RESUMEN
In a statewide survey of 856 Iowa municipal drinking water supplies in 1986-1987 the Rathbun rural water system was found to contain elevated levels of triazine herbicides. Rates of low birth weight, prematurity, and intrauterine growth retardation (IUGR) in live singleton births during the period 1984-1990 by women living in 13 communities served by the Rathbun water system were compared to other communities of similar size in the same Iowa counties. The Rathbun communities had a greater risk of IUGR than southern Iowa communities with other surface sources of drinking water (relative risk = 1.8; 95% CI = 1.3, 2.7). Multiple linear regression analyses revealed that levels of the herbicides atrazine, metolachlor, and cyanzinc were each significant predictors of community IUGR rates in southern Iowa after controlling for several potentially confounding factors including maternal smoking and socioeconomic variables. The association with IUGR was strongest for atrazine, but all three herbicides were intercorrelated and the independent contributions of each to IUGR risk could not be determined. We conclude that communities in southern Iowa with drinking water supplies contaminated with herbicides have elevated rates of IUGR compared to neighboring communities with different water supplies. Because of the limitations of the ecologic design of this study, including aggregate rather than individual measures of exposure and limited ability to control for confounding factors related to source of drinking water and risk of IUGR, a strong causal relationship between any specific water contaminant and risk of IUGR cannot yet be inferred. The association between the water supplied to the Rathbun communities and the increased risk of IUGR should be considered a preliminary finding that needs to be verified by more detailed epidemiologic studies.
Asunto(s)
Retardo del Crecimiento Fetal/etiología , Herbicidas/efectos adversos , Contaminantes Químicos del Agua/efectos adversos , Abastecimiento de Agua , Atrazina/efectos adversos , Atrazina/análisis , Femenino , Retardo del Crecimiento Fetal/epidemiología , Herbicidas/análisis , Humanos , Recién Nacido de Bajo Peso , Recién Nacido , Iowa/epidemiología , Embarazo , Atención Prenatal , Contaminantes Químicos del Agua/análisisRESUMEN
The potential reproductive effects of long-term, low-dose exposure to chloroform have received little attention despite the known, acute toxicity of high exposures and the wide-spread occurrence of low concentrations in drinking water. We studied the association of waterborne chloroform with low birthweight (less than 2,500 gm), prematurity (less than 37 weeks gestation), and intrauterine growth retardation (less than 5th percentile of weight for gestational age). Cases were not mutually exclusive, but each outcome was analyzed independently. Birth certificates from January 1, 1989, to June 30, 1990, were used to identify cases and randomly selected controls. All were live, singleton infants born to non-Hispanic, white women from Iowa towns with 1,000-5,000 inhabitants. Exposures to chloroform and other trihalomethanes were ecologic variables based on maternal residence and a 1987 municipal water survey. After adjustment for maternal age, parity, adequacy of prenatal care, marital status, education, and maternal smoking by multiple logistic regression, residence in municipalities where chloroform concentrations were greater than or equal to 10 micrograms/liter was associated with an increased risk for intrauterine growth retardation (odds ratio = 1.8, 95% confidence interval = 1.1-2.9). The major limitations of this study involve the ascertainment and classification of exposures to trihalomethanes, including such issues as the imprecision of using aggregate municipal measures for classifying exposure at the level of the individual, the potential misclassification due to residential mobility, and the fluctuation of trihalomethane levels.
