Formalin asthma in hospital staff

Asthma from hair straightening treatment containing formaldehyde: Two cases and a review of the literature

We report two cases of formaldehyde-containing hair straighteners causing new onset asthma. Formaldehyde has been reported to cause asthma in other settings. The purpose of this article is to examine two cases of asthma in hairdressers exposed to hair smoothing products and to review the relevant literature on formaldehyde exposure and asthma. The results indicated that both subjects developed asthma from repeated occupational exposure to formaldehyde during hair treatments. Both subjects became unable to tolerate hair straightening activity in their vicinity. Formaldehyde-containing hair smoothing products are sources of exposure, and the risk of developing asthma is high in salon settings where hair straightening is performed using formaldehyde.

Fractional Exhaled Nitric Oxide (FeNO) and Spirometry as Indicators of Inhalation Exposure to Chemical Agents in Pathology Workers

OBJECTIVE

The objective of this study was to examine whether fractional exhaled nitric oxide (FeNO) and spirometry can be used as indices to evaluate adverse health effects of low-concentrated chemical inhalation exposure, mainly to formaldehyde.

METHODS

Thirty-three subjects (pathology technicians) and 30 controls (workers without handling any chemicals in the same hospitals) participated in this study. All participants underwent FeNO measurement and spirometry before and after 5 days of work.

RESULTS

FeNO significantly increased in the subjects with a history of asthma (P < 0.05), whereas forced vital capacity (FVC) and forced expiratory volume in the first second (FEV1) decreased in the subjects (P < 0.05). Furthermore, work duration and pre-work levels of FEV1 in the subjects had a significant association.

CONCLUSION

The results suggest that FeNO, FVC, and FEV1 represent effective health-effect indices of low-concentrated chemical inhalation exposure.

The pre-analytical phase in surgical pathology

Several sequential passages are involved in the pre-analytical handling of surgical specimens from resection in the surgical theater to paraffin-embedding and storage. Each passage is highly critical and can significantly affect the preservation of morphology, antigens, and nucleic acids. Some key points in this process are still undefined and are subject to high variability among hospitals. High quality and standardization are demanded and pathologists should therefore work to comply with all novel clinical requests (such as genomic and antigenic testing for targeted molecular therapies). Under-vacuum sealing of surgical pieces can be a safe and reliable alternative to storage in large formalin-filled boxes; it prevents dehydration and favors cooling by removing air. Moreover, it implements tissue banking and preservation of nucleic acids. After transport of specimens to pathological anatomy laboratories, the next passage, fixation, has been the object of several attempt to find alternatives to formalin. However, none of the substitutes proved successful, and formalin fixation is still considered the gold standard for preservation of morphology and antigens. RNA has instead been found to be heavily affected by degradation and fragmentation in formalin-fixed tissues. Based on the hypothesis that RNA degradation would be inhibited by maintaining a low temperature, a protocol based on processing tissues with formalin at low temperature (cold fixation) was evaluated and proved useful in obtaining a reduction in RNA fragmentation. Finally, the problem of storage is discussed, in order to find ways to guarantee feasibility of molecular analyses even years after the original diagnosis.

Bronchial asthma and COPD due to irritants in the workplace - an evidence-based approach

BACKGROUND

Respiratory irritants represent a major cause of occupational obstructive airway diseases. We provide an overview of the evidence related to irritative agents causing occupational asthma or occupational COPD.

METHODS

We searched MEDLINE via PubMed. Reference lists of relevant reviews were also screened. The SIGN grading system was used to rate the quality of each study. The modified RCGP three-star system was used to grade the body of evidence for each irritant agent regarding its causative role in either occupational asthma or occupational COPD.

RESULTS

A total of 474 relevant papers were identified, covering 188 individual agents, professions or work-sites. The focus of most of the studies and the predominant diagnosis was occupational asthma, whereas occupational COPD arose only incidentally.The highest level assigned using the SIGN grading was 2+ (well-conducted systematic review, cohort or case-control study with a low risk of confounding or bias). According to the modified RCGP three-star grading, the strongest evidence of association with an individual agent, profession or work-site ("**") was found for 17 agents or work-sites, including benzene-1,2,4-tricarboxylicacid-1,2-anhydride, chlorine, platinum salt, isocyanates, cement dust, grain dust, animal farming, environmental tobacco smoke, welding fumes or construction work. Phthalic anhydride, glutaraldehyde, sulphur dioxide, cotton dust, cleaning agents, potrooms, farming (various), foundries were found to be moderately associated with occupational asthma or occupational COPD ("*[+]").

