Residential proximity to naturally occurring asbestos: health risk or ecologic fallacy?
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Asbestos↗
Biomedical subjects
Mark R Cullen
Publications and source records attributed to Mark R Cullen.
Respiratory protection from isocyanate exposure in the autobody repair and refinishing industry.
This study, part of the Survey of Painters and Repairers of Auto bodies by Yale (SPRAY), evaluated the effectiveness of respiratory protection against exposure to aliphatic polyisocyanates. A total of 36 shops were assessed for respiratory protection program completeness; 142 workers were measured for respirator fit factor (FF) using PortaCount Plus respirator fit tester. Twenty-two painters from 21 shops were sampled using NIOSH method 5525 to determine the workplace protection factor (WPF) of negative pressure, air-purifying half-facepiece respirators equipped with organic vapor cartridges and paint prefilters during spray-painting and priming activities. Only 11 shops (30%) had written respiratory protection programs. Eighty percent of all fit tested workers passed the test on the first try with FF >or= 100, and 92% passed the second test after respirator use training. Overall geometric mean (GM) FF was 1012 for all fit tested workers. Significant differences on pass rate (92% vs. 72%) and on FF (1990 vs. 736) were found between previously fit tested workers vs. nontested workers. Twenty-nine WPF samples were collected. The outside facepiece GM concentration of total isocyanate group (NCO) was 378.4 micro g NCO/m(3) with 96% concentrations exceeding the U.K. short-term exposure limit, 70 micro g NCO/m(3), but no in-facepiece concentrations exceeded the limit. The GM WPF of total NCO was 319 (GSD 4) and the 5th percentile was 54. WPF of total NCO was positively correlated with the duration of painting task. FF positively correlated with WPF when FF was 450. We conclude that negative pressure, air-purifying half-facepiece respirators equipped with organic vapor cartridges and paint prefilters provide effective protection against isocyanate exposure in spray and priming operations if workers are properly trained and fitted.
Adult↗
Trends in the prevalence of hearing loss among young adults entering an industrial workforce 1985 to 2004.
OBJECTIVES: Studies have suggested that hearing loss due to recreational noise exposure may be on the rise among adolescents and young adults. This study examines whether the hearing status of young US adults entering an industrial workforce has worsened over the past 20 yr. DESIGN: The baseline audiograms of 2526 individuals ages 17 to 25 beginning employment at a multisite US corporation between 1985 and 2004 were analyzed to determine the yearly prevalence of hearing loss. RESULTS: Approximately 16% of the young adults in the sample had high frequency hearing loss (defined as hearing thresholds greater than 15 dB in either ear at 3,4, or 6 kHz). In a linear regression model, this prevalence decreased over the 20-yr period (odds ratio (OR) = 0.96, 95% confidence interval (CI): 0.94, 0.99). Almost 20% of subjects had audiometric "notches" consistent with noise exposure; this rate remained constant over the 20 yr, as did the prevalence (5%) of low frequency hearing loss. CONCLUSIONS: These results indicate that despite concern about widespread recreational noise exposures, the prevalence of hearing loss among a group of young US adults has not significantly increased over the past two decades.
Adolescent↗
Incidence of asthma among aluminum workers.
Exposures to respiratory irritants encountered in aluminum smelters in Europe, Australia, and New Zealand have been suggested as the cause of "potroom asthma." However, there remains disagreement in North America regarding the existence of this entity. This study was designed to assess whether asthma occurs excessively among potroom workers and if so, delineate dose-response relationships for possible causal risk factors. The asthma incidence ratio between potroom and nonpotroom workers after adjusting for smoking was 1.40. Although bivariate analyses showed a relationship between asthma incidence and exposure to total fluoride, gaseous fluoride, particulate fluoride, sulfur dioxide, and smoking, only the effects of gaseous fluoride (relative risk [RR] = 5.1) and smoking (RR = 7.7) remained significant in a multivariate model. Potroom asthma appears to occur at the studied U.S. aluminum smelters at doses within regulatory guidelines.
Adult↗
Use of medical insurance claims data for occupational health research.
OBJECTIVE: The objective of this study was to demonstrate that health claims data, widely available due to the unique nature of the U.S. healthcare system, can be linked to other relevant databases such as personnel files and exposure data maintained by large employers. These data offer great potential for occupational health research. METHODS: In this article, we describe the process for linking claims data to industrial hygiene exposure data and personnel files of a single large employer to conduct epidemiologic research. RESULTS: Our results demonstrate the ability to replicate previously published findings using commonly maintained data sets and illustrate methodological issues that may arise as newer hypotheses are tested in this way. CONCLUSIONS: Health claims files offer potential for epidemiologic research in the United States, although the full extent and guidelines for successful application await further clarification through empiric research.
