Jeffrey L. Levin

Pesticide/Environmental Exposures and Parkinson's Disease in East Texas

ABSTRACT Epidemiological evidence suggests that pesticides and other environmental exposures may have a role in the etiology of idiopathic Parkinsons disease (PD). However, there is little human data on risk associated with specific pesticide products, including organic pesticides such as rotenone with PD. Using a case-control design, this study examined self-reports of exposure to pesticide products, organic pesticides such as rotenone, and other occupational and environmental exposures on the risk of PD in an East Texas population. The findings demonstrated significantly increased risk of PD with use of organic pesticides such as rotenone in the past year in gardening (OR = 10.9; 95% CI = 2.5–48.0) and any rotenone use in the past (OR = 10.0; 95% CI = 2.9–34.3). Use of chlorpyrifos products (OR = 2.0; 95% CI = 1.02–3.8), past work in an electronics plant (OR = 5.1; 95% CI = 1.1–23.6), and exposure to fluorides (OR = 3.3; 95% CI = 1.03–10.3) were also associated with significantly increased risk. A trend of increased PD risk was observed with work history in paper/lumber mill (OR = 6.35; 95% CI = 0.7–51.8), exposure to cadmium (OR = 5.3; 95% CI = 0.6–44.9), exposure to paraquat (OR = 3.5; 95% CI = 0.4–31.6), and insecticide applications to farm animals/animal areas and agricultural processes (OR = 4.4; 95% CI = 0.5–38.1). Cigarette smoking, alcohol use, and fish intake were associated with reduced risk. In summary, this study demonstrates an increased risk of PD associated with organic pesticides such as rotenone and certain other pesticides and environmental exposures in this population.

Culture-Independent Characterization of Bacteria and Fungi in a Poultry Bioaerosol Using Pyrosequencing: A New Approach

Work in animal production facilities often results in exposure to organic dusts. Previous studies have documented decreases in pulmonary function and lung inflammation among workers exposed to organic dust in the poultry industry. Bacteria and fungi have been reported as components of the organic dust produced in poultry facilities. To date, little is known about the diversity and concentration of bacteria and fungi inside poultry buildings. All previous investigations have utilized culture-based methods for analysis that identify only biota cultured on selected media. The bacterial tag-encoded flexible (FLX) amplicon pyrosequencing (bTEFAP) and fungal tag-encoded flexible (FLX) amplicon pyrosequencing (fTEFAP) are modern and comprehensive approaches for determining biodiversity of microorganisms and have not previously been used to provide characterization of exposure to microorganisms in an occupational environment. This article illustrates the potential application of this novel technique in occupational exposure assessment as well as other settings. An 8-hr area sample was collected using an Institute of Medicine inhalable sampler attached to a mannequin in a poultry confinement building. The sample was analyzed using bTEFAP and fTEFAP. Of the bacteria and fungi detected, 116 and 39 genera were identified, respectively. Among bacteria, Staphylococcus cohnii was present in the highest proportion (23%). The total inhalable bacteria concentration was estimated to be 7503 cells/m 3 . Among the fungi identified, Sagenomella sclerotialis was present in the highest proportion (37%). Aspergillus ochraceus and Penicillium janthinellum were also present in high proportions. The total inhalable fungi concentration was estimated to be 1810 cells/m 3 . These estimates are lower than what has been reported by others using standard epifluorescence microscope methods. However, no study has used non-culture-based techniques, such as bTEFAP and fTEFAP, to evaluate bacteria and fungi in the inhalable fraction of a bioaerosol in a broiler production environment. Furthermore, the impact of this bTEFAP and fTEFAP technology has yet to be realized by the scientific community dedicated to evaluating occupational and environmental bioaerosol exposure.

