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

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.

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.

Workplace Safety Interventions for Commercial Fishermen of the Gulf.

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.

The significance of Mycobacterium abscessus subspecies abscessus isolation during Mycobacterium avium complex lung disease therapy.

BACKGROUND: Isolation of Mycobacterium abscessus subspecies abscessus (MAA) is common during Mycobacterium avium complex (MAC) lung disease therapy, but there is limited information about the clinical significance of the MAA isolates. METHODS: We identified 53 of 180 patients (29%) treated for MAC lung disease who had isolation of MAA during MAC lung disease therapy. Patients were divided into those without (group 1) and those with (group 2) MAA lung disease. RESULTS: There were no significant demographic differences between patients with and without MAA isolation or between groups 1 and 2. Group 1 and 2 patients had similar total sputum cultures obtained (P = .7; 95% CI, -13.4 to 8.6) and length of follow-up (P = .8; 95% CI, -21.5 to 16.1). Group 2 patients had significantly more total positive cultures for MAA (mean±SD, 15.0 ± 11.1 vs 1.2 ± 0.4; P < .0001; 95% CI, -17.7 to -9.9), were significantly more likely to develop new or enlarging cavitary lesions while on MAC therapy (P > .0001), and were significantly more likely to meet all three American Thoracic Society diagnostic criteria for nontuberculous mycobacterial disease (21 of 21 [100%] vs 0 of 32 [0%]; P < .0001) compared with group 1 patients. Group 1 patients were significantly more likely to have single, positive MAA cultures than group 2 patients (25 of 31 vs 0 of 21; P < .0001). CONCLUSIONS: Microbiologic and clinical follow-up after completion of MAC lung disease therapy is required to determine the significance of MAA isolated during MAC lung disease therapy. Single MAA isolates are not likely to be clinically significant.

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.

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

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.

Hypothyroidism among former workers of a nuclear weapons facility.

BACKGROUND: Ionizing radiation alters thyroid function, and workers at a nuclear weapons facility may be exposed to above environmental levels of radiation. METHODS: Hypothyroid status was determined for 622 former workers of a nuclear weapons facility located in Texas, using a combination of measured thyroid stimulating hormone (TSH) levels and thyroid medication history, as part of an on-going health surveillance program. We classified 916 unique job titles into 35 job categories. RESULTS: According to the most stringent TSH definition used in this study (0.3-3.0 IU/ml), 174 (28.0%) former workers were considered to be hypothyroid; of these 66 (41.8%) were females and 108 (23.3%) were males. In logistic regression analysis adjusted for age, gender, and smoking status, only having worked as a material handler (n = 18) exhibited an elevated risk of developing hypothyroidism compared to other jobs (OR 3.88, 95% CI 1.43-11.07). This is one of the jobs with suspected exposure to radiation. No excess risk of hypothyroidism was observed for any of the other job categories. CONCLUSIONS: There is suggestive evidence that only material handlers at this nuclear weapons facility may have elevated risk of hypothyroidism; further evaluation of thyroid health in this population is warranted.

Factors influencing safety among a group of commercial fishermen along the Texas Gulf Coast.

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.

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

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 (OR(adj) = 2.89; 95% CI = 1.28-6.56) and (OR(adj) = 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 (OR(adj) = 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.

Pesticide/environmental exposures and Parkinson's disease in East Texas.

Epidemiological evidence suggests that pesticides and other environmental exposures may have a role in the etiology of idiopathic Parkinson's 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.

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 microm 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 microm and would not have been counted in a light microscopy count scheme that included only those fibers > 5 microm. 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.

Clinical and molecular analysis of macrolide resistance in Mycobacterium avium complex lung disease.

