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Safety Limit (safety + limit)
Selected AbstractsSkeletal Fluorosis From Instant Tea,,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 5 2008Michael P Whyte MD Abstract Introduction: Skeletal fluorosis (SF) can result from prolonged consumption of well water with >4 ppm fluoride ion (F,; i.e., >4 mg/liter). Black and green teas can contain significant amounts of F,. In 2005, SF caused by drinking 1,2 gallons of double-strength instant tea daily throughout adult life was reported in a 52-yr-old woman. Materials and Methods: A 49-yr-old woman developed widespread musculoskeletal pains, considered fibromyalgia, in her mid-30s. Additionally, she had unexplained, increasing, axial osteosclerosis. She reported drinking 2 gallons of instant tea each day since 12 yr of age. Fluoxetine had been taken intermittently for 5 yr. Ion-selective electrode methodology quantitated F, in her blood, urine, fingernail and toenail clippings, tap water, and beverage. Results: Radiographs showed marked uniform osteosclerosis involving the axial skeleton without calcification of the paraspinal, intraspinal, sacrotuberous, or iliolumbar ligaments. Minimal bone excrescences affected ligamentous attachments in her forearms and tibias. DXA Z-scores were +10.3 in the lumbar spine and +2.8 in the total hip. Her serum F, level was 120 ,g/liter (reference range, 20,80 ,g/liter), and a 24-h urine collection contained 18 mg F,/g creatinine (reference value, <3). Fingernail and toenail clippings showed 3.50 and 5.58 mg F,/kg (control means, 1.61 and 2.02, respectively; ps < 0.001). The instant tea beverage, prepared as usual extra strength using tap water with ,1.2 ppm F,, contained 5.8 ppm F,. Therefore, the tea powder contributed ,35 mg of the 44 mg daily F, exposure from her beverage. Fluoxetine provided at most 3.3 mg of F, daily. Conclusions: SF from habitual consumption of large volumes of extra strength instant tea calls for recognition and better understanding of a skeletal safety limit for this modern preparation of the world's most popular beverage. [source] Alcohol Consumption, Lung Function, and Quality of Life in PneumoconiosisALCOHOLISM, Issue 7 2005Wai Kwong Tang Background: To our knowledge, there are no previous data on drinking problems in patients with pneumoconiosis. The aim of this study was to examine drinking patterns and the impact of drinking on lung function and health-related quality of life (HRQOL) in Chinese patients with pneumoconiosis. Methods: Three hundred patients with pneumoconiosis were recruited from a community-based case registry. The HRQOL was measured with the St. George's Respiratory Questionnaire (SGRQ). Pulmonary function, comorbidity, and psychosocial variables were also assessed. The alcohol use of the patients was evaluated with the Alcohol Use Disorders Identification questionnaire. Results: Of the 300 patients, 72.3% (217) reported that they had not consumed any alcohol during the past year, whereas 83 patients (27.7%) did report drinking alcohol. In the drinking group, 88.0% (73) consumed <7 standard drinks per week, and none of them exceeded the safety limit of 21 standard drinks per week. The drinking group (n= 83) was younger, had less concurrent medical diseases, and lower (i.e., better) unadjusted SGRQ symptom, activity, impact, and total scores than the nondrinking group (n= 217). The SGRQ scores, which were adjusted for age, duration of occupation, concurrent medical diseases, smoking status, and forced expiratory volume in 1 sec predicted tests (FEV1%), remained significantly lower for the drinking group. Although the drinking group had a higher unadjusted FEV1% predicted, the difference between the FEV1% of the two groups, after adjustment for covariates, was of borderline significance only. Conclusions: Most Chinese patients with pneumoconiosis in this study did not consume alcohol, and among those who did, the level of alcohol consumption was low. This low level of alcohol consumption was associated with a better HRQOL and possibly with better lung function. [source] Maximum limits of organic and inorganic mercury in fish feedAQUACULTURE NUTRITION, Issue 2 2004M.H.G. Berntssen Abstract The relatively high levels of mercury found in fish feeds might form a fish health and food safety risk. The present study aims to establish sublethal toxic threshold levels in fish and assess feed-fillet transfer of dietary mercury. Atlantic salmon (Salmo salar L.) parr were fed for 4 months on fish meal-based diets supplemented with mercuric chloride (0, 0.1, 1, 10 or 100 mg