RESUMEN
Chronic arsenic exposure has been associated with a range of neurologic, vascular, dermatologic, and carcinogenic effects. However, limited research has been directed at the association of arsenic exposure and human reproductive health outcomes. The principal aim of this study was to investigate the trends in infant mortality between two geographic locations in Chile: Antofagasta, which has a well-documented history of arsenic exposure from naturally contaminated water, and Valparaíso, a comparable low-exposure city. The arsenic concentration in Antofagasta's public drinking water supply rose substantially in 1958 with the introduction of a new water source, and remained elevated until 1970. We used a retrospective study design to examine time and location patterns in infant mortality between 1950 and 1996, using univariate statistics, graphical techniques, and Poisson regression analysis. Results of the study document the general declines in late fetal and infant mortality over the study period in both locations. The data also indicate an elevation of the late fetal, neonatal, and postneonatal mortality rates for Antofagasta, relative to Valparaíso, for specific time periods, which generally coincide with the period of highest arsenic concentration in the drinking water of Antofagasta. Poisson regression analysis yielded an elevated and significant association between arsenic exposure and late fetal mortality [rate ratio (RR) = 1.7; 95% confidence interval (CI), 1.5-1.9], neonatal mortality (RR = 1.53; CI, 1.4-1.7), and postneonatal mortality (RR = 1.26; CI, 1.2-1.3) after adjustment for location and calendar time. The findings from this investigation may support a role for arsenic exposure in increasing the risk of late fetal and infant mortality.
Asunto(s)
Arsénico/efectos adversos , Exposición a Riesgos Ambientales , Contaminantes Ambientales/efectos adversos , Mortalidad Infantil/tendencias , Chile/epidemiología , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Estudios Retrospectivos , Medición de Riesgo , Abastecimiento de AguaRESUMEN
The selenium in the diet of persons in arsenic-endemic areas, high levels of arsenic in the drinking water, was evaluated. The methodology used was that of 24-hr dietary recall. Daily selenium intakes of two rural towns in northern Mexico were found to be similar, approximating 72.9 and 60.6 micrograms. These values were similar to those of a previously arsenic-exposed area from California, Edison community. The Edison participants had a daily selenium intake of 61.8 micrograms. The possible negative effect of selenium to produce differences in reported geographical variation in disease could not be substantiated in this study. Other nutrient intakes, protein and energy were also found similar for communities. Differences were noted in vitamin A intake where one-third the daily requirement was experienced by Mexican participants compared to two-thirds the requirement being satisfied by those participants from Edison.
Asunto(s)
Arsénico , Dieta , Ingestión de Alimentos , Selenio/análisis , Contaminación Química del Agua , Abastecimiento de Agua , Adulto , Proteínas en la Dieta/análisis , Femenino , Humanos , Masculino , México , Persona de Mediana Edad , Necesidades Nutricionales , Selenio/administración & dosificación , Vitamina A/administración & dosificación , Vitamina A/análisisRESUMEN
A study of the prevalence of skin cancer among 40,421 persons consuming arsenic-contaminated drinking water in Taiwan was used for a cancer dose-response assessment of ingested arsenic. The numbers of persons at risk over three dose intervals and four exposure durations were estimated from the data in order to apply the method of maximum likelihood to a multistage-Weibull time/dose-response model. A constant exposure level since birth for each of the exposure categories was assumed. It was found that the cumulative hazard increases as a power of three in age, and is linear or quadratic (with a linear coefficient) in dose. Observations from a smaller epidemiologic survey in Mexico were similar to what would be predicted from the model of the Taiwan data. Assuming that the skin cancer risk from ingested arsenic in the American population would also be similar to the Taiwan population, an American male would have a lifetime risk of developing skin cancer of 1.3 x 10(-3) (3.0 x 10(-3] if exposed to 1 microgram/kg/day for a 76-year lifespan (median lifespan in the U.S.).