The interpretation of zinc protoporphyrin changes in lead intoxication: a case report and review of the literature.

BACKGROUND: Zinc protoporphyrin (ZPP) has been used both as a screening and diagnostic test for overexposure to lead for nearly 30 years, although limitations for both purposes are recognized. METHODS: We present longitudinal findings for ZPP and whole-blood lead in a man with two episodes of acute lead intoxication and review the literature on the use of ZPP. RESULTS AND CONCLUSIONS: ZPP elevations in both chronic and acute exposure settings lag behind elevations in whole-blood lead by approximately 8-12 weeks. Therefore, ZPP measurement, in conjunction with whole-blood lead determination, has clinical utility in cases of substantial overexposure by providing information on how long an individual may have been overexposed to lead. A guide to the interpretation of various combinations of whole-blood lead and ZPP results is provided. However, while ZPP levels do correlate with whole-blood lead measurements in aggregate, the considerable individual variability of ZPP measurements, poor sensitivity at lower ranges of lead exposure, poor specificity and delayed changes in unstable exposure conditions indicate that this test contributes little to screening programs. Finally, our results confirm that basophilic stippling is seen in acute as well as chronic lead intoxication, and may provide the first indication of lead intoxication.

Understanding work-related injuries in children: a perspective in West Virginia using the state-managed workers' compensation system.

BACKGROUND/PURPOSE: Little data exist that defines the consequences of occupational injuries in children. Traditional assessment of work-related injury is coupled with disability payments based on salary, which give little insight into etiology and severity. The authors hypothesize that the risk and pattern of occupational injuries in young workers are different then adults. METHODS: Claims from 1996 through 2000 were analyzed from the West Virginia Bureau of Workers Compensation. To define the significance of an injury, child and adult groups were subdivided into injuries that required surgery (ie, serious injuries). Current Procedural Terminology (CPT) codes for anesthesia and surgical procedures were cross referenced with the claims to ensure group designation. Relative risks (RR) were used to compare groups. RESULTS: Between 1996 and 2000, 364,063 claims were submitted, 14,093 in workers < or =19 years of age. Two hundred seventy claims in children required surgery. Serious injuries in children occur more often in boys 2.2x mainly in the (16 to 24 hours) evening (48% v 23.13%; P <.05) and in July/August (26.5 v 18.4; P <.001). Falls were the main mechanism of injury. Proportionately fingers (1.70x) and hands (1.64x, 1.6 to 1.7) were injured in children. Lacerations (3.4x), fractures (1.4x), and amputations (3.75x) frequently resulted in general anesthetic procedures, and the RR of these injuries were increased versus adults. Service, manufacturing, construction, and agriculture were the main injury-related occupations in children. CONCLUSIONS: For any job category, injuries in children have unique features, tend to be more serious, and require a surgical intervention proportionately more frequently than adults.

Incidence and risk of work-related fracture injuries: experience of a state-managed workers' compensation system.

Incidence rates of occupational fractures at various anatomic sites and associated risk factors have not been well documented. We identified 3490 work-related fractures from a West Virginia Workers Compensation database that occurred between July 1, 1994, and June 30, 1995. The annual incidence rate was 55 per 10,000 workers, which is substantially higher than the work-related fracture rates reported previously. The incidence rate of fracture was highest in the agricultural sector, followed by the mining, construction, and manufacturing sectors (202.0, 165.2, 116.7, and 88.0 per 10,000 workers, respectively). The age-specific gender distribution comparing fracture and non-fracture injuries showed a bimodal distribution, with greater proportions of female employees at the younger and older age groups. Fracture of the phalanges was the most common, followed by fractures of the foot bone and carpal bone (15.8, 9.5, and 7.9 per 10,000 workers, respectively). In a multiple logistic regression analysis, age, gender, occupation, caught in-between objects, fall, struck by or against object, and vehicle collision were significant independent predictors of fracture (all sites combined). We believe work-related fractures to be a bigger problem than previously reported. The association among gender, age, occupation, and causes of fractures identified in this study will be useful in developing gender- and occupation-specific prevention intervention.

Gender differences in work-related injury/illness: analysis of workers compensation claims.