Asunto(s)
Cloroformo/efectos adversos , Retardo del Crecimiento Fetal/inducido químicamente , Abastecimiento de Agua , Adulto , Estudios de Casos y Controles , Femenino , Retardo del Crecimiento Fetal/epidemiología , Edad Gestacional , Humanos , Hidrocarburos Halogenados/efectos adversos , Recién Nacido , Recien Nacido Prematuro , Recién Nacido Pequeño para la Edad Gestacional , Iowa/epidemiología , Embarazo , Distribución Aleatoria , Factores de RiesgoRESUMEN
Data collected by population-based cancer registries in Iowa and metropolitan Atlanta were evaluated to determine prognostic factors for gastrointestinal (n = 270) and bronchopulmonary (n = 151) carcinoids. The predictors considered in univariate and multivariate analyses were: age, sex, race, marital status, anatomic subsite, stage, occurrence of other malignancies, and surgery. For surgically treated gastrointestinal tumors, the cumulative percentages of survivors at five years were: appendix, 85.6%; small intestine, 66.0%; and large intestine, 37.7%. The likelihood of death from gastrointestinal carcinoids was found to be related independently to increasing age (P = 0.001), advanced stage (P less than 0.0001), location within the large intestine (P less than 0.0001), and occurrence of another malignancy (P = 0.02). The overall five-year survival rate for bronchopulmonary carcinoids was 87.6%, and lack of surgical treatment (P less than 0.0001) and advanced stage (P = 0.006) were associated independently with unfavorable prognosis.
Asunto(s)
Tumor Carcinoide/mortalidad , Neoplasias Gastrointestinales/mortalidad , Neoplasias Pulmonares/mortalidad , Georgia , Humanos , Iowa , Pronóstico , Estadística como AsuntoRESUMEN
Independent review of slides of 668 cases of non-Hodgkin's lymphoma (NHL) by a panel of 4 experienced pathologists using the Working Formulation (WF) allowed determination of the agreement between reported diagnoses and panel review of slides. The panel agreed with the reported diagnosis of NHL in 93% of cases, but with the NHL subtype in only 55% of cases overall. The ability of the panelists to agree among themselves, however, was only slightly better than the panelists' agreement with the reported diagnosis (60% vs. 54%, respectively). Agreement of the panel with the reported subtype diagnosis varied from 14% to over 90%. The best agreement was with small lymphocytic lymphoma and follicular subtypes. Conclusions from this study are: 1) The WF functions well as common language for translation and comparison of diagnoses of subtypes of NHL. 2) Relative to time and cost involved, panel review using only light microscopy may not be useful in epidemiologic studies of NHL. 3) Small lymphocytic and follicular subtypes of NHL can be used more confidently in epidemiologic studies than can other subtypes whether the subtyping is done from abstracted reports or by panel review.
Asunto(s)
Linfoma no Hodgkin/diagnóstico , Humanos , Linfoma no Hodgkin/clasificación , Linfoma no Hodgkin/patología , Terminología como AsuntoRESUMEN
With data from the Iowa Cancer Registry, age-adjusted sex-specific cancer incidence rates for the years 1969-1981 were determined for towns with a population of 1,000-10,000 and a public water supply from a single stable ground source. These rates were related to levels of volatile organic compounds and metals found in the finished drinking water of these towns in the spring of 1979. Results showed association between 1,2 dichloroethane and cancers of the colon and rectum and between nickel and cancers of the bladder and lung. The effects were most clearly seen in males. These associations were independent of other water quality and treatment variables and were not explained by occupational or other sociodemographic features including smoking. Because of the low levels of the metals and organics, the authors suggest that they are not causal factors, but rather indicators of possible anthropogenic contamination of other types. The data suggest that water quality variables other than chlorination and trihalomethanes deserve further consideration as to their role in the development of human cancer.
