Steven E. Lacey

Barriers and benefits of protective eyewear use by Latino farm workers

Abstract Agricultural work is one of the riskiest occupations for the eyes. Protective eyewear can prevent eye injuries in upward of 90% of cases. Latino migrant and seasonal farm workers (LFWs) are at particular risk of eye injury because of economic, social, and cultural barriers to safe employment. The goal of this project was to determine the perceived benefits and barriers to use of protective eyewear during agricultural work among LFWs. In the year 2000, 55 workers who spent at least part of their time working in Illinois and Michigan as seasonal, hired farm workers were interviewed either individually (9) or in six focus groups (46) regarding their perceptions of eye hazards and the factors that encourage or discourage the use of protective eyewear. Subsequently, safety glasses and training on eye safety were delivered by promotores de salud to LFWs from the same cohort over two summer seasons. During the second season, the promotores observed the use of safety eyewear by farm workers at least once per week on 17 farms over a three-month period. At each point of observation, the promotores asked those wearing the glasses why they chose to wear them and those who were not wearing them, why not. At both points of the study (pre-intervention interviews and post-intervention observations), the reasons for use fell into the following categories: protection from hazards, appearance, whether it was mandated/provided by the employer, and whether others used it. The reasons for non-use include perceived lack of protection, discomfort, undesirable appearance, interference with visual acuity, slowing down the work pace, and no mandate from employers. Since eliminating the eye injury hazard is not possible in most agricultural settings, administrative strategies and use of personal protective equipment are critical. Perceptions of the target audience, LFWs, should be used to develop a comprehensive eye safety program; this should include allowing LFWs to select a style from effective prototypes, providing eyewear and promoting/mandating its use in hazardous job tasks, and implementing a comprehensive PPE program for eye safety. In addition, addressing functional problemsfalling off, fogging, loss and forgetting glasses, the pace slowdown that reduces production and leads to lower wages for workersshould be addressed.

Laser-Generated Air Contaminants from Medical Laser Applications: A State-of-the-Science Review of Exposure Characterization, Health Effects, and Control

The clinical use of lasers in surgery began in 1973 with applications of the carbon dioxide laser in otolaryngology, and since then the use of lasers has become commonplace in many medical and surgical specialties. Nonetheless, when biological tissue is subjected to laser radiation, the target cells can be vaporized, resulting in the aerosolization of their contents and the subsequent exposure of health care workers to laser-generated air contaminants (LGACs). The purpose of our analysis was to summarize and present all of the published literature pertaining to the laser-induced plume chemical and physical composition, health effects, and methods of control. The objective was to identify knowledge gaps within exposure science to set a research agenda for the protection of health care personnel exposed to LGACs. A literature search was performed using the PubMed database using a variety of search strategies and keyword combinations. To locate additional studies, we systematically searched the reference lists of all studies identified by our search, as well as key review papers. To date, researchers have identified roughly 150 chemical constituents of plume, as well as fine and ultrafine particulate matter, which has been shown to include viable cellular material, viruses, and bacteria. However, very few studies have attempted to characterize the effects of laser system type, power, and tissue treated, as it relates to LGAC exposure. Furthermore, current control strategies do not appear to be adequate in preventing occupational exposure to LGACs.

Eye Injury in Migrant Farm Workers and Suggested Hazard Controls

The eyes are a common site of injury in agricultural operations. Identification of the cause of injury is important to inform preventive interventions. The objective of this study was to describe the hazards and mechanisms of acute traumatic injury to the eyes of agricultural workers who are hired in farming operations on a seasonal basis. A review of the literature was performed to summarize the mechanisms of eye injuries in agriculture. Field observations and informal interviews were performed to verify the literature and to determine whether there are eye hazards for farm workers that have not been reported in the literature. Additional mechanisms of injury were elicited, and suggested methods of injury prevention are presented here.

An assessment of the occupational hazards related to medical lasers.

Objective:Occupational hazards associated with medical laser applications remain poorly understood and uncharacterized. Methods:A literature search was performed using PubMed, and all articles relevant to beam and nonbeam medical laser hazards were reviewed. The Rockwell Laser Industries Laser Accident Database was searched for medical laser injuries and abstracted. Results:Eye injuries, skin burns, injuries related to the onset of fires, and electric shock have been reported in relation to medical laser use. It is probable that both acute and chronic health effects have been experienced by medical personnel as the result of exposure to laser generated air contaminants. Conclusions:Because of the clinical benefits they provide, the growth of laser technologies and applications are anticipated to result in an increase in the number and type of medical personnel with future exposure to laser hazards.

