Cancer mortality in agricultural regions of Minnesota.
Because of its unique geology, Minnesota can be divided into four agricultural regions: south-central region one (corn, soybeans); west-central region two (wheat, corn, soybeans); northwest region three (wheat, sugar beets, potatoes); and northeast region four (forested and urban in character). Cancer mortality (1980-1989) in agricultural regions one, two, and three was compared to region four. Using data compiled by the National Center for Health Statistics, cancer mortality was summarized by 5-year age groups, sex, race, and county. Age-standardized mortality rate ratios were calculated for white males and females for all ages combined, and for children aged 0-14. Increased mortality rate ratios and 95% confidence intervals (CIs) were observed for the following cancer sites: region one--lip (men), standardized rate ratio (SRR) = 2.70 (CI, 1.08-6.71); nasopharynx (women), SRR = 3.35 (CI, 1.20-9.31); region two--non-Hodgkin's lymphoma (women), SRR = 1.35 (CI, 1.09-1.66); and region three--prostate (men), SRR = 1.12 (CI, 1.00-1.26); thyroid (men), SRR = 2.95 (CI, 1.35-6.44); bone (men), SRR = 2.09 (CI, 1. 00-4.34); eye (women), SRR = 5.77 (CI, 1.90-17.50). Deficits of smoking-related cancers were noted. Excess cancers reported are consistent with earlier reports of agriculturally related cancers in the midwestern United States. However, reports on thyroid and bone cancer in association with agricultural pesticides are few in number. The highest use of fungicides occurs in region three. Ethylenebisdithiocarbamates, whose metabolite is a known cause of thyroid cancer in rats, are frequently applied. This report provides a rationale for evaluation of the carcinogenic potential of this suspect agent in humans. (+info)
Geography of intestinal permeability and absorption.
BACKGROUND: Intestinal morphology and function vary geographically. AIMS: These functions were assessed in asymptomatic volunteers in European, North American, Middle Eastern, Asian, African, and Caribbean countries. METHODS: Five hour urine collections were obtained from each subject following ingestion of a 100 ml iso-osmolar test solution containing 3-0-methyl-D-glucose, D-xylose, L-rhamnose, and lactulose after an overnight fast, to assess active (3-0-methyl-D-glucose) and passive (D-xylose) carrier mediated, and non-mediated (L-rhamnose) absorption capacity, as well as intestinal permeability (lactulose:rhamnose ratio). RESULTS: A comparison of results for subjects from tropical countries (n=218) with those resident in the combined temperate and subtropical region (Europe, United States, Qatar) (n=224) showed significant differences. Residents in tropical areas had a higher mean lactulose:rhamnose ratio and lower mean five hour recoveries of 3-0-methyl-D-glucose, D-xylose, and L-rhamnose, indicating higher intestinal permeability and lower absorptive capacity. Investigation of visiting residents suggested that differences in intestinal permeability and absorptive capacity were related to the area of residence. Subjects from Texas and Qatar, although comprised of several ethnic groups and resident in a subtropical area, showed no significant difference from European subjects. CONCLUSIONS: There are clearly demarcated variations in intestinal permeability and absorptive capacity affecting asymptomatic residents of different geographical areas which correspond with the condition described as tropical enteropathy. Results suggest the importance of environmental factors. The parameters investigated may be relevant to the predisposition of the indigenous population and travellers to diarrhoeal illness and malnutrition. Intestinal function in patients from the tropics may be difficult to interpret, but should take into account the range of values found in the asymptomatic normal population. (+info)
Asthma-like disease in the children living in the neighborhood of Mt. Sakurajima.
We conducted self-administered questionnaire surveys of school children living in the vicinity of Mt. Sakurajima using ATS-DLD questionnaire. In this paper, we report the results of analysis comparing the proportion of children with asthma-like disease in the area exposed to the volcanic ash and gases released by Mt. Sakurajima and control areas. Asthma-like disease was ascertained using ATS-DLD questionnaire and the definition proposed by the study group established by Environmental Protection Agency in Japan. The proportion of children with asthma-like disease was not different between the exposed and control groups. The odds ratio of asthma-like disease comparing the exposed and control groups was 1.1 and its 95% confidence interval was 0.7-1.8 (P = 0.583). When the exposed area was divided into Tarumizu city. Sakurajima town and Kagoshima city, none of them showed an elevated proportion of children with asthma-like disease when compared with the control area. In the entire study population including both the exposed and control groups, the proportion of children with asthma-like disease was 6 and 3% in boys and girls, respectively. These values were quite similar to those obtained from a survey of 45,674 school children in western districts in Japan in 1992. In conclusion, the present study indicates that the proportion of children with asthma-like disease is not elevated in the exposed area. Further investigations are necessary to confirm our conclusions. (+info)
Is sunlight an aetiological agent in the genesis of retinoblastoma?
The incidence of unilateral, but not bilateral, retinoblastoma in human populations at different geographical locations increases significantly with ambient erythemal dose of ultraviolet B radiation from sunlight. This supports the hypothesis that sunlight plays a role in retinoblastoma formation. (+info)
Living at high altitude and risk of sudden infant death syndrome.