CONCLUSION

This study let us assume that irritant-induced occupational asthma and especially occupational COPD are considerably underreported. Defining the evidence of the many additional occupational irritants for causing airway disorders will be the subject of continued studies with implications for diagnostics and preventive measures.

Evaluation of the health impact of lowering the formaldehyde occupational exposure limit for Quebec workers

This study aimed at assessing the impact on irritating effects of lowering the current occupational exposure limit (OEL) for formaldehyde in occupational settings in the Province of Quebec, Canada, from a 2 ppm ceiling value to 1, 0.75 or 0.3 ppm. This was achieved through (i) a re-assessment of the exposure-response relationship based on a pooled analysis of published controlled human studies on the incidence of the most sensitive effects related to acute formaldehyde exposure (irritation of the eyes, nose and throat) and (ii) application of this relationship to the data on current exposure to formaldehyde in industrial sectors of Quebec. Results show that the exposure-irritating effect relationship compiled by concentration ranges and by degree of severity was best described by quadratic regression. Considering the current distribution of formaldehyde exposure among the 143,491 Quebec workers concerned, eye irritation, the most sensitive effect, could affect 526 workers (0.367%) at a moderate degree and 50 workers (0.035%) at a severe degree. By reducing the OEL to 1, 0.75 and 0.3 ppm, the proportion of these effects estimated to be avoided would be 442/526 (84%), 526/526 (100%) and 526/526 (100%), respectively. Results for nose and throat irritation follow the same trend. The greatest gain would thus be obtained by respecting the current OEL; the additional gain was estimated to be negligible below 0.75 ppm. The level of 0.75 ppm can be considered as a safe level that allows protecting virtually all workers.

Occupational airway diseases

In this review we describe characteristics of occupational airway diseases, as well as physical and chemical characteristics of agents inducing airway disease. Occupational airway diseases include industrial bronchitis, reactive airway dysfunction syndrome, bronchiolitis obliterans, and occupational asthma. High- and low-molecular weight substances associated with occupational airway disease are listed. The importance of host factors is stressed. Diagnostic approaches, particularly indicators for specific challenge testing with occupational materials, are described. Preventive and control measures are presented.

Short-term effects of formaldehyde on peak expiratory flow and irritant symptoms

The authors studied the respiratory effects of formaldehyde exposure among students who dissected cadavers in a gross anatomy laboratory. Peak expiratory flow and respiratory symptoms were measured before and after each weekly laboratory session. Each of 38 students was exposed to formaldehyde for 2.5 hr/wk for 14 wk. Individual, daily formaldehyde measurements averaged 1.1 ppm (standard deviation = 0.56 ppm). Multivariate models demonstrated two different time scales of effect of formaldehyde on peak expiratory flow: (1) exposure during the previous 2.5 hr reduced peak expiratory flow by -1.0% per ppm, and (2) average exposure during all preceding weeks reduced peak expiratory flow by an additional -0.5% per ppm of formaldehyde. However, the short-term exposure effect was diminished during the first 4 wk, suggesting at least partial acclimatization. Symptom reporting was also associated with exposure during the previous 2.5 hr, and similar evidence of acclimatization was observed. These results suggest that there are two different time scales of response to formaldehyde, and they emphasize the need for longitudinal studies, characterized by quantitative exposure characterization, and frequent measurements of outcome.

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.

Response of respiratory epithelium of BN and F344 rats to formaldehyde inhalation

BN rats are well-known for their high capacity for IgE production and hyperresponsiveness to exposure to allergens or other chemicals. We examined the histological changes in the nasal cavity, trachea and lungs of BN and F344 rats after the inhalation of aerosol formaldehyde (HCHO), which exerts direct toxic effects on the respiratory system. The incidence of clinical signs such as sneezing and abnormal respiration in HCHO-treated F344 rats was higher than that in HCHO-treated BN rats. The mean body weight of HCHO-treated F344 rats apparently decreased in comparison with control F344 rats, but that of HCHO-treated BN rats was not significantly different from that of control BN rats. Changes such as squamous metaplasia, stratification, degeneration and desquamation were observed by light microscopy in nasal, tracheal and bronchial mucosa in the lungs of the HCHO-treated F344 rats. In the HCHO-treated BN rats, similar but milder lesions were restricted to the nasal mucosa. Scanning electron microscopic observation supported these light microscopic observations. These results suggest that BN rats have lower sensitivity to HCHO inhalation than F344 rats.