Asunto(s)
Carcinógenos Ambientales/análisis , Neoplasias/epidemiología , Contaminantes Químicos del Agua/efectos adversos , Contaminantes del Agua/efectos adversos , Adolescente , Adulto , Anciano , Niño , Preescolar , Cloro , Neoplasias del Colon/epidemiología , Dicloruros de Etileno/análisis , Femenino , Humanos , Lactante , Iowa , Neoplasias Pulmonares/epidemiología , Masculino , Persona de Mediana Edad , Neoplasias/inducido químicamente , Níquel/análisis , Neoplasias del Recto/epidemiología , Riesgo , Factores Socioeconómicos , Tetracloroetileno/análisis , Tricloroetanos/análisis , Tricloroetileno/análisis , Neoplasias de la Vejiga Urinaria/epidemiologíaRESUMEN
Death certificate analyses of white male Iowans over age 30 who died of multiple myeloma, non-Hodgkin's lymphoma, prostate cancer or stomach cancer between 1964 and 1978 were completed. Each case was matched to two controls on age (within two years) at death, county of residence, and year of death. Consideration of usual occupation, as recorded on the death certificate, resulted in the following odds ratios for mortality due to the specified cancers among farmers: multiple myeloma, 1.48; non-Hodgkin's lymphoma, 1.26; prostate cancer, 1.19; and stomach cancer, 1.32. Each is statistically significant (p less than 0.05). Odds ratios were computed separately for three birth cohorts according to counties stratified by crop and livestock production. Multiple myeloma was elevated in those born after 1890 and was associated with number of egg-laying chickens, hog production, insecticide use, and herbicide use. Non-Hodgkin's lymphoma was elevated in those born before 1901 and was associated with egg-laying chickens, milk products sold, hog production, and herbicide use. Although prostate cancer was elevated in those born before 1901, it was not associated with any agricultural practice. Stomach cancer was elevated in each birth cohort. It was associated with milk products sold, cattle production, and corn per acre.
Asunto(s)
Enfermedades de los Trabajadores Agrícolas/mortalidad , Neoplasias/mortalidad , Adulto , Factores de Edad , Anciano , Enfermedades de los Trabajadores Agrícolas/etiología , Certificado de Defunción , Métodos Epidemiológicos , Humanos , Iowa , Masculino , Persona de Mediana Edad , Neoplasias/etiología , Factores de TiempoRESUMEN
Age-adjusted, sex-specific cancer incidence rates for the years 1969-1978 were determined for municipalities in Iowa having a population of 1000 or over and public water supply that had remained stable for a minimum of 14 years. The incidence rates for the municipalities were examined according to major source of water supply (surface or ground) and depth of well. As municipality size increased, incidence rates increased for cancer of the lung among males and females. A slight gradient of increasing cancer incidence was seen for cancer of the bladder among males and females. When stratified for population size, incidence rates for cancers of the lung and rectum among males and females were higher for municipalities on surface water compared with those on ground sources. Incidence rates for cancer of the prostate rose as well depth increased, while a trend was seen toward decreasing incidence rates for cancer of the colon among females as well depth increased. When time trends were examined, an increase in cancer rates over time was seen for several cancer sites, with the increase most noticeable in municipalities supplied by surface water or shallow wells. These results are not always consistent with the hypothesis of an association between cancer and chlorinated water.
Asunto(s)
Neoplasias/epidemiología , Abastecimiento de Agua , Métodos Epidemiológicos , Femenino , Humanos , Iowa , Masculino , Factores de TiempoRESUMEN
Iowa towns of 1000-10,000 population, whose water came solely from wells of over 500 feet (152 meters) in depth and was not treated by a process that would remove radioactivity, were identified. Age-adjusted, sex-specific, cancer incidence rates were determined for these towns for the years 1969-1978 (excluding 1972) and related to the mean level of radium-226 in the municipal water supply. Incidence rates of cancers of the lung and bladder among males and of cancers of the breast and lung among females were higher in towns with a radium-226 level in the water supply exceeding 5.0 pCi/l. A gradient of increasing cancer incidence associated with rising radioactivity level for three time periods was also seen for lung cancer among males. The associations between cancer incidence and radioactivity of water supply could not be explained by smoking patterns, water treatment factors, other water quality measurements, or known socio-demographic features.
