Factors Associated with Leguminous Green Manure Incorporation and Fusarium Wilt Suppression in Watermelon.

Fall-planted Vicia villosa or Trifolium incarnatum cover crops, incorporated in spring as a green manure, can suppress Fusarium wilt (Fusarium oxysporum f. sp. niveum) of watermelon. During cover crop growth, termination, and incorporation into the soil, many factors such as arbuscular mycorrhizae colonization, leachate, and soil respiration differ. How these cover-crop-associated factors affect Fusarium wilt suppression is not fully understood. Experiments were conducted to evaluate how leachate, soil respiration, and other green-manure-associated changes affected Fusarium wilt suppression, and to evaluate the efficacy of the biocontrol product Actinovate AG (Streptomyces lydicus WYEC 108). General and specific suppression was examined in the field by assessing the effects of cover crop green manures (V. villosa, T. incarnatum, Secale cereale, and Brassica juncea) on soil respiration, presence of F. oxysporum spp., and arbuscular mycorrhizal colonization of watermelon. Cover crop treatments V. villosa, T. incarnatum, and S. cereale and no cover crop were evaluated both alone and in combination with Actinovate AG in the greenhouse. Additionally, in vitro experiments were conducted to measure the effects of cover crop leachate on the mycelial growth rates of F. oxysporum f. sp. niveum race 1 and Trichoderma harzianum. Soil microbial respiration was significantly elevated in V. villosa and Trifolium incarnatum treatments both preceding and following green manure incorporation, and was significantly negatively correlated with Fusarium wilt, suggesting that microbial activity was higher under the legumes, indicative of general suppression. Parallel to this, in vitro growth rates of F. oxysporum f. sp. niveum and Trichoderma harzianum on V. villosa leachate amended media were 66 and 213% greater, respectively, than on nonamended plates. The F. oxysporum spp. population (based on CFU and not differentiated into formae specialis or races) significantly increased in V. villosa-amended field plots. Additionally, the percentage of watermelon roots colonized by arbuscular mycorrhizae following V. villosa and Trifolium incarnatum green manures was significantly higher than in watermelon following bare ground (58 and 44% higher, respectively). In greenhouse trials where cover crops were amended to soil, Actinovate AG did not consistently reduce Fusarium wilt. Both general and specific disease suppression play a role in reducing Fusarium wilt on watermelon.

Impact of Five Cover Crop Green Manures and Actinovate on Fusarium Wilt of Watermelon.

Triploid watermelon cultivars are grown on more than 2,023 ha in Maryland and in Delaware. Triploid watermelon cultivars have little host resistance to Fusarium wilt of watermelon (Fusarium oxysporum f. sp. niveum). The effects of four different fall-planted cover crops (Vicia villosa, Trifolium incarnatum, Secale cereale, and Brassica juncea) that were tilled in the spring as green manures, and bare ground, were evaluated alone and in combination with the biocontrol product Actinovate (Streptomyces lydicus) on Fusarium wilt severity and watermelon fruit yield and quality. Six field experiments were conducted over 3 years in Beltsville and Salisbury, MD and Georgetown, DE. Both V. villosa and T. incarnatum significantly suppressed Fusarium wilt of watermelon as much as 21% compared with watermelon in nonamended plots. However, no suppression of Fusarium wilt occurred at low disease levels or where low cover crop biomass was present. In general, Beltsville, MD had lower disease levels than Salisbury, MD and Georgetown, DE. T. incarnatum was the only cover crop that yielded significantly more fruit than nonamended treatments (129% more fruit per hectare) but only for one field trial. The Actinovate product either did not reduce Fusarium wilt or the magnitude of the reduction was nominal. Actinovate significantly reduced Fusarium wilt by 2% in 2009 and as much as 7% in 2010, and increased Fusarium wilt severity by 2.5% in 2011. Actinovate significantly increased yield for one field trial but only when applied to nonamended or Secale cereal-amended plots. This is the first report of a reduction in Fusarium wilt following a T. incarnatum cover crop incorporated as a green manure.

Zirconium compound-induced pulmonary fibrosis.

Despite suspicion that inhalation of zirconium should be capable of causing human pulmonary disease, documentation of zirconium pneumoconiosis in humans has been lacking. We studied a likely case of zirconium compound-induced pulmonary fibrosis. The diagnosis was based on the following: (1) a history of gradual increase in symptoms and slowly progressing pulmonary fibrosis by chest roentgenogram compatible with a pneumoconiosis; (2) an appropriate history of exposure and a latency period of about 15 years before the onset of dyspnea and of roentgenographic changes; (3) analysis of open lung biopsy material revealing end-stage fibrosis and honeycombing, a moderate number of birefringent particles, and extremely high levels of a variety of zirconium compounds; and (4) no other potential cause of fibrosis. We conclude that zirconium should be considered a likely cause of pneumoconiosis and that appropriate precautions should be taken in the workplace.