Experimental assessment of the sensitizing properties of formaldehyde

Formaldehyde causes upper respiratory tract irritation and has been reported in some investigations to be a cause of occupational allergic asthma. The data are equivocal, however, and it has proved difficult to confirm that exposure to formaldehyde induces respiratory sensitization or provokes the production of specific immunoglobulin E (IgE) antibody. In this study the sensitizing properties of formaldehyde were examined experimentally. This chemical elicited strong positive responses in three independent methods for the prospective identification of contact sensitizing chemicals-the guinea pig maximization test, the occluded patch test of Buehler and the murine local lymph node assay. In contrast, in a novel predictive test method for assessment of respiratory sensitization potential-the mouse IgE test-formaldehyde at the same test concentrations was negative. Furthermore, formaldehyde induced in mice a pattern of cytokine secretion by draining lymph node cells inconsistent with the stimulation of IgE antibody responses or respiratory sensitization. These data indicate that, although formaldehyde is a potent contact allergen, it lacks a significant potential to cause sensitization of the respiratory tract.

Respiratory effects of organic solvent exposure

Organic solvents are widely used in industrial processes and found in many common household products. Exposures to solvents are common in both idustrialized and industrializing countries. While organic solvents exposure is well known to produce central nervous system toxicity, hepatic, renal and dermatologic injury, the respiratory effects of solvent exposure are poorly documented. Several recent population-based epidemiologic studies have found an independent association of occupational solvent exposure with respiratory symptoms, impaired pulmonary function or respiratory disease, but interpretation of these studies is limited by self-reported exposure data. Animal studies have demonstrated adverse effects in both the conducting and the respiratory airways, although often at very high exposure levels. Human chamber studies have most consistently reported irritation of the eyes, nose and throat without evidence of airway hyper-responsiveness. Case series have observed obstructive and restrictive effects in patients with high level inhalational exposures to solvents, particularly formaldehyde, but occupational epidemiologic studies have not consistently demonstrated changes in pulmonary function. Finally, mortality studied have not found increased mortality rates from respiratory disease in occupations associated with solvent use. In general, solvents have been demonstrated to cause mucosal irritation of the eyes and upper airways, but studies of pulmonary impairment following exposure have been limited and inconsistent. Solvent-mediated respiratory toxicity is biologically plausible, but further research is needed to better characterize exposures and to elucidate the specific mechanisms associated with injury.

Occupational asthma due to indirect exposure to lauryl dimethyl benzyl ammonium chloride used in a floor cleaner

The case is described of a 44 year old pharmacist who developed severe occupational asthma threatening his continued employment, confirmed by serial measurement of peak expiratory flow at home and work. The cause was found to be the cleaning agent used in his office when it was unoccupied. Bronchial challenge testing identified the specific agent to which he was sensitised as lauryl dimethyl benzyl ammonium chloride, a constituent of the floor cleaner. Substitution of this floor cleaner by a simple detergent cleaner led to a substantial improvement in his asthma, confirmed by repeated serial peak flow measurements.

Asthma risk and occupation as a respiratory therapist

In the modern hospital environment, many health care workers are exposed to hazardous substances. Among these hazards are respiratory sensitizers, irritants, and infectious agents. A previous cross-sectional study of Rhode Island respiratory therapists reported an excess risk of asthma after entry into that profession. Before the results of that study were published, we conducted a confirmatory mailed questionnaire survey of 2,086 Massachusetts respiratory therapists and 2,030 physical therapists and physical therapy assistants. Neither the survey questionnaire nor the accompanying cover letter revealed the focus of our investigation. A history of physician-diagnosed asthma was reported by 16% of respiratory therapists and 8% of control subjects. When analysis was restricted to those who developed asthma after entry into their profession, respiratory therapists still had a significant excess, 7.4 versus 2.8%. The odds ratio for respiratory therapy was 2.5 (95% Cl, 1.6 to 3.3) after adjustment for age, family history, atopic history, smoking, and gender. These results confirm the previous report of excess risk of asthma among respiratory therapists. This excess risk develops after entry into the profession and does not appear to be explained by bias or confounding. Efforts should be directed to identifying potential agents responsible for this form of occupational asthma.