Asunto(s)
Neoplasias/epidemiología , Contaminantes Radiactivos del Agua/envenenamiento , Contaminantes del Agua/envenenamiento , Anciano , Métodos Epidemiológicos , Femenino , Humanos , Iowa , Masculino , Persona de Mediana Edad , Neoplasias/etiología , Radio (Elemento)/análisis , Fumar , Contaminantes Radiactivos del Agua/análisisRESUMEN
Death certificate analyses of 1675 white, male Iowans over age 30 years who died of leukemia in 1964-1978 were completed. Each case was matched to two controls on age (within two years) at death, county of usual residence and year of death. Consideration of usual occupation, as recorded on the death certificate, resulted in an odds ratio for leukemia mortality among farmers of 1.24 (p less than 0.05). The highest odds ratios for farmers were observed in those born after 1890, those dying after 1970, and those dying at age 65 years or younger. Odds ratios for farmers were also elevated in counties with high soybean and corn production per acre for those born between 1890 and 1900. For those born after 1900, odds ratios for farmers were increased in counties with the greatest numbers of egg-laying chickens and largest number of acres treated with herbicides. The types of leukemia causing elevated mortalities in Iowa farmers were chronic lymphatic and unspecified lymphatic. Mortality from unspecified lymphatic leukemia was associated with corn per acre, number of milk cows and number of egg-laying chickens.
Asunto(s)
Enfermedades de los Trabajadores Agrícolas/mortalidad , Leucemia/mortalidad , Adulto , Anciano , Enfermedades de los Trabajadores Agrícolas/epidemiología , Certificado de Defunción , Métodos Epidemiológicos , Humanos , Iowa , Leucemia/epidemiología , Masculino , Persona de Mediana Edad , Nebraska , RiesgoAsunto(s)
Neoplasias/epidemiología , Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Humanos , Iowa , Masculino , Persona de Mediana Edad , Neoplasias/mortalidadRESUMEN
Measles incidence in the United States was calculated from estimates of the United States Immunization Survey for the years 1965 to 1975. These data were examined according to birth cohorts and cross-sectionally by age to determine the effect of live measles virus vaccine on measles epidemiology. The results showed a high rate of infection for children aged 1 year, followed by a decrease in the infection rates for preschool children, with rates increasing agin at ages 5 and 6 years. It was hypothesized that an effective vaccine-induced herb immunity exists in preschool children until they are of school age. When incidence rates were based on susceptible children, the highest rates occurred in the school-aged populations.
Asunto(s)
Vacuna Antisarampión/uso terapéutico , Sarampión/epidemiología , Factores de Edad , Niño , Preescolar , Humanos , Lactante , Estudios Longitudinales , Sarampión/prevención & control , Probabilidad , Estados UnidosAsunto(s)
Azul de Metileno , Schistosoma mansoni/patogenicidad , Schistosoma/patogenicidad , Animales , Color , Medios de Cultivo , Larva/patogenicidad , Ratones , Schistosoma/embriología , Schistosoma/inmunología , Schistosoma mansoni/embriología , Schistosoma mansoni/inmunología , Coloración y EtiquetadoRESUMEN
The in vitro effect of the lethal antibody on schistosomula in sera of rhesus monkeys immunized with highly X-irradiated cercariae of Schistosoma mansoni or S. japonicum was studied. In all 6 experimental monkeys, 4 unchallenged and 2 challenged, the effects of lethal antibody on schistosomula were demonstrated. The sera of the challenged monkeys had no stronger lethal effect than those of the unchallenged monkeys. This shows that the lethal antibody can be produced by the antigenic stimulation of schistosomula alone. The mortality rates of schistosomula in immune sera were already high at day 1, increased to a certain extent from day 1 to day 4, but showed no significant further increase in days 5 and 6. Two kinds of immunological reactions were observed: perischistosomular precipitate (PSP) and perischistosomular envelope (PSE). Schistosomula surrounded with PSP were usually dying or dead and those enclosed in PSE were usually alive and motile. Thus PSP may be related with the lethal antibody and PSE with a kind of enhancing antibody. Schistosomula with PSP showed a positive fluorescent reaction when stained with fluorescein-labeled rabbit anti-rhesus IgG. Scanning electron micrographs of schistosomula with PSP showed a highly degenerated tegument. These facts indicate that the antibody in PSP contains a fraction of IgG which acts on the tegument of schistosomula.