Hg kg,1 dry weight (DW)) or methylmercuric chloride (0, 0.1, 0.5, 5 or 10 mg MeHg kg,1 DW). At the end of the experiment, dietary inorganic mercury mainly accumulated in intestine (80% of body burden) and assimilation was low (6%). In contrast, methylmercury readily accumulated in internal organs and muscle (80% of body burden) and had a relatively high assimilation (23%). Highest accumulation of dietary inorganic mercury was observed in the gut and kidney. Fish fed 10 mg Hg kg,1 had an early (after 2 months) significant increase in renal metallothionein (MT) level and intestinal cell proliferation, followed by intestinal pathological conditions after 4 months of exposure. At 100 mg Hg kg,1, intestinal and renal function were reduced as seen from the significantly reduced protein and glycogen digestibility and increased plasma creatinine levels. For dietary methylmercury (MeHg), highest accumulation was found in blood and muscle. Intestinal cell proliferation and liver MT significantly increased at 5 mg MeHg kg,1 after 2 months of exposure. At the end of the experiment, blood haematology was significantly affected in fish fed 5 mg MeHg kg,1 and these fish exceeded the current food safety limit for mercury. Tissue MT induction and intestinal cell proliferation appeared to be useful and quantifiable early indicators of toxic mercury exposures. Based on the absence of induction of these early biological markers such as MT and cell proliferation, nonobserved effect levels (NOELs) could be set to 0.5 mg Hg kg,1 for dietary methylmercury and 1 mg Hg kg,1 for inorganic mercury. Lowest observed effect levels (LOELs) levels could be set to 5 mg kg,1 for methylmercury and 10 mg Hg kg,1 for inorganic mercury. [source] Safety evaluation of individual non-fried and fried sunflower oil, paraffin oil, jojoba oil and their binary mixtures on rat healthINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 10 2008Radwan S. Farag Summary Sunflower, jojoba, paraffin oils and binary oil mixtures of sunflower, jojoba and sunflower,paraffin oils were continuously heated at 180 °C for 12 h. Aliquots of potato chips were fried in the aforementioned oil samples. Organoleptic tests were performed on fried chips and safety limits of the oil samples were measured by certain biochemical tests. Histopathological examinations of rat liver and kidney tissues were microscopically done. Organoleptic results for fried potato chips indicate that all types of chips obtained from heated oils were categorised good. Histopathological examinations indicate changes in rat tissues of liver and kidney paralleled the biochemical data. In general, the results suggest that paraffin oil alone and in mixtures with sunflower oil have to ban its use in frying processes. [source] Plasma membrane permeabilization by 60- and 600-ns electric pulses is determined by the absorbed doseBIOELECTROMAGNETICS, Issue 2 2009Bennett L. Ibey Abstract We explored how the effect of plasma membrane permeabilization by nanosecond-duration electric pulses (nsEP) depends on the physical characteristics of exposure. The resting membrane resistance (Rm) and membrane potential (MP) were measured in cultured GH3 and CHO cells by conventional whole-cell patch-clamp technique. Intact cells were exposed to a single nsEP (60 or 600 ns duration, 0,22 kV/cm), followed by patch-clamp measurements after a 2,3 min delay. Consistent with earlier findings, nsEP caused long-lasting Rm decrease, accompanied by the loss of MP. The threshold for these effects was about 6 kV/cm for 60 ns pulses, and about 1 kV/cm for 600 ns pulses. Further analysis established that it was neither pulse duration nor the E-field amplitude per se, but the absorbed dose that determined the magnitude of the biological effect. In other words, exposure to nsEP at either pulse duration caused equal effects if the absorbed doses were equal. The threshold absorbed dose to produce plasma membrane effects in either GH3 or CHO cells at either pulse duration was found to be at or below 10 mJ/g. Despite being determined by the dose, the nsEP effect clearly is not thermal, as the maximum heating at the threshold dose is less than 0.01 °C. The use of the absorbed dose as a universal exposure metric may help to compare and quantify nsEP sensitivity of different cell types and of cells in different physiological conditions. The absorbed dose may also prove to be a more useful metric than the incident E-field in determining safety limits for high peak, low average power EMF emissions. Bioelectromagnetics 30:92,99, 2009. © 2008 Wiley-Liss, Inc. [source] | ||||||||||