The role of elevated levels of sodium in diet and drinking water on the development of hypertension in animal models and humans.
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Age Factors↗
Biomedical subjects
E J Calabrese
Publications and source records attributed to E J Calabrese.
The influence of elevated levels of sodium in drinking water on elementary and high school students in Massachusetts.
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Adolescent↗
G6PD-deficiency: a potential high-risk group to copper and chlorite ingestion.
Although humans may accept fairly large amounts of orally ingested copper (0.25 to 1.0 gm) without visible harmful effects, patients with Wilson's disease, and persons with G6PD deficiency may represent persons at unusual risk to hemolytic anemia from ingestion of Cu(II). This study reports that in vitro exposure of G6PD deficient red blood cells to copper produced marked elevations of methemoglobin and decreases in GSH when compared with normal red cells. Chlorite, a by-product of chlorine dioxide disinfection of water, produced decreases in GSH and G6PD activity, while increasing methemoglobin levels markedly over red cells with normal G6PD activity. The combined action of chlorite and copper was additive in producing increased levels of hemoglobin and decreases in levels of GSH and G6PD deficient cells. The combined ingestion of copper and chlorite may represent an increased risk to persons with G6PD deficiency.
Adult↗
Groups at potentially high risk from chlorine dioxide treated water.
Chlorite, a by-product of chlorine dioxide disinfection of water, is a strong oxidant compound that produces markedly exaggerated effects in vitro on red cells of G6PD deficient humans when compared to normal human cells. Levels of methemoglobin are significantly greater and GSH levels significantly lower in the G6PD deficient cells than in normal cells after chlorite exposure. Persons with G6PD deficiency may be 3 to 4 times more likely to develop hemolytic anemia from chlorite exposure as persons with normal activity levels when GSH levels are used as a measure of susceptibility. The proposed use of chlorine dioxide as an alternate disinfectant for drinking water supplies should consider this potential high risk group.
Adult↗
The effects of chlorine dioxide and sodium chlorite on erythrocytes of A/J and C57L/J mice.
Because chlorinated surface drinking water supplies have been implicated in an increased risk of cancer, alternative methods of disinfection are being proposed; chlorine dioxide is the most seriously considered. This study reports that chlorine dioxide exposure of two strains of laboratory mice (A/J and C57L/J) to 100 ppm chlorine dioxide in their drinking water for 30 days produced no changes in 11 hematological parameters measured. Chlorite (a product formed from chlorine dioxide disinfection) produced increases in MCV (mean corpuscular volume); osmotic fragility; G6PD (glucose-6-phosphate dehydrogenase) activity; and the number of acanthocytes at exposure to 100 ppm, but not 1.0 or 10.0 ppm. These findings are consistent with membrane damage to the red cell and, in particular, the lipid fraction. Since chlorite is formed at a rate of 50 percent of the chlorine dioxide demand, serious consideration must be given to limiting chlorite formation before chlorine dioxide is adopted as a disinfectant to replace chlorine.
Animals↗
Lead and cadmium contamination during acid preservation of water samples.
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Acids↗
Does exposure to elevated levels of lead enhance sodium induced hypertension?
Numerous community drinking water sources have elevated levels of both sodium and lead. Recently reported studies have indicated that elevated levels of sodium in drinking water may be a facter in the development of elevated blood pressure. The question of how elevated levels of lead may affect sodium induced elevated blood pressure is addressed. The hypothesis is developed which states that elevated levels of lead exposure will not interact with sodium to enhance the development of renin angiotensin aldosterone related hypertension but in fact may even diminish the effects of exposure to elevated amounts of sodium on blood pressure through a depression of plasma renin activity.
Animals↗
Conjoint use of laetrile and megadoses of ascorbic acid in cancer treatment: possible side effects.
