Analysis of chromium and sulphate origins in construction recycled materials based on leaching test results.

Twenty samples of recycled aggregates from construction and demolition waste (CDW) with different compositions collected at six recycling plants in the Andalusia region (south of Spain) were characterised according to the Landfill Directive criteria. Chromium and sulphate were identified as the most critical compounds in the leachates. To detect the sources of these two pollutant constituents in recycled aggregate, environmental assessments were performed on eight construction materials (five unused ceramic materials, two old crushed concretes and one new mortar manufactured in the laboratory). The results confirmed that leached sulphate and Cr were mainly released by the ceramic materials (bricks and tiles). To predict the toxicological consequences, the oxidation states of Cr (III) and Cr (VI) were measured in the leachates of recycled aggregates and ceramic materials classified as non-hazardous. The bricks and tiles mainly released total Cr as Cr (III). However, the recycled aggregates classified as non-hazardous according to the Landfill Directive criteria mainly released Cr (VI), which is highly leachable and extremely toxic. The obtained results highlight the need for legislation that distinguishes the oxidative state in which chromium is released into the environment. Leaching level regulations must not be based solely on total Cr, which can lead to inaccurate predictions.

Clinical and epidemiological aspects of smoking and tuberculosis: a study of 13,038 cases.

SETTING AND OBJECTIVE: Smoking habit and tuberculosis (TB) appear to have common epidemiological and clinical links. The present study was to evaluate risk factors in TB patients with and without a smoking habit. DESIGN: A cross-sectional observational study of cases (TB with smoking) and controls (TB without smoking) from the same registry. Data were retrieved from case notes and interviews of patients registered in the Tuberculosis Control Programme in Cataluuña, Spain, between 1 January 1996 and 31 December 2002. Statistical analyses included univariate and stepwise multiple logistic regression analyses. RESULTS: There were 13,038 recorded patients. Social factors associated with TB in smokers were male sex (adjusted odds ratio [aOR] 2.2), age <64 years, alcohol use >30 g/day (aOR 7.4) and intravenous drug use (aOR 1.5). Smokers developed more pulmonary disease (aOR 1.5) and more cavitary lesions (aOR 1.9), and were more likely to require hospitalisation (aOR 1.8) which was more protracted. Differences in mortality and delay in diagnosis did not reach statistical significance. CONCLUSIONS: Smoking leads to faster and more severe progression of TB. The cost of TB-related hospitalisation for smokers increases by approximately one million euros per year.

Immunoglobulin production in man stimulated by an orally administered bacterial lysate.

The concentrations of secretory immunoglobulins in the saliva, and of immunoglobulin in the serum, have been measured by the radial immunodiffusion method in 12 healthy volunteers, before and after oral administration of Broncho-Vaxom which is a lysate of bacteria that usually cause infection in the upper respiratory tract. The mean concentration of secretory IgA in the saliva was increased by over 100% after the 10-day administration of the product. This increase was statistically significant between the 20th and 33rd day after the beginning of the treatment (p < 0.05). It fell to a normal level after a month in 4 subjects who received one treatment course only. In 8 subjects who received a second treatment course beginning 1 month after termination of the first course, the high concentration of IgAs in the saliva persisted for at least 3 months. A significant increase in the serum concentrations of IgG of about 50% and of IgM of at least 100% above the initial level was observed in the treated subjects in the time between day 35 and 5 months after the beginning of the experiment (p < 0.05).