RESUMO
Radiological protection is a matter of concern for members of the public and thus national authorities are more likely to trust the quality of radioactivity data provided by accredited laboratories using common standards. Normative approach based on international standards aims to ensure the accuracy or validity of the test result through calibrations and measurements traceable to the International System of Units. This approach guarantees that radioactivity test results on the same types of samples are comparable over time and space as well as between different testing laboratories. Today, testing laboratories involved in radioactivity measurement have a set of more than 150 international standards to help them perform their work. Most of them are published by the International Standardization Organization (ISO) and the International Electrotechnical Commission (IEC). This paper reviews the most essential ISO standards that give guidance to testing laboratories at different stages from sampling planning to the transmission of the test report to their customers, summarizes recent activities and achievements and present the perspectives on new standards under development by the ISO Working Groups dealing with radioactivity measurement in connection with radiological protection.
Assuntos
Exposição à Radiação , Proteção Radiológica , Meio Ambiente , Exposição Ambiental , Humanos , Laboratórios , Radioatividade , Padrões de ReferênciaRESUMO
A national anti-tuberculosis program has been in operation in Madagascar since 1991. Despite the significant efforts made in the management, education and surveillance of patients, the number of patients lost to treatment remains high (18.8%). Noncompliance with treatment is the principal cause of treatment failure and of the development of resistance to tuberculosis drugs. This study investigated the profile of the patients who discontinue treatment. The study population consisted of the patients withdrawing from a clinical trial carried out between August 1994 and September 1996. The aim of the trial was to compare several treatments in routine practice conditions in Madagascar. The treatments tested were streptomycin (S) or ethambutol (E) associated with isoniazid (H), rifampicin (R) or pyrazinamide (Z) for the first two months, followed by 6 months of treatment H and thiacetazone (T). The trial involved four public and three private diagnosis and treatment centers in Antananarivo, Fianarantsoa and Mahajanga. A total of 1, 023 patients were included in the trial and 192 (18.8%) withdrew during the eight-month treatment period. We tracked down 109 of these patients (56.8%) and 19 patients came back to the treatment center on their own initiative for a checkup. The rate of response to a recall letter sent by mail was low. The 106 patients interviewed mostly gave professional, financial or family reasons for discontinuing treatment. Many patients stopped the treatment as soon as they began to feel better. To reduce the number of patients discontinuing treatment, the National Anti-Tuberculosis Program should improve the education of patients and their families.
