Hydrogen sulfide and particle matter levels associated with increased dispensing of anti-asthma drugs in Iceland's capital.

BACKGROUND: Air pollutants in Iceland's capital area include hydrogen sulfide (H2S) emissions from geothermal power plants, particle pollution (PM10) and traffic-related pollutants. Respiratory health effects of exposure to PM and traffic pollutants are well documented, yet this is one of the first studies to investigate short-term health effects of ambient H2S exposure. OBJECTIVES: The aim of this study was to investigate the associations between daily ambient levels of H2S, PM10, nitrogen dioxide (NO2) and ozone (O3), and the use of drugs for obstructive pulmonary diseases in adults in Iceland's capital area. METHODS: The study period was 8 March 2006 to 31 December 2009. We used log-linear Poisson generalized additive regression models with cubic splines to estimate relative risks of individually dispensed drugs by air pollution levels. A three-day moving average of the exposure variables gave the best fit to the data. Final models included significant covariates adjusting for climate and influenza epidemics, as well as time-dependent variables. RESULTS: The three-day moving average of H2S and PM10 levels were positively associated with the number of individuals who were dispensed drugs at lag 3-5, corresponding to a 2.0% (95% confidence interval [CI] 0.4, 3.6) and 0.9% (95% CI 0.1, 1.8) per 10 µg/m3 pollutant concentration increase, respectively. CONCLUSION: Our findings indicated that intermittent increases in levels of particle matter from traffic and natural sources and ambient H2S levels were weakly associated with increased dispensing of drugs for obstructive pulmonary disease in Iceland's capital area. These weak associations could be confounded by unevaluated variables hence further studies are needed.

Evidence for obstructive and restrictive lung pathology among tetra-ethyl lead handlers and petrol tanker fillers at a petrochemical industry in Nigeria.

Described here is a computer predicted and computer measured pulmonary function in a randomly selected population sample of 111 men. These consisted of 36 primary school teachers (control), 35 Tetra-ethyl Lead handlers (TEL) and 40 Tanker Loaders (TL) at a petrochemical industry in Warri, Delta State, Nigeria. Productive cough and headache were commoner among the TL (45%, 38%) and the TEL handlers (43%, 31%). TEL handlers were 5 times likely to develop insomnia and other sleep disturbances than the control group. TL were more than 3 1/2 times more likely to develop nervousness than the control group. Measured FEF25-75% was significantly lower than its predicted value among the TEL handlers (56%) and TL (55%) when compared with the control group (36%) (P < 0.05 respectively). Although there were distinct reductions in the measured values of FEF75-85% among the TEL handlers (41%) and the TL (40%) compared to the control group (28%), this difference did not reach a level of significance when the TEL or the TL were compared individually to the control group. Predicted and measured forced mid expiratory flow time (FMFT) was not significantly varied among the cases and the control. There was statistically significant disparities (P < 0.005) in the values of predicted and measured maximum voluntary ventilation (litres) of the TEL handlers (47%) and of the TL (46%) compared with that of the control group (29%). The data suggest obstruction of the big and small airways of those occupationally exposed at a petrochemical factory in Nigeria especially the tetra-ethyl lead handlers and the tanker loaders. This data also suggests that pulmonary impairment may lead to an increased respiratory absorption of lead in its organic form. Efforts should be made to ascertain the degree of impairment and to treat the affected workers.

Segmental necrosis of small bronchi after prolonged intakes of Sauropus androgynus in Taiwan.

Since 1994 an endemic of chronic obstructive pulmonary disease (COPD) has developed in Taiwan after a prevalent use of a body-weight-reducing vegetable, Sauropus androgynus (SA). All conventional treatments for COPD, including steroids and bronchodilators, had been ineffective. Studies of limited lung biopsy specimens from these patients revealed bronchiolitis obliterans. A few patients died, but many developed protracted chronic respiratory failure. Because of the chronic debilitation and ineffective conventional treatments, single lung transplants were performed as the last resort in four patients. The excised lungs revealed focal fibromuscular sclerosis and obliteration of bronchial arteries in the wall of large bronchi 4 to 5 mm in diameter with segmental necrosis of bronchi 2 to 4 mm in diameter. Bronchi immediately proximal to the necrotic zone showed fibrosis and atrophy of cartilage, bronchial glands, and smooth muscle cells; bronchioles immediately distal showed obstruction or dilatation. Most bronchi larger than 5 mm, pulmonary vessels, small bronchioles, and alveoli were little altered. The pathologic changes were most consistent with segmental ischemic necrosis of bronchi at the water-shed zone of bronchial and pulmonary circulation. The specific etiologic agent and detail of pathogenesis of this SA-related COPD needs further investigation.

Lung function in workers refining phosphorus rock to obtain elementary phosphorus.

Elevated levels of phosphoric acid, phosphorus pentoxide, fluorides and coal tar pitch volatiles were present in workplace air of a two-oven industrial refinery. One hundred thirty-one workers prospectively underwent annual pulmonary function testing (forced vital capacity, forced expiratory volume in 1 second, and forced expiratory flow). Regression of these spirometric data, analyzed longitudinally over 3 to 7 years and also cross-sectionally reveals no residual significant effect of industrial exposure after adjusting for the effect of age and smoking. This industrial exposure contributes only weakly and inconsistently to the well-documented reduction of spirometric lung function that occurs from smoking alone. No significant reductions of spirometry occurred in exposed nonsmokers or former smokers.

Acute hydrogen selenide inhalation.

Acute exposure to selenium hydrochloride resulted in severe dyspnea and a pneumomediastinum in a young healthy man. Pulmonary function tests revealed restrictive and obstructive airways disease. Although the patient's pulmonary function slowly improved, subsequent studies revealed persistent impairment. Therefore, exposure to selenium gas may result acutely in severe coughing and wheezing and may lead to irreversible obstructive lung disease.