Long-term health experience of jet engine manufacturing workers: II. Total and cause-specific mortality excluding central nervous system neoplasms.

Objective: As part of an exploratory investigation of an unusual occurrence of glioblastoma at one jet engine manufacturing facility located in North Haven, Connecticut (CT), we examined total and cause-specific (excluding central nervous system neoplasms) mortality rates at eight of the company’s CT facilities. Methods: Subjects were 223,894 workers ever employed in one or more of the manufacturing facilities from 1952 to 2001. Vital status was determined through 2004 for 99% of subjects and cause of death for 95% of 68,701 deaths. We computed standardized mortality ratios (SMRs) based on US and CT state rates and modeled internal cohort rates. Results: We observed overall deficits in deaths based on national and state comparisons from all causes, all cancers and most of the cause of death categories examined. State comparisons revealed statistically significant excesses in deaths greater than 25% for kidney cancer (68 deaths, SMR = 1.30, CI = 1.01–1.65) and “other non-malignant respiratory disease” (291 deaths, SMR = 1.27, CI = 1.13–1.42) among subjects employed only at North Haven, and for bronchitis (713 deaths, SMR = 1.28, CI = 1.18–1.37) among all hourly workers. These excesses occurred mainly among short-term workers and hourly workers. Conclusions: We found no evidence of elevated mortality risks for all causes combined, all cancers combined and most of the causes of death categories examined. The pattern of findings for kidney cancer, bronchitis and other non-malignant respiratory disease, based on currently available data, suggests these excesses may be due to non-occupational risk factors or to external occupational factors. We will investigate these excesses further when detailed work history and exposure data from the companion exposure assessment project become available.

Methodological Issues in a Retrospective Cancer Incidence Study

The authors traced incidence of central nervous system cancer in a large occupational cohort of jet engine manufacturing workers from 1976 to 2004 in the 24 US states that comprised 95% of the cohort deaths. The cohort of approximately 224,000 employees was matched with cancer registry data; all central nervous system cancer matches were requested with their diagnostic data. This paper highlights the obstacles encountered while conducting this retrospective cancer incidence study. The authors spent approximately 700 hours completing applications and obtaining the cohort matches. Approximately 70% of the cases were identified in the state in which the facility of interest is located. In addition to the large amount of time involved, identified issues include complicated approval processes, high costs, temporal differences among the registries, and registry agency difficulty in performing the matching. Several states do not allow individual-level data to be used for research purposes. Researchers can gain important cancer incidence information by matching retrospective cohorts to multiple state cancer registries. However, they should carefully weigh the time and costs required and plan accordingly. Despite some serious obstacles, many of which are potentially resolvable, cancer incidence studies of retrospective cohorts using multiple cancer registries are feasible.

Long-term health experience of jet engine manufacturing workers: I. Mortality from central nervous system neoplasms

Objective: In response to an unusual occurrence of glioblastoma at one jet engine manufacturing facility located in North Haven (NH), Connecticut (CT), we examined mortality rates from central nervous system (CNS) neoplasms at NH and seven other company facilities. Methods: Subjects were 223,894 workers ever employed in one or more of the company’s eight CT manufacturing facilities from 1952 to 2001. Vital status was determined through 2004 for 99% of subjects and cause of death for 95% of 68,701 deaths. We computed standardized mortality ratios (SMRs) based on US and CT state rates and modeled internal relative risks (RRs). Results: State comparisons revealed overall deficits in deaths from all CNS neoplasms (606 deaths, SMR = 0.84, confidence interval [CI] = 0.78 to 0.91), including all malignant (462 deaths, SMR = 0.87, CI = 0.79 to 0.95), all benign (23 deaths, SMR = 0.65, CI = 0.41 to 0.98), and all unspecified (121 deaths, SMR = 0.79, CI = 0.65 to 0.94). Not statistically significant excesses in deaths from all malignant brain neoplasms were found among subjects who worked only at NH (49 deaths, SMR = 1.11, CI = 0.82 to 1.47) or partly at NH (24 deaths, SMR = 1.04, CI = 0.67 to 1.55) compared with deficits in non-NH plant groups. In the combined NH plant groups, we found not statistically significant higher risks of malignant brain neoplasms for salaried workers, older hires and the most recent time period, but no association with duration of employment or time since first employment. Conclusions: Total cohort mortality rates for malignant, benign or unspecified CNS neoplasms were not elevated relative to the US and CT general populations. The malignant brain neoplasm excesses in certain subgroups of workers from NH may reflect external occupational factors, nonoccupational factors or workplace factors unique to NH that were not measured in the current study. We will explore reasons for the NH excesses and examine specific types of brain neoplasms (eg, glioblastoma) in our companion cancer incidence, case–control and exposure assessment studies.

