In situ enhancement of pulmonary surfactant function using temporary flow reversal.

Acute respiratory distress syndrome is a pulmonary disease with a mortality rate of ∼40% and 75,000 deaths annually in the United States. Mechanical ventilation restores airway patency and gas transport but leads to ventilator-induced lung injury. Furthermore, surfactant replacement therapy is ineffective due to surfactant delivery difficulties and deactivation by vascular proteins leaking into the airspace.

Lung function, radiological changes and exposure: analysis of ATSDR data from Libby, MT, USA.

In 2000, the Agency for Toxic Substances and Disease Registry (ATSDR; Atlanta, GA, USA) investigated lung disease in those exposed to the tremolite-contaminated vermiculite mine in Libby, MT, USA. Previously unreported spirometric results are presented here in relation to exposure and radiographic findings. 4,524 study participants were assigned to one of seven mutually exclusive exposure categories.

Workplace spirometry monitoring for respiratory disease prevention: a methods review.

This report reviews methods applicable in workplace spirometry monitoring for the identification of individuals with excessive lung function decline. Specific issues addressed include 1) maintaining longitudinal spirometry data precision at an acceptable level so that declines due to adverse physiological processes in the lung can be readily detected in an individual; 2) applying interpretative strategies that have a high likelihood of identifying workers at risk of developing lung function impairment; and 3) enhancing effectiveness of spirometry monitoring for intervention and disease prevention. Applications in ongoing computerized spirometry monitoring programs are described that demonstrate approaches to improving spirometry data precision and quality, and facilitating informed decision-making on disease prevention.

A survey of size-fractionated dust levels in the U.S. wood processing industry.

A survey of size-fractionated dust exposure was carried out in 10 wood processing plants across the United States as part of a 5-year longitudinal respiratory health study. The facilities included a sawmill, plywood assembly plants, secondary wood milling operations, and factories producing finished wood products such as wood furniture and cabinets. Size-fractionated dust exposures were determined using the RespiCon Personal Particle Sampler.

Longitudinal respiratory health study of the wood processing industry.

Background: A 5-year longitudinal study examined nonmalignant respiratory effects of wood processing dust exposure.

Methods: Ten study plants, investigator selected from 447 candidate plants, included 1 sawmill-planing-plywood, 1 plywood, 1 milling, 3 cabinet and 4 furniture facilities. Personal dust samples (2363) were divided into three size fractions (extrathoracic, tracheobronchial, and respirable) which were apportioned into wood solids (WS) and residual particulate matter (RPM), and used to compute each individuals TWA exposure for the 6 exposure types.

Limits of longitudinal decline for the interpretation of annual changes in FEV1 in individuals.

Objective: Spirometry-based screening programmes often conduct annual assessment of longitudinal changes in forced expiratory volume in 1 second (FEV1) to identify individuals with excessive rates of decline. Both the American Thoracic Society (ATS) and the American College of Occupational and Environmental Medicine (ACOEM) recommend a reference limit value of > or =15% for excessive annual decline. Neither the ATS nor the ACOEM adjust this limit for the precision of the existing spirometry data.

Case definitions for chronic obstructive pulmonary disease.

The objective of this study was to evaluate the definitions for classification of chronic obstructive pulmonary disease (COPD) recommended by the American Thoracic Society (ATS) and the Global Initiative for Chronic Obstructive Lung Disease (GOLD). Using data from the U.S.

Longitudinal limits of normal decline in lung function in an individual.

Objectives: The objectives of this study were to propose a method of calculating longitudinal limits of normal decline (LND) in forced expiratory volume in 1 second to identify individuals with an excessive decline in lung function and to compare the method with other published LND methods.

Methods: We used longitudinal data from 11 workplace-based spirometric monitoring programs conducted from 1987 to 2001 on 12,729 workers to evaluate effectiveness of each LND method in identifying a "true" excessive decline in forced expiratory volume in 1 second defined using two criteria: slope >60 mL/year or >90 mL/year estimated over 5 or more years of follow up.

