RESUMO
Under the North American Commission for Environmental Cooperation (CEC) and its Sound Management of Chemicals (SMOC) program, a tri-national human contaminant monitoring initiative was completed to provide baseline exposure information for several environmental contaminants in Canada, Mexico and the United States (U.S). Blood samples were collected from primiparous women in Canada and Mexico, and were analysed for a suite of environmental contaminants including polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene(p,p'-DDE),beta-hexachlorocyclohexane (ß-HCH), mercury and lead. A multiple stepwise linear regression analysis was conducted using data from Canadian and Mexican primiparous mothers, adjusting for ethnicity group, age, pre-pregnancy BMI, years at current city and ever-smoking status. Concentrations of p,p'-DDE, ß-HCH, and lead were found to be higher among Mexican participants; however, concentrations of most PCBs among Mexican participants were similar to Canadian primiparous women after adjusting for covariates. Concentrations of total mercury were generally higher among Mexican primiparous women although this difference was smaller as age increased. This initial dataset can be used to determine priorities for future activities and to track progress in the management of the selected chemicals, both domestically and on a broader cooperative basis within North America.
Assuntos
Poluentes Ambientais/sangue , Exposição Materna/estatística & dados numéricos , Metais/sangue , Adulto , Canadá , Diclorodifenil Dicloroetileno/sangue , Feminino , Humanos , Mercúrio/sangue , México , Bifenilos Policlorados/sangue , GravidezRESUMO
OBJECTIVE: Factors influencing survival among persons with Down syndrome (DS) are not well understood. We sought to evaluate survival of infants with DS and potential prognostic factors. STUDY DESIGN: Infants with DS who were born alive during 1979 to 1998 were identified using the Metropolitan Atlanta Congenital Defects Program (MACDP), a population-based surveillance system. To document vital status, we used data from hospital records, the National Death Index (NDI), and Georgia vital records. We estimated survival probability using the Kaplan-Meier product limit method and hazard ratios using a Cox proportional hazards model. RESULTS: Survival probability to 1 year was 92.9% (95% CI: 90.9-94.9) and to 10 years was 88.6% (95% CI: 85.0-92.2). Univariate analysis demonstrated that black maternal race, low birth weight, preterm birth, lower paternal education, presence of heart defects, and presence of other major congenital anomalies were important prognostic factors. After multivariate analysis, maternal race, presence of heart defects, low birth weight, and an interaction between maternal race and presence of heart defects were significantly associated with mortality risk. CONCLUSIONS: A racial disparity is apparent in survival for children with Down syndrome. Further study is needed to elucidate possible reasons for the racial disparity.