Acute pulmonary response in healthy, nonsmoking adults to inhalation of formaldehyde and carbon

Formaldehyde (HCHO) is a common chemical found in occupational and residential environments and has been suggested as a cause of asthmalike symptoms in some individuals. Clinical and animal studies suggest that HCHO adsorbed on respirable particles may elicit a greater pulmonary physiologic and inflammatory effect than gaseous HCHO alone. The purpose of this study was to determine if respirable carbon particles have a synergistic effect on the acute symptomatic and pulmonary physiologic response to HCHO inhalation. We randomly exposed 24 normal, nonsmoking, methacholine-nonreactive subjects to 2 h each of clean air, 3 ppm formaldehyde, 0.5 mg/m3 respirable activated carbon aerosol, and the combination of 3 ppm formaldehyde plus activated carbon aerosol. The subjects engaged in intermittent heavy bicycle exercise (VE = 57 l/min) for 15 min each half hour. Measures of response included symptom questionnaires, spirometry, body plethysmography, and postexposure serial peak flows. Formaldehyde exposure was associated with significant increases in reported eye irritation, nasal irritation, throat irritation, headache, chest discomfort, and odor. We observed synergistic increases in cough, but not in other irritant respiratory tract symptoms, with inhalation of formaldehyde and carbon. Small (less than 5%) synergistic decreases in FVC and FEV3 were also seen. We observed no HCHO effect on FEV1; however, we did observe small (less than 10%) significant decreases in FEF25-75% and SGaw which may be indicative of increased airway tone. Overall, our results demonstrated synergism, but the effect is small and its clinical significance is uncertain.

Pulmonary function in histology technicians compared with women from Michigan: effects of chronic low dose formaldehyde on a national sample of women

Chronic workplace exposure to formaldehyde and solvents at low doses reduced pulmonary function in 280 non-smoker white women working as histology technicians. They were studied during national workshops at four United States cities for four years. Height and age adjusted comparisons of pulmonary function were made with women in a stratified random population sample of Michigan and with a selected subset of the population that was used to model predictive pulmonary equations for function. The major functional change in histology technicians was a steeper decrement in vital capacity and flows from age 20 to 60 by regression analysis than occurred in the modelled Michigan population. Furthermore non-smoking and currently smoking women studied at two sites had significantly lower flows than were found in the sample of Michigan women. There was no consistent effect of an aerosol bronchodilator on flows of women at the four sites. Diffusing capacity for carbon monoxide single breath and alveolar volume were below the comparison group of Michigan women only when tested at Washington DC.

Acute resin phenol-formaldehyde intoxication. A life threatening occupational hazard

1. A 38-year-old previously healthy worker accidentally spilled phenol-formaldehyde resin over a large area of his skin. 2. Several days later he was hospitalized with extensive necrotic skin lesions, fever, hypertension, adult respiratory distress syndrome (ARDS), proteinuria and renal functional impairment. 3. All symptoms improved progressively and eventually disappeared. 4. We propose that toxic materials originating from the necrotic skin lesions and the continued facilitated absorption of the resin and/or its components via the skin lesions were the main factors responsible for this alarming multisystem involvement. 5. Workers handling this material should be instructed to take appropriate precautions and physicians should be alerted to the potential pathophysiological consequences.

Acute airway narrowing in monkeys from challenge with 2.5 ppm formaldehyde generated from formalin

Nine adult male Cynomolgus monkeys (Macaca fascicularis) were exposed for 10 min to 2.55 +/- 0.03 ppm formaldehyde (HCHO; mean +/- standard error of the mean, SEM) generated from formalin with a newly developed HCHO challenge system. The generation system was capable of producing highly stable HCHO vapor concentrations with fluctuations of HCHO concentrations of less than +/- 5%. The experimental design included pre-exposure methacholine challenge to determine if responses to HCHO were associated with pre-existing bronchial hyperreactivity. Significant changes in average pulmonary flow resistance (RL) were observed (compared to control RL values) at 2 (p less than 0.01), 5 (p less than 0.01), and 10 min (p less than 0.005) post-HCHO challenge. Pre-challenge RL values (mean +/- SEM) were 11.3 +/- 1.4 cm H2O.l/s, while at 2, 5, and 10 min after HCHO challenge, values were 16.1 +/- 2.1, 16.9 +/- 2.8 and 20.0 +/- 3.4 cm H2O.l/s, respectively. Methacholine challenge data suggest that reactions to HCHO tend to be greater in monkeys hyperreactive to methacholine, but the relationship does not reach statistical significance in this small series of animals. These data indicate that significant pulmonary function deficits occur immediately after challenge with 2.55 ppm HCHO vapor in monkeys.