Adult↗
Serum osteopontin levels--is it time to screen asbestos-exposed workers for pleural mesothelioma?
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Asbestos↗
Evidence for excess colorectal cancer incidence among asbestos-exposed men in the Beta-Carotene and Retinol Efficacy Trial.
The relation between asbestos exposure and colorectal cancer remains controversial. The authors of this 1984-2004 US study examined the association among 3,897 occupationally exposed participants in the Beta-Carotene and Retinol Efficacy Trial (CARET) for chemoprevention of lung cancer, followed prospectively for 10-18 years. When a Cox stratified proportional hazards model was used, risks of colorectal cancer were elevated among male heavy smokers exposed to asbestos. Their relative risk was 1.36 (95% confidence interval: 0.96, 1.93) when compared with that for CARET heavy smokers not exposed to asbestos, after adjusting for age, smoking history, and intervention arm. The presence of asbestos-induced pleural plaques at baseline was associated with a relative risk of 1.54 (95% confidence interval: 0.99, 2.40); colorectal cancer risk also increased with worsening pulmonary asbestosis (p = 0.03 for trend). A dose-response trend based on years of asbestos exposure was less evident. Nonetheless, these data suggest that colorectal cancer risk is elevated among men occupationally exposed to asbestos, especially those with evidence of nonmalignant asbestos-associated radiographic changes.
Adult↗
A laboratory investigation of the effectiveness of various skin and surface decontaminants for aliphatic polyisocyanates.
Isocyanates may cause contact dermatitis and respiratory sensitization leading to asthma. Dermal exposure to aliphatic isocyanates in auto body shops is very common. However, little is known about the effectiveness of available commercial products used for decontaminating aliphatic polyisocyanates. This experimental study evaluated the decontamination effectiveness of aliphatic polyisocyanates for several skin and surface decontaminants available for use in the auto body industry. The efficiency of two major decontamination mechanisms, namely (i) consumption of free isocyanate groups via chemical reactions with active hydrogen components of the decontaminant and (ii) physical removal processes such as dissolution were studied separately for each decontaminant. Considerable differences were observed among surface decontaminants in their rate of isocyanate consumption, of which those containing free amine groups performed the best. Overall, Pine-Sol(R) MEA containing monoethanolamine was the most efficient surface decontaminant, operating primarily via chemical reaction with the isocyanate group. Polypropylene glycol (PPG) had the highest physical removal efficiency and the lowest reaction rate with isocyanates. All tested skin decontaminants performed similarly, accomplishing decontamination primarily via physical processes and removing 70-80% of isocyanates in one wiping. Limitations of these skin decontaminants are discussed and alternatives presented. In vitro testing using animal skins and in vivo testing with field workers are being conducted to further assess the efficiency and identify related determinants.
Automobiles↗
Predictors of lung cancer among asbestos-exposed men in the {beta}-carotene and retinol efficacy trial.
Despite numerous published studies, debate continues regarding the risk of developing lung cancer among men exposed occupationally to asbestos, particularly those without radiographic or functional evidence of asbestosis. The beta-Carotene and Retinol Efficacy Trial (CARET), a study of vitamin supplementation for chemoprevention of lung cancer, has followed 4,060 heavily exposed US men for 9-17 years. Lung cancer incidence for 1989-2002 was analyzed using a stratified proportional hazards model. The study confirmed excessive rates of lung cancer among men with radiographic asbestosis. Comparison of study arms revealed a strong, unanticipated synergy between radiographic profusion category and the active intervention. In the large subgroup of men with normal lung parenchyma on chest radiograph at baseline, there was evidence of exposure-related lung cancer risk: Men with more than 40 years' exposure in high-risk trades had a risk approximately fivefold higher than men with 5-10 years, after adjustment for covariates. The effect in these men was independent of study intervention arm, but pleural plaques on the baseline radiograph and abnormal baseline flow rate were strong independent predictors of subsequent lung cancer. Residual confounding by subclinical asbestosis, exposure to unmeasured lung carcinogens, or differences in smoking are unlikely to explain these observations better than a carcinogenic effect of asbestos per se.
Adult↗
Screening for chronic beryllium disease: one hurdle down, two to go.
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Berylliosis↗
Advancing worker health and safety in the developing world.
