Chlorination of drinking water in Spain and bladder cancer

Objectives: Drinking water chlorination generates trihalomethanes and other by-products with mutagenic and carcinogenic properties in animal experiments. Epidemiological studies have associated trihalomethanes to an increased risk of bladder cancer. We evaluate trihalomethane levels in four Spanish areas and calculate the bladder cancer risk attributable to this exposure.Methods: Trihalomethanes have been analysed in 111 drinking water samples from four Spanish areas using gas chromatography. Water utilities were contacted and information on drinking water consumption in Spain has been collected. We reviewed the epidemiological studies that assess the association between bladder cancer risk and exposure to chlorination by-products. Attributable risk was calculated on the basis of these levels, mortality data per area and risk estimates obtained from the literature.Results: Mediterranean areas present the highest levels of trihalomethanes with 81, 80, 61 and 52 μg/l in Sabadell, Alicante, Barcelona and Manresa respectively. Lower levels are found in Tenerife and Asturias with 7 and 20 μg/l respectively. The bladder cancer attributable risk in high trihalomethane exposure areas may be, on average, around 20%.Conclusions: The trihalomethane levels found are high compared to those of other European Union countries. In the high exposure areas, drinking water chlorination may generate a considerable number of bladder cancer cases. These estimations have to be carefully interpreted and verified with more extensive studies.     

Mammographic surveillance of asymptomatic breast cancer relatives in general practice: rate of re-attendance and GP- and patient-related barriers

BACKGROUND: Several guidelines have been formulated for mammographic screening of breast cancer relatives. No studies have examined the adherence of GPs and their patients to these recommendations. OBJECTIVES: We aimed to determine the rate of re-attendance of breast cancer relatives for mammographic screening requested by GPs and specify the barriers for non-attending follow-up mammography. METHODS: The study included all asymptomatic women aged 35 years or older with a first-degree family history of breast cancer, referred for mammography to our department of radiology by their GP between 1 January 1992 and 1 September 1994. Reasons for not re-attending mammography within 2 years were obtained by sending a questionnaire to GPs and, if necessary, telephone calls to GPs or their patients. The questionnaire was accompanied by a reminder, in which we advised re-attendance. The number of women who still underwent repeated mammographic screening within the 2 months following the reminder was determined. RESULTS: In 123 out of 234 patients (52.6%) follow-up mammography had been performed within 2 years. Barriers to undergoing follow-up mammography were GP-related in 70.3% of cases and patient-related in 29.7%. Of the 111 non-re-attenders, 52 (47.7%) still underwent follow-up mammography within 2 months after the reminder. This examination was performed more often if the barriers to re-attendance were GP-related rather than patient-related (57.7% versus 24.2%, 95% confidence interval (CI) 13.0- 53.9). Significantly more patients re-attended after the reminder if the GP-related barrier was an insufficient retrieval system rather than disagreement with mammography guidelines (81.3% versus 20.0%, 95% CI 40.4-82.0). CONCLUSIONS: Many breast cancer relatives did not undergo regular mammographic screening. Non-re-attendance resulted from a limited degree of acceptance and implementation of the screening recommendations by physicians as well as reluctance of the patient to adhere to such recommendations. A reminder, generated by a radiology department, may increase the performance of follow-up mammography.      

Guidelines for the management of traumatic dental injuries. I. Fractures and luxations of permanent teeth

Crown fractures and luxations occur most frequently of all dental injuries. An appropriate treatment plan after an injury is important for a good prognosis. Guidelines are useful for delivering the best care possible in an efficient manner. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialties were included in the group. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion of the IADT board members. The guidelines represent the current best evidence, based on literature research and professional opinion. In this first article of three, the IADT Guidelines for management of fractures and luxations of permanent teeth will be presented.