ABSTRACTS Abstracts published in EPIDEMIOLOGY have been reviewed by the organizations of EPIDEMIOLOGY. Affliate Societies at whose meetings the abstracts have been accepted for presentation. These abstracts have not undergone review by the Editorial Board of EPIDEMIOLOGY. ISEE 21st Annual Conference, Dublin, Ireland, August 25–29, 2009 ORAL PRESENTATIONS ISEE-0003 What Measure of Temperature is the Best Predictor of Mortality? Adrian Barnett,* Shilu Tong,* and Archie Clements,† *Queensland University of Technology, Brisbane, Queensland, Australia; and †University of Queensland, Brisbane, Queensland, Australia. Background and Objective: Hot and cold temperatures significantly increase the risk of death in many regions of the world. Different measures of temperature, including minimum, maximum and apparent temperature, have been used in previous research. Which temperature measure is the best predictor of mortality is not known. Methods: We used mortality data from 106 cities in the US NMMAPS study (years 1987–2000). We examined the association between temperature and mortality using Poisson regression and fitted a non-linear spline for temperature. We examined five measures of temperature, the effect of including relative humidity, and various degrees of freedom for the temperature spline. The best model was defined as that with the minimum absolute residual. The residuals were calculated using cross- validation. Results: Maximum temperature was selected as the best temperature measure the most often (40 cities in the 65-year age group), and apparent temperature the least often (8 cities in the 65-year age group). Maximum temperature was the best measure in 10 out of 12 months in both age groups. Geographically, maximum temperature was the best measure in cold regions, and minimum temperature in warm regions. Humidity was important in almost every city in the 65 year age group. The seasonal variation in humidity showed a surprising peak in usefulness in winter. Conclusion: Apparent temperature is no better than standard measures of temperature in predicting mortality. Maximum temperature was generally the best measure in cold climates and minimum temperature in warm climates. Humidity is an important predictor of mortality in the elderly and its effect should be estimated separately from temperature. ISEE-0005 Investigation of Nephrolithiasis in Children with Tainted Chinese Dairy Product Consumption in Taiwan I-Jen Wang,* , † Yu-Nian Wu,* Wen-Chiuo Wu,* Giovanni Leonardi,‡ Yen-Jen Sung,§ Shuei-Liong Lin,¶ Tien-Jen Lin,** Kuen-Yuh Wu,†† Wei-Chih Cheng,‡‡ Pau-Chung Chen,†† Chang-Chuan Chan,†† and Kung-Chang Hwang,* *Department of Pediatrics, Taipei Hospital, Department of Health, Taipei, Taiwan; †Department of Health Risk Management, China Medical University, Taichung, Taiwan; ‡Health Protection Agency, Centre for Radiation, Chemical, and Environmental Hazards, Chemical Hazards & Poisons Division, Oxon, United Kingdom; §Institute of Cell Biology and Anatomy, National Yang Ming University, Taipei, Taiwan; ¶Taipei Hospital, Department of Health, Taipei, Taiwan; **Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan; ††Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University College of Public Health, Taipei, Taiwan; and ‡‡Bureau of Food and Drug Analysis, Department of Health, Taipei, Taiwan. Background: Little is known about the renal effects of melamine in humans. We evaluated risk factors, clinical manifestations, exposure patterns, and biomarkers for nephrolithiasis in children who consumed melamine-contaminated dairy products. Methods: From September 24 to October 31 in 2008, 1222 children whose parents were concerned that they may have consumed melamine- contaminated dairy products were investigated at Department of Health hospitals in Taiwan. The high exposure group was those who consumed China-brand dairy products with melamine levels 2.5 ppm. The low exposure group was those who consumed dairy products imported from China with melamine levels 0.05–2.5 ppm. Our control group was those who consumed dairy products without detected melamine levels 0.05 ppm. Clinical presentation, urinalysis, urine calcium, creatinine, and renal ultrasonography were evaluated. Urine melamine tests were checked for those with nephrolithiasis and age- and gender-matched controls selected from the study population. Results: No hematuria, hypercalciuria, flank pain, or acute renal failure was noted in the high exposure group. Nine out of the 14 nephrolithiasis cases had a history of having resided in China and China-brand dairy product consumption. The age of children with nephrolithiasis in the high exposure group was younger than those without nephrolithiasis (P = 0.011). The duration of contaminated product consumption was longer in children with nephrolithiasis in the high exposure group than those without nephrolithiasis (P = 0.017). The risk of nephrolithiasis was found to increase with estimate melamine exposure levels (P for trend 0.001). Of the 10 nephrolithiasis cases that received urine melamine analysis, two had elevated levels. Comparatively, age- and gender- matched controls were all lower than the detection limit. Conclusions: Due to lack of symptoms and signs, we recommend renal ultrasonography for children with high melamine exposure. Urine melamine tests might be helpful in confirming the diagnosis of melamine related nephrolithiasis. ISEE-0008 The Association Between Socioeconomic Status and Exposure to Mobile Telecommunication Networks in Children and Adolescents Silke Thomas, Sabine Heinrich, Anja Ku ¨hnlein, and Katja Radon, Institute and Outpatient Clinic for Occupational-, Social- and Environmental Medicine, Munich, Germany. Background: A potential association between socioeconomic status (SES) and self-reported use of mobile phones has been investigated in a few studies. Whether objective exposure to mobile phone networks differs by SES in children and adolescents has not yet been studied. Methods: Data was taken from a cross-sectional study investigating a possible association between exposure to mobile phone networks and well-being in children and adolescents. In total, data of 1481 children and 1505 adolescents was used. During a Computer Assisted Personal Epidemiology • Volume 20, Number 6, November Supplement 2009 www.epidem.com | S13