Allergy in chronic haemodialysis. 1. Double-blind intravenous challenge with formaldehyde

Patients undergoing chronic haemodialysis are often exposed to formaldehyde formaldehyde (F) has been reported to cause IgE-mediated anaphylactic shock. Many other patients reported pruritus or anaphylaxis-like symptoms when dialysed with F-sterilized dialysers. Ten patients presenting such symptoms were compared with five control subjects. Intravenous double-blind challenges were performed on six consecutive occasions, with capillary flow dialysers sterilized with or without F. Dialysis was performed by an investigator who was not aware of the sterilization procedure. Among the ten F-sensitive patients, five had symptoms with F-sterilized dialysers and no symptoms with new dialysers, sterilized by ethylene oxide and free of F. Symptoms included pruritus and hypotension. These five patients were subsequently dialysed with new dialysers, not sterilized with F, and symptoms subsided. The five other patients had inconclusive challenges. The five control subjects had no symptoms during challenges. Skin-prick tests with F showed that only one of the five patients who had symptoms with F-dialysers had a strongly positive prick test. RAST to F was titrated with HSA-discs but it was negative in all patients and control subjects. Formaldehyde was shown to cause symptoms in some patients under chronic haemodialysis but an IgE-mediated mechanism was not demonstrated.

Asthma and rhinitis after exposure to glutaraldehyde in endoscopy units

Four nurses working in endoscopy units complained of respiratory symptoms on exposure to alkaline glutaraldehyde used as a disinfectant for fibre-optic endoscopes. A provocation test was positive in two of these patients. This is the first report to use provocation testing to confirm a relation between exposure to alkaline glutaraldehyde and respiratory disease.

A study of respiratory effects from exposure to 2 ppm formaldehyde in healthy subjects

Formaldehyde (FA) is a common indoor air pollutant with irritative properties. It has been suggested that FA may produce physiologic alterations of the respiratory system. To study such responses, 15 nonsmoking, healthy subjects were exposed in a double blind, random manner to 0 and 2 ppm FA for 40 min in an environmental chamber. In addition, the same exposures were repeated on a separate day with the subjects performing moderate exercise (450 kpm/min) for 10 min. Exposures were carried out under controlled environmental conditions (temperature = 23 degrees C, relative humidity = 50%). Pulmonary function was measured before, during, and after exposures using partial and maximal flow-volume curves and airway resistance. Symptom diaries were given to the subjects; upper and lower airway symptoms were recorded for up to 24 hr following exposures. No significant bronchoconstriction was noted in this group. In 3 subjects, sequential measurements of peak flow over a 24-hr period following FA exposure failed to reveal any delayed airway response. On a separate day, 6 healthy subjects failed to demonstrate changes from their baseline responsiveness to methacholine after exposure to 2 ppm FA. Respiratory symptoms were, in general, confined to the upper airways and were mild to moderate in severity. We conclude that short exposures to 2 ppm FA do not result in acute or subacute changes in lung function among healthy individuals either at rest or with exercise. Subjective complaints following such exposures are confined to irritative phenomena of the upper airways.

Health effects of urea formaldehyde foam insulation: evidence of causation

Studies of health effects of urea formaldehyde foam insulation (UFFI) were critically reviewed by means of accepted rules for evidence of causation. Three categories of health effects were examined: reported symptoms, primarily of the upper respiratory tract, lower respiratory tract disease and cancer. Most of the studies purporting to demonstrate health effects of UFFI failed to meet minimal methodologic criteria for evidence of causation. Evidence from the adequate studies provides little support for the hypothesis of a causative role of UFFI in health problems.

