Integrated criteria document radon

De engelse versie heeft rapportnummer 710401021Abstract niet beschikbaarThe document contains a critical risk-evaluation of Radon to humans and the environment. Radon is an inert gas of which the main risk is induction of lung cancer. Considering the nature of its effects and its presence only the by-products of Rn-222 are important for man in the indoor environment. In the indoor environment the average Rn-222 concentration is about 10 times higher than in the outdoor air. The average exposure to Radon in the Netherlands results in an estimated risk of 60 cases of fatal lung cancer per million people per year, of which 80% as a result of Rn-222 and 20% as a result of Rn-200. This risk is partly present by nature (the emission is determined by the soil for about 95%) and is therefore not always controlable. Without taking measures the risk will increase as a result of building new houses. By taking measures in all houses that will be built in future (increased ventilation of crawl space, sealing the ground floor) an annual decrease of the average individual risk of o.6% seems attainable. The spread of the exposure level is large and restriction of the individual risks can only be reached by organizing the problems.DGM/SSedee AGJ/Brederode LE va

Predictors of trend in CD4-positive T-cell count and mortality among HIV-1-infected individuals with virological failure to all three antiretroviral-drug classes

Background Treatment strategies for patients in whom HIV replication is not suppressed after exposure to several drug classes remain unclear. We aimed to assess the inter-relations between viral load, CD4-cell count, and clinical outcome in patients who had experienced three-class virological failure. Methods We undertook collaborative joint analysis of 13 HIV cohorts from Europe, North America, and Australia, involving patients who had had three-class virological failure (viral load >1000 copies per mL for >4 months). Regression analyses were used to quantify the associations between CD4-cell-count slope, HIV-1 RNA concentration, treatment information, and demographic characteristics. Predictors of death were analysed by Cox's proportional-hazards models. Findings 2488 patients were included. 2118 (85%) had started antiretroviral therapy with single or dual therapy. During 5015 person-years of follow-up, 276 patients died (mortality rate 5.5 per 100 person-years; 3-year mortality risk 15.3% (95% Cl 13.5-17.3). Risk of death was strongly influenced by the latest CD4-cell count with a relative hazard of 15.8 (95% CI 9.28-27.0) for counts below 50 cells per muL versus above 200 cells per muL. The latest viral load did not independently predict death. For any given viral load, patients on treatment had more favourable CD4-cell-count slopes than those off treatment. For patients on treatment and with stable viral load, CD4-cell counts tended to be increasing at times when the current viral load was below 10 000 copies per mL or 1.5 log(10) copies per mL below off-treatment values. Interpretation In patients for whom viral-load suppression to below the level of detection is not possible, achievement and maintenance of a CD4-cell count above 200 per muL becomes the primary aim. Treatment regimens that maintain the viral load below 10 000 copies per mL or at least provide 1.5 log(10) copies per mL suppression below the off-treatment value do not seem to be associated with appreciable CD4-cell-count decline