Cancer mortality and asbestos deposits

Asbestos deposits are found in many parts of the United States. In this paper the question is asked: Is there an increase in risk from cancer associated with naturally-occurring asbestos? In an attempt to control for the urban effect, geographic gradient and socioeconomic class, each county in the United States with asbestos deposits was matched for percent of area that was urban and for median years in school with two nearby counties that did not have known asbestos deposits. The study of cancer mortality rates in these matched counties provides no evidence that naturally-occurring asbestos is a great hazard to the general population of counties with asbestos depostis.     

Cancer mortality in a Chinese population exposed to hexavalent chromium in water

In the neuronal activation study of normal animals, precise anatomical correlation, preferentially to a detailed brain atlas, is required for the activation foci co-registration. To obtain precise regional correlation between H(2)15O-PET images and the brain atlas, a method of stereotaxic image reorientation was applied to an activation study with vibrotactile stimulation. Cats anesthetized with halothane underwent repeated measurements of regional cerebral blood flow (rCBF) in the resting condition and during vibration of the right forepaw. The image set was adjusted three-dimensionally to the atlas. The postmortem brain was sectioned according to the atlas planes. The activated areas were determined by the stimulus-minus-resting subtraction images, and the areas were projected to the atlas. The PET images of the cat brain were compatible both to the postmortem brain slices and to the brain atlas. The activation foci obtained from the subtraction images corresponded to the area around the coronal sulcus, which is electrophysiologically known as the primary sensory area as described in the atlas. There were precise regional correlations between the PET image and anatomy in a PET activation study of the cat by means of stereotaxic image reorientation.     

Cancer mortality in relation to monitoring for radionuclide exposure in three UK nuclear industry workforces

Cancer mortality in 40,761 employees of three UK nuclear industry facilities who had been monitored for external radiation exposure was examined according to whether they had also been monitored for possible internal exposure to tritium, plutonium or other radionuclides (uranium, polonium, actinium or other unspecified). Death rates from cancer were compared both with national rates and with rates in radiation workers not monitored for exposure to any radionuclides. Among workers monitored for tritium exposure, overall cancer mortality was significantly below national rates [standardized mortality ratio (SMR) = 83, 165 deaths; 2P = 0.02] and none of the cancer-specific death rates was significantly above either the national average or rates in non-monitored workers. Although the overall death rate from cancer in workers monitored for plutonium exposure was also significantly low relative to national rates (SMR = 89, 581 deaths; 2P = 0.005), mortality from pleural cancer was significantly raised (SMR = 357, nine deaths; 2P = 0.002); none of the rates differed significantly from those of non-monitored workers. Workers monitored for radionuclides other than tritium or plutonium also had a death rate from all cancers combined that was below the national average (SMR = 86, 418 deaths; 2P = 0.002) but prostatic cancer mortality was raised both in relation to death rates in the general population (SMR = 153, 37 deaths; 2P = 0.02) and to death rates in radiation workers who had not been monitored for exposure to any radionuclide [rate ratio (RR) = 1.65; 2P = 0.03]. Mortality from cancer of the lung was also significantly increased in workers monitored for other radionuclides compared with those of radiation workers not monitored for exposure to radionuclides (RR = 1.31, 164 deaths; 2P = 0.01). For cancers of the lung, prostate and all cancers combined, death rates in monitored workers were examined according to the timing and duration of monitoring for radionuclide exposure, with rates of radiation workers not monitored for any radionuclide forming the comparison group. In tritium-monitored workers, RRs for prostatic cancer varied significantly according to the number of years in which they were monitored (2P = 0.03). In workers monitored for plutonium exposure, RRs for all cancers combined increased with the number of years in which they were monitored (2P = 0.04) and with the number of years since first monitoring (2P = 0.0003). There was little suggestion of systematic variation in RRs for workers monitored for other radionuclides in relation to the timing or duration of monitoring, nor did it appear that their raised rates of cancer of the lung and prostate were explained by external radiation dose. These analyses of cancer mortality in relation to monitoring for radionuclide exposure reported in a large cohort of nuclear industry workers suggest that certain patterns of monitoring for some radionuclides may be associated with higher death rates from cancers of the lung, pleura, prostate and all cancers combined. Some of these findings may be due to chance. Moreover, because of the paucity of related data and lack of information about other possible exposures, such as whether plutonium workers are more likely to be exposed to asbestos, firm conclusions cannot be drawn at this stage. Further investigations of the relationship between radionuclide exposure and cancer in nuclear industry workers are needed.     

市政供水工程中长距离输水问题探讨

结合工程实例对长距离输水工程中的系统设计、管材选择、水锤防护等方面进行了阐述。     

Rural water supplies: what ways and means?

The development of rural water supplies in Finland is outlined, with particular reference to consumer-managed cooperatives. Lessons are drawn which could be of value in developing countries.     