Pulmonary and neurobehavioral effects of formaldehyde exposure

Two groups of male workers who were exposed to formaldehyde, the first group in phenol-formaldehyde-plastic foam matrix embedding of fiberglass (batt making), and the second in the fixation of tissues for histology, were studied for work-related neuro-behavioral, respiratory, and dermatological symptoms; and for pulmonary functional impairment. Forty-five male fiberglass batt makers who were studied across the initial work-shift after a holiday had average frequencies of combined neurobehavioral, respiratory, and dermatological symptoms of 17.3 for the hot areas and 14.7 for the cold areas of the process. Their symptom counts were significantly greater than those for 18 male histology technicians who averaged 7.3, and for 26 unexposed male hospital workers who averaged 4.8. During their first workshift after holidays, 58% of the batt makers had a decrease in one or more tests of pulmonary function. Nine nonsmokers had decreases more frequently than did 35 smokers; forced expiratory volume in one second FEV1.0 decreased in 16%, diffusing capacity for carbon monoxide (sb) decreased in 30%, forced expiratory flow 25-75 decreased in 16%, and forced expiratory flow) 75-85 decreased in 36%. Thirty-five percent of all 44 men had drops in FEV1.0, forced vital capacity, or in diffusing capacity (sb).

Report on the Consensus Workshop on Formaldehyde

The Consensus Workshop on Formaldehyde consisted of bringing together scientists from academia, government, industry and public interest groups to address some important toxicological questions concerning the health effects of formaldehyde. The participants in the workshop, the Executive Panel which coordinated the meeting, and the questions posed, all were chosen through a broadly based nomination process in order to achieve as comprehensive a consensus as possible. The subcommittees considered the toxicological problems associated with formaldehyde in the areas of exposure, epidemiology, carcinogenicity/histology/genotoxicity, immunology/sensitization/irritation, structure activity/biochemistry/metabolism, reproduction/teratology, behavior/neurotoxicity/psychology and risk estimation. Some questions considered included the possible human carcinogenicity of formaldehyde, as well as other human health effects, and the interpretation of pathology induced by formaldehyde. These reports, plus introductory material on the procedures used in setting up the Consensus Workshop are presented here. Additionally, there is included a listing of the data base that was made available to the panel chairmen prior to the meeting and was readily accessible to the participants during their deliberations in the meeting. This data base, since it was computerized, was also capable of being searched for important terms. These materials were supplemented by information brought by the panelists. The workshop has defined the consensus concerning a number of major points in formaldehyde toxicology and has identified a number of major deficits in understanding which are important guides to future research.

Lack of bronchomotor response to up to 3 ppm formaldehyde in subjects with asthma

A study was undertaken to determine whether exposure to concentrations of formaldehyde occasionally encountered in polluted indoor air would cause bronchoconstriction in subjects with mild asthma. In seven subjects the increase in specific airways resistance (SRaw) caused by inhalation of 1 ppm formaldehyde for 10 min was compared with the response caused by inhalation of formaldehyde-free air. Also, the increase in SRaw caused by inhalation of 1 and 3 ppm formaldehyde during moderate exercise for 10 min was compared with the response caused by inhalation of formaldehyde-free air during exercise for 10 min. Inhalation of formaldehyde at rest and during exercise did not cause a significant increase in SRaw in the subjects. It is concluded that brief exposure to these concentrations of formaldehyde, even in association with moderate exercise, is unlikely by itself to cause significant bronchoconstriction in most subjects with mild asthma.

Preparation and evaluation of biodegradable polymeric systems for the intra-articular delivery of drugs

Colloidal suspensions of four biodegradable polymers, polylactic acid (PLA), polybutylcyanoacrylate (PBCA), gelatin (PG) and albumin (PA) were prepared within the size range 1-10 micron. In-vivo biocompatibility tests with synovial tissues were carried out to assess the irritancy of the polymers following intra-articular injection into rabbit knee joints. PLA, PBCA and PG were found to cause joint inflammation whereas PA was well tolerated by the tissues. PA microspheres may provide a means of sustaining the release and reducing the rate of clearance of drugs from the knee joint.

