We examined the relationship between intrapulmonary particle distribution of carbonaceous and mineral dusts and remodeling of the airways along anatomically distinct airway paths in the lungs of Hispanic males from the central valley of California. Lung autopsy specimens from the Fresno County Coroner's Office were prepared by intratracheal instillation of 2% glutaraldehyde at 30 cm H(2)O pressure. Two distinct airway paths into the apico-posterior and apico-anterior portions of the left upper lung lobe were followed. Tissue samples for histologic analysis were generally taken from the intrapulmonary second, fourth, sixth, and ninth airway generations. Parenchymal tissues beyond the 12th airway generation of each airway path were also analyzed. There was little evidence of visible particle accumulation in the larger conducting airways (generations 2-6), except in bronchial-associated lymphoid tissues and within peribronchial connective tissue. In contrast, terminal and respiratory bronchioles arising from each pathway revealed varying degrees of wall thickening and remodeling. Walls with marked thickening contained moderate to heavy amounts of carbonaceous and mineral dusts. Wall thickening was associated with increases in collagen and interstitial inflammatory cells, including dust-laden macrophages. These changes were significantly greater in first-generation respiratory bronchioles compared to second- and third-generation respiratory bronchioles. These findings suggest that accumulation of carbonaceous and mineral dust in the lungs is significantly affected by lung anatomy with the greatest retention in centers of lung acini. Furthermore, there is significant remodeling of this transitional zone in humans exposed to ambient particulate matter.

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The aim of this study was to determine the prevalences and regional risk factors for respiratory symptoms in European and Californian farmers.Farmers participating in the 1993-1997 surveys performed in Europe (n=7,188) and California (n=1,839) were included in this cross-sectional study. Respiratory symptoms and farming characteristics were assessed by questionnaire and risk factors associated with symptoms using logistic regression.The prevalences of rhinitis and asthma were lower in European (12.7% and 2.8%) than in Californian farmers (23.9% and 4.7%), but chronic bronchitis and toxic pneumonitis were more prevalent in Europe (10.7% and 12.2%) than in California (4.4% and 2.7%). Respiratory symptoms were associated with poultry and rabbit farming, flower growing and the cultivation of grain and oil plants. Working in Europe was a statistically significant risk factor for chronic bronchitis and toxic pneumonitis. Chronic bronchitis was related to toxic pneumonitis, work inside confinement buildings and greenhouses.Chronic bronchitis and toxic pneumonitis are highly prevalent among European farmers and are mainly attributable to indoor work.

This study tested the hypothesis that fabrication room (fab) work in the silicon-based semiconductor industry is associated with an increased risk of spontaneous abortion (SAB). The study was conducted nationwide at 14 companies representing a spectrum of large to small manufacturers. A small increase in risk of SAB was observed among fab workers compared with nonfabrication room (nonfab) workers in two cohorts, historical (adjusted RR = 1.43,95% confidence interval [CI] 0.95-2.09) and prospective (adjusted RR = 1.25, 95% CI = 0.63-1.76). Analysis of specific fab exposures in the historical cohort showed a consistent, dose-response association of SAB with photoresist and developer solvents, whose major component was ethylene-based glycol ethers. The consistency of our findings and the toxicological data for these agents suggest that this is a causal association. Independent associations of SAB with selfreported stress and with etching fluorides were observed and require further research. No significant decrease in fertility was observed among men or women working in fabs, but reduced fecundability was suggested for some women fab workers.

The aim of this study was to determine characteristics of personal exposure to inorganic and organic dust during manual harvest operations of California citrus and table grapes. Personal exposures to inhalable dust and respirable dust were measured five times over a 4-month period of harvesting season. We analyzed components of the dust samples for mineralogy, respirable quartz, endotoxin, and total and culturable microorganisms. Workers manually harvesting were exposed to a complex mixture of inorganic and organic dust. Exposures for citrus harvest had geometric means of 39.7 mg/m(3) for inhalable dust and 1.14 mg/m(3) for respirable dust. These exposures were significantly higher than those for table grape operations and exceeded the threshold limit value for inhalable dust and respirable quartz. Exposures for table grape operations were lower than the threshold limit value, except inhalable dust exposure during leaf pulling. Considered independently, exposures to inhalable dust and respirable quartz in citrus harvest may be high enough to cause respiratory health effects. The degree of vigorous contact with foliage appeared to be a significant determining factor of exposures in manual harvesting.

