摘要:

Blackfoot disease is an endemic peripheral vascular disease found among people in a limited area on the southwest coast of Taiwan, where artesian well water has a high concentration of arsenic and was used since the turn of this century. This is an important public health problem and was noted by the authorities, who began improving the water supply in such communities in 1956. This enabled us to test the relationship between arsenic and malignant tumors using a specific exposed community. Study subjects were divided into four groups according to age (under or over 40 yr) and gender. Two methods were used for the estimation of the age-adjusted mortality rate ratios. First, using the first time interval (1971-1973) as the standard, the mortality rate ratio for all malignant tumors was estimated from this interval through to the last interval (1992-1994) using Poisson regression. Cancers that were found to be related to arsenic in previous reports, such as liver, lung, bladder, kidney, and skin cancers, were examined and other malignant tumors except these cancers were also assessed. The same calculations were performed for all of Chiayi and Tainan counties, excluding the study areas, which were used as the local reference, and for the general population of Taiwan, which was used as a national reference group. Second, mortality rate ratios for the study area were compared to the local and national reference for the same time intervals for each disease category. From our results, significantly declining trends for mortality rate ratios of all malignant tumors with 1971-1973 as the standard were found for the study areas, especially in females. A decrease of mortality rate ratios from malignant cancers, compared to the local or national references, was found in those aged over 40 yr for both sexes. The decreases are mainly due to a fall in internal and skin cancer mortality rates. In conclusion, our results suggest that the improvement of drinking water supply to eliminate arsenic exposure from artesian well water decreased the mortality incidence of arsenic-related cancers in blackfoot disease endemic communities.

ISSN:1528-7394    

DOI:10.1080/009841098158322

出版商:Informa UK Ltd    

年代:1998

数据来源: Taylor

摘要:

Fishing is often perceived as an enjoyable activity, and eating fish is viewed as safe and healthful. However, with recent increases in consumption advisories because of contamination, the public is faced with whether to eat fish or not. In this article I examine the knowledge base of people fishing along the Savannah River, where South Carolina has issued consumption advisories because of mercury and radionuclides. Over 250 people fishing from the Augusta lock and dam to south of the Department of Energy's Savannah River Site (SRS) were interviewed from early April until late November 1997. Overall 82% of the fishermen thought the fish were safe to eat, even though 62% had heard some warnings about eating the fish. There were significant differences in whether people thought the fish were safe to eat as a function of income, age, education, and whether they were employed at the Savannah River Site. Significantly more fishermen thought the fish were safe who made more than $20,000/year, were over 34 yr of age, worked at SRS, and had no college or technical training, compared to others. Significantly fewer blacks had heard of consumption advisories than whites, fewer low-income people had heard, and fewer people who had not worked at SRS had heard, compared to others. Most people heard about the advisories from television, newspapers, and other people, although more blacks than whites heard about advisories from the radio. There were also significant ethnic differences in distance traveled, and in whether specific fish were frozen for later consumption. These data can be used to design an information program to target the people who may be most at risk from eating fish obtained from the Savannah River.

ISSN:1528-7394    

DOI:10.1080/009841098158331

出版商:Informa UK Ltd    

年代:1998

数据来源: Taylor

摘要:

Benzene (BZ) requires oxidative metabolism catalyzed by cytochrome P-450 2E1 (CYP 2E1) to exert its hematotoxic and genotoxic effects. We previously reported that male mice have a two-fold higher maximum rate of BZ oxidation compared with female mice; this correlates with the greater sensitivity of males to the genotoxic effects of BZ as measured by micronuclei induction and sister chromatid exchanges. The aim of this study was to quantitate levels of BZ metabolites in urine and tissues, and to determine whether the higher maximum rate of BZ oxidation in male mice would be reflected in higher levels of hydroxylated BZ metabolites in tissues and water-soluble metabolites in urine. Male and female B6C3F mice were exposed to 100 or 600 ppm 14C-BZ by nose-only inhalation 1 for 6 h. An additional group of male mice was pretreated with 1% acetone in drinking water for 8 d prior to exposure to 600 ppm BZ; this group was used to evaluate the effect of induction of CYP 2E1 on urine and tissue levels of BZ and its hydroxylated metabolites. BZ, phenol (PHE), and hydroquinone (HQ) were quantified in blood, liver, and bone marrow during exposure and postexposure, and water-soluble metabolites were analyzed in urine in the 48 h after exposure. Male mice exhibited a higher flux of BZ metabolism through the HQ pathway compared with females after exposure to either 100 ppm BZ (32.0 +/- 2.03 vs. 19.8 +/- 2.7% ) or 600 ppm BZ (14.7 +/- 1.42 vs. 7.94 +/- 0.76% ). Acetone pretreatment to induce CYP 2E1 resulted in a significant increase in both the percent and mass of urinary HQ glucuronide and muconic acid in male mice exposed to 600 ppm BZ. This increase was paralleled by three- to fourfold higher steady-state concentrations of PHE and HQ in blood and bone marrow of acetone-pretreated mice compared with untreated mice. These results indicate that the higher maximum rate of BZ metabolism in male mice is paralleled by a greater proportion of the total flux of BZ through the pathway for HQ formation, suggesting that the metabolites formed along this pathway may be responsible for the genotoxicity observed following BZ exposure.

ISSN:1528-7394    

DOI:10.1080/009841098158340

出版商:Informa UK Ltd    

年代:1998

数据来源: Taylor

摘要:

Aluminum (Al) has been said to associate with the Alzheimer's-like neurodegeneration in humans. One of the proposed mechanisms for the action of Al is that excess Al might interfere with trace metal metabolism. In this study, the levels of Ca, Mg, Cu, and Zn in blood, liver, and different regions of the brain (separated into the cortex, hippocampus, cerebellum, and brainstem) were measured in mice after daily oral administration of AlCl (100 mg/kg body weight) for 2 mo. It was found that upon prolonged oral admin3 istration of Al, serum Al level was elevated significantly. There was no marked change in serum Ca, Mg, Zn, or Cu content. In the liver, Al content was not increased but there was a significant elevation in Cu and Zn content compared to control animals, probably due to the prolonged administration of the acidic salt solution. In brain, there was a significant twofold increase in Al in the hippocampus and a significant decrease in Al in the cortex. In addition to regional changes in Al content, Zn content in the hippocampus and increased Cu content in the hippocampus, cortex, and brainstem were significantly reduced. Data demonstrated that Al could alter Zn and Cu homeostasis in selected brain regions. The possible relation between Al and neuronal cell injury was discussed.

ISSN:1528-7394    

DOI:10.1080/009841098158359

出版商:Informa UK Ltd    

年代:1998

数据来源: Taylor