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Biomedical subjects

D T Wigle

Publications and source records attributed to D T Wigle.

At least 55 records · Page 3Linked to original sources
PubMedDate not supplied

Cancer mortality in relation to asbestos in municipal water supplies.

The mortality experience of twenty-two municipalities in Quebec grouped by evidence of exposure to asbestos fibers in water supplies (known high, possible high, and probable low exposures) was evaluated. Excess mortality due to cancer of the stomach (males), pancreas (females), and lung (males) was observed in the two municipalities with known high exposures. The excesses among males have been due to occupational exposure to asbestos. The absence of excess mortality due to pancreatic cancer among males suggested that the excess among females was not due to waterborne asbestos. The study therefore did not reveal evidence of excess cancer mortality that could be attributed to exposure to asbestos in drinking water.

Adult↗
PubMedDate not supplied

Electric kettles as a source of human lead exposure.

Five hundred and seventy-four households in Ottawa were surveyed to evaluate water boiled in electric kettles as a source of lead exposure. Samples of boiled water exceeded the World Health Organization mandatory limit for drinking water (50 microgram/l) in 42.5% of the households. Excessive lead concentrations were observed in 62.8% of water samples from kettles more than 5 years old. Multiple regression analysis indicated that age, sex, and cigarette smoking habits, but not lead concentration in boiled water, nor weekly consumption of boiled water were significantly associated with blood-lead concentration. Lead exposure from electric kettles may be a significant problem only in infants receiving formula prepared with boiled water.

Adult↗
PubMedDate not supplied

Long-term survival rates among patients with cancer in Saskatchewan, 1967-1986.

We calculated relative survival rates from 5 to 15 years after diagnosis for cancer cases diagnosed in Saskatchewan, Canada, between 1967 and 1986. Cancers with high 15-year relative survival (greater than 60%) included lip, melanoma among women, other male genital sites, and corpus uteri. As anticipated, relative survival rates declined with increasing length of follow-up, with the largest relative declines noted among those in the oldest age group (65+ years). Only small declines in relative survival were noted for cancers of the colon and cervix with increasing length of follow-up. Improved survival of cases diagnosed in the period 1980-1984 compared to 1970-1974 was observed for all sites combined, as well as the following sites: colon, lung, prostate, brain, ill-defined sites, non-Hodgkin's lymphoma, and lymphoid leukemia. For colorectal cancer, stage at diagnosis was a more important independent predictor of survival than age.

Adult↗
PubMedDate not supplied

Mortality study of Canadian male farm operators: cancer mortality and agricultural practices in Saskatchewan.

The present investigation involved an analysis of approximately 70,000 male Saskatchewan farm operators, a subset of the 365,000 Canadian farm operators to be investigated in the Canadian Farm Operator Mortality Study. The results of the Saskatchewan analysis indicate that during the interval studied, overall mortality among Saskatchewan farmers was 25% lower than that for all Saskatchewan men, and that, during the same time interval, the risk of death from all types of cancer was also about 25% lower among Saskatchewan farmers than to all Saskatchewan men. Although the present study indicates that overall mortality of death from cancer was 25% lower among Saskatchewan male farmers, there was a relationship between non-Hodgkin's lymphoma mortality and acres sprayed for weeds; a similar risk relationship between expenditures on fuel oil and risk of death from non-Hodgkin's lymphoma was also evident. The magnitude of risk for Saskatchewan farmers is probably greater than that reflected in the estimates in this study, due to the likelihood of misclassification of exposure. There is a particular need for further studies in this area to improve the quantification of farming-related exposures, and to study the exposure history of individuals who develop non-Hodgkin's lymphoma.

Adult↗
PubMedDate not supplied

Suicide in Canada: an epidemiological assessment.

Suicide rates in Canada rapidly increased during the 1960s and 1970s. More recent analysis of these trends indicates that in males suicide rates have stabilized and in females a notable decrease has been identified. The greatest changes in suicide rates have occurred among the youngest age groups (15 to 19), while little change has occurred in suicide mortality rates for males aged 50 years and over. The age-specific death rates in 1986 are uniformly distributed in males above age 20, while in females an inverted "U" curve is demonstrated with the peak at age 45-50. Males continue to have higher rates and the difference between males and females is expanding. A birth cohort analysis indicates that the contribution of the birth cohort to explaining suicide rates has diminished and been replaced by a more recent period effect. Suicide remains the second most important cause of death of persons between 15 and 34 years of age. Provincial variation is discussed through geographic variation, cause-specific rankings and potential years of life lost. In contrast to national trends, suicide mortality in Alberta, Quebec and New Brunswick continues to increase. An atlas is provided to display Canadian census divisions that exhibit elevated rates of suicide.

