Environmental research
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Environmental research · Jan 1995
Comparative StudyAdverse effects of the indoor environment on respiratory health in primary school children.
Exposure to various factors from the indoor environment on respiratory health of 470 Dutch primary school children was studied. We investigated which of the factors, such as home dampness, passive smoking, unvented kitchen geysers, or pets, affected children's respiratory health the most, and whether airway sensitivity to these indoors exposures differed between boys and girls. Information on respiratory morbidity and characteristics of the housing was obtained by a written questionnaire, completed by the parents of the children. ⋯ Furthermore, no associations were found with the dampness indicators and with pets, but unvented kitchen geysers were significantly related to impairments in some of the impedance indices. This study shows detrimental effects of several indoor factors on the prevalence of chronic respiratory symptoms and lung function in children, which are most pronounced for passive smoking, and somewhat less pronounced for dampness and the presence of unvented kitchen geysers. Airway sensitivity to these exposures appeared to be higher in boys than in girls.
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Environmental research · May 1994
Chronic bronchitis, emphysema, and low-level air pollution in Helsinki, 1987-1989.
The effects of low levels of air pollution and weather conditions on the number of patients admitted to hospitals for exacerbation of chronic bronchitis or emphysema (n = 2807) was studied in Helsinki during a 3-year period, 1987-1989. The daily number of admissions via the emergency room was significantly associated with prevailing levels of sulfur dioxide (SO2) and nitrogen dioxide (NO2) in Poisson regressions controlled for weather, season, time trends, and day of the week, whereas the total number of admissions (via the emergency room and otherwise) was not significantly associated with these pollutants. The effect of SO2 was observed only among those under 65 years old; a significant peak of admissions was seen during the same day (RR, 1.31 for a 2.7-fold increase in SO2; 95% CI, 1.01-1.70; P = 0.039), and another after a 3-day lag (RR, 1.39; 95% CI, 1.05-1.86; P = 0.021). ⋯ However, the number of admissions among those over 64 years of age was significantly lower, irrespective of temperature, during the summer than during other seasons. The mean daily concentration of O3 was fairly low (22 micrograms/m3 or 0.011 ppm), but that of TSP was high, 76 micrograms/m3. the mean temperature was low, +4.7 degrees C. These results suggest that SO2 and NO2 concentrations lower than those given as guidelines in many countries, and lower than previously shown, may increase the incidence of symptoms in some patients with chronic bronchitis or emphysema.
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Environmental research · Dec 1992
Dose-dependent pulmonary effects of inhaled endotoxin in guinea pigs.
As a cell wall component of gram-negative bacteria, endotoxin is thought to play a significant role in the respiratory effects of inhaled organic dusts which are microbially contaminated. Assessment of occupational survey data and clinical studies suggests that few measureable, acute functional changes occur below 30-50 ng/m3 endotoxin (as sampled in airborne dust with a vertical elutriator). Little information is available on the inflammatory effects of inhaled endotoxin at these low concentrations. ⋯ Polymorphonuclear leukocyte influx into the alveolar region was also dependent on the concentration of inhaled endotoxin. Thus, LDH activity, a biochemical marker of cell injury, and total cell counts and polymorphonuclear leukocytes, markers of inflammation, were more sensitive indices of adverse pulmonary effects from inhaled endotoxin than a functional measurement. These results suggest that subtle inflammatory changes may occur at airborne endotoxin concentrations which may produce no acute respiratory symptoms.
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To mouse cells in culture, SiC whiskers (SiCW) and asbestos are similarly cytotoxic, disrupting cell membranes and killing cells. Both shorten cell generation time, increase the rate of DNA synthesis, increase total cell DNA content, and cause a loss in growth control often associated with malignant cellular transformation. Within the narrow size range of materials examined, the amount of damage appeared to be more a function of the number of whiskers present than of their size. Silicon carbide whiskers, if mishandled, may pose a serious health hazard to humans.