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Biomedical subjects

G F Craun

Publications and source records attributed to G F Craun.

At least 37 records · Page 2Linked to original sources
PubMed1984

Trace metals in drinking water: lack of influence on blood pressure.

It has been suggested that certain trace metals may affect human blood pressure. We recently measured trace metals in the tapwater from the homes of 246 male participants of the Normative Aging Study. Participants were free of any disease or medication known to influence blood pressure. No statistically significant relationship was found between lead concentration and systolic blood pressure in an analysis of covariance, controlling for age and body mass index. Diastolic pressure was examined as well and the results were almost identical. Since educational level and town of residence were potential confounders, we stratified on these variables but no association between lead concentration and blood pressure emerged. Similarly, no statistically significant relationships were found between blood pressure and copper or iron. Blood pressure did differ significantly among zinc concentration groups but no uniform trend appeared. In light of evidence from other studies suggesting that blood pressure is influenced by lead or other elements in drinking water, further investigations with more highly exposed subjects or a prospective design appear warranted.

Adult↗
PubMed1983

Epidemiology study of the use of asbestos-cement pipe for the distribution of drinking water in Escambia County, Florida.

Cancer mortality for the population census tracts of Escambia County, FL, which use asbestos-cement (AC) pipe for public potable water distribution, was compared with cancer mortality data collected from census tracts in the same county where other types of piping materials are used. An analysis of covariance was run to test for differences in standard mortality ratios for seven cancer sites among three potential asbestos exposure groups based on AC pipe usage. Twelve variables representing nonexposure-related influences on disease rates were combined in four independent factors and used as covariates in these analyses. No evidence for an association between the use of AC pipe for carrying drinking water and deaths due to gastrointestinal and related cancers was found. The limitations on the sensitivity of the analysis are discussed.

Adolescent↗
PubMed1981

Methaemoglobin levels in young children consuming high nitrate well water in the United States.

The EPA limit for nitrate (10 mg/l No3-N) in drinking water was established to prevent infantile methaemoglobinemia, an acute condition confined almost exclusively to infants less than three months. This condition is clinically detectable at methaemoglobin levels of approximately 10%. Several studies in the Soviet Union have suggested that elevated methaemoglobin levels from ingested nitrate may not be confined to the young infant and have reported an association between increased methaemoglobin levels of up to 7% in schoolchildren and drinking water with a nitrate concentration of 23-204 mg/l NO3-N. an epidemiologic study of 102 children aged 1-8 conducted in Washington County, Illinois, did not show that ingestion of water with a nitrate concentration of 22-111 mg/l NO3-N was related to increasing methaemoglobin levels nor that the children had high or above normal methaemoglobin levels. The potential for transmission of infections waterborne disease in this area was demonstrated, however, as a large percentage of the wells used for drinking water contained high numbers of total and faecal coliforms.

Child↗
PubMed1980

An epidemiologic study of the relationship between hepatitis A and water supply characteristics and treatment.

Outbreaks of hepatitis A (HA) attributable to water contamination have been reported; however, the impact of water supply characteristics on the endemic rates of HA has not been quantified. This study did not detect any statistically significant associations between endemic HA rates and water supply characteristics. Because of the sample size, this finding suggests that the total variation of HA rates attributable to water supply characteristics is probably less than 8 per cent of the annual reported cases of HA in the United States.

Cross-Sectional Studies↗
PubMed1979

Waterborne giardiasis in the United States: a review.

Twenty-three waterborne outbreaks of giardiasis have been reported in the US, 1972-77. Data indicate that disinfection as the only treatment for surface water sources is ineffective in preventing waterborne transmission of this organism. To protect against transmission, all surface water should receive chemical pretreatment, preferably with sedimentation, and filtration in addition to disinfection. Outbreak data indicate that negative coliform tests do not provide assurance that water is free of Giardia cysts.

Disease Outbreaks↗
PubMed1978

An investigation of the use of asbestos cement pipe for public water supply and the incidence of gastrointestinal cancer in Connecticut, 1935-1973.

The age adjusted sex specific incidence data for stomach, colon, and rectal cancer for Connecticut townships for the period 1935 to 1973 were used to investigate whether asbestos cement pipe usage for domestic drinking water is associated with gastrointestinal cancer. The townships were grouped according to the Assessment of Exposure (AOE) and Risk Factor (RF) for asbestos. These are composite indices of asbestos exposure including factors relating to the age of the pipe, the ability of water to leach asbestos from the pipe, and the length of pipes used by the population. No association was noted between these asbestos risk scores and gastrointestinal tumor incidence.

Asbestos↗
PubMed1978

Epidemiology of common-source outbreaks of shigellosis in the United States, 1961-1975.

In 1961-1975, there were 72 foodborne and 38 waterborne outbreaks of shigellosis reported in the United States. Foodborne outbreaks were most often caused by salads with contamination attributed to poor hygiene of a food handler. Waterborne outbreaks most often involved semipublic water systems, and were usually the result of inadequate chlorination of water contaminated by human feces. In 110 common-source outbreaks, 16,541 persons were ill. The attack rate for both food- and waterborne shigellosis was 47%, and the case-fatality ratio was 0.1% in foodborne outbreaks and 0.2% in waterborne outbreaks.

Disease Outbreaks↗
PubMed1977

Cholera on Guam, 1974: epidemiologic findings and isolation of non-toxinogenic strains.

In August 1974, six cases of cholera occurred on Guam. The index case had severe diarrhea and metabolic acidosis and died from pneumonia on the ninth day of illness; the other five cases had only mild to moderate diarrhea. Fish caught in Agana Bay and home-preserved was found to be the vehicle most likely responsible for the cases. Vibrio cholerae, El Tor Ogawa, was isolated from two patients, the Guam sewerage system, and a river emptying into Agana Bay. V. cholerae, El Tor Inaba, was isolated from the sewerage system, three storm drains imptying into Agana Bay, and Agana Bay. The Ogawa and Inaba isolates differed in their sucrose fermentation and hemolysis reactions, phage type and ability to produce toxin. Although this was the first reported cholera outbreak on Guam, the isolation of differentV. cholerae strains suggested that multiple introductions of V. cholerae had occurred on the island.

Cholera↗
PubMed1976

An epidemic of gastroenteritis traced to a contaminated public water supply.

Between January 1 and March 15, 1974, approximately 1200 cases of acute gastrointestinal illness occurred in Richmond Heights, Florida, a residential community of 6500 in south Dade County. Over one-third of all families in the area had at least one member affected. The findings of 10 culture-proven cases of shigellosis among those who became ill and clinical signs and symptoms in the others suggest that most of the other cases that were not cultured may have been shigellosis also. Epidemiologic investigation showed that consumption of tap water was associated with illness in the initial cases of affected families. Evaluation of the Richmond Heights public water supply disclosed numerous inadequacies in both design and operation. One of the wells providing water to the community was continuously contaminated with excessive levels of fecal coliforms from a nearby septic tank, and a breakdown in chlorination on January 14-15 caused approximately 1 million gallons of inadequately chlorinated water from the contaminated well to be distributed to the community 48 hours before the epidemic began. Correction of deficiencies in the water plant was undertaken by the utility company; the residents of Richmond Heights were instructed to boil their drinking water or to use commercially bottled water pending completion of corrective measures. A FUll scale study is planned for all similar public water supplies in Dade County.

Adolescent↗