Adolescent↗
PubMedDate not supplied

Effects of residential exposure to environmental tobacco smoke on Canadian children.

The effects of residential exposure to environmental tobacco smoke were studied in a sample of 6,529 Canadian children under 15 years of age. Univariate analysis indicated an elevated risk of bronchitis among children whose mothers were single, or under age 25, or whose income or educational level was low. Multivariate analysis indicated that the relative risk of bronchitis among children whose mothers were current smokers relative to those whose mothers never smoked was 3.0 (95% CI:1.6,5.2). Significant dose-response relationships between risk of bronchitis and amount smoked as well as duration of exposure were observed. Using the composite exposure score of all smokers in the household as the source of exposure, the risk of bronchitis decreased slightly but remained significantly elevated. Examination of the risk conferred by the mother's smoking relative to the total household exposure showed that most of the elevation in risk was associated with the mother's smoking contribution. Asthma was also studied, but failed to show a statistically significant association with smoking.

Adolescent↗
PubMedDate not supplied

Premature deaths in Canada: impact, trends and opportunities for prevention.

The impact, time trends and potential for prevention of premature deaths in Canada were assessed. There were almost 100,000 deaths before age 75 in Canada during 1986 resulting in over 1.7 million potential years of life lost (PYLL). The three leading broad disease categories responsible for PYLL were cancer, injuries/violence and cardiovascular disease. In both sexes, coronary heart disease, car accidents, lung cancer and perinatal conditions ranked in the top 5 specific diseases responsible for PYLL; breast cancer (females) and suicide (males) also ranked in the top 5 conditions. Over the period 1969 to 1986, death rates among persons less than age 75 increased for 3 conditions among females and 11 conditions among males. Lung cancer and brain cancer death rates increased in both sexes, chronic obstructive pulmonary disease death rates increased among females only and death rates for suicide and 8 types of cancer increased among males only. Over the same period, death rates declined for 37 discrete disease categories among both females and males including particularly large improvements for coronary heart disease, stroke, car accidents and perinatal conditions. An estimated 50,000 or over 50% of all premature deaths per year are preventable through control of smoking, hypertension, elevated serum cholesterol, diabetes and alcohol abuse. About 6,000 premature deaths are avoidable through improvements in medical care.

Adolescent↗
PubMedDate not supplied

Seasonality in epidemics of asthma mortality and hospital admission rates, Ontario, 1979-86.

Monthly trends in mortality and hospital admission rates attributed to asthma for those aged 15 to 34 for the province of Ontario were examined for the period 1979 to 1986. Graphs showing the monthly variation after the elimination of trend are presented. Time series models were constructed to evaluate the statistical significance. Asthma hospital separations peaked in the autumn and a test for seasonality was statistically significant (p less than 0.001). Although the pattern for asthma mortality was similar, the test for seasonality was not significant (p greater than 0.10).

Adolescent↗
PubMedDate not supplied

Decline of acute myocardial infarction death rates not due to cause of death coding.

The recent decline in coronary heart disease (CHD) mortality has been attributed to reduction in risk factors, improved management and the possibility of statistical artifacts. The purpose of this study is to assess the impact of geographic and time variation in the coding of cause of death from death certificates into ICD codes upon CHD mortality rates in Canada. Equal samples of death certificates were recoded for Nova Scotia and Saskatchewan for each of the years 1970 and 1984: 1) a first set of 1,600 death certificates originally coded as acute myocardial infarction (AMI) and 2) a second set of 800 death certificates from all causes of death. The coding error rates increased with age and with the number of contributing and underlying causes of death reported on the death certificates. The net effect of false positive and false negative AMI codes on death certificates did not vary significantly by province or year. Thus, variation of death certificate coding over time and geographic regions do not contribute toward the explanation of the AMI mortality rate decline.

Canada↗