BACKGROUND: Risk of work-related injuries/illnesses among females has not been well documented. This study compares compensable work-related injuries/illnesses between females and males across all major industrial sectors and occupations using a state-managed Workers Compensation database. METHODS: Incidence rates were calculated by dividing the number of compensable injuries/illnesses among West Virginia Workers Compensation claimants by the total number of female and male workers in each specific industry class (based on SIC codes). Gender-specific denominators for occupations were estimated using 1990 U.S. Census data. RESULTS: The overall injury/illness rate was significantly lower in females than males (5. 5 vs. 11.5 per 100 employees), a trend that extended to all major industrial classes with the exception of service and agricultural sectors. The distribution of types of injury/illness varied by gender, occupation, and industry with significantly higher risk of carpal tunnel syndrome, burn, sprain, and fracture in females compared to males. CONCLUSIONS: Female workers have a greater risk of specific injury/illness compared to males in various industries. Further research will be needed to understand the role of differential job-tasks within each occupation in explaining the risk difference.

Epidemiologic basis for an occupational and environmental policy on environmental tobacco smoke.

ETS contains numerous toxins. Robust epidemiologic evidence implicates ETS as a cause of lung cancer and as a primary cause and source of exacerbation of excess respiratory disease. There is also increasing evidence that ETS may be associated with other outcomes, including heart disease. There is currently little doubt that ETS is an important and avoidable health hazard. Unfortunately, ETS is frequently encountered in the workplace--where it is no safer than in other environments and where it presents hazards to exposed workers and to others. A unique aspect of workplace ETS is that exposure is rarely an outcome of essential manufacturing, extraction, or service delivery processes. Moreover, ETS exposure, with its growing list of known hazards, is preventable by engineering or policy means. Implementation of policies to prevent workplace ETS can be highly effective while entailing low costs and yielding primary and secondary benefits to employers and employees. ACOEM strongly supports an increase in the scope and effectiveness of policies and efforts that protect against exposure to ETS in the workplace and elsewhere. To that end, ACOEM supports voluntary, regulatory, and legislative initiatives to eliminate ETS from the workplace, including public spaces such as bars, casinos, restaurants, schools, day-care centers, and public transportation. ACOEM also encourages employers to provide employee training concerning the health hazards of ETS and voluntary personal smoking-cessation programs.

Epidemiology of work-related burn injuries: experience of a state-managed workers' compensation system.

BACKGROUND: Population-based incidence rates of work-related burn injuries and associated risk factors specific to anatomic sites and degree of burn are not known. METHODS: Using a state-managed workers' compensation database, we estimated incidence rates of work-related burn injuries and identified high-risk occupations and associated exposures. RESULTS: The annual incidence rate of occupational burn was 26.4 per 10,000 workers, with the highest rate observed in the manufacturing sector for males and in the service sector for females. Welders, cooks, laborers, food service workers, and mechanics had higher incidence rates of burn injury compared with other occupations. Wrist and hand burns accounted for a majority of burn injuries, with females experiencing greater incidence of these distal upper extremity burns (8.9 in females and 6.7 in males per 10,000 workers, respectively). Third-degree burns (incidence rate, 1.3 per 10,000 workers) were also most frequently observed in the upper extremities compared with other anatomic sites. The majority of wrist and hand burns were caused by hot liquids/ objects, whereas the majority of eye burns were associated with chemical exposures. Younger cooks and food service workers were at greater risk of burn than older coworkers. CONCLUSION: Specific occupations are associated with degree of burn, anatomic site, and exposures. This information will be useful for targeted intervention among high-risk occupations and work groups.

Epidemiology of compensable work-related ocular injuries and illnesses: incidence and risk factors.

Incidence rates of work-related compensable ocular injuries/illnesses and associated risk factors were estimated by using a state-managed workers' compensation database. The annual incidence rate was estimated to be 537 per 100,000 employees. The majority of the ocular injuries and illnesses resulted from foreign bodies in the external eye (incidence rate 194 per 100,000 employees). Incidence rates for superficial eye injury, atopic conjunctivitis, burn, keratitis, chronic conjunctivitis, and contusion were 168.3, 30.9, 28.0, 23.4, 17.9, and 15.3 per 100,000 employees, respectively. The highest incidence rate was observed in the agricultural sector, with male employees having higher rates than female employees. Cooks, housekeepers, and food service workers had higher risk of atopic conjunctivitis (relative risk, 3.2 to 7.3) compared with other workers. The majority of the atopic conjunctivitis illnesses and burn injuries were associated with chemical exposures. Reduction of exposures and targeted intervention among high-risk workers should reduce the incidence of work-related ocular injuries and illnesses.

Too hot to handle: an unusual exposure of HDI in specialty painters.

