Exhaled Nitric Oxide Measurement in Workers in a Microwave Popcorn Production Plant

Abstract

Airways obstruction in microwave-popcorn workers has been attributed to inhalation of flavoring agents. Two former workers at a microwave-popcorn plant were found by lung biopsy to have bronchiolitis obliterans. The study's aim was to determine whether exhaled nitric oxide (FE_NO) levels were associated with exposure levels, respiratory symptoms, or airways obstruction. A questionnaire, spirometry, and FE_NO measurements were completed by 135 workers. The FE_NO levels of workers with high flavoring exposures (n = 107) were compared with those of workers with low exposures (n = 28) and healthy external con troIs (n = 31). FE_NO levels were significantly lower in the high-exposure group (p < 0.05). There is no indication that FE_NO is useful as a marker of lung injury in a flavoring-exposed worker population with a substantial lung disease burden, but the finding of low FE_NO in the high-exposure group should not be dismissed.     

Environmental characterization of a coffee processing workplace with obliterative bronchiolitis in former workers

Obliterative bronchiolitis in five former coffee processing employees at a single workplace prompted an exposure study of current workers. Exposure characterization was performed by observing processes, assessing the ventilation system and pressure relationships, analyzing headspace of flavoring samples, and collecting and analyzing personal breathing zone and area air samples for diacetyl and 2,3-pentanedione vapors and total inhalable dust by work area and job title. Mean airborne concentrations were calculated using the minimum variance unbiased estimator of the arithmetic mean.

Workers in the grinding/packaging area for unflavored coffee had the highest mean diacetyl exposures, with personal concentrations averaging 93 parts per billion (ppb). This area was under positive pressure with respect to flavored coffee production (mean personal diacetyl levels of 80 ppb). The 2,3-pentanedione exposures were highest in the flavoring room with mean personal exposures of 122 ppb, followed by exposures in the unflavored coffee grinding/packaging area (53 ppb). Peak 15-min airborne concentrations of 14,300 ppb diacetyl and 13,800 ppb 2,3-pentanedione were measured at a small open hatch in the lid of a hopper containing ground unflavored coffee on the mezzanine over the grinding/packaging area. Three out of the four bulk coffee flavorings tested had at least a factor of two higher 2,3-pentanedione than diacetyl headspace measurements.

At a coffee processing facility producing both unflavored and flavored coffee, we found the grinding and packaging of unflavored coffee generate simultaneous exposures to diacetyl and 2,3-pentanedione that were well in excess of the NIOSH proposed RELs and similar in magnitude to those in the areas using a flavoring substitute for diacetyl. These findings require physicians to be alert for obliterative bronchiolitis and employers, government, and public health consultants to assess the similarities and differences across the industry to motivate preventive intervention where indicated by exposures above the proposed RELs for diacetyl and 2,3-pentanedione.     

Popcorn lung and bronchiolitis obliterans: a critical appraisal

Purpose  To perform a critical review of a series of journal articles and Health Hazard Evaluation Reports (HHER) by the National Institute for Occupational Safety and Health (NIOSH), where they have described the incidence of fixed obstructive pulmonary disease in a population of workers exposed to butter flavorings. Methods  The clinical presentations, diagnostic modalities frequently employed and a review of the pertinent clinical literature are discussed for constrictive bronchiolitis and bronchiolitis obliterans with intraluminal polyps; two distinct forms of bronchiolitis obliterans (BO). An analysis of the NIOSH reports and scientific articles is provided, followed by suggestions for evaluating this public and occupational health concern moving forward. Findings  Cases of lung disease in the food flavorings industry discussed in the literature have not been sufficiently documented to allow the conclusion that BO has been caused by diacetyl or butter flavoring. Further research is required to establish the causative agent(s). Conclusion  The diagnosis of bronchiolitis obliterans should be reserved for those individuals who have diagnostic lung biopsy findings, obtained and interpreted by clinicians who are experienced with this complex disorder.

