Wood smoke exposure and lung adenocarcinoma in non-smoking Mexican women.

OBJECTIVE: To determine the association between long-term exposure to wood smoke from cooking and lung adenocarcinoma in non-smoking Mexican women. METHODS: We reviewed records of hospitalized patients at a chest referral hospital in Mexico City and identified 113 histologically proven lung adenocarcinoma cases in non-smoking women. Four control groups of non-smoking women were also selected: 99 patients with pulmonary tuberculosis (PTB), 110 with interstitial lung disease (ILD), 64 with miscellaneous pulmonary conditions (MISC), and the three control groups combined (COMB) (n = 273). RESULTS: Exposure was assessed on the basis of questionnaire responses at the time of hospital admission. Exposure to wood smoke for more than 50 years, but not for shorter periods, was associated with lung cancer after adjusting for age, education, socio-economic status and environmental tobacco smoke (ETS) exposure. Adjusted odds ratios from the multivariable logistic regression models were 1.4 (95%CI 0.6-2.0) for cases vs. TB controls, 1.9 (95%CI 0.9-4.0) for cases vs. ILD controls, 2.6 (95%CI 1.0-6.3) for cases vs. MISC controls and 1.9 (95%CI 1.1-3.5) for cases vs. COMB controls. CONCLUSION: These findings suggest that long-term exposure to wood smoke from cooking may contribute to the development of lung cancer.

Transmission electron microscopy findings in the respiratory epithelium of guinea pigs exposed to the polluted air of southwest Mexico City.

We evaluated the nature and the extent of the damage to the respiratory epithelium of guinea pigs after a 4-month exposure to the mixture of air pollutants in southwest Mexico City. Guinea pigs were placed outdoors on the roof of our facility, 8 hours daily, from February to May 1995. At the same time, control guinea pigs were kept indoors breathing filtered air. Air pollutants, temperature, and humidity data were obtained from the nearest station of the Environmental Monitoring Net. The airways and lung parenchyma were analyzed after 120 days using transmission electron microscopy (TEM). During the 4-month exposure period, ozone (O3) exceeded the norm during 511 hours, and suspended particles less than 10 microm in diameter (PM10) during 52 hours. Both pollutants reached peak levels of more than twice the norm. TEM revealed no important abnormalities in the control group. In the exposed group, there was loss of cilia, detachment of epithelial cells, and eosinophil and macrophage migration toward alveolar spaces through type I pneumocytes with destruction of their basal membranes. In six guinea pigs in the exposed group, we noted bacteria along the airways, with associated inflammatory response. We explain the colonization of the respiratory epithelium by bacteria as the result of the impairment on the defense mechanism caused by the exposure to environmental O3 and PM10.

Air pollution and respiratory health in Mexico City.

To determine the effect of air pollution in Mexico City on respiratory health, patient visits for upper respiratory tract infections were monitored in five clinics. Levels of ozone, nitrogen dioxide, carbon monoxide, and sulfur dioxide, and climatological variables were collected. Correlations of filtered data revealed an association between NO2 and O3 with an increase in visits to clinics because of respiratory problems. Autoregressive analysis indicated that pollutant levels/respiratory visits associations remained significant even after simultaneous inclusion of temperature, suggesting that air pollution was associated with 10 to 16% of the clinic visits. The relative risk indicated that high levels of O3 and NO2 could increase the total number of clinic visits to between 19 and 43% above average. The other pollutants and the control group did not demonstrate significant associations.

[Early respiratory function disorders secondary to tobacco smoking]. / Alteraciones funcionales respiratorias tempranas secundarias al tabaquismo.

The volume of isoflow (VisoV) in 29 asymptomatic smokers with normal radiographic and pulmonary function studies was studied, with the purpose of investigating the presence of early alterations of the transitional airways in a group of 256 chronic smokers. The VisoV was measured using a body test plethysmograph, and two flow-volume curves with air and with helium were performed. 13 out of the 29 subjects (45%) showed an abnormal VisoV of between 17 and 39 per cent (normal 0-10%). This findings suggest that smoking initially damages the small transitional airways and that VisoV is an useful procedure for investigating early damage in this zone.

Relationship between lung inflammation or fibrosis and frequency dependence of compliance in interstitial pulmonary diseases.

In order to find a physiological parameter which discriminates between the predominance of inflammation or fibrosis, pulmonary function tests and open lung biopsy were performed on 19 patients with interstitial lung disease. Our results showed that the only test which may be useful is the dynamic lung compliance/quasi-static lung compliance (Cdyn/Cst) index. In this context, values equal or lower than 0.85 of the Cdyn/Cst index indicate that inflammation predominates, and values higher than 0.85 suggest that interstitial fibrosis is the main feature.

Manejo del nino asmatico en las instituciones de salud. / Management of the asthmatic child in health institutions

Se describe la frecuencia de consultas de pacientes con asma bronquial en el Servicio de Neumologia del Hospital de Pediatria del Centro Medico Nacional del IMSS y su atencion a los tres niveles de trabajo de la institucion. Se senala la ruta critica para el manejo institucional del nino asmatico

Diagnosis of lactose intolerance through the quantification of hydrogen in exhaled air.

Considerations are made on diarrhea secondary to intestinal malabsorption of carbohydrates and on the diagnostic means available in our environment, among which are the reactive strip, the clinitest tablet, tolerance curves and research of intestinal enzymes. The quantification of exhaled hydrogen is mentioned as a diagnostic method, used by several other authors, and a review of the literature on the subject is made. Considerations are made on a hydrogen quantification in the breath of patients with a transitory lactose intolerance. 16 patients were studied, 15 of whom showed an increase in the exhaled H2. 32 children with diarrhea, free from lactose intolerance, were studied. The method used did not show a significant increase in the exhaled hydrogen. 27 patients showed no H2 in their breath. In 4 there was elimination of H2 (false positives). 17 diarrhea-free children were studied. A significant difference was found when comparing the children with diarrhea and lactose intolerance to the other two groups who were free from lactose-intolerance. It is considered that this method can be useful in the diagnosis of intolerance to lactose and other sugars.

[Atmospheric pollution and spirometry in healthy children of the Distrito Federal]. / Contaminación atmosférica y espirometría en niños sanos del Distrito Federal.

Investigation of the vital capacity, maximum expiratory flow and maximum mean expiratory flow was carried out in children living in two areas of Mexico City, one of them with a high degree (azcapotzalco) and the other one with low degree (Tizapán) of air pollution. Timed spirometry was carried out on children attending 4th, 5th and 6th grades in two official grammar schools so both groups were as uniform as possible in their social-economical level and nutritional and health conditions. This goal was attained quite satisfactorily and groups turned similar, after comparing results and analysing statistically somatometric data, together with scholarship of the parents, economical income, history of respiratory diseases and physical examination. However, quite a significant statistical difference (p less than 0.001) was found between the parameters involving measurements of ventilation in favor of Tizapán children. The difference between Azcapotzalco and Tizapán children in terms of the three ventilatory parameters analyzed was possibly due to the fact the former lived in a greater polluted area.