Factors influencing safety among a group of commercial fishermen along the Texas gulf coast

ABSTRACT The commercial fishing trades are among the most dangerous jobs in the world. Little published information exists regarding some populations of commercial fishermen such as along the United States Gulf Coast. Studying these unique and often vulnerable groups is important to characterize potential influences on or barriers to safety in anticipation of designing interventions that can change safety behaviors. Working closely with the United States Coast Guard (USCG), a cross-sectional convenience sample of Gulf Coast shrimp fishermen in and near the Port of Galveston, Texas, was surveyed. The survey included demographic factors and broadly covered areas such as type of work and fishing activities, general or global perceptions and beliefs related to safety and accidents, self-report of ability to use safety equipment or apply procedures aboard vessel, and training considerations. Surveys were obtained following informed consent (n = 133). Of the participants, 96.7% were male with 60.9% ≥40 years old. A majority were of Asian descent (57.1% of all fishermen, 82.1% of shrimp fishermen). Over half claimed to speak little or no English and nearly 60% considered the job to be very safe to neutral. A third to half of respondents expressed doubt about their knowledge of using essential safety equipment in the event of emergency. A large portion of the participants preferred hands-on safety training (40.6%). Important findings about this group of commercial fishermen will help with future development of effective prevention practices through the delivery of culturally appropriate safety awareness training. One element that must be addressed in training programs is to increase the awareness among fishermen about the severe occupational risks inherent in this type of work. Community trust and collaborative partnerships are essential to the success of such initiatives.

Asbestos Burden in Cases of Mesothelioma from Individuals from Various Regions of the United States

Mesothelioma is a rare tumor that is considered an asbestos marker disease. It occurs in individuals following a longer latency period from first exposure than other asbestos-related diseases. The tumor also occurs in individuals with a wide range of exposures, including individuals with lower level or secondary exposures. In the present study lung tissue from 54 individuals with a pathological diagnosis of mesothelioma was evaluated for ferruginous body and uncoated asbestos fiber content. The data were compared with an earlier study of mesothelioma cases from the northwestern United States. Tissue was prepared via a digestion procedure, with the collected digestate reviewed by light microscopy for quantification of asbestos bodies and analytical transmission electron microscopy for determination of uncoated fiber burden. Twenty-seven cases in the present study had over 1000 ferruginous bodies per gram of dry tissue. The data suggest that amosite provides a more likely stimulus for ferruginous coating than the other forms of asbestos. All individuals were found to have asbestos fibers in their lung tissue. Amosite was the most commonly found fiber, with anthophyllite being the second most commonly found type of asbestos. The finding of tremolite in the tissue most often was associated with the finding of anthophyllite. A limited number of asbestos fibers of each type would have been seen in the light microscope, with the least detected being chrysotile. The majority of all fiber types were found as short fibers (< 8 μm), although some longer fibers were represented in each type of asbestos. The majority of the individuals were found to have mixed types of asbestos in their lungs.

Occupational Health Outcomes for Workers in the Agriculture, Forestry and Fishing Sector: Implications for Immigrant Workers in the Southeastern US

BACKGROUND Workers in the Agriculture, Forestry, and Fisheries (AgFF) sector experience exposures directly related to the work itself, as well as the physical environment in which the work occurs. Health outcomes vary from immediate to delayed, and from acute to chronic. METHODS We reviewed existing literature on the health outcomes of work in the AgFF sector and identified areas where further research is needed to understand the impact of these exposures on immigrant Latino workers in the southeastern US. RESULTS Outcomes related to specific body systems (e.g., musculoskeletal, respiratory) as well as particular exposure sources (e.g., pesticides, noise) were reviewed. The most extensive evidence exists for agriculture, with a particular focus on chemical exposures. Little research in the southeastern US has examined health outcomes of exposures of immigrant workers in forestry or fisheries. CONCLUSION As the AgFF labor force includes a growing number of Latino immigrants, more research is needed to characterize a broad range of exposures and health outcomes experienced by this population, particularly in forestry and fisheries.

