Pumice Characteristics and Their Utilization on the Synthesis of Mesoporous Minerals and on the Removal of Heavy Metals.

Wastewater treatment of some heavy metals was carried out by synthetic zeolite P1, which was prepared by alkaline hydrothermal treatment of the pumice. Both of the pumice raw materials and synthetic zeolite were investigated for their chemical phase composition, physical properties, and microstructure. The adsorption behavior of Na-zeolite P1 with respect to Co(+2), Cu(+2), Fe(+2), and Cd(+2) has been studied to be applied in the industrial wastewater treatment. Metal removal was investigated using synthetic solutions at different ions concentrations, time, and Na-P1 zeolite doses as well as constant temperature and pH. It is concluded that the optimum conditions for synthesis of highly active Na-P1 zeolite from natural pumice raw material are one molar NaOH concentration, temperature at 80°C, and one week as a crystallization time. In addition to the effect of time and zeolite dose as well as the ion concentration of the reaction efficiency for metals removals are recorded.

Prevalence of cigarette smoking by birth cohort among males and females in Spain, 1910-1990.

We analysed the prevalence of cigarette smoking among subsequent birth cohorts of Spanish males and females. Data were drawn from the Spanish NHIS conducted in 1993 ( = 26 400), 1995 ( = 8300) and 1997 ( = 8300). From the original computer files, the three surveys were pooled to obtain a single sample. A total of 33 223 subjects (16 036 men and 17 187 women) born between 1900 and 1979, >/= 16 years old, were directly interviewed and with complete information on the history of smoking included for analysis. Based on each respondent's sex and calendar year of birth, the person was classified into a particular sex-birth cohort in the decades from 1900-09 to 1970-79. For each year from date of birth to date of survey, respondents were further classified as either cigarette smoker or nonsmoker. The prevalence of cigarette smoking among successive cohorts of Spanish men and women was estimated, with correction for excess mortality of smokers. In men, the peak in smoking was reached in the 1950-59 birth cohort (prevalence rate of 68% at ages 20-29), after increases during the previous calendar years. Smoking among women was rare until 1960. Female smoking prevalence rates increased progressively among subsequent cohorts until 1980. The age distribution of smoking prevalence in women in 1990 mimics that observed in men 40 years earlier. A substantial delay in the spread of the tobacco epidemic among men is apparent. In women, the delay in the initiation of the smoking epidemic ended with a quick diffusion of the habit.

Case studies in international tobacco surveillance: cigarette smuggling in Brazil.

OBJECTIVE: This article is the first in a series of international case studies developed by the American Cancer Society to illustrate use of publicly available surveillance data for regional tobacco control. DESIGN: A descriptive analysis of Brazil and Paraguay cigarette production and trade data from official sources. METHODS: Per capita cigarette consumption for Brazil and its neighbour was calculated from 1970 to 1998 using data on production, imports, and exports from NATIONS, the National Tobacco Information Online System. RESULTS: A 63% decrease was observed in the estimate of per capita consumption of cigarettes in Brazil between 1986 and 1998 (from 1913 cigarettes per person in 1986 to 714 cigarettes per person in 1998) and a 16-fold increase in Paraguay was observed during the same period (from 678 cigarettes per person in 1986 to 10 929 cigarettes per person in 1998). Following Brazil's 1999 passage of a 150% cigarette export tax, cigarette exports fell 89% and Brazil's estimated per capita consumption rose to 1990 levels (based on preliminary data). Per capita consumption in Paraguay also fell to 1990 levels. CONCLUSIONS: These trends coincide with local evidence that large volumes of cigarettes manufactured in Brazil for export to Paraguay are smuggled back and consumed as tax-free contraband in Brazil. It is hoped that this case study will draw wider public attention to the problems that smuggling presents for tobacco control, help identify other countries confronting similar issues, and stimulate effective interventions.

Hernioplasty using the hernial sac in repair of inguinal hernia.

Hernioplasty with use of the hernial sac appears to offer advantages over operations previously used to repair large defects in the posterior wall of the inguinal canal. This operation was performed on 66 patients without recurrence of the lesion in the 55 patients for whom follow-up data are available.