Mortality among California highway workers

Standardized proportional mortality ratios (PMR) were computed for a population of highway workers. Hazards of highway maintenance work include exposure to solvents, herbicides, asphalt and welding fumes, diesel and auto exhaust, asbestos, abrasive dusts, hazardous material spills, and moving motor vehicles. Underlying cause of death was obtained for 1,570 workers who separated from the California Department of Transportation between 1970 and 1983, and who died in California between 1970 and 1983 (inclusive). Among 1,260 white males, the major findings were statistically significant excesses of cancers of digestive organs (PMR = 128), skin (PMR = 218), lymphopoietic cancer (PMR = 157), benign neoplasms (PMR = 343), motor vehicle accidents (PMR = 141), and suicide (PMR = 154). Black males (N = 66) experienced nonsignificant excesses of cancer of the digestive organs (PMR = 191) and arteriosclerotic heart disease (PMR = 143). Among 168 white females, deaths from lung cancer (PMR = 189) and suicide (PMR = 215) were elevated. White male retirees, a subgroup with 5 or more years of service, experienced excess mortality due to cancers of the colon (PMR = 245), skin (PMR = 738), brain (PMR = 556), and lymphosarcomas and reticulosarcomas (PMR = 514). Deaths from external causes (PMR = 135) and cirrhosis of the liver (PMR = 229) were elevated among white males with a last job in landscape maintenance. White males whose last job was highway maintenance experienced a deficit in mortality from circulatory diseases (PMR = 83) and excess mortality from emphysema (PMR = 250) and motor vehicle accidents (PMR = 196). Further epidemiologic and industrial hygiene studies are needed to confirm the apparent excess mortality and to quantify occupational and nonoccupational exposures. However, reduction of recognized hazards among highway maintenance workers is a prudent precautionary measure.     

Mortality of aircraft manufacturing workers in Southern California

A retrospective cohort mortality study was conducted among men and women employed for four or more years, between 1958 and 1982, at an aircraft manufacturing company in San Diego County. Specific causes of death under investigation included cancer of the brain and nervous system, malignant melanoma, and cancer of the testicle, which previous reports have suggested to be associated with work in aircraft manufacturing. Follow-up of the cohort of 14,067 subjects for a mean duration of 15.8 yr from the date of first employment resulted in successful tracing of 95% of the cohort and found 1,804 deaths through 1982. Standardized mortality ratios (SMRs) were calculated based on U.S. national mortality rates and separately based on San Diego County mortality rates. Mortality due to all causes was significantly low (SMR = 75), as was mortality due to all cancer (SMR = 84). There was no significant excess of cancer of the brain, malignant melanoma, cancer of the testicle, any other cancer site, or any other category of death. Additional analyses of cancer sites for which at least ten deaths were found and for which the SMR was at least 110 showed no increase in risk with increasing duration of work or in any specific calendar period. Although this study found no significant excesses in cause-specific mortality, excess risks cannot be ruled out for those diseases that have latency periods in excess of 20 to 30 yr, or for exposures that might be restricted to a small proportion of the cohort.     

Changes in lung function and respiratory symptoms during pesticide spraying season among male sprayers

Abstract

Exposure to pesticides via inhalation might impair lung function and develop further severe respiratory symptoms and diseases. Thus, the purpose of the study was to compare lung function between pre- and post-pesticide spraying seasons among male sprayers. The study also evaluated the association of lung function changes and other factors with respiratory symptoms. The follow-up study was conducted on 58 male sprayers. The subjects were interviewed and measured lung function before and after pesticide spraying season. The results found that forced vital capacity (FVC), forced expiratory volume in one second (FEV₁), and peak expiratory flow rate in the post-spraying season were significantly lower than in the pre-spraying season. With regard to respiratory symptoms, cough symptoms were associated with changes in FEV₁/FVC [odd ratio (OR) = 1.29, 95% confidence interval (CI) = 1.01–1.67)] and smoking status (OR = 12.95, 95%CI = 1.35–124.34). Phlegm symptoms were also associated with changes in FVC (OR = 2.07, 95%CI = 1.01–4.25) and FEV₁ (OR = 0.41, 95%CI = 0.18–0.91). The study provides evidence that pesticide spraying may increase risks for significant alteration of lung function and respiratory symptoms.     

Metabolism of triethylamine in polyurethane foam manufacturing workers

In 20 workers studied before, during, and after exposure to triethylamine (TEA) in a polyurethane-foam producing plant the amount of TEA and its metabolite triethylamine-N-oxide (TEAO) excreted in urine corresponded to an average of 80% of the inhaled amount. An average of 27% was TEAO, but with a pronounced interindividual variation. Older subjects excreted more than younger ones; less than 0.3% was excreted as diethylamine. The data indicate half-lives for TEA and TEAO excretion in urine of about 3 hr. The postshift level of TEA in urine and plasma are good indicators of the time-weighted average air level during the preceding work day, and might thus be used for biological monitoring. An air level of 10 mg/m3 (proposed occupational standard) corresponds to a urinary excretion of 65 mmol TEA/mol creatinine and a plasma level of 1.9 mumol/liter (biological exposure indices).     

