was poorer, and the frequency of nasal obstruction measured with rhinomanometry was higher for the MDF group, while mucociliary activity was lower in the group handling traditional board. In both groups forced vital capacity was low when compared with expected values. Histological specimens from the middle turbinate of the nose showed, in a few cases, nasal epithelial dysplasia in the traditional board group, but histological changes in terms of scoring did not differ significantly between the groups.

To investigate health effects of long-term exposure to formaldehyde a cross-sectional field study was performed. Seventy formaldehyde-exposed workers were compared with a control group. A higher frequency of symptoms from upper and lower airways, headache, and dermal discomfort was found in the formaldehyde-exposed group. Further, formaldehyde-exposed workers showed disturbances of nasal physiologic conditions, such as slow nasal clearance, impairment of the sense of smell, more pronounced nasal mucosal swelling, and by spirometry lower forced vital capacity than expected was found. Nasal biopsies from the concha media showed more frequent histologic changes such as loss of cilia and metaplasia in the formaldehyde-exposed group. Histologic lesions did not correlate to current or cumulative exposure doses to formaldehyde. In an experimental study of Sprague-Dawley rats exposed to formaldehyde (12.7 mg/m3, 6 hours/day, 5 days/week for 24 months), one rat developed a squamous cell carcinoma in the nose and another nasal dysplasia and in seven other rats pronounced nasal metaplasia was seen in the nasal mucosa. In a control group of rats no significant histologic lesions were found.

In the nasal mucosa of rodents, both formaldehyde and wood dust have proved to be carcinogenic. Wood dust is also a well-known nasal carcinogen in man. The effects of long-term exposure of humans to formaldehyde, however, are more obscure. In this investigation two groups of workers with well-defined exposure to formaldehyde and to formaldehyde and wood dust, respectively, were compared with a control group regarding histological changes in nasal specimens from the middle turbinate. Significant changes were found in the formaldehyde group but not in the group exposed to both formaldehyde and wood dust. No correlation was found between histological changes and duration of exposure, doses of exposure or smoking habits.

Wood dust is a well known nasal carcinogen in man, as formaldehyde is in rats. In certain occupational environments, combined exposure to wood dust and formaldehyde is common. Little is known about the effects of this combination. A pilot study was performed on four groups of Sprague-Dawley rats: one exposed to wood dust (25 mg/m3), another to formaldehyde (12.4 ppm) and a third to both wood dust and formaldehyde; the fourth group served a control group. After 104 weeks of exposure the nose and lungs were examined histologically. One well differentiated squamous cell carcinoma was found in the formaldehyde group. Squamous cell metaplasia was found significantly more often among the formaldehyde-exposed rats. Squamous cell metaplasia with dysplasia was most frequently observed, however, in the group exposed to both formaldehyde and wood dust. There were also significantly more rats with pulmonary emphysema in the groups exposed to wood dust than in the other groups.

Sprague-Dawley rats were vaccinated with pneumococcal polysaccharide antigens and tetanus toxoid to evaluate the immunologic effects of long-term formaldehyde exposure. The antibody response to vaccination was measured 3 to 4 weeks later by enzyme-linked immunosorbent assay. An IgG response to pneumococcal polysaccharides and to tetanus toxoid was found in both the formaldehyde-exposed group and a control group of rats not exposed to formaldehyde. The IgM response to tetanus toxoid was significant in both groups but neither group showed a significant IgM response to pneumococcal polysaccharides. There were thus no signs of impaired B-cell function in rats exposed to a high concentration (12.6 ppm) of formaldehyde for nearly 2 years.

The hazards of exposure to formaldehyde have been widely discussed in recent years on account of the health complaints of exposed persons. Both domestic and occupational exposure to formaldehyde is common. In the present study the effects of formaldehyde alone and in combination with wood dust, another nasal irritant, on the upper and lower respiratory tract have been investigated. The effects were correlated with the duration and degree of exposure. Discomfort from both the upper and lower airways was more frequent in the exposed group than in the unexposed group. Nasal obstruction among the exposed subjects in general could not be detected by rhinomanometric measurements, but, for the group exposed to formaldehyde alone and with a history of nasal blocking, there was significant nasal mucosal swelling. The nasal mucociliary clearance was significantly delayed, and the sense of smell was significantly reduced in the exposed groups when they were compared with the referents. Spirometry showed a significantly decreased forced vital capacity in the exposed groups. There were no signs in this investigation that duration of exposure or level of exposure to formaldehyde would have any influence on the severity of symptoms or the impairment of physiological conditions.

A consecutive series of 57 patients who had undergone an operation on the nasal septum was followed up 1.5-3.5 years postoperatively. Rhinomanometric measurements, a clinical examination of the exterior of the nose, and rhinoscopy were performed. These same examinations had been carried out preoperatively and the results recorded preoperatively. The results of the preoperative rhinomanometry were not known to the surgeon and the indication for surgery was based on clinical examination alone. At follow-up the patients also answered a questionnaire. According to the findings at rhinomanometry 52 of the 57 patients had a better airway after the operation. In 11 patients who subjectively did not consider the nasal airway to have been improved by the operation, an allergy or vasomotor rhinitis was found and in some cases the results of preoperative rhinomanometry (total nasal resistance) were normal. To measure the error of the method, a separate series of duplicate measurements was performed on 50 subjects. The standard deviation of the difference between duplicate measurements was found to be 15% of the mean value and the error of the method was considered small enough to justify rhinomanometry as a method for interindividual comparisons, provided the laboratory standard is well known.