RATIONALE: The clinical features and outcome of macrolide-resistant Mycobacterium avium complex (MAC) lung disease are not known. OBJECTIVES: Characterize patients, treatment, and isolates in macrolide-resistant MAC lung disease. METHODS: Retrospective chart review, susceptibility testing, molecular fingerprinting, and DNA sequence analyses of resistant MAC isolates. MEASUREMENTS AND MAIN RESULTS: We identified 51 patients over a 15-yr period with clarithromycin-resistant MAC (minimum inhibitory concentration (MIC)>or=32 microg/ml) lung disease at a single referral center. Twenty-four (47%) patients had nodular disease with bronchiectasis and 27 (53%) had upper lobe cavitary disease. Most patients (77%) had M. intracellulare. Sequencing of the 23S r-RNA gene showed 49 of 51 isolates (96%) with the expected mutation in adenine 2058 or 2059. Risk factors for resistance included macrolide monotherapy or combination with a quinolone only (39/51 or 76%). Macrolide resistance developed in 12 of 303 (4.0%) patients started on the American Thoracic Society-recommended two companion drugs, with no risk difference in clarithromycin versus azithromycin and daily versus intermittent therapy. Sputum conversion with macrolide-resistant MAC occurred in 11 of 14 (79%) patients who received more than 6 mo of injectable aminoglycoside therapy and lung resection, compared with 2 of 37 (5%) who did not. The 1-yr mortality in patients who remained culture positive was 34% (13/38) compared with 0% (0/13) of patients who became culture negative (converted). CONCLUSIONS: Macrolide resistance rarely occurs in patients also receiving ethambutol and a rifamycin. Macrolide-resistant MAC lung disease requires aggressive drug and surgical therapy for cure.

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 mum), 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.

Agroterrorism workshop: engaging community preparedness.

INTRODUCTION: Agroterrorism is the deliberate tampering with and/or contamination of the food supply with the intent of adversely affecting the social, economic, physical, and psychological well-being of society. Testimony before the Government Affairs Committee of the U.S. Senate has suggested that agriculture is an area that has received comparatively little attention with regard to terrorism. METHODS: In February of 2004, the NIOSH Southwest Center for Agricultural Health, Injury Prevention, and Education developed a workshop on agroterrorism designed to engage local community leaders in a process to prepare for and respond to a terrorist event involving the food supply. The workshop was an effective collaboration between NIOSH Ag Centers, the state department of health (Texas), a school of public health, and the Texas Agricultural Research and Extension Centers in five urban and rural locations with substantial agricultural production. In order to reach a diverse and geographically widespread audience, the workshop was conducted by synchronous two-way interactive televideo (9 geographic sites). The audience of 155 participants was comprised of numerous stakeholders. The workshop format involved separate modules addressing food and fiber, livestock and poultry, food distribution, and emergency preparedness, with participants developing priorities for future consideration within their communities to address all phases of an event from preparedness to follow-up debriefing. There were 13 additional individuals (for a total of 168) who participated in the workshop subsequently through use of a video. RESULTS: Workshop evaluation components included pre- and post-workshop objective assessment of factual information presented (tests), and follow-up for implementation of priorities developed by conference participants. Statistically significant improvement was noted in knowledge acquisition. The six-month follow-up demonstrated implementation of preparedness planning priorities. CONCLUSIONS: This is an effective method of reaching a geographically widespread and diverse audience of community members who will be on the front lines of an agroterrorism event. An attempt was made to enhance communication and collaboration among involved groups for effectively detecting and addressing such an event. This workshop can serve as a model for use in other communities.

Ethambutol ocular toxicity in treatment regimens for Mycobacterium avium complex lung disease.

Ethambutol (EMB) is an important component of multidrug treatment regimens for Mycobacterium avium complex lung disease. Ocular toxicity is the most important potential EMB toxicity, especially in the elderly population with M. avium complex lung disease. Two hundred twenty-nine patients with M. avium complex lung disease, 55% women and 53% with nodular/bronchiectatic disease, received a mean of 16.1 +/- 10.8 months of multidrug therapy that included EMB. Fifty patients (22%) were known to have preexisting ocular disease. While on EMB, 97 (42%) patients consulted an opthalmologist and 24 (10%) stopped EMB at least temporarily. Eight of 139 patients (6%) on daily therapy were diagnosed with EMB ocular toxicity, whereas 0 of 90 patients on intermittent therapy had EMB ocular toxicity (p = 0.05). All patients with EMB ocular toxicity developed symptoms between outpatient clinic appointments; none were diagnosed with routine visual acuity and color vision testing. All patients with EMB ocular disease returned to baseline ocular status after discontinuation of EMB. Intermittent EBM administration was associated with less ocular toxicity than daily EMB administration in this patient population.