Cancer incidence among alachlor manufacturing workers

A historical cohort study was conducted to evaluate cancer incidence among chemical workers with occupational and environmental exposure to alachlor, the active ingredient in a family of pre-emergent acetanilide herbicides. The study followed 943 workers with at least 1 year of cumulative employment at the Monsanto plant in Muscatine. Iowa, from startup of the alachlor manufacturing process in March 1968 through December 1990. Approximately 96% of all workers were successfully traced to determine their last known residence and cancer status. Eighteen workers were diagnosed with cancer during the follow-up period, based on pathology information from the statewide cancer registry maintained by the State Health Registry of Iowa. The standardized incidence ratio for all cancers was 1.5 (95% CI 0.9–2.4) for all workers exposed to alachlor, which was due primarily to elevated rates for colorectal cancer and chronic myeloid leukemia. Workers with 5 or more years in estimated high alachlor exposure jobs had elevated rates of colorectal cancer (3 cases, SIR = 5.2, 95% CI 1.1–15.1). Interpretation of the study results is limited by the small size of the study population, minimal length of follow-up, and current information concerning alachlor metabolism in primates and humans. Nonetheless, the findings suggest the need for continued evaluation of this and other alachlor-exposed cohorts. © 1996 Wiley-Liss, Inc.     

Respiratory function in shoe manufacturing workers

A study of respiratory findings was performed on 376 female workers employed in a shoe manufacturing plant. The mean age of the workers was 32 years and the mean duration of their employment was 12 years. These workers were predominantly nonsmokers. Acute and chronic respiratory symptoms were recorded for each worker, and lung function was measured before and after the work shift. Maximum expiratory flow-volume (MEFV) curves were performed on which forced vital capacity (FVC), 1-second forced expiratory volume (FEV₁), and flow rates at 50% and the last 25% (FEF₅₀, FEF₂₅) were measured. Significantly higher prevalences of all chronic respiratory symptoms were recorded in exposed compared to control workers; in particular, chest tightness (exposed: 44.7%; control: 0%), dyspnea (exposed: 42.6%; control: 2.0%), and rhinitis (exposed: 46.3%; control: 2.4%) were far more prevalent in workers than in controls. Among the shoe workers, there was also a high prevalence of acute symptoms that developed during the work shift, being most pronounced for nose and throat irritation (61.4%). The prevalence of acute and chronic respiratory symptoms increased with duration of employment. Statistically significant across-shift reductions were recorded for all ventilatory capacity tests for the group as a whole. In comparison to predicted, the measured ventilatory capacity parameters were significantly lower for all workers (p < 0.01). Lung function abnormalities increased with duration of employment. Environmental measurements demonstrated that benzene, fur, and synthetic fibers were found at higher than allowable maximal concentrations (Croatian standards). The data suggest that work in the shoe manufacturing industry may be responsible for the development of acute and chronic respiratory impairment. Am. J. Ind. Med. 31:50–55 © 1997 Wiley-Liss, Inc.     

2012年天津市某汽车制造企业噪声作业岗前职业健康监护结果

目的在噪声作业岗前人员中进行职业禁忌证的筛查,为企业做好职业健康监护提供依据。方法根据GBZ188—2007（职业健康监护技术规范》的要求,对2012年度天津市某汽车制造企业的3551名噪声作业岗前人员的职业性岗前健康检查结果的资料进行分析。结果共检出职业禁忌证67人,检出率1．89％。男性检出率为2．09％,女性为0．25％,男性职业禁忌证检出率高于女性。结论在接触职业危害因素之前进行职业健康检查对有效预防职业病的发生具有重要意义。     

Outbreak of hypersensitivity pneumonitis among mushroom farm workers.

Between April 1982 and August 1985, seven cases of mushroom worker's lung (MWL), a form of hypersensitivity pneumonitis, were diagnosed among workers at one mushroom farm in Florida. The cases suffered from episodic shortness of breath, cough, fever and chills, myalgia, malaise, and difficulty breathing. Pulmonary function testing revealed restrictive ventilatory impairment and reduced diffusing capacity; chest radiographs exhibited diffuse interstitial pulmonary infiltrates. The seven cases occurred among workers from different farm operations, suggesting that workers throughout the farm were exposed to the disease causing agent(s). Six of the affected workers left employment at the farm in order to remain free of symptoms. The other affected worker was able to continue working at the farm, but only by remaining in a maintenance shop which was physically separated from the rest of the farm facilities. An industrial hygiene survey demonstrated that farm workers from every work area were exposed to organic dust constituents suspected of causing MWL, but no specific antigens were identified as the cause of the cases. Of the remaining workers who participated in a cross-sectional respiratory morbidity survey at the farm, approximately 20% of the more heavily exposed workers reported occasionally experiencing symptoms consistent with MWL. Approximately 10% of the workers had below normal spirometry test results, but interpretation was hampered by the diverse racial makeup of the population and lack of an adequate comparison group. No abnormalities consistent with either acute or chronic MWL were seen on the chest radiographs. Serologic tests demonstrated that almost all workers had been exposed to antigens capable of causing MWL, but the results were not associated with health status. At the time of the cross-sectional survey, no workers were found to be suffering acute respiratory problems consistent with MWL.     