Cultural Influences on Safety and Health Education Among Vietnamese Fishermen

ABSTRACT Every ethnic group has its own cultural background and history that influences how it views health behaviors. By virtue of their work history, many Vietnamese have pursued the fishing industry when migrating to the United States. Even though the fishing trades are among the most dangerous jobs in the world, there has been little attention in the literature to the significant role that culture plays in the expression and experience of occupational health practices among Vietnamese shrimp fishermen. Three focus group sessions were conducted to identify factors that hinder or facilitate receptivity to available training and to guide culturally appropriate content. Participants were recruited using purposive sampling among various Vietnamese shrimp fishermen communities in Texas. Utilizing a series of open-ended questions, sessions were conducted in their native language among owners/captains/deckhands; support infrastructure—adult family members and religious/community leaders; and industry management and insurance representatives. Translations of transcribed documents were compared with simultaneous translations to ensure thematic consistency. Conducting hands-on training among Vietnamese by experienced fishermen, specifically targeting captains, was considered key to safety culture on the vessels. Findings of the study support that training should occur in a variety of formats (hands-on), but should be periodic, current, practical, convenient, taught in the primary language of the audience by an experienced individual, culminate in a certificate of completion, and target captains first. These findings illustrate the importance of considering cultural factors in the design of workplace interventions that focus on changes in safety and occupational health behaviors.

Characteristics of Asbestos Concentration in Lung as Compared to Asbestos Concentration in Various Levels of Lymph Nodes that Collect Drainage from the Lung

Inhaled dust particulates are able to relocate to the extrapulmonary compartments, particularly the lymph nodes that drain the lung. There is little information about the concentration and type of asbestos in the lymphatics and lymph nodes. Quantitative analysis of asbestos lymph node burden conducted by light and analytical transmission electron microscopy has shown ferruginous bodies in lymph nodes that drain the lung and appreciable numbers of short asbestos fibers accumulate in lymph nodes in occupationally exposed individuals. The location of lymph nodes in the thoracic cavity was categorized according to the Naruke anatomical map. Tissue from eleven individuals with a history of asbestos exposure were selected for a comparative study of the asbestos content of lung with that found in the thoracic lymph nodes. The study used a digestion technique for tissue preparation and evaluated ferruginous body burden and concentration of asbestos fibers (> 0.5 µm in length). Comparison was made between sites and analysis was made as to the population of fibers detectable by light microscopy and defined as “Stanton fibers.” The findings indicated the vast majority of all asbestos fiber types in all sites were shorter than 5 µm and would not have been counted in a light microscopy count scheme that included only those fibers > 5 µm. There were reproducible patterns of asbestos types of found in various lymph nodes, although there were variations in the amount of asbestos found in the sites sampled. In summary, asbestos fibers found in thoracic lymph nodes have predominately short fibers and, in this study group, consisted of a mixture of commercial and noncommercial amphiboles. When a long/thin fiber was found in the lung or lymph tissue, its detection required the use of analytical transmission electron microscopy for identification.

Asbestosis and small cell lung cancer in a clutch refabricator.

OBJECTIVES: To present a case of asbestosis and small cell lung cancer caused by asbestos in a clutch refabricator. METHODS: Exposed surfaces of used clutches similar to those refabricated in the workers workplace were rinsed, and the filtrate analysed by analytical transmission electron microscopy. Tissue samples were also analysed by this technique. RESULTS: Numerous chrysotile fibres of respirable dimensions and sufficient length to form ferruginous bodies (FBs) were detected from rinsed filtrates of the clutch. Bronchoalveolar lavage fluid contained many FBs, characteristic of asbestos bodies. Necropsy lung tissue showed grade 4 asbestosis and a small cell carcinoma in the right pulmonary hilum. Tissue analysis by light and analytical electron microscopy showed tissue burdens of coated and uncoated asbestos fibres greatly exceeding reported environmental concentrations (3810 FBs/g dry weight and 2,080,000 structures > or = 0.5 micron/g dry weight respectively). 72% Of the cores were identified as chrysotile. CONCLUSIONS: Clutch refabrication may lead to exposure to asbestos of sufficient magnitude to cause asbestosis and lung cancer.