BACKGROUND: Hexamethylene Diisocyanate (HDI) is a color stable aliphatic isocyanate that is used in specialty paints as a hardener. Due to the lower vapor pressure of its commercial biuret form, it is considered a relatively "safe" isocyanate from an exposure standpoint. This case series reports on an unusual toxic exposure to HDI. Between November 1993 and May 1994, seven specialty painters and one boiler maker who were working at three different power plants were examined at the Institute of Occupational and Environmental Health at West Virginia University. At their respective work sites, HDI was applied to the hot surfaces of boilers that were not shut down, and allowed sufficient time to cool. Consequently, these workers were exposed to volatile HDI and its thermal decomposition products. METHODS: All of these workers underwent a complete physical examination, spirometry, and methacholine challenge testing. RESULTS: All 8 workers complained of dyspnea, while 4 of the 8 also complained of rash. On examination 3 workers were methacholine challenge positive and 2 had persistent rash. At follow-up 4 years later, 5 workers still had to use inhalation medication and one had progressive asthma and dermatitis. All 8 workers, by the time of the follow-up, had gone through economic and occupational changes. CONCLUSIONS: This case series reports on an unusual exposure to HDI. It is unusual in that: 1) There were two simultaneous sentinel cases with two different Material Safety Data Sheets (MSDS) for the same product, 2) Exposure was to volatile HDI and its decomposition products and 3) Hazardous conditions of exposure occurred at three different sites.

The West Virginia Occupational Safety and Health Initiative: practicum training for a new marketplace.

CONTEXT: Occupational medicine practice has experienced a shift from larger corporate medical departments to organizations providing services for a variety of industries. Specific training needs will accompany this shift in practice patterns; these may differ from those developed in the traditional industrial or corporate medical department setting. METHODS: The West Virginia Occupational Health and Safety Initiative involves occupational medicine residents in consultation to a variety of small industries and businesses. It uses the expertise of occupational physicians, health and safety extension faculty, and faculty in engineering and industrial hygiene. Residents participate in multidisciplinary evaluations of worksites, and develop competencies in team-building, workplace health and safety evaluation, and occupational medical consulting. OUTCOME MEASURES: Specific competencies that address requirements for practicum training are used to measure the trainee's acquisition of knowledge and skills. Particular attention is paid to the acquisition of group problem-solving expertise, skills relevant to the current market in practice opportunities, and the specific career interests of the resident physician. Preliminary evaluation indicates the usefulness of training in evaluation of diverse industries and worksites. CONCLUSIONS: We offer this program as a training model that can prepare residents for the challenges of a changing marketplace for occupational health and safety services.

An estimate of prostate cancer prevalence for a demographically similar workforce population.

To obtain an estimate of prostate cancer prevalence when screening is applied to a workforce, we conducted a search of the English world literature from West Virginia University. Thirty-one papers which met selection criteria for screening were followed by histopathologic diagnosis. Publications using Prostate Specific Antigen (PSA) as a screening test were reviewed. The data from these papers were combined. Population characteristics were then selected to represent the demographics of a working population. Prostate cancer prevalence estimates for the demographics of a working population were calculated using a weighted mean after relevant studies lacked homogeneity and therefore failed meta-analysis. The expected prevalence of prostate cancer in a workplace surveillance population is 2.03% (95% C.I. from 1.69% to 2.37%). This information is useful to entities considering workplace surveillance. Selection bias, geographic location, and uncertainty in prediction of a representative workforce population may strongly influence estimates.

Injuries to volunteer fire fighters in West Virginia.

The distribution and characteristics of workplace injuries for West Virginia volunteer fire fighters (VFFs) are described using 1992 workers' compensation data. Most of the injuries occurred in VFFs who were less than 30 years of age (62%). The most common type of injuries were those in the category of lacerations and contusions (28.9%), with a notable percentage of injuries due to smoke inhalation and respiratory problems (13.7%). The proportional rates related to falls in VFFs were almost twice the national figures for the same year (39.3% versus 22.3%). County population density was found to be directly associated with injury rates, even when adjusted for number of responses. Claims statistics mirror a similar geographical trend in overall workers' compensation claims for all injuries in West Virginia. The results of this study provide a foundation for additional follow-up studies in order to develop improved occupational safety policies and target educational programs aimed at the prevention of injuries in volunteer fire fighters. Several findings have already resulted in programmatic recommendations.

Prevalence of small lung opacities in populations unexposed to dusts. A literature analysis.