Long-Term Health Experience of Jet Engine Manufacturing Workers: III. Incidence of Malignant Central Nervous System Neoplasms

Objective: To explore a perceived unusual occurrence of glioblastoma at one jet engine manufacturing facility located in North Haven (NH), Connecticut (CT). Methods: Subjects were 212,513 workers ever employed in 1 of 8 manufacturing facilities from 1952 to 2001 and at risk from 1976 to 2004. We identified 722 cases of CNS neoplasms mainly by tracing through 19 state cancer registries. We computed standardized incidence ratios (SIRs) based on CT state and national rates and modeled internal relative risks (RRs). Results: We found overall deficits in cases for glioblastoma (275 cases, SIR = 0.77, CI = 0.68–0.87) and most other histology categories examined. NH workers had a not statistically significant overall 8% excess in glioblastoma (43 cases, SIR = 1.08, CI = 0.78–1.46). Salaried NH workers had a statistically significant twofold risk of glioblastoma compared with hourly workers (17 cases, RR = 2.04, CI = 1.15–3.57). Other subgroups of NH workers revealed elevated but not statistically significant glioblastoma risks but little evidence of an association with duration of employment or time since first employment. Conclusions: Incidence rates for glioblastoma and other malignant CNS neoplasm histologies were not elevated in the total cohort. The glioblastoma excesses observed among NH workers may reflect external occupational factors, non-occupational factors or workplace factors unique to NH unmeasured in the current study.

A Pilot Study to Determine Medical Laser Generated Air Contaminant Emission Rates for a Simulated Surgical Procedure

The U.S. Occupational Safety and Health Administration (OSHA) estimates that half a million health-care workers are exposed to laser surgical smoke each year. The purpose of this study was to establish a methodology to (1) estimate emission rates of laser-generated air contaminants (LGACs) using an emission chamber, and to (2) perform a screening study to differentiate the effects of three laser operational parameters. An emission chamber was designed, fabricated, and assessed for performance to estimate the emission rates of gases and particles associated with LGACs during a simulated surgical procedure. Two medical lasers (Holmium Yttrium Aluminum Garnet [Ho:YAG] and carbon dioxide [CO2]) were set to a range of plausible medical laser operational parameters in a simulated surgery to pyrolyze porcine skin generating plume in the emission chamber. Power, pulse repetition frequency (PRF), and beam diameter were evaluated to determine the effect of each operational parameter on emission rate using a fractional factorial design. The plume was sampled for particulate matter and seven gas phase combustion byproduct contaminants (benzene, ethylbenzene, toluene, formaldehyde, hydrogen cyanide, carbon dioxide, and carbon monoxide): the gas phase emission results are presented here. Most of the measured concentrations of gas phase contaminants were below their limit of detection (LOD), but detectable measurements enabled us to determine laser operation parameter influence on CO2 emissions. Confined to the experimental conditions of this screening study, results indicated that beam diameter was statistically significantly influential and power was marginally statistically significant to emission rates of CO2 when using the Ho:YAG laser but not with the carbon dioxide laser; PRF was not influential vis-a-vis emission rates of these gas phase contaminants.

Long-term health experience of jet engine manufacturing workers: VI: Incidence of malignant central nervous system neoplasms in relation to estimated workplace exposures

Objective: To determine whether glioblastoma (GB) incidence rates among jet engine manufacturing workers were associated with specific chemical or physical exposures. Methods: Subjects were 210,784 workers employed from 1952 to 2001. We conducted a cohort incidence study and two nested case–control studies with focus on the North Haven facility where we previously observed a not statistically significant overall elevation in GB rates. We estimated individual-level exposure metrics for 11 agents. Results: In the total cohort, none of the agent metrics considered was associated with increased GB risk. The GB incidence rates in North Haven were also not related to workplace exposures, including the “blue haze” exposure unique to North Haven. Conclusions: If not due to chance alone, GB rates in North Haven may reflect external occupational factors, nonoccupational factors, or workplace factors unique to North Haven unmeasured in the current evaluation.