Abstracts / Toxicology Letters 196S (2010) S37–S351 S47 P102-008 Chilean childhood poisoning 2006–2009: Characterization using INTOX DMS M. Bettini Silva 1 , J.J. Mieres Araya 1 , J.C. Rios Bustamante 2 , S. Solari Gajardo 2 , M. Perez Cabrera 1 , V. Bravo Gonzalez 1 , P. Cerda Jimenez 1 , E. Paris Mancilla 1 1 Centro de Información Toxicológica de la Pontificia Universidad Católica de Chile (CITUC), Chile, 2 Departamento de Laboratorios Clínicos, Facultad de Medicina, Pontificia Universidad Católica de Chile, Chile In Chile, 4–7% of pediatric emergencies account for poison expo- sures, hence the importance of studying exposure patterns in this population. Objective: To describe epidemiological characteristics of poi- soning cases in patients younger than 5 years during the period 2006–2009. Methods: All cases received by the Poison Control Center of the Catholic University during the period studied that involved chil- dren younger than 5-year-old were included. Variables analyzed were: total number of cases, gender, age, route of exposure, cir- cumstance, causal agent and communication source. Information was recovered using IPCS INTOX Data Management System. Results: During the period studied, 100,913 cases were received, 36,764 cases involved children younger than 5 years, most of them were male (56%). Two percent were infants and 35% preschool- ers. Route of exposure was mainly ingestion (91%). Predominant agents were pharmaceutical products (49%), household products (27%), cosmetics (5%) and pesticides (5%). Most common pharma- ceuticals were neurological (29%), respiratory system (20%) and gastrointestinal system agents (12%). Most frequent neurologic agents were analgesic/antipyretics (36%), psycholeptics (34%) and psychoanaleptics (16%). Fifty-six percent of calls were received from the patient’s home. Discussion: Most poisonings are unintentional, since children have a natural tendency to explore without a developed sense of danger. Agents involved show a similar pattern to the general pop- ulation. It is important to notice that one third of poisonings involve household products. Conclusions: It is a main concern to reduce the rate of poisonings in this population because of a higher risk of morbidity/mortality. This requires health authorities and caretakers to raise awareness on this issue, to be involved in active education and in the creation of norms to regulate those agents that are most commonly associ- ated with poisonings in this population, especially those with phys- ical characteristics that make them attractive to young children. doi:10.1016/j.toxlet.2010.03.192 P102-009 Global DNA methylation and risk of breast cancer in Mexican women R.U. Hernández-Ramírez 1 , J. Chen 2 , X. Xu 2 , M.E. Cebrian 3 , M. Galván-Portillo 1 , L. Torres-Sánchez 1 , I. Silva-Zolezzi 4 , L. López-Carrillo 1 1 National Institute of Public Health, 2 Mount Sinai School of Medicine, 3 Research and Advanced Studies Center of the National Polytechnic Institute of Mexico (Cinvestav - IPN), 4 National Institute of Genomic Medicine DNA methylation is an important epigenetic process in gene regula- tion. Aberrant DNA methylation has been implicated in etiology of breast cancer (BC). Global hypomethylation is a hallmark of most cancer genome, including BC. However, the association between global methylation status in peripheral blood and BC risk is less known. This study is aimed to examine this association in a case–control study conducted in Mexico. Global DNA methylation was quantified using LU minometric methylation assay (LUMA) blood samples collected from 142 BC cases and 209 control women residing in northern Mexico. Socio-demographic and reproductive characteristics were obtained by direct interviews. BC odds ratios (OR) were estimated using unconditional logistic regression models adjusting for known BC risk factors. Contradictory to the prevailing hypothesis of global hypomethy- lation being a risk factor for BC, the median methylation percentage was higher in cases than in controls (78.57% vs. 77.58%; p value = 0.001). Individuals in the highest tertile of methylation lev- els had significantly increased BC risk compared to those in the lowest tertile (OR tertile 3 vs. tertile 1: 2.77; 95%CI: 1.53–4.81; p for trend < 0.001); this association remained significant after con- trolling for known BC risk factors (age, age of menarche, parity and menopausal status) as well as polymorphism in the key one- carbon-metabolizing gene MTHFR. Our study is the first to report positive association between LUMA levels and BC risk. Our results indicate that global methylation–BC relationship may differ between target (breast) and surrogate (blood) tissues. Factors influencing global methyla- tion, including environmental, nutrition, and genetics should be evaluated in further studies. Supported by Fogarty D43TW00640, and CONACYT (SEP) 14373,111384, (79912). doi:10.1016/j.toxlet.2010.03.193 P102-010 Estimation of postnatal internal exposure to organochlorine compounds in the INMA-Sabadell birth cohort (Spain) M.A. Verner 1 , M. Guxens 2 , J. Sunyer 2 , J.O. Grimalt 3 , R. Mcdougall 4 , M. Charbonneau 5 , S. Haddad 1 1 Université du Québec à Montréal, Canada, 2 Centre de Recerca en Epidemiologia Ambiental (CREAL), Spain, 3 Department of Environmental Chemistry, IDÆA-CSIC, Spain, 4 University of Ontario Institute of Technology, Canada, 5 INRS-Institut Armand-Frappier, Canada Decades after they were banned in most countries, several organochlorine compounds (OC) are still detected in human breast milk samples. Some studies on humans and non-human pri- mates suggest that lactational exposure to these compounds can interfere with neurodevelopment. These findings prompt further assessment of infant OC toxicokinetics and associations between internal levels and neurodevelopmental outcomes. We conducted this study to estimate postnatal exposure to OCs in infants enrolled in the Infancia y Medio Ambiente (INMA)-Sabadell longitudi- nal birth cohort using a physiologically based pharmacokinetic (PBPK) model validated for OCs. Postnatal toxicokinetic profiles of 2,2 ′ ,4,4 ′ ,5,5 ′ -hexachlorobiphenyl (PCB-153), hexachlorobenzene (HCB) and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) were estimated for 491 infants. Information on mothers’ and infants’ physiology, age of mother at delivery, maternal blood OC concentration as measured during the first trimester of pregnancy, sex of infant, duration of breast-feeding and the monthly contribu- tion of breast-feeding to infants’ diet were integrated to simulate individualized profiles of internal exposure. We compiled sim- ulated cord blood OC concentration, infant blood level at each