OBJECTIVE: To investigate the association between altitude of residence and risk of sudden infant death syndrome (SIDS). METHODS: A retrospective, case control study in the Tyrol, Austria enrolled 99 infants with SIDS occurring between 1984 and 1994, and 136 randomly selected control cases. Data on pregnancy, delivery, child care practice, and socio-demographic characteristics including altitude of residence were collected with a standardised questionnaire. RESULTS: The risk of SIDS increased gradually with increasing altitude of residence. This relation remained independently significant when the analysis was adjusted for gestational age, birth weight, prenatal care, mother's age at delivery, educational level of parents, and cigarette smoking during pregnancy. The prone sleeping position emerged as an obligatory cofactor in this association. In the whole of Austria, a similar trend of association emerged between the average altitudes in the 99 political counties and the rates of SIDS. CONCLUSIONS: This study identified altitude of residence as a significant risk predictor of SIDS, primarily in combination with the prone sleeping position. Respiratory disturbances, reduced oxygen saturation, and lower temperatures at high altitude might explain this association. (+info)
Clinical algorithm for malaria during low and high transmission seasons.
OBJECTIVES: To assess the proportion of children with febrile disease who suffer from malaria and to identify clinical signs and symptoms that predict malaria during low and high transmission seasons. STUDY DESIGN: 2490 children aged 2 to 59 months presenting to a health centre in rural Ethiopia with fever had their history documented and the following investigations: clinical examination, diagnosis, haemoglobin measurement, and a blood smear for malaria parasites. Clinical findings were related to the presence of malaria parasitaemia. RESULTS: Malaria contributed to 5.9% of all febrile cases from January to April and to 30.3% during the rest of the year. Prediction of malaria was improved by simple combinations of a few signs and symptoms. Fever with a history of previous malarial attack or absence of cough or a finding of pallor gave a sensitivity of 83% in the high risk season and 75% in the low risk season, with corresponding specificities of 51% and 60%; fever with a previous malaria attack or pallor or splenomegaly had sensitivities of 80% and 69% and specificities of 65% and 81% in high and low risk settings, respectively. CONCLUSION: Better clinical definitions are possible for low malaria settings when microscopic examination cannot be done. Health workers should be trained to detect pallor and splenomegaly because these two signs improve the specificity for malaria. (+info)
Geographic variation in stroke risk in the United States. Region, urbanization, and hypertension in the Third National Health and Nutrition Examination Survey.
BACKGROUND: In the United States, stroke mortality is higher in the south than in other regions. Hypertension is the main risk factor for stroke among older adults; however, few studies have examined group-specific regional and urbanization differences in hypertension prevalence. METHODS: Data from the Third National Health and Nutritional Examination Survey (NHANES III), 1988 to 1994, were analyzed to calculate the prevalence of hypertension (systolic >140 mm Hg and/or diastolic >90 mm Hg and/or taking antihypertensive medication) by region and urbanization for age (40 to 59 and 60 to 79 years), sex, and ethnic subgroups. Logistic regression models were fitted to estimate the association of hypertension with region and urbanization. RESULTS: With age and urbanization kept constant, southern residence was associated with hypertension among middle-aged non-Hispanic white men (odds ratio [OR], 1.49; 95% confidence interval [CI], 1.12 to 1.90; P<0.006), non-Hispanic black men (OR, 1.36; 95% CI, 1.05 to 1.66; P=0.019), and non-Hispanic black women (OR, 1.23; 95% CI, 1.01 to 1.45; P=0.034). Among older non-Hispanic white men, a significant interaction was noted between region and urbanization (P=0.01), with a higher prevalence in the south only for nonmetropolitan residents (OR, 1.32; 95% CI, 1.06 to 1.56; P<0.013). A similar but not statistically significant trend was also confirmed among non-Hispanic black men in logistic regression analysis (OR, 1.38; 95% CI, 0.97 to 1.68; P=0.061). No statistically significant association was observed for urbanization or region in the other subgroups. CONCLUSIONS: Southern residence was associated with increased hypertension prevalence among middle-aged non-Hispanic white men, non-Hispanic black men and women, and older non-Hispanic white men. (+info)
Season of birth in schizophrenia: no latitude at the equator.
BACKGROUND: If the established winter excess in births of people who subsequently develop schizophrenia is an effect of 'seasonality', this would be testable by examining the pattern of births in an equatorial region with no formal seasons. AIMS: To investigate whether there is any variation in month of birth among patients from equatorial Singapore with a diagnosis of schizophrenia. METHOD: All 9655 patients discharged from Singapore's national psychiatric hospital with a diagnosis of schizophrenia were included (year of birth range 1930-1984). We analysed aggregated data, as well as the data of subsamples grouped according to birth-year periods, in order to examine secular trends. One patient subsample (those born 1960-84) allowed exact matching against the general population data set and close testing of any seasonal influence. RESULTS: Monthly variation in births was evident for both patients and controls; the patterns were very similar, apart from the patient sample showing a trough in March-April. CONCLUSIONS: In an equatorial region, where 'seasons' are absent, no seasonal excess in births of those later developing schizophrenia was evident. (+info)