Bronchial challenge with formaldehyde gas: lack of bronchoconstriction in 13 patients suspected of having formaldehyde-induced asthma

We studied 13 selected patients with symptoms suggestive of asthma who suspected exposure to formaldehyde as a cause. These patients had a history of exposure to formaldehyde gas which either coincided with the onset of or aggravated their symptoms of asthma. The levels of exposure at their homes or at work ranged from 0.1 to 1.2 parts per million (ppm) of formaldehyde gas. The patients were tested with bronchial challenges of 0.1-, 1-, and 3-ppm concentrations of formaldehyde gas and randomly interspersed room-air placebos. The formaldehyde gas or placebo was delivered via a Dynacalibrator . The period of exposure to formaldehyde gas or placebo with each challenge was 20 minutes. Pulmonary function was measured before and for 24 hours after each bronchial challenge. No patient had a significantly greater decrease in the forced expiratory volume in 1 second after exposure to formaldehyde than after exposure to air. In no case were we able to substantiate that exposure to formaldehyde gas (3 ppm or less) was indeed causing or aggravating the asthmatic symptoms.

Occupational asthma caused by cedar urea formaldehyde particle board

Two carpenters developed asthma and rhinitis related to occupational exposure to a cedar urea formaldehyde (CUF) particle board. One patient developed nasal and chest symptoms and an equivocal early asthmatic response after CUF sawdust exposure, but not after spruce or western red cedar sawdust exposure; possible late asthmatic response may have been inhibited by beclomethasone treatment. The other patient developed marked nasal and chest symptoms and a dual asthmatic response after CUF exposure, but not after spruce or cedar exposure. Both patients developed increased bronchial responsiveness to inhaled histamine, which persisted for at least six days in the first patient, and which was associated with increased asthmatic symptoms of days' to weeks' duration in both. A previously unexposed asthmatic patient, with more markedly hyperreactive bronchi, developed no symptoms, no change on spirometric testing, and no change in histamine response after CUF exposure. Specific IgE antibodies directed against formaldehyde-human serum albumin conjugate could not be demonstrated using the radioallergosorbent test. This investigation documents the occurrence of occupational asthma caused by urea formaldehyde used as a bonding agent in particle boards. Absence of a response in a previously unexposed, more severe asthmatic patient suggests specific sensitization to some component of the urea formaldehyde resin complex had developed.

Formaldehyde exposure in nonoccupational environments

Free formaldehyde may be released from wood products and foam insulation where urea-formaldehyde resins have been used. From January, 1978 to November, 1979, 100 structures were investigated by the Wisconsin Division of Health after receiving complaints of health problems from occupants. Air samples were collected in midget impingers and analyzed for formaldehyde content by the chromotropic acid procedure. Health information was obtained from the occupants via questionnaires. Mean formaldehyde concentration observed ranged from below the limit of detection to 3.68 ppm. Eye irritation, burning eyes, runny nose, dry or sore throat, headache, and cough were the primary symptoms which were reported by the occupants. Statistically significant associations were seen between formaldehyde levels and age of home/building materials. Observations presented suggest nonoccupational, indoor environmental exposure to formaldehyde is significant and may reach levels which exceed occupational exposure standards.

Occupational formalin asthma

Hypersensitivity to formalin used to sterilise artificial kidney machines was shown by inhalation provocation tests to be responsible for attacks of wheezing accompanied by productive cough in two members of the nursing staff of a haemodialysis unit. Three further members of the staff of 28 who were continually exposed to this substance occupationally had developed similar recurrent but less frequent episodes since joining the unit. Two underwent inhalation provocation tests with formalin which did not reproduce these symptoms. Single episodes of these symptoms had been noted by three additional staff members so that altogether eight (29%) had experienced attacks described as bronchitic since becoming exposed to formalin. We suggest that, while exposure to formalin did not seem to be directly responsible in all cases, it might have increased susceptibility to other provoking agents or induced a hyper-reactive responsiveness of the airways. The responses observed in the two nurses after inhalation provocation tests with fromalin were predominantly of airways obstruction. Wheezing began between two and three hours after exposure, and peak expiratory flow rates fell maximally by approximately 50%. Reactions persisted for 10 hours to 10 days depending on the exposure dose. A productive cough was a prominent feature. The sputum appeared to be mucopurulent, but culture produced a scanty growth of Haemophilus influenzae only, together with upper respiratory tract commensals. The cellular content was not homogeneous, neutrophil leucocytes and eosinophil leucocoytes variably dominating. Variable responses of neutrophil and eosinophil leucocytes were also seen in the peripheral blood.