Results: In comparison to the LND proposed by the American College of Occupational and Environmental Medicine, the proposed method had 5.

The effects of ethanol ingestion on the accuracy of pulmonary diffusing capacity measurement.

Background: Erroneous diffusing capacity of the lung for carbon monoxide (Dlco) values as measured by spectrophotometry were observed at our facility in ethanol-intoxicated subjects. An atypical methane curve tracing was noted in these subjects.

Study Objectives: We hypothesized that ethanol intoxication interferes with Dlco measurements obtained using methane and designed a study to assess the blood ethanol level at which this occurs.

The precision of longitudinal lung function measurements: monitoring and interpretation.

Background: The efficacy of decision making based on longitudinal spirometric measurements depends critically on the precision of the available data, which is determined by the magnitude of the within-person variation.

Aims: Firstly, to describe and investigate two statistical methods-a pairwise estimate of within-person standard deviation s(p) and the reliability coefficient G-for use in the monitoring of precision of longitudinal measurements of forced expiratory volume in one second (FEV1). Secondly, to investigate the effect of longitudinal data precision on the detectable excess rate of decline in FEV1.

On-filter determination of collected wood dust by diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS).

A new analytical technique based on DRIFTS spectroscopy has been developed for the specific and sensitive determination of size-fractionated wood dust from 37 mm glass fiber filter samples collected with the Respicon sampler. A translational diffuse reflectance apparatus was modified to accept filter samples by incorporating a special filter holder in the sample stage and a clockwork motor to drive the translational stage during infrared scanning, thus providing an average analysis across the filter face. Filter samples were pre-treated with ethyl acetate to uniformly redeposit dust onto the filter and extract potential chemical interferences.

Field performance of the RespiCon for size-selective sampling of industrial wood processing dust.

The RespiCon sampler is a multistage virtual impactor that simultaneously collects the ISO/CEN/ACGIH size fractions of inhalable, thoracic, and respirable particulate matter. The field performance of the device for measurement of industrial wood processing dust was evaluated against reference size-selective samplers: the IOM sampler (inhalable dust), the GK 2.69 cyclone (thoracic dust), and the SKC aluminum cyclone (respirable dust).

Spray-painting and chronic airways obstruction.

Background: The aim was to investigate the respiratory response of HDI-based paint aerosol within the context of the protection afforded by current exposure guidelines.

Methods: A cross-sectional study of 240 painters spraying polyurethane enamels was undertaken at four aircraft maintenance plants. Questionnaire and spirometric data were related to gravimetric measures of cumulative total and respirable paint aerosol (TPA and RPA) and estimated isocyanate in total and respirable aerosols (TIA and RIA).

Relationship of asthma to irritant gas exposures in pulp and paper mills.

The potential of chronic or acute irritant gas exposures to cause asthma or a variant condition, reactive airways dysfunction syndrome (RADS) was investigated by observing asthma incidence in a large working population, using person-years at risk (P-YR) to compute relative rates (RR). Health data came from employee examinations at 62 pulp and paper plants. The 39122 workers who denied asthma beginning before the observation period included: 19326 denying irritant exposures, with no gassing exposures; 19349 with self-reported irritant exposures, and no gassing; and 447 with documented gassings.

Adjusting FVC for the effect of obstruction.

Objective: To derive a method of taking into account the effects of obstruction on the FVC, allowing more accurate assessment of other negative ("restrictive") influences.

Design: In 656 subjects with airways obstruction, defined as FEV1/FVC of 0.70 or less, regression of FVC was expressed as percentage of predicted value (FVC %PRED) on potential explanatory variables, including FEV1/FVC.

Blue-collar normative spirometric values for Caucasian and African-American men and women aged 18 to 65.