Loss of lung function among sheet metal workers: Ten-year study

One hundred and twenty-two sheet metal workers in New England were examined over a 10-year interval for loss of pulmonary function and the development of asbestosis or asbestos-related pleural fibrosis. Regression models using the generalized estimating equation (GEE) approach were created to investigate the relationship between exposure and pulmonary function after adjusting for smoking status, age, height, and asbestos-related x-ray changes. A history of shipyard work was a significant contributor to the loss of forced vital capacity (FVC). Among smokers, loss in forced expiratory volume at 1 sec (FEV₁) also had a significant relationship to prior shipyard work. There was a borderline significant relationship between percentage predicted FEV₁ and cumulative years of asbestos exposure in smokers, as well as years-since-initial-exposure in never-smokers. This study supports previous findings of obstructive airway changes in asbestos-exposed workers and identifies shipboard work as an important predictor of loss in pulmonary function even years after shipyard exposure to asbestos has ceased. Am. J. Ind. Med. 32:460–466, 1997. © 1997 Wiley-Liss, Inc.     

Cholinesterase activity depression among California agricultural pesticide applicators

Cholinesterase activity measurements for 542 California agricultural pesticide applicators under medical supervision during the first 9 months of 1985 were analyzed. Twenty-six workers, 4.8% of the sample, had cholinesterase values at or below the California threshold values for removal from continued exposure to cholinesterase-inhibiting pesticides (60% of baseline for red blood cell cholinesterase and 50% of baseline for plasma cholinesterase activity). Eight of these 26 workers, 31.5%, had pesticide-related illnesses. Pesticides most frequently associated with cholinesterase depressions exceeding California threshold values included mevinphos (Phosdrin), oxydemeton methyl (Metasystox-R), methomyl (Lannate), and acephate (Orthene); these pesticides included organophosphates in toxicity categories I and II and one carbamate in toxicity category I.     

Silicosis and lung function decrements among female ceramic workers in Italy

It is well known that male ceramic workers have elevated risks of chronic silicosis. The objective of this study was to assess whether female ceramic workers also have an increased risk of silicosis and whether these women have decreased lung function related to silica exposure. Ceramic workers from Civitacastellana, Italy, were enrolled in health surveillance during the 1970s. A total of 642 women were under surveillance; a respiratory monitoring program was conducted from 1974 to 1987, with follow-up through 1991 that included annual chest radiography and measurement of lung function. Radiography findings were defined as silicosis if the chest films were > or =1/0 with small, rounded opacities. Multiple linear regression models for repeated measures (generalized estimating equations) were run to evaluate associations of forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV(1)) with years of exposure and radiograph opacities. Nine cases of silicosis were identified on the basis of radiographic evidence. Silicosis risk was not associated with smoking but was related to employment before 1970 and demonstrated a dose-response gradient for years of exposure. FVC and FEV(1) both showed significant (p < 0.05) associations with duration of exposure and with positive radiography findings. The results for female ceramic workers are consistent with those for male employees regarding exposure to fibrogenic dusts.     

Epidemiological study of the lung function of workers at a factory manufacturing polyvinylchloride.

A preliminary epidemiological study has been carried out to investigate a report that some men working in a factory manufacturing polyvinylchloride (PVC) had abnormally low values of the single breath diffusing capacity for carbon monoxide (TLCO). All monoxide (TLCO). All 265 present and past employees of the PVC factory were studied, together with 219 men from the workforce of a nearby foundry. Each man's TLCO was measured and a smoking history and detailed occupational history obtained. The distribution of standardised TLCO results from all persons examined was symmetrical and did not indicate an unexpectedly high proportion of men with having allowed for age, height, weight, and smoking habit, TLCO was associated with a history of working in the PVC factory before 1975 (when levels of vinylchloride monomers (VCM) were much higher than subsequently), and slightly associated with working in jobs where exposure to VCM was likely to have been highest. The men with low TLCO also tended to have smoked more heavily than controls. The relative importance of occupational factors and smoking in relation to low TLCO is not clear, but the results give some support to the hypothesis that work in the PVC factory before 1975 entailed exposure to a substance that caused impairment of lung function in a small number of men.