Sara Shepherd

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.

Macrolide/Azalide Therapy for Nodular/Bronchiectatic Mycobacterium avium Complex Lung Disease

BACKGROUND There is no large study validating the appropriateness of current treatment guidelines for Mycobacterium avium complex (MAC) lung disease. This is a retrospective single-center review evaluating the efficacy of macrolide/azalide-containing regimens for nodular/bronchiectatic (NB) MAC lung disease. METHODS Patients were treated according to contemporary guidelines with evaluation of microbiologic responses. Macrolide susceptibility of MAC isolates was done at initiation of therapy, 6 to 12 months during therapy, and on the first microbiologic recurrence isolate. Microbiologic recurrence isolates also underwent genotyping for comparison with the original isolates. RESULTS One hundred eighty patients completed > 12 months of macrolide/azalide multidrug therapy. Sputum conversion to culture negative occurred in 154 of 180 patients (86%). There were no differences in response between clarithromycin or azithromycin regimens. Treatment regimen modification occurred more frequently with daily (24 of 30 [80%]) vs intermittent (2 of 180 [1%]) therapy (P = .0001). No patient developed macrolide resistance during treatment. Microbiologic recurrences during therapy occurred in 14% of patients: 73% with reinfection MAC isolates, 27% with true relapse isolates (P = .03). Overall, treatment success (ie, sputum conversion without true microbiologic relapse) was achieved in 84% of patients. Microbiologic recurrences occurred in 74 of 155 patients (48%) after completion of therapy: 75% reinfection isolates, 25% true relapse isolates. CONCLUSIONS Current guidelines for macrolide/azalide-based therapies for NB MAC lung disease result in favorable microbiologic outcomes for most patients without promotion of macrolide resistance. Intermittent therapy is effective and significantly better tolerated than daily therapy. Microbiologic recurrences during or after therapy are common and most often due to reinfection MAC genotypes.

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.

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.

Workplace Safety Interventions for Commercial Fishermen of the Gulf

ABSTRACT Commercial fishing continues to have one of the highest rates of occupational fatalities compared with other work sectors in the United States. Attitudes/beliefs among Vietnamese shrimp fishermen of the Gulf of Mexico may influence behaviors that are risk factors for fatal and nonfatal injuries. The study employs a community trial with quasi-experimental pretest/posttest intervention design. An advisory group made up of key stakeholders including representatives from the US Coast Guard was assembled. A survey was designed using the Theory of Planned Behavior as the theoretical framework. Three community groups at port sites along the Texas/Louisiana Gulf Coasts were identified. Focus groups were convened at each site to select priority areas for risk intervention using training and awareness measures. Initial and follow-up surveys were administered pre-/post-interventions for each of the three community groups (2008, n = 217 completed surveys; 2012, n = 206 completed surveys). The follow-up survey was condensed and “intent to act” questions were added for the priority concerns identified (noise-induced hearing loss, machinery/winches, and fatigue). Statistically significant changes (P ranging from .000 to .042) were observed in selective attitude/belief responses for hearing/noise and fatigue. Intent to action or to adopt the intervention was high among all three groups of shrimp fishermen (hearing conservation, 82.4%; machinery/winch safety, 94.6%; fatigue awareness, 95.3%). Simple, yet culturally appropriate training and awareness measures in the form of visual and written safety messages favorably influence attitudes, beliefs, and behavioral intent related to priority risk factors identified by Vietnamese commercial shrimp fishermen along the Texas and Louisiana Gulf Coasts.

Helping Gulf shrimpers adopt safety measures: importance of partnerships and research to practice.

ABSTRACT Commercial fishing continues to be a dangerous line of work. There are many hazards and the work is complex, even on a small scale. Along the United States Gulf Coast, the make-up of the commercial fishing population is diverse, with many Vietnamese shrimpers. Cultural barriers can interfere with critical communication and with receptivity to necessary safety training. In the course of studying these factors, it became apparent that language was a significant barrier among Vietnamese shrimp fishermen learning sound signals and making Mayday calls, potentially contributing to adverse events. This article is a qualitative description of a pilot project in response to this observation and aimed at the development of a model simulating the bridge of a commercial fishing vessel (including horn blast and radio). The model is used to improve knowledge and skills of the fishermen by providing instruction in Vietnamese. As a Mayday call must be made in English, instructional aids are provided to assist fishermen in the exercise. This example of research to practice (r2p) demonstrates how research findings may enhance acquisition of safety knowledge and skills through development of these types of models as well sustainable instructional tools like the multi-lingual interactive CD described here. It further illustrates the importance of partnerships in the design and delivery of workplace safety training interventions. The model, instructional aids, and CD are timely as they coincide with new regulation which mandates certification of these competencies or skills.