Reproductive hazards in the workplace: what the practitioner needs to know about chemical exposures.

A growing body of scientific evidence implicates occupational chemical exposures in the etiology of human adverse reproductive outcomes. Most reproductive toxins that have been investigated in sufficient detail have been shown to exert multiple effects on and through both men and women. In the face of growing public awareness, it is essential that clinicians develop a knowledgeable and effective approach to patient concerns about reproductive hazards in the workplace. Of vital importance is the accurate characterization of exposure at the worksite. Intervention strategies for worrisome situations include amelioration of worksite exposure or, as a last resort, temporary, compensated job modification or transfer. The clinician can obtain assistance in addressing the problem from several resources, including local regulatory agencies and occupational health clinics. Widespread involvement of knowledgeable health professionals can have a dramatic impact on improving this important contemporary public health problem.

Health services research in workers' compensation medical care: policy issues and research opportunities.

OBJECTIVE: To describe some of the unique aspects of medical care offered under workers' compensation insurance systems and discuss the major policy considerations relevant to health services researchers undertaking investigations in this area. BACKGROUND AND FINDINGS: State-based workers' compensation (WC) insurance systems requiring employers to pay for medical care and wage replacement for workplace injuries and illnesses were first developed between 1910 and 1920 in the United States. Employers are generally required to purchase state-regulated workers' compensation insurance that includes first-dollar payment for all medical and rehabilitative services and payment of lost wages to workers with work-related illness or injury. Injured workers have variable but usually limited latitude in choosing their health care provider. Employers and workers' compensation insurers have incentives for controlling both the cost of medical care and lost wages. CONCLUSION: The major policy issues in WC medical care--the effect of patient choice of provider and delivery system structure, the ensuring of high-quality care, the effect of integrating benefits, and investigation of the interrelationships between work, health, and productivity--can be informed by current studies in health services research and by targeted future studies of workers' compensation populations. These studies must consider the extent of patient choice of physician, the regulatory environment, the unique role of the workplace as a risk and modifying factor, and the complex interaction between health and disability insurance benefits.

Measuring functional outcomes in work-related upper extremity disorders. Development and validation of the Upper Extremity Function Scale.

Questionnaire-based measures of function have been validated extensively in studies of chronic illness and work-related low back pain. These measures have only recently been developed for upper extremity disorders (UEDs), and there is little information on their utility in evaluation of injured workers. We developed the Upper Extremity Function Scale (UEFS), an eight-item, self-administered questionnaire, to measure the impacts of UEDs on function. This instrument was tested in a cohort of 108 patients with work-related UEDs and 165 patients with the carpal tunnel syndrome (CTS); both groups were enrolled in prospective follow-up studies. The UEFS demonstrated excellent psychometric properties, including good internal consistency (Cronbach's alpha > 0.83), relative absence of floor effects, and excellent convergent and discriminant validity, compared with measures of symptom severity and clinical findings. In the CTS group, the UEFS was more responsive to significant improvements over time than clinical measures such as grip and pinch strength. These data support the use of a self-reported functional scale as a measure of outcome in studies of work-related UEDs. Further investigations in working populations are needed to substantiate its utility in workers with UEDs who have not yet sought medical care.

Screening for carpal tunnel syndrome in the workplace. An analysis of portable nerve conduction devices.