Individuals who have a reduced capacity to detoxify cyanide to thiocyanate are at increased risk to experience adverse side effects from laetrile, a cyanide containing substance used in cancer treatment. Since megadoses of ascorbic acid may markedly diminish body stores of cysteine, a sulfur containing amino acid which facilitates the detoxification of cyanide, it is predicted that persons consuming megadoses of ascorbic acid will be at increased risk to experience the adverse side effects from laetrile treatment.
Amygdalin↗
Possible adverse side effects from treatment with laetrile.
Individuals who have a diminished capacity to detoxify cyanide to thiocyanate because of either a genetic predisposition (e.g. as occurs in those with Leber's Optic Atrophy) or a diet low in sulfur containing amino acids are predicted to be at increased risk to developing adverse side effects from laetrile, a cyanide containing substance used in cancer treatment.
Amygdalin↗
Is the role of the environment in carcinogenesis overestimated?
The dominant role of the physical and chemical environment in the development of cancer is challenged. Analyses of the etiology of skin, bladder, respiratory and gastric cancers are presented which demonstrate the considerable extent to which one's health status may modify the initiation and promotion of environmentally associated cancers. It is concluded that although environmental factors may initiate and/or promote 85 to 90 percent of all cancers this is misleading since it neglects the critical role of the individual's health status as a factor modifying carcinogenesis.
Ascorbic Acid↗
Is the selenium drinking water standard justified?
Four cases are presented which suggest that the present U.S.E.P.A. drinking water standard for selenium of 10 micrograms/L in inappropriate. The rationale upon which this standard is based is that selenium is carcinogenic, induces dental caries formation, and is highly toxic to animals. However, a critical assessment of this literature can not support these claims. Case no. 1 demonstrates that there is insufficient evidence to classify selenium as a carcinogen. Data derived from the three respective groups of researchers claiming a carcinogenic effect induced by selenium are obscure due to 1) the inability to accurately identify malignancies, 2) the apparent opposite effects of different selenium compounds, and 3) the lack of proper controls. Case no. 2 reviews recent evidence that selenium reduces the incidence of cancer in laboratory animals and in man, an effect which can probably be attributed to the antioxidant properties of selenium compounds. Case no. 3 provides evidence which does not permit the classification of selenium as a cariogenic element. Epidemiological studies supporting such a claim are inadequate since they lack properly matched control groups. Animal data do not support this link as well. Case no. 4 is a review of studies which clearly demonstrate the essentiality of selenium, an aspect of selenium metabolism that was not considered when the 10 micrograms/L standard was promulgated. In light of the four cases presented and an assessment of selenium toxicity in man, it is concluded that the 10 micrograms/L standard can not be justified. Instead, it is suggested that 50 micrograms/L selenium should provide sufficient protection from the toxic effects of this element. This is consistent with the current state of knowledge with respect to the potential adverse health effects associated with selenium.
9,10-Dimethyl-1,2-benzanthracene↗
Increased sensitivity to lead -- animal model: feline porphyria.
Individuals with the genetically inherited condition of latent porphyria have been previously hypothesized (1) as being a potential high risk group to elevated lead exposure. More specifically, persons with either clinical symptoms of porphyria or the latent form who also are exposed to excessive lead may have their clinical symptoms exacerbated or possibly induced prematurely, respectively. This paper presents evidence that an animal model (i.e., domestic cats with congenital porphyria) may facilitate the testing of the previous hypothesis.
Animals↗
Can drinking water standards be reliably derived from industrial TLVs?
The accuracy of TLV derived drinking water standards is evaluated. When using the identical TLV conversion methodology which Stokinger and Woodward (1) used in deriving the standard for barium in drinking water, standards for arsenic, cadmium, chromium and lead offer 6, 200, 60, and 10 times less protection than the present drinking water standards, respectively. However, using the same methodology, the TLV derived drinking water standard for fluoride offers greater protection than the present standard by a factor of approximately 2. Thus, the use of the TLV conversion factor should be viewed in as one of many lines of potential evidence which should be reviewed in the standard derivation process - but it should not, if at all possible, be considered alone - as in the case of barium.