OBJECTIVES: Working conditions in the developing world seldom meet the minimum standards required by international agencies. This article addresses some of the major obstacles to occupational and environmental health and suggests methods by which they can be overcome. METHODS: International agencies such as the World Health Organization (WHO) and the International Labor Organization (ILO) offer a number of programs that address the problem. RESULTS: The results of international efforts to date have been disappointing. There is a need for renewed efforts on the part of international agencies and the developed countries. CONCLUSIONS: Occupational health and safety can be advanced in the developing world with modest funding of innovative programs.
Accidents, Occupational↗
The Beta-Carotene and Retinol Efficacy Trial: incidence of lung cancer and cardiovascular disease mortality during 6-year follow-up after stopping beta-carotene and retinol supplements.
BACKGROUND: The Beta-Carotene and Retinol Efficacy Trial (CARET) tested the effect of daily beta-carotene (30 mg) and retinyl palmitate (25,000 IU) on the incidence of lung cancer, other cancers, and death in 18,314 participants who were at high risk for lung cancer because of a history of smoking or asbestos exposure. CARET was stopped ahead of schedule in January 1996 because participants who were randomly assigned to receive the active intervention were found to have a 28% increase in incidence of lung cancer, a 17% increase in incidence of death and a higher rate of cardiovascular disease mortality compared with participants in the placebo group. METHODS: After the intervention ended, CARET participants returned the study vitamins to their study center and provided a final blood sample. They continue to be followed annually by telephone and mail self-report. Self-reported cancer endpoints were confirmed by review of pathology reports, and death endpoints were confirmed by review of death certificates. All statistical tests were two-sided. RESULTS: With follow-up through December 31, 2001, the post-intervention relative risks of lung cancer and all-cause mortality for the active intervention group compared with the placebo group were 1.12 (95% confidence interval [CI] = 0.97 to 1.31) and 1.08 (95% CI = 0.99 to 1.17), respectively. Smoothed relative risk curves for lung cancer incidence and all-cause mortality indicated that relative risks remained above 1.0 throughout the post-intervention follow-up. By contrast, the relative risk of cardiovascular disease mortality decreased rapidly to 1.0 after the intervention was stopped. During the post-intervention phase, females had larger relative risks of lung cancer mortality (1.33 versus 1.14; P = .36), cardiovascular disease mortality (1.44 versus 0.93; P = .03), and all-cause mortality (1.37 versus 0.98; P = .001) than males. CONCLUSIONS: The previously reported adverse effects of beta-carotene and retinyl palmitate on lung cancer incidence and all-cause mortality in cigarette smokers and individuals with occupational exposure to asbestos persisted after drug administration was stopped although they are no longer statistically significant. Planned subgroup analyses suggest that the excess risks of lung cancer were restricted primarily to females, and cardiovascular disease mortality primarily to females and to former smokers.
Adult↗
Polyisocyanates in occupational environments: a critical review of exposure limits and metrics.
BACKGROUND: Determination of polyisocyanates is important because they are a major contributor of exposure to the isocyanate functional group in many workplace environments and are capable of inducing sensitization and asthma. However, with multiple different measurement metrics in use, comparison of isocyanate exposure data between studies and development of occupational exposure limits (OELs) for polyisocyanates is difficult. METHODS: An analysis of existing problems in the measurement and regulation of isocyanates is presented based on the published analytical, toxicological, and regulatory literature, and the authors' own analytical data and experience with isocyanates. RESULTS: This analysis supports a need for standardization of isocyanate measurement metrics and provides a framework for the development of an OEL for polyisocyanates. CONCLUSIONS: The total isocyanate group (microg NCO/m(3)) is recommended as the most feasible and practical metric (unit) by which to express polyisocyanate exposures for research, control, and regulatory purposes. The establishment of a comprehensive isocyanate OEL that simplifies the current agent-by-agent approach and expands coverage to polyisocyanates is also recommended.
Air Pollutants, Occupational↗
Isocyanate exposures in autobody shop work: the SPRAY study.
