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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.

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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.

construite un simulate situation de operationes dental in le qual le ventilation e le dilution aeree poteva esser regulate pro le objective de studiar le effecto de aerosol producite per pecias de mano propulsionate (1) per corregia e (2) per turbina a aere. Un frescamente extradite tertie molar esseva montate in un dispositivo de cauchu attachate al appoio-capite del sede operatori. Illo esseva equipate con un cophino de cauchu e un adjustate suspension de Serratia marcescens. Placas de Petri sin copertura e collectores de specimens de aere del typo Andersen esseva arrangiate in un configuration semi-circular o linear relative al dente montate. Durante le uso del pecia de mano a propulsion per corregia, practicamente nulle particulas de aerosol continent le organism indicatori esseva detegite. Tamen, le numero de nucleos de guttetta in le ordine de magnitude de approximativemente 5,M o minus-un magnitude capace a penetrar ad in le spatios alveolar accresceva con le distantia ab le dente, durante que le numero total de particulas de aerosol declinava con le accrescentia de ille distantia.

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Serum specimens which originally exhibited a narrow (indeterminate) 24-kilodalton core protein (p24) or p24/p55 pattern of reactivity with human immunodeficiency virus (HIV) in the Western blot (immunoblot) test were studied to gather information on antibody specificity. A total of 12 specimens were initially reevaluated with an indirect immunofluorescence assay (IFA), three enzyme-linked immunosorbent assays (ELISAs), and Western blot analyses. Five of the specimens were IFA positive and contained anti-gp160/gp120 antibodies which were observed only when an HIV Western blot antigen rich in gp160 and gp120 was used. The remaining seven serum specimens were nonreactive by IFA and showed variable reactivity in HIV antibody ELISAs. The specimens did not cross-react with core antigens for human T-cell leukemia virus types 1 and 2 or contain detectable levels of HIV p24 antigen. The p24/p55 reactivity of six of the seven indeterminate specimens could be reduced or eliminated by preincubating the specimens with disrupted, HIV-infected H9 cells but not with uninfected H9 cells. The six specimens also exhibited discernible reactivity with recombinant HIV p24 antigen. When an additional 23 indeterminate specimens were assayed, all of the serum specimens were nonreactive by IFA while 65% (15 of 23) showed various degrees of reactivity with the recombinant p24 protein. There was no indication that any of the HIV core antibody reactivity was caused by HIV infection. Indeterminate results for five patients with specific p24 reactivity, who were retested after a period of weeks or months, remained indeterminate for HIV antibody with no significant change in ELISA or Western blot reactivity.