Several devices have been developed for rapid motor or sensory median nerve conduction testing. We evaluated the validity and reliability of the Neurosentinel (NS) and NervePace (NP) electroneurometer for sensory and motor testing, respectively, compared with formal electrodiagnostic studies (EDS), and examined their potential role in workplace screening for carpal tunnel syndrome (CTS). Thirty-two working subjects without CTS were examined and tested with the NS, NP, and EDS, and retested one week later. Subjects were selected who did not have CTS, other hand or nerve problems, or jobs with significant ergonomic risks, in order to decrease the likelihood of changes over time in median nerve function. Mean correlations of NP and NS with EDS latencies ranged from r = 0.069 to r = 0.85, with somewhat better correlation for NS (sensory) than NP (motor). Test-retest reliability was greatest for motor EDS (r = 0.86 to 0.91) and similar for sensory EDS, NS, and NP (r = 0.72 to 0.79); mean results were very similar. Based on the observed relationship between NS or NP and EDS results, confidence intervals were calculated to represent the range of EDS results consistent with a single NS or NP measurement. These intervals ranged from +/- 0.3 milliseconds (ms) for NS to +/- 0.6 msec for NP, with similar ranges for change over time in an individual. The magnitude of these intervals for a single test or individual implies that the NS and NP are unlikely to identify individuals with CTS or to detect changes over time that are not accompanied by symptoms or signs. The screening devices are not likely to be useful in confirming early CTS, when single latency values may be normal, and detailed EDS may be necessary to detect nerve entrapment. Compared with EDS, these devices have moderate validity and similar reliability; they are probably most useful for cross-sectional or longitudinal studies of groups, but care must be taken in using them for pre-placement or surveillance tests of individual workers. False-positive results may lead to discrimination, inappropriate referrals and interventions; false-negative tests can result in inappropriate reassurance and missed opportunities for intervention.

Exposure in a household using gasoline-contaminated water.

Contamination of drinking water with petroleum products is an increasingly common problem. Physicians are often asked to advise patients about such exposures. This study assessed household exposure from gasoline-contaminated drinking water in a New England household. A sampling strategy was designed to estimate inhalation and ingestion exposure to benzene and three other aromatic hydrocarbons typically found in gasoline-contaminated water. The estimated inhaled doses of all agents were similar to the estimated ingested dose. Over half the inhaled dose of all four agents was associated with shower activities as was over half the estimated total dose by all routes of exposure. Under these conditions, discontinuing ingestion of water contaminated with these agents may decrease the dose of benzene by less than one third, whereas discontinuing both ingestion and showering may decrease the dose of benzene by over three quarters. This limited study suggests that routes of exposure other than ingestion are important and should receive attention in the regulatory and risk-assessment process.

Work-related upper-extremity disorders and work disability: clinical and psychosocial presentation.

Work-related upper-extremity disorders (WRUEDs) are an increasingly common cause of work-related symptoms and disability. Although most upper-extremity disorders are acute and self-limited, a small percentage of workers with symptoms go on to permanent disability and account for the majority of costs associated with these conditions. Little is known, however, about this progression from symptoms to disability and how it might be prevented. In this study, we evaluate the demographic, vocational, medical, and psychosocial characteristics of patients with WRUEDs and examine several hypotheses regarding the differences between working and work-disabled patients. One hundred twenty-four consecutive patients were evaluated in a clinic specializing in occupational upper-extremity disorders. Patients currently working (n = 55) and work-disabled patients (n = 59) were similar with regard to age, gender, and reported job demands. The work-disabled group reported less time on the job, more surgeries, a higher frequency of acute antecedent trauma, and more commonly had "indeterminate" musculoskeletal diagnoses. They also reported higher pain levels, more anger with their employer, and a greater psychological response or reactivity to pain. These findings, though cross-sectional in nature, suggest that, in addition to medical management, more aggressive approaches to pain control, prevention of unnecessary surgery, directed efforts to improve patients' abilities to manage residual pain and distress, and attention to employer-employee conflicts may be important in preventing the development of prolonged work disability in this population.

Work-related upper-extremity disorders: prospective evaluation of clinical and functional outcomes.

The purpose of this study was to describe the demographic, vocational, medical, workplace, and psychosocial characteristics of patients treated for work-related upper-extremity disorders, to document treatment patterns in a community-practice setting, and to determine which of these factors predicts subsequent employment and functional status outcomes. A questionnaire was administered by mail or telephone to 112 patients seen at the University of Massachusetts Occupational Upper Extremities Disorders Clinic and included measures of disease-specific functional status, pain, reactions to pain, employer-employee relations, and number and type of interventions used to treat the disorder. Results were compared with baseline data obtained, on average, 16 months prior to follow-up. Of the original cohort (n = 124), 112 participated in the prospective study. Although most patients reported improvement in pain severity, fear of pain, life situation, and functional status, there was little change in employment status. Patients' self-reported intentions of return to work at baseline did not predict work status at follow-up. In general, those who were employed at baseline remained employed, had a greater reduction in symptom severity over time, and were significantly more likely to report improvement in their problem than those who were unemployed. The efficacy of various interventions was examined by type, mix, and intensity (number of different interventions undergone by the patient). No positive relationship was found between these measures and employment status, self-reported change in the problem, or self-reported improvement in functional status. Significant negative relationships were found between surgery, psychotherapeutic interventions, and outcomes. This was likely to have occurred because of a selection bias toward the more chronic and severely disabled patients for these treatments. However, the relative ineffectiveness of such intensive interventions as surgery in improving the work and health status of chronically symptomatic work-related upper-extremity patients cannot be overlooked. The findings suggest that more emphasis be placed on interventions aimed at resolving differences between employers and injured employees. More careful selection of patients for expensive and invasive procedures is recommended.