冶炼厂工业用水供水系统的节能改造

针对冶炼厂工业水供水系统存在的问题，提出了利用PLC和计算机自动控制的改造方案。通过实践，取得了显著的节能效果。     

Postoperative fistulas after gastrectomy: risk factors in relation to incidence and mortality

The relations between incidence and prognosis of postoperative fistulas after gastrectomy and some different variables were analysed in the present retrospective study. Thirteen digestive fistulas of 113 patients (11.9%) submitted to gastrectomy during the period 1989-1994 represent the study population. The incidence of postoperative fistulas was compared to the kind of gastric pathology, to the extension of gastrectomy, to different nutritional (serum haemoglobin, albumin and transferrin level, weight loss) and immunological factors (serum lymphocytes) and, for oncological patients, to the stage of the disease. Incidence was directly related to the extension of gastrectomy, to serum albumin and haemoglobin level, and to weight loss rate. The results were not statistically significant at Kruskal-Wallis and ANOVA tests. No relation was found between incidence of fistulas and serum transferrin level, number of lymphocytes and adoption of early postoperative enteral nutrition. Six patients had spontaneous closure of the fistula with conservative therapy. Seven patients required reoperation because of abdominal sepsis (53.8%). Three patients died (23%). Although spontaneous closure, reoperation and mortality were related to nutritional and immunological state, no examined variables showed a statistically significative relation. The adoption of early postoperative enteral nutrition was not related to the prognosis, unlike the stage of the disease: patients submitted to reoperation had a TNM III or IV stage; dead patients had a TNM IV stage. Treatment of metabolic-nutritional unbalance can prevent anastomotic failure and fistula after gastrectomy and improve the prognosis. The relation between early postoperative enteral nutrition and incidence and prognosis of postoperative fistulas remains unclear.     

Insulation workers in Belfast. A further study of mortality due to asbestos exposure (1940-75)

A follow-up study of 162 men already working as insulators (laggers) in 1940 has been extended from 1965 to 1975. By the end of 1975 there were 40 survivors when 108 had been expected. Until 1965 there had been an overall excess of deaths; these were due to asbestosis with or without tuberculosis and to alimentary cancer, as well as to bronchial carcinoma and mesothelioma. From 1965 onwards the overall death rate among survivors is not so excessive but there is still a marked excess of deaths from bronchial cancer and mesothelioma. The continued risk of death attributable to malignancy after asbestosis had ceased to contribute directly, does not appear to be caused by any changes which occurred before 1940 in the conditions at work.     

Nutritional and socioeconomic factors in relation to prostate cancer mortality: a cross-national study

BACKGROUND: Large international variations in rates of prostate cancer incidence and mortality suggest that environmental factors have a strong influence on the development of this disease. The purpose of this study was to identify predictive variables for prostate cancer mortality in data from 59 countries. METHODS: Data on prostate cancer mortality, food consumption, tobacco use, socioeconomic factors, reproductive factors, and health indicators were obtained from United Nations sources. Linear regression models were fit to these data. The influence of each variable fit in the regression models was assessed by multiplying the regression coefficient b by the 75th (X75) and 25th (X25) percentile values of the variable. The difference, bX75 - bX25, is the estimated effect of the variable across its interquartile range on mortality rates measured as deaths per 100000 males aged 45-74 years. Reported P values are two-sided. RESULTS: Prostate cancer mortality was inversely associated with estimated consumption of cereals (bX75 - bX25 = -7.31 deaths; P = .001), nuts and oilseeds (bX75 - bX25 = -1.72 deaths; P = .003), and fish (bX75 - bX25 = -1.47 deaths; P = .001). In the 42 countries for which we had appropriate data, soy products were found to be significantly protective (P = .0001), with an effect size per kilocalorie at least four times as large as that of any other dietary factor. Besides variables related to diet, we observed an association between prostate cancer mortality rates and a composite of other health-related, sanitation, and economic variables (P = .003). CONCLUSIONS: The specific food-related results from this study are consistent with previous information and support the current dietary guidelines and hypothesis that grains, cereals, and nuts are protective against prostate cancer. The findings also provide a rationale for future study of soy products in prostate cancer prevention trials.     

Cancer surveillance with particular reference to the uses of mortality data

As it is impossible to use alveolar CO as an useful index of the exposure to ambiant CO in smokers, young children between 8 and 11 were used in this study, who had no contact with smoking. In a sample of 306 schoolchildren living in rural or urban areas, it was shown: a) that the technique which is usually employed in adults to get a sample of alvelolar air was applicable to young children, b) that alveolar CO concentrations did reflect very closely in these children ambiant CO concentrations, c) that smoking habits of parents have to be taken into account before assessing the relationship between alveolar CO concentrations and exposure.     

Drinking water and cancer mortality in Louisiana

Multivariant regression analysis indicates a statistically significant relation between cancer mortality rates in Louisiana and drinking water obtained from the Missippi River. This is true for total cancer, cancer of the urinary organs, and cancer of the gastrointestinal tract.     

Macro-to-micro links in the relation between income inequality and mortality

A growing literature points to links between income inequality and mortality. Any examination of the link should distinguish, both theoretically and empirically, between shifts in inequality that result from changes in the bottom and top of the income distribution. When state-level data from the U.S. censuses of 1980 and 1990 were used to measure differences in mortality, the results indicated that inequality measures reflecting depth of poverty show stronger correlations with mortality than do inequality measures reflecting heights of affluence. In addition, longitudinal data from the Panel Study of Income Dynamics were used to related state-level inequality measures to individual-level data on mortality. This comparison revealed significant associations between degree of income inequality in state of residence and individual risk of death only for nonelderly individuals with middle-class incomes in 1990.