Douglas J. Myers

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

Abstract 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.

Risk of Sharp Device–Related Blood and Body Fluid Exposure in Operating Rooms

OBJECTIVE The risk of percutaneous blood and body fluid (BBF) exposures in operating rooms was analyzed with regard to various properties of surgical procedures. DESIGN Retrospective cohort study. SETTING A single university hospital. METHODS All surgical procedures performed during the period 2001-2002 (n=60,583) were included in the analysis. Administrative data were linked to allow examination of 389 BBF exposures. Stratified exposure rates were calculated; Poisson regression was used to analyze risk factors. Risk of percutaneous BBF exposure was examined separately for events involving suture needles and events involving other device types. RESULTS Operating room personnel reported 6.4 BBF exposures per 1,000 surgical procedures (2.6 exposures per 1,000 surgical hours). Exposure rates increased with an increase in estimated blood loss (17.5 exposures per 1,000 procedures with 501-1,000 cc blood loss and 22.5 exposures per 1,000 procedures with >1,000 cc blood loss), increased number of personnel ever working in the surgical field (20.5 exposures per 1,000 procedures with 15 or more personnel ever in the field), and increased surgical procedure duration (13.7 exposures per 1,000 procedures that lasted 4-6 hours, 24.0 exposures per 1,000 procedures that lasted 6 hours or more). Associations were generally stronger for suture needle-related exposures. CONCLUSIONS Our results support the need for prevention programs that are targeted to mitigate the risks for BBF exposure posed by high blood loss during surgery (eg, use of blunt suture needles and a neutral zone for passing surgical equipment) and prolonged duration of surgery (eg, double gloving to defend against the risk of glove perforation associated with long surgery). Further investigation is needed to understand the risks posed by lengthy surgical procedures.

Estimates of historical exposures by phase contrast and transmission electron microscopy in North Carolina USA asbestos textile plants

Objectives: To develop a job-exposure matrix (JEM) for fibre exposures in three asbestos textile plants and to develop estimates of fibre size-specific exposures. Methods: Historical dust samples from three North Carolina, USA asbestos textile plants were obtained. Plant specific samples were used to express impinger dust concentrations as fibre concentrations by phase contract microscopy (PCM). Mixed models were used to estimate PCM exposures by plant, department, job and calendar time. Archived membrane filter samples were analysed by transmission electron microscopy (TEM) to determine the bivariate diameter/length distribution of airborne fibres by plant and operation. Results: PCM fibre levels estimated from the models were very high in the 1930s, with some operations having in excess of 200 fibres/ml, and decreased appreciably over time. TEM results for 77 airborne dust samples found that only a small proportion of airborne fibres were measured by PCM (>0.25 μm in diameter and >5 μm in length) and the proportion varied considerably by plant and operation (range 2.9% to 10.0%). The bivariate diameter/length distribution of airborne fibres demonstrated a relatively high degree of variability by plant and operation. PCM adjustment factors also varied substantially across plants and operations. Conclusions: These data provide new information concerning airborne fibre levels and characteristics in three historically important asbestos textile plants. PCM concentrations were high in the early years and TEM data demonstrate that the vast majority of airborne fibres inhaled by the workers were shorter than 5 μm in length, and thus not included in the PCM-based fibre counts.

Safety, incentives, and the reporting of work‐related injuries among union carpenters: “You're pretty much screwed if you get hurt at work”

BACKGROUND In the high-risk construction industry little is known about the prevalence or effects of programs offering rewards for workers and/or their supervisors for improved safety records or those that punish workers in some way for injury. METHODS We conducted an anonymous survey of 1,020 carpenter apprentices in three union training programs to document prevalence of their exposure to such efforts. We explored associations between perceptions of the reporting of work-related injury and elements of these programs. RESULTS Fifty-eight percent (58%; n = 592) reported some safety incentive or negative consequence of work-related injuries on their current jobsite. Reporting of work-related injuries was 50% less prevalent when workers were disciplined for injury experiences. Otherwise, we saw minimal evidence of association between injury reporting practices and safety incentive programs. However, considerable evidence of fear of reprisal for reporting injuries was revealed. Less than half (46.4%) reported that work-related injuries were reported in their current workplace all or most of the time; over 30% said they were almost never or rarely reported. CONCLUSIONS There are multiple layers of disincentives to the reporting of work-related injuries that hamper understanding of risk and pose threats to workplace safety and productivity. These pressures do not arise in a vacuum and are likely influenced by a host of contextual factors. Efforts that help us understand variation across jobsites and time could be enlightening; such inquiries may require mixed methodologies and should be framed with consideration for the upper tiers of the public health hierarchy of hazard control.

Mortality among sheet metal workers participating in a medical screening program

BACKGROUND The Sheet Metal Occupational Health Institute Trust (SMOHIT) was formed in 1985 to examine the health hazards of the sheet metal industry in the U.S. and Canada through an asbestos disease screening program. A study of mortality patterns among screening program participants was undertaken. METHODS A cohort of 17,345 individuals with 20 or more years in the trade and who participated in the asbestos disease screening program were followed for vital status and causes of death between 1986 and 2004. Data from the screening program included chest X-ray results by International Labour Office (ILO) criteria and smoking history. Standardized mortality ratios (SMRs) by cause were generated using U.S. death rates and Cox proportional hazards models were used to investigate lung cancer risk relative to chest X-ray changes while controlling for smoking. RESULTS A significantly reduced SMR of 0.83 (95% CI = 0.80-0.85) was observed for all causes combined. Statistically significant excess mortality was observed for pleural cancers, mesothelioma, and asbestosis in the SMR analyses. Both lung cancer and COPD SMRs increased consistently and strongly with increasing ILO profusion score. In Cox models, which controlled for smoking, increased lung cancer risk was observed among workers with ILO scores of 0/1 (RR = 1.17, 95% CI = 0.89-1.54), with a strong trend for increasing lung cancer risk with increasing ILO profusion score >0/0. CONCLUSIONS Sheet metal workers are at increased risk for asbestos-related diseases. This study contributes to the literature demonstrating asbestos-related diseases among workers with largely indirect exposures and supports an increased lung cancer risk among workers with low ILO profusion scores.