OBJECTIVES: Despite the wide use of the International Labor Organization (ILO) system for reading chest radiographs, little information is available regarding the prevalence of abnormalities in populations unexposed to dusts. Prevalence studies of radiographic changes consistent with dust inhalation, as classified by the system, would be more meaningful if there were better understanding regarding the extent of abnormalities in unexposed populations. DESIGN: To determine small opacity prevalence in unexposed populations, a review of articles published since 1970 that used the ILO system to classify radiographs of the unexposed, either as subjects or control subjects, was performed. Criteria for inclusion in this review included ascertainment of the lack of exposure of subjects to occupational dusts, and independent reading of radiographs by at least two readers certified in the ILO system (B readers) or experienced in its use. A total of eight published articles presenting data on nine study populations were included in this study. RESULTS: The prevalence of small opacities graded 1/0 or greater varied widely, with a range from 0.21 to 11.7%. A meta-analysis of the published data yielded a population prevalence of 5.3% (95% confidence interval [CI] = 2.9 to 7.7%). The prevalence was significantly greater in Europe than in North America (Europe, 11.3%; 95% CI = 10.1 to 12.5%; North America, 1.6%; 95% CI = 0.6 to 2.6%). A subset of the studies contained information on gender that showed greater prevalence of lung opacities in male subjects than female subjects (male subjects, 5.5%; 95% CI = 3.4 to 7.6%; female subjects, 3.5%; 95% CI = 1.3 to 5.8%). Based on estimated age information, the studies were divided into two strata (mean age < 50 years vs > or = 50 years). The age-specific pooled prevalence was higher in the studies with mean age > or = 50 years than studies with mean age < 50 years in both Europe (11.7% vs 9.6%) and North America (2.3% vs 0.6%). Prevalence of lung opacities remained significantly higher in Europe and North America in each age stratum. The large difference in the prevalence between Europe and North America could not be explained on the basis of age, gender, or smoking history, although available age and smoking data are less robust. CONCLUSIONS: These results indicate that a background level of opacities consistent with the radiographic appearance of pneumoconiosis exists in populations considered to be free of occupational dust exposure. Environmental and unaccounted occupational exposures, as well as reader variability, all may play a role in the determination of small opacity prevalence in these subjects and may explain the large differences between Europe and North America. Thorough ascertainments of occupational and environmental exposures are essential to determine the true significance of opacities in populations who are not exposed to dust.

Laser hazards in research laboratories.

Laser use is expanding rapidly in laboratories, where multiple use strategies of research are not often amenable to laser engineering safeguards employed in industry. We report on five cases of laser-associated incidents requiring medical follow-up from a single research institution, and present exposure circumstances from four other incidents. Eye injuries from direct and reflected beams resulted from open alignment procedures in the absence of appropriate eye protection. Nd:YAG lasers operated with doubling crystals appear to create a considerable risk. For several reasons, we believe the importance of laser-associated injuries are underestimated and the incidence underreported in the research setting. Although knowledge personnel are shown to suffer lapses in standard operating procedures, most incidents and all injuries involved relatively inexperienced personnel. We propose that research laser users be registered and required to undergo formal training in laser safety. Student researchers are a key target population. Collaborative implementation between the equipment supplier and research user will be required to achieve this widespread implementation of effective training.

Occupational physicians and environmental medicine.

Physicians who practice environmental medicine seek to identify and to prevent patient and population exposures that cause adverse human health outcomes. Epidemiologic, toxicologic, clinical, and public health skills essential to this enterprise are indistinguishable from those of the occupational physician. Several important controversies illustrate the essential role of occupational physicians in environmental health science and policy, including environmental asbestos, dioxin, electromagnetic fields, and carcinogenicity testing. Our continuing involvement in "environmental" issues is predicted by three conditions, each unlikely to change. The human remains the animal of greatest interest; the "natural" experiment will have been performed (however unwittingly); and the work site will continue to provide that first and clearest setting for measuring the outcome. Therefore, residency training must be expanded so that future occupational and environmental physicians will recognize their fundamental role in environmental health. The results of our industry cross factory walls with ease. So must our efforts.

Disease clusters in occupational medicine: a protocol for their investigation in the workplace.

Disease clusters have been an important source of epidemiologic and medical information in the history of occupational medicine. Many accepted disease-exposure linkages were first observed and investigated as disease clusters in the workplace setting. Recent interest in disease cluster methodology has focused on traditional environmental settings. There has been very little work on a similar methodology for the investigation of disease clusters in the workplace, despite the many advantages of workplace cluster investigations for recognizing new etiologic associations. In this paper, a protocol is proposed and discussed which can be implemented in both acute and chronic disease cluster outbreaks in the workplace, where no obvious previously recognized cause is identified. A standardized approach to occupational disease cluster investigation will lead to increased efficiency, decreased social-political tensions, and a greater yield of scientific information.