Risk factors for musculoskeletal symptoms among crawfish farmers in Louisiana-a pilot study

ABSTRACT The prevalence of musculoskeletal symptoms (MSS) among crawfish farmers is unknown. The purpose of this study was to assess the prevalence of MSS in nine body regions among crawfish farmers, and to examine associations between MSS and crawfish farm work activities. Questionnaires were mailed to randomly selected crawfish farmers in the State of Louisiana, USA. Site-specific MSS, demographics, and crawfish farm work information was obtained from the previous six months. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated with logistic regression adjusting for potential confounders. Among the participants (N = 184), shoulder MSS were reported most frequently (62%). Wrist/hand and low back MSS were significantly associated with tractor use (ORadj = 2.89; 95% CI = 1.28–6.56) and (ORadj = 2.41; 95% CI = 1.03–5.67), respectively. Also, upper back MSS were associated with the number of years working on a crawfish farm (ORadj = 3.07; 95% CI = 1.17–8.04). Shoulder and low back MSS were common. Tractor use may increase the risk of wrist/hand and low back MSS. Future studies need accurately assess exposures to physical risk factors for MSS so ergonomic interventions can be developed.

Hearing loss and noise exposure among commercial fishermen in the gulf coast

Objective: Noise is a hazard in commercial fishing. This cross-sectional study associates occupational noise exposure with hearing loss in commercial fishermen. Methods: A comprehensive survey and audiometric testing were administered to 227 participants in the Gulf Coast. Sound-level measurements were obtained aboard a sample of fishing vessels. Criteria specific for hearing impairment (HI) and noise-induced hearing loss (NIHL) were applied to each audiogram. Results: The majority of these fishermen work shifts more than 16 hours for an extended duration. Hazardous noise levels were measured in the engine rooms ranging from 94.8 to 105.0 dBA. NIHL was significantly associated with years spent fishing, but not with age. HI was significantly associated with age, but not with years fishing. Conclusions: Commercial fishermen in the Gulf may be at a considerable risk of occupational NIHL and would benefit from hearing conservation programs.

Tyler asbestos workers: A mortality update in a cohort exposed to amosite

ABSTRACT The Tyler asbestos plant produced pipe insulation from 1954 to 1972 and exclusively used amosite asbestos. There were 1130 former workers of this plant during the period of operation. A death certificate mortality analysis was published regarding this plant in 1998 for the period through 1993. This study represents an update of the mortality analysis with additional certificates collected for deaths occurring through 2011.Searches of the National Death Index database were conducted in 2004 and again in 2013. At the time of the latter search, only deaths occurring through 2011 were available. In total, 265 distinct additional death certificates were secured and added to 304 available from the original study. After the new certificates were coded (ICD-9), data were analyzed using the Centers for Disease Control and Prevention Life Table Analysis System (LTAS) and standard mortality ratios (SMR) generated with 95% confidence limits (CL). LTAS constructs cause-specific mortality rates by age, gender, race, and person-time at risk, and compares observed rates with a referent population in order to derive SMR. A significant excess number of deaths due to nonmalignant respiratory disease (asbestosis) and from select malignant neoplasms were identified. There were in total 23 mesothelioma deaths (4% of deaths), with 16 pleural and 7 peritoneal. The SMR for malignant neoplasms of the trachea, bronchus, and lung was 244 (with 95% CL 196, 300), suggesting that exposed workers from this cohort were nearly 2.5-fold (244 %) more likely to die from this cause as the general referent population. The analysis also showed that exposures of short duration (<6 mo) produced significantly elevated SMR for all respiratory cancers, lung cancer, and pleural mesothelioma. There was a significant difference in median duration of exposure for mesothelioma types, confirming association of peritoneal mesothelioma with longer duration of exposure. Deaths due to intestinal cancer (predominantly colon; not including rectum) were also found in excess. The mortality experience of the Tyler cohort continues to be followed with great interest, given the exclusivity of exposure to amosite. Data confirm the inherent pathogenicity of this fiber type for nonmalignant disease as well as select cancers, particularly relevant given the importance of this amphibole’s use in the United States.

Hypothyroidism among former workers of a nuclear weapons facility (Pantex), Amarillo, Texas

Objectives Ionising radiation can alter thyroid function, and workers at a nuclear weapons facility may be exposed to elevated levels of radiation. The Pantex Plant, located in Amarillo, Texas, is the only remaining facility in the United States that assembles and disassembles nuclear weapons, and since 1958 it has manufactured 60–70% of the countrys nuclear weapons arsenal. Methods As part of an on-going health surveillance program, hypothyroid status was determined for 622 former workers of Pantex, using a combination of measured thyroid stimulating hormone levels and thyroid medication history. Next, 916 unique job titles identified in questionnaires were classified into 35 job categories. Results Fifty-five (34.8%) females and seventy-eight (16.8%) males were hypothyroid. In logistic regression analysis adjusted for age, gender and smoking, only ‘material handlers’ (n=18) exhibited an elevated risk of developing hypothyroidism (OR 3.64, 95% CI 1.30 to 9.97) compared to other job categories. This is one of the groups with suspected exposure to radiation. Conclusions There is suggestive evidence that some occupational groups exposed to radiation at Pantex may have an elevated risk of hypothyroidism. Further evaluation of thyroid health in this population is warranted.