Nonfatal tool- or equipment-related injuries treated in US emergency departments among workers in the construction industry, 1998-2005

BACKGROUND Individuals in the construction industry are exposed to a variety of tools and pieces of equipment as they work. METHODS Data from the National Institute for Occupational Safety and Health (NIOSH) occupational supplement to the National Electronic Injury Surveillance System (NEISS-Work) were used to characterize tool- and equipment-related injuries among workers in the construction industry that were treated in US emergency departments between 1998 and 2005. Based on a national stratified probability sample of US hospitals with 24 hr emergency services, NEISS-Work allows calculation of national injury estimates. RESULTS Over the 8-year period between 1998 and 2005, we estimated 786,900 (95% CI 546,600-1,027,200) ED-treated tool- or equipment-related injuries identified by the primary or secondary source of injury code. These injuries accounted for a quarter of all ED-treated construction industry injuries. Although over 100 different tools or pieces of equipment were responsible for these injuries, seven were responsible for over 65% of the injury burden: ladders, nail guns, power saws, hammers, knives, power drills, and welding tools in decreasing order. CONCLUSIONS Current injury estimates and their severity, marked by the proportion of cases that were not released after ED treatment, indicate interventions are particularly needed to prevent injuries associated with use of ladders as well as nail guns and power saws. Attention should focus on design and guarding to more efficiently prevent these injuries rather than simply calling for the training of workers in how to safely use a dangerous tool or piece of equipment.

The little engine who could not: rehabilitating the individual in safety research

Safety science is one of the enduring enlightenment projects, which believes that rationality can create a better, more controllable world. Accidents are not seen as meaningless coincidences, but as failures of risk management, as something that can be improved in the future. The tragedy of safety research is that it has to simultaneously deny and affirm the primacy of human agency. As it has gradually expanded away from the sharp end to see accidents as bureaucratic or administrative in origin, the research keeps supplying linguistic and analytic resources that focus on individual shortcomings in leadership, communication or supervision. This paper concludes that individual human agency is useful to safety work, but not just as an instrument of political or organizational expedience. It is useful because it deeply reflects and reinforces how in the West we understand failure and success. The explanatory power of this discourse is confirmed or taken for granted by safety researchers because it appears so ordinary, self-evident and commonsensical.

Informal social status among coworkers and risk of work-related injury among nurse aides in long-term care.

BACKGROUND A social network measure was used to explore whether ones rank in an informal social hierarchy of nurse aides employed in a single long-term care facility was associated with risk of work-related injury. METHODS Six months of administrative staff schedule data and self-reported injury records were examined. Using survey data, social status rank in the informal hierarchy for each aide was operationalized as the number of coworkers who would approach the aide for advice about work-related matters. Conditional logistic regression was used to model the effect of social status on injury risk; cases were matched to controls consisting of coworkers present on the floor, shift, and date of the injury event. This allowed for a comparison of social status rank within social groups among workers with the same job title. RESULTS Injury incidence rates decreased across tertiles of social status rank scores. A non-significant drop in injury risk in the highest tertile of social status was observed (adjusted OR = 0.24 95% CI [0.05, 1.32]). CONCLUSION Findings of this exploratory study were internally consistent and support a theoretical framework suggesting that patterns of social relations between individuals based on informal social status in the workplace may contribute to differences in work-related injury risk among individuals with the same job title.

Occupational health literacy and work-related injury among U.S. adolescents

Building on the concept of ‘health literacy’ used in the US, we developed an analogous measure specific to safety in the workplace labeled ‘occupational health literacy’ (OHL) and investigated whether OHL is a protective factor against work-related injury (WRI) among adolescents. Using cross-sectional survey data from 2262 14 to 18-year olds in five high schools across the US, we found that OHL (level of occupational safety and health (OSH) information and training received combined with knowledge and awareness of OSH information and concepts) is positively associated with WRI prevalence. This association appears to be largely driven by the OHL subscale on respondents’ receipt of safety training, which likely represents job hazardousness and may be overwhelming any protective effect of OHL on work injury. This exploratory study has shown that more precise measurement of OHL and confounding variables (job hazardousness) will be crucial in further studies exploring a OHL–WRI relationship.

The food industry's solution to the obesity epidemic: take a walk.

An internationally known obesity expert recently delivered a lecture on strategies for reversing the obesity epidemic at a large public university. His view was that a reduction in exercise, not an increase in intake, has caused the epidemic. He stated that dieting strategies have largely been failures because they asked too much of people. A better solution, he suggested, is to teach people to pursue the more attainable goal of increasing their caloric output by a mere 100 calories a day. To achieve this, he designed a Web-based program, sponsored by a giant soda corporation and an international agribusiness conglomerate, which instructs individuals to take a walk.