To determine the sources of lip closing pressure (P(LC) ) generation during passive spoon feeding, we used a fine pressure transducer glued into a wooden spoon, as well as electromyography (EMG) of the upper and lower lips and the submental muscle complex, in normal adult volunteers (average age 24·5 years). An assistant fed a seated subject 0·6 mL of yogurt and then withdrew the spoon from the subject's closed mouth. The spoon was held at an angle of 0° (i.e. in the naso-auricular plane) during serving and at either 0° or 60° during withdrawal. We detected simultaneous increases in P(LC) and in EMG activity in the lips and the submental muscle complex. The maximum P(LC) was significantly higher at 60° [65 ± 11 g cm(-2) (mean ± s.e.m)] than at 0° (42 ± 8 g cm(-2)). The former was correlated with the maximum EMG amplitude, which was analysed by using the mean of the root-mean-square EMG and presented as a percentage of the maximum EMG obtained in the lower lip region and the submental muscle complex during subsequent swallowing in each subject. In conclusion, in healthy adult subjects, perioral muscles of the lower lip region and the submental muscle complex participate in P(LC) generation, particularly at a steep spoon withdrawal angle. The results suggest that a steep withdrawal angle not only increases P(LC) but also promotes these muscles' activities in passive spoon feeding.

A variety of methods were used to address communication problems in the Semiconductor Health Study (SHS). The diverse employee population required investigators to consider language, ethnic, and cultural differences in planning and implementing the study design. Studies of reproductive health in the workplace raise special concerns, including the critical need to preserve confidentiality and privacy of subjects. Notification of results of epidemiological studies reporting workplace hazards requires sensitivity to needs of workers. SHS investigators directly communicated overall results of this multicomponent study to participating employees at all sites and notified subjects of results of individual industrial hygiene monitoring and endocrine hormone assays. Key words: risk communication, confidentiality, ethnicity, language, semiconductor manufacturing, worker notification INTRODUCTIONThe Semiconductor Health Study (SHS) presented several challenges in communicating with subjects who were geographically, ethnically, educationally, and culturally diverse. Investigating human reproductive outcomes, especially among subjects in an occupational setting, requires awareness of the sensitivity of the research as well as strict attention to confidentiality of data and privacy of research subjects. The SHS was conducted at multiple sites of companies with differing management policies and employee communication practices. Most sites had a multitude of shifts and work schedules. Because the workforce was not unionized, communication via union representatives was not possible. Study investigators, including industrial hygienists in the exposure assessment group, were required to devise effective ways to communicate with current and former employees in the historical component, and with current employees in the prospective and cross-sectional com- ponents. The research designs for the three components called for different communication methods (e.g., telephone vs. personal).Our obligations to research subjects were of primary concern in our communication efforts. These obligations included: protecting the subjects' welfare, communicating clearly, obtaining the subjects' informed consent, preserving the subjects' privacy, maintaining the confidentiality of data from and about research subjects, and, at the conclusion of the research, disseminating results to subjects in a clear, unbiased, and timely manner. This discussion of communication methods and issues in the SHS may assist other investigators studying occupational exposures and reproductive health. LANGUAGE, CULTURE, AND ETHNlClTYThe ethnicity of study subjects required investigators to develop culturally and educationally appropriate methods to communicate with different groups; to explain differences in exposures, covariates, and health outcomes among groups; and to interpret the significance of these differences in data analyses and presentation of the results.Because semiconductor employees in the U.S. are a culturally and ethnically diverse population (Fig. l), ...