Isocyanates, known to cause respiratory sensitization and asthma, are widely used in automotive refinishing where exposures to aliphatic polyisocyanates occur by both inhalation and skin contact. The work reported here, the characterization of isocyanate exposure in the autobody industry, was part of an epidemiologic study of workers in 37 autobody shops in Connecticut. This article describes workplaces, tasks, and controls, and outlines the frequency, duration, and intensity of isocyanate exposures. Personal air samples taken outside of respirators had median concentrations of 66.5 microg NCO/m3 for primer, 134.4 microg (NCO)/m3 for sealer, and 358.5 microg NCO/m3 for clearcoat. Forty-eight percent of primer, 66% of sealer, and 92% of clearcoat samples exceeded the United Kingdom Health and Safety Executive guideline for isocyanate, though none exceeded the National Institute for Occupational Safety and Health (NIOSH) recommended exposure limit for monomer. Nonisocyanate-containing primers and sealers are used in more than half the shops, but nonisocyanate clearcoats are rare. Eighty-two percent of personal samples taken within a spray booth exceeded the U.K. guideline: 81% of those in downdraft spray booths, 74% in semidowndraft booths, and 92% in crossdraft booths. Only 8% of shops reported that spraying is done exclusively in spray booths. All painters wore some type of respirator. In 30% of shops, painters used supplied air respirators; the rest relied on half face organic vapor cartridge respirators with N95 overspray pads. All shops provided some type of gloves, usually latex, not recommended for isocyanate protection. Despite improvements in autobody shop materials, practices, and controls, there are still opportunities for substantial exposures to isocyanates.
Air Pollution, Indoor↗
Responding to the challenge of novel technology: an industrial hygiene and safety program for antibody production in maize.
The production of pharmaceutical proteins in plants, particularly in maize (corn), offers solutions to the limited production capacity and flexibility of current cell culture technologies. Implementation of this technology presents unique challenges to industrial hygiene, safety, and occupational medicine, including the handling of pharmaceuticals in the context of agricultural production and the processing of grain for extraction. Protein-related challenges include: (1) widely varying potential for hazard depending upon the activity of the protein and nature and location of the target molecule; (2) limited data related to industrial routes of exposure; and (3) the inability to obtain relevant animal data because of high species-specificity. These challenges necessitate the development of novel approaches to industrial hygiene and safety. Realizing that much remains to be learned, our approach uses conservative assumptions to assure protection of employee health.
Biological Availability↗
Variable response to long-term corticosteroid therapy in chronic beryllium disease.
OBJECTIVES: Chronic beryllium disease (CBD) shares many of its characteristics with sarcoidosis and is often treated with corticosteroids. There is limited available literature regarding the effect of long-term corticosteroid therapy on the natural history of CBD. METHODS AND MATERIALS: We conducted an observational retrospective study of six patients with CBD who received prolonged corticosteroid treatment with a mean pulmonary function test follow-up period of 10.1 years. Five of the six patients were exposed to beryllium at the same workplace. The diagnosis in four of the six cases was confirmed by a positive beryllium lymphocyte proliferation test result on blood or BAL fluid. Periodic pulmonary function tests were analyzed in relation to removal from beryllium exposure and treatment with corticosteroids. MEASUREMENTS AND RESULTS: Two broad patterns of response were noted in these patients. The first pattern seen in two patients showed no improvement in FVC or diffusion capacity of the lung for carbon monoxide (Dlco) with corticosteroids. However, a significant improvement in these parameters was noted on cessation of beryllium exposure in one of the two patients. The second pattern showed an initial improvement in FVC and Dlco with corticosteroids, which was not sustained. An improvement was noted on stopping beryllium exposure. CONCLUSIONS: The response to long-term corticosteroids in CBD, quite like that in sarcoidosis, is variable. Significant lung function improvement may be seen following cessation of beryllium exposure.
Adult↗
Truncating the dose range for methacholine challenge tests: three occupational studies.
The methacholine challenge test protocol was assessed in the reanalysis of three occupational studies. We evaluated the impact of truncating the range of methacholine on responsiveness, as defined by slope and PC(20). In original analysis, reactivity was similar for apprentices and auto body shop workers, whereas boilermakers were more responsive. Truncating high concentrations did not change the classification of subjects with PC(20) <8 or 16 in any population. However, when responsiveness was measured by slope, the mean responsiveness increased, from -7.9 to -15.3 for apprentices and -7.2 to -10.0 for auto-body shop workers. Results support the American Thoracic Society's recommended maximum of 16 mg/ml and provide evidence that extending the dose range beyond that does not increase sensitivity, whereas stopping before 16 may exaggerate response. Furthermore, to ensure validity, neither slope nor PC(20) should be extrapolated beyond data.
Adult↗
Effects of a cost-sharing exemption on use of preventive services at one large employer.
In 2004, Alcoa introduced a new health benefit for a portion of its workforce, which eliminated cost sharing for preventive care while increasing cost sharing for many other services. In this era of increased consumerism, Alcoa's benefit redesign constituted an effort to reduce health care costs while preserving use of targeted services. Taking advantage of a unique natural experiment, we find that Alcoa was able to maintain rates of preventive service use. This evidence suggests that differential cost sharing can be used to preserve the use of critical health care services.
Consumer Behavior↗