Normative spirometric values were derived from 5,042 white (of mainly European ancestry) and black (of mainly African ancestry) men and women paper plant workers who are never-smokers, with no respiratory symptoms or diagnoses and no history of occupational exposure to fibrogenic dusts or irritant chemicals. This cohort was selected from a much larger population under long-term respiratory surveillance (n > 50,000 at 50 plants). Standardized equipment, procedures, and data reduction methods complied with ATS recommendations.

Cotton dust and across-shift change in FEV1 as predictors of annual change in FEV1.

In this report of a 5-yr longitudinal study of workers employed at six cotton textile mills, exposure and across-shift FEV1 change were evaluated as possible predictors of the annual change in FEV1 for yarn manufacturing workers. A total of 611 workers had three repeatable spirometric tests, over at least 3 yr, and at least one (average of three) across-shift test, while always working the same shift. The "same shift" criterion controlled for the effect of diurnal variation.

Follow up study of workers exposed to man made mineral fibres.

A survey of workers in seven man made mineral fibre (MMMF) production plants, the subject of a previous report, was conducted, with other blue collar workers serving as regional comparisons. Based on the median reading of chest radiographs by five readers, a low prevalence of small opacities, all at the 1/0 and 1/1 profusion levels, was again found: for workers with MMMFs, 23/1435 (1.6%); for comparison workers, 2/305 (0.

Abnormal lung function in polyurethane foam producers. Weak relationship to toluene diisocyanate exposures.

Exposures to toluene diisocyanate (TDI) were studied for effects on respiratory health of workers in two plants manufacturing polyurethane foams. Intensive personal monitoring was used to characterize job exposures. Of 4,845 12-min personal samples, 9% exceeded 5 ppb and 1% exceeded 20 ppb.

Exposure-related declines in the lung function of cotton textile workers. Relationship to current workplace standards.

To evaluate the effectiveness of the current workplace standards in preventing chronic health effects from cotton dust exposure, a 5-yr longitudinal study of a large multimill population of cotton textile and synthetic process workers, employed at a major U.S. textile company, was conducted.

Progression of asbestos effects: a prospective longitudinal study of chest radiographs and lung function.

From an original prospective cohort of 244 current and ex-workers in two asbestos cement plants, longitudinal radiographic data covering ten years were available for 165 and lung function data covering about six years for 150. Estimates of average and cumulative dust exposure were available for each participant, all men. Radiographic progression (onset or worsening) was assessed by comparing earliest and latest films side by side.

Role of inhalation challenge testing in the diagnosis of isocyanate-induced asthma.

Results of isocyanate challenge tests performed on 63 workers referred with a diagnosis of probable isocyanate asthma between 1974 and 1988 were reviewed. Thirty (48 percent) had an acute episode of asthma with a greater than 20 percent decline in FEV1 following subirritant exposure to isocyanates. No difference in the frequency or type of respiratory complaints between isocyanate reactors and nonreactors was found.

Contributing factors to sandblasters' silicosis: inadequate respiratory protection equipment and standards.

National concordance standards for respiratory protection during abrasive blasting have existed for more than 50 years; however, these standards have not kept pace with advances in blast equipment, have not provided realistic estimates of expected protection in the workplace, and have been misused by manufacturers and distributors of respiratory protective equipment who have assured, through sales literature, that the equipment is acceptable for conditions under which they have never been tested. This situation has contributed to exposure of sandblasters to hazardous levels of respirable free silica, and is reviewed here to prevent a continuation of the incompatibility of these and other standards for respiratory protection with the actual exposures to various noxious inhalants in the workplace.

Cigarette smoke-sensitive asthma: challenge studies.

The effects of exposure to environmental tobacco smoke on pulmonary function were assessed in 21 subjects with asthma who claimed respiratory complaints (cough, shortness of breath, and chest tightness) on previous exposure to cigarette smoke. Exposure to mechanically produced tobacco smoke was performed in a static inhalation chamber for two-hour intervals at two distinct smoke levels (as measured by carbon monoxide, nicotine, and particulate levels). Seven of the 21 smoke-challenged subjects experienced a significant (greater than 20%) decline in FEV1 during passive exposure to tobacco smoke.