A model for worksite cancer prevention: integration of health protection and health promotion in the WellWorks Project.

OBJECTIVES: To describe a theoretic approach and rationale for the integration of health protection and health promotion in worksite cancer prevention programs and to describe an intervention study designed to implement this integration. METHODS: Twenty-four worksites were recruited to participate in this randomized, controlled study. The theoretically based intervention model integrates health promotion and health protection through (1) joint worker-management participation in program planning and implementation, (2) consultation on worksite changes, and (3) educational programs targeting health behavior change. RESULTS: Although the primary purpose of this paper is to describe a theoretic approach to the integration of health promotion and health protection, preliminary results are also noted. In these predominantly manufacturing worksites, many workers faced the double jeopardy of exposures to occupational carcinogens and personal risks such as smoking or poor dietary habits. Production workers' job responsibilities frequently limited their full participation. Barriers to participation were identified early in the project, and strategies were developed to facilitate maximal worker involvement and worksite changes. CONCLUSIONS: Lifestyle changes such as smoking cessation or dietary changes may be more effectively promoted among blue collar audiences when programs also encourage management actions to reduce occupational exposures. Public health professionals trained in health promotion and health protection must work together to effectively address the health concerns of this population.

Working on reform. How workers' compensation medical care is affected by health care reform.

The medical component of workers' compensation programs-now costing over $24 billion annually-and the rest of the nation's medical care system are linked. They share the same patients and providers. They provide similar benefits and services. And they struggle over who should pay for what. Clearly, health care reform and restructuring will have a major impact on the operation and expenditures of the workers' compensation system. For a brief period, during the 1994 national health care reform debate, these two systems were part of the same federal policy development and legislative process. With comprehensive health care reform no longer on the horizon, states now are tackling both workers' compensation and medical system reforms on their own. This paper reviews the major issues federal and state policy makers face as they consider reforms affecting the relationship between workers' compensation and traditional health insurance. What is the relationship of the workers' compensation cost crisis to that in general health care? What strategies are being considered by states involved in reforming the medical component of workers compensation? What are the major policy implications of these strategies?

Development of a multidisciplinary research clinic for patients with work-related upper extremity disorders.

The health care reform debate has focused attention on the need for outcomes research performed in ambulatory care settings. In this article, the authors describe the development of a research clinic focusing on symptomatic, functional, and vocational outcomes of patients with work-related upper extremity disorders. The authors describe the programmatic and research challenges associated with performing such research and emphasize the need for balancing the research and clinical agendas. Research efforts in this setting require careful consideration of the patient selection process and allocation of sufficient time for the clinical staff to collect and record essential research data.

Improving the physician role in evaluating work ability and managing disability: a survey of primary care practitioners.

PURPOSE: In the US health care system, most work-related issues are addressed by primary care practitioners (PCP's). Prior investigations of PCP's have focused on disability claims, whereas evaluations of work status and work capacity are more common. This study was conducted to identify challenges and opportunities for improvement in this area from a physician perspective. METHODS: A validated survey was mailed to a random sample of 423 Massachusetts PCP's, with a 43% response rate. RESULTS: On average, PCP's were requested to provide opinions regarding work ability in 9% (range, 1-100%) of all visits, about half of which involved non-work-related conditions. Their assessments were largely based on patient input and observations; direct communication with employers was rare. Only 6% agreed that PCP's should not have a role in facilitating safe return to work (RTW). However, 25% believed they had little influence over disability outcomes. While patient-specific factors were viewed as significant barriers to providers' efforts to successfully encourage RTW, lack of alternative work at the workplace was seen as the most significant problem. CONCLUSIONS: Evaluations of work status and work ability are common PCP activities, but little formal training has been provided in this area. Rehabilitation professionals can have a significant role through provider education, developing improved systems for communication with employers, and encouraging employers to provide more alternative duty assignments.

Worker fitness and risk evaluations in context.

The role of worker fitness and risk evaluations in society is described and the types of examinations and terminology used are defined, with emphasis on the commonly performed preplacement examination.