Nachman Gruener

A sensitive micromethod for the determination of methemoglobin in blood.

Abstract A modification of the Evelyn and Malloy method for the determination of methemoglobin in blood is presented. A higher precision of the assay is achieved, and sample stability is increased up to 24 h, thus making the procedure suitable for field surveys aimed at detecting slightly raised methemoglobin levels.

A micromethod for the determination of nitrite in blood

Abstract The diazotization-coupling reaction for the determination of nitrite is modified and adapted for micro-analysis of blood and plasma. The limit of detection by the proposed method is 0.01 μg of nitrite-nitrogen and only 0.1 ml of blood is needed for analysis. The results showed high reproducibility; the standard deviation at nitrite concentrations of 1–6 μg ml′-1 varied from 0.025 to 0.110. Some applications of the method showing the recovery of nitrite from blood and its components are discussed.

Infant methemoglobinemia and other health effects of nitrates in drinking water

SUMMARY Nitrates in water supplies in concentrations over 45 mg/1 (as NO3) have led to numerous cases of infant methomoglobinemia, particularly in infants up to six months of age, whose main liquid intake is powdered milk formula made up with tap water containing high concentrations of nitrates. Other possible negative health effects associated with the ingestion of nitrates in water for extended periods have been detected in animal studies including changes in heart blood vessels, and behavioral effects. The possible association of nitrates in water with the formation of the potent carcinogens nitrosamines, is still to be determined. However, sufficient evidence is presently available to support the strict adherence to current nitrate drinking water stanard of 45 ppm.

Air and blood lead levels in a battery factory

Blood lead (Pb B) and air lead (Pb A) exposure levels were studied in workers (62) in a battery plant. Thirty-five battery workers had Pb B higher than 60 μg/100ml (OSHA Proposed Biologic Limit Value, (BLV), 1975). Fifty-eight workers had Pb Bs exceeding 40 μg/100 ml (OSHA Proposed BLV, 1978). Average Pb A for 33 battery workers was greater than 100 μg/m3, the newly recommended TWA. Average Pb A of approximately 50 μg/m3, (6 workers), 85 μg/m3 (17 workers), and 190 μg/m3 (10 workers) were associated with virtually identical mean Pb B (55.0, 59.5, and 58.4 μg/100ml). For 10 of 29 battery workers, Pb A less than 100 μg/m3 was associated with Individual Pb B greater than 60 μg/100 ml. At exposure levels of 329 μg/m3 (15 workers), 885 μg/m3 (3 workers), and 1187 μg/m3 (4 workers), associated mean Pb B was 75.2, 76.3, and 90.7 μg/100 ml, respectively. Complaints of fatigue, headache, abdominal pain, and loss of appetite were more frequent among 35 workers with Pb B > 60 μg/100 ml compared to 26 workers with Pb B < 60 μg/100 ml (relative risks 1.5, 1.4, 1.9, and 1.9, respectively). The relationship between group Pb A and individual Pb B was expressed by the equation: log Pb B (μg/100 cc) = 1.430 + 0.165 × log Pb A (μg/m3), r = 0.69. Battery factory data do not support the assumption that if Pb A were kept at or below 100 μg/m3, the blood lead levels would be less than 60 μg/100 ml.

Ontogenetic development of NADH-dependent methemoglobin reductase in erythrocytes of man and rat.

Ontogenetic development of NADH-dependent methemoglobin reductase was followed in humans and rats. The human kinetic profile differs from that in the rat. The low level of methemoglobin reductase in human infants at birth and for the first months of life may provide a partial explanation of the particular susceptibility to methemoglobinemic agents of this age group.

The effect of changes in nitrate concentration in drinking water on methemoglobin levels in infants

For a five‐day period infants consuming powdered milk formula made up with tap water were exposed to water of controlled nitrate content. There was a significant rise in MetHb levels above normal in most children after the first day of exposure to high nitrate water (108 mg/1 NO3). This was followed by some indication of a drop in MetHb levels despite the continued exposure and finally a return to normal levels when the exposure to nitrates stopped. No clinical signs of methemoglobinemia developed. The possible existence of an adaption mechanism is suggested but requires further elucidation.

The effect of nitrites on isolation-induced aggression in mice

Abstract Chronic administration of sodium nitrite (1 g/1) in drinking water of pregnant mice and their offspring caused a significant increase in the isolation-induced aggression of the male young. The cessation of administration of sodium nitrite reduced the aggressive behavior of the experimental group to the control level.

The effect of chronic exposure to sodium nitrite on the electroencephalogram of rats

Abstract Brain electrical changes were observed in rats chronically treated with NaNO2 in drinking water ranging in concentration from 100 to 2000 mg/l. The brain electrical patterns did not return to normal after the withdrawal of NaNO2, even at the lowest exposure dose of 100 mg/liter which was equivalent to a daily dose of 14 mg/kg. Each concentration of NaNO2 drinking solution presented a characteristic picture of its own, i.e., in the unfolding electroencephalogram several types of changes became discernible tallying with the specific dosages of NaNO2 drinking solutions consumed by the rats, having a strong common denominator. These brain electrical activity changes are discussed in this paper.