Arsenic↗
Should the concept of the recommended dietary allowance be altered to incorporate interactive effects of ubiquitous pollutants?
Using ascorbic acid as a model, this paper proposes that the concept of the RDA should be broadened to take into account the effects of ubiquitous pollutants on human health, a factor presently not incorporated in RDA derivations. It is now widely accepted that ascorbic acid nutritional status markedly affects the toxicity and/or carcinogenicity of greater than 50 pollutants, many of which are ubiquitous in the air, water, and food environments. At the present time, the data do not warrant changing the ascorbic acid RDA in light of the knowledge of pollutant interactions.
Animals↗
The possible role of hypertension in aggravating hemolytic episodes in G-6PD deficient persons.
Approximately 13 percent of American Negro males carry a mutant [A-variant] glucose-6-phosphate dehydrogenase enzyme in their red blood cells that predisposes them to hemolytic episodes following exposure to oxidant drugs such as primaquine. Most hemolytic episodes to standard prophylactic treatment are mild and self-limited, but as many as 2 percent of Negro males develop severe hemolysis when similarly treated. The exaggerated response may be due in part to the combination of G-6-PD deficiency and hypertension since hypertension can cause red cell fragmentation, and the stressed cells of G-6-PD deficient person would be more sensitive to such fragmentation.
Anemia, Hemolytic, Congenital↗
Can elevated levels of copper in drinking water precipitate aucte hemolysis in G-6-PD deficient individuals?
The hypothesis that elevated levels of copper in drinking water may be a factor in the precipitation of acute hemolysis in those with a G-6-PD deficiency in their erythrocytes is developed. The present U.S. EPA drinking water standards do not have a primary (or human health) standard for copper but only a secondary standard which is designed to prevent an unacceptable taste. Because of the widespread occurrence of elevated levels of copper in drinking water in areas where the water is corrosive and the households have copper piping, it is recommended that environmental health regulatory agencies develop a risk assessment concerning the effects of copper on those high risk groups who are predisposed to develop a copper induced hemolysis.
Copper↗
The influence of ambient ozone on the incidence of bone fractures especially among the elderly.
Elevated levels of breatheable ozone will reduce the amount of UV radiation in the range of 280-305 nm reaching the surface of earth. This range of UV converts the provitamin 7-dehydrocholesterol to vitamin D, within the human. Since most typical diets contain low levels of vitamin D, the role of UV related vitamin D synthesis in the skin is considered to provide very important contributions to the total vitamin D content of the blood. Thus, elevated levels of ambient ozone should result in a decreased level of vitamin D synthesis which may be expressed as an increase in the incidence of histological osteomalacia and ultimately bone fractures, especially among the elderly.
Aged↗
Age as a function in the development of sodium-related hypertension.
The populations of the developed nations of the world exhibit an increase in blood pressure with age, while in primitive societies blood pressure remains relatively constant throughout adult life. Hypertension may be a complex of diseases all having the same clinical manifestations but not being caused necessarily by the same factors. A possible common denominator in the development of any chronic elevation of blood pressure is the need for the kidney to increase urine volume to promote sodium excretion and, thereby, prevent a chronically expanded extracellular fluid (ECF). Hypertension may be viewed as a maladaptation of the body in its attempt to maintain homeostasis of the ECF. Man evolved under conditions of relative scarcity of salt and even now can maintain normal body function with an intake of less than 2 g/day. The high risk person appears to have a hereditary predisposition to a rise in blood pressure in the presence of a high sodium (NaCl) intake. Actually, the degree of rise in blood pressure may be an interaction between the amount of genetic predisposition and the level of sodium and its relation to potassium intake. Recent work in two Massachusetts communities supports this interpretation and suggests that differences in blood pressure distribution may increase with age between a higher and lower sodium community.
Adolescent↗