Role of p53-fibrinolytic system cross-talk in the regulation of quartz-induced lung injury

Silica is the major component of airborne dust generated by wind, manufacturing and/or demolition. Chronic occupational inhalation of silica dust containing crystalline quartz is by far the predominant form of silicosis in humans. Silicosis is a progressive lung disease that typically arises after a very long latency and is a major occupational concern with no known effective treatment. The mechanism of silicosis is not clearly understood. However, silicosis is associated with increased cell death, expression of redox enzymes and pro-fibrotic cytokines and chemokines. Since alveolar epithelial cell (AEC) death and disruption of alveolar fibrinolysis is often associated with both acute and chronic lung injuries, we explored whether p53-mediated changes in the urokinase-type plasminogen activator (uPA) system contributes to silica-induced lung injury. We further sought to determine whether caveolin-1 scaffolding domain peptide (CSP), which inhibits p53 expression, mitigates lung injury associated with exposure to silica. Lung tissues and AECs isolated from wild-type (WT) mice exposed to silica exhibit increased apoptosis, p53 and PAI-1, and suppression of uPA expression. Treatment of WT mice with CSP inhibits PAI-1, restores uPA expression and prevents AEC apoptosis by suppressing p53, which is otherwise induced in mice exposed to silica. The process involves CSP-mediated inhibition of serine-15 phosphorylation of p53 by inhibition of protein phosphatase 2A-C (PP2A-C) interaction with silica-induced caveolin-1 in AECs. These observations suggest that changes in the p53-uPA fibrinolytic system cross-talk contribute to lung injury caused by inhalation of silica dust containing crystalline quartz and is protected by CSP by targeting this pathway.

Evaluation of Parlor Cleaning as an Intervention for Decreased Occupational Exposure to Dust and Endotoxin Among Dairy Parlor Workers—A Pilot Study

Agreater prevalence of respiratory symptoms has been observed among workers involved in animal production compared to other farmers and rural residents.(1) In addition, respiratory diseases such as byssinosis,(2) asthma,(3) allergic alveolitis,(4) chronic bronchitis,(5) and the organic dust toxic syndrome (ODTS)(6) have been reported among workers in the animal feed industry, slaughterhouses, compost facilities, and other agriculture-related industries.(7) Respiratory hazards such as organic dust, microorganisms, fungi, molds, and endotoxin are common in the dairy industry.(8) Exposure to organic dust and endotoxin may lead to pulmonary inflammation among dairy parlor workers.(9–11) Organic dusts are associated with intensive livestock operations, such as dairy, swine, and poultry production; however differences in the components of these organic dusts have been reported.(12,13) A substantial amount of work has evaluated the effects of organic dust exposure among swine workers, whereas less is known about these exposures among dairy parlor workers.(13–16) Sources of organic dust on dairy farms include feed/hay grinding and animal sources, such as hair and feces.(17) Little information is available on the impact of these exposures among workers in the dairy industry. However, a few studies have demonstrated an association of dust and endotoxin exposure with markers of lung inflammation among dairy parlor workers.(9,12,18) The primary task of dairy parlor workers is to milk the cows. Cows are moved through the parlor building using workers to guide the animals as well as mechanical gating systems. Cows enter the parlor on an elevated platform for milking. Cows are typically milked three times a day over a series of three 8-hr shifts.(19) The walkways and other surfaces that come into contact with the animals become soiled with animal waste. Workers use an automated cleaning system to remove animal waste from the parlor surfaces. Therefore, increasing the frequency in which these walkways and other surfaces are cleaned may reduce the concentration of aerosolized dust and endotoxin in the milking parlor. Parlor workers spend their work shift in proximity to cows and animal waste, which may be sources of inhalation exposure to organic dust and endotoxin. Therefore, these workers may be more exposed to inflammatory agents, as organic dust and endotoxin, compared to other workers on the dairy farm. The objective of our study was to assess occupational exposure to dust and endotoxin among dairy parlor workers. This study also evaluated the effectiveness of increasing the frequency of cleaning the dairy parlor surfaces on dust and endotoxin inhalation exposure among parlor workers.