Molecular handling of cadmium in transporting epithelia

Organic substances in potable water and in its precursor. I. Methods for their determination by gas-liquid chromatography.

Controlling cadmium in the human food chain: A review and rationale based on health effects

This article provides a review of available information on the chemistry, environmental toxicology, and mammalian toxicology of nitrilotriacetic acid (NTA). The ability of NTA to chelate metal ions such as Mg++ and Ca++ into water soluble complexes makes NTA useful as an additive to boiler water, as a builder in laundry detergents, and as a stabilizer in textile, paper, and pulp processing. Environmental fate studies show NTA biodegrades in wastewater treatment plants, in natural waters, and in soils under a wide variety of conditions. Studies on the environmental effects of NTA indicate that no adverse effects occur in treatment plants or receiving waters at anticipated levels. Monitoring programs have established that only low steady-state concentrations of NTA occur in natural waters as a result of NTA usage. In mammalian systems, NTA is not metabolized and is excreted rapidly by filtration in the kidney. No reproductive, teratogenic, or adverse bone effects have been observed at highly exaggerated doses. In numerous genotoxicity assay systems, both in vivo and in vitro, NTA is nongenotoxic. Chronic oral exposure of rodents to high doses of NTA is associated with tumorigenicity in, and restricted to, the urinary tract. The urinary tract tumors are the consequence of chronic toxicity that is caused by changes in Zn and Ca distributions between the urinary tract tissues and urine at high doses of NTA. Thresholds for the effects of NTA on Zn and Ca distributions are 10(5) to 10(6) greater than the possible maximum human exposure resulting from the low levels of NTA that are known to occur in the environment.

A Review of the Environmental and Mammalian Toxicology of Nitrilotriacetic Acid

In order to recommend the levels of lead concentration in fresh water which will not adversely affect various water uses, a literature survey was carried out on the toxic effects of lead and lead compounds on human health, laboratory animals, aquatic life, terrestrial plants and livestock. The information is summarized in this paper.

Toxic effects of lead and lead compounds on human health, aquatic life, wildlife plants, and livestock

As no major investigation has reported the signs of cadmium toxicity in sheep, the following experiment was undertaken Thirty male lambs were allotted by weight into five lots of six and fed ad libitum diets for 191 days The diets contained 0, 5, 15, 30 and 60 pm of cadmium Dietary cadmium at 30 and 60 ppm had a significant effect on growth rate and feed intake but no effect on feed efficiency Apparent absorption of the metal was 5% in the 60 ppm group Excretion in the urine and reexcretion in the bile of cadmium was negligible Little cadmium accumulated in blood, fat or muscle but cadmium accumulated in large quantities in liver and kidney Blood hematocrit was significantly lower and dry liver weight significantly higher at the highest level of cadmium intake when compared with controls Dietary cadmium had no significant effect on wool cadmium 30 references, 9 tables

Effect of dietary cadmium on growth, cadmium absorption and cadmium tissue levels in growing lambs.

The determination of part-per-billion levels of citric and nitrilotriacetic acids in tap water and sewage effluents.

Toxic heavy metals in vegetables and forage grasses in Missouri's lead belt.

A procedure is described for the determination of submicrogram. quantities of mercury in urine. The method is based on the absorption of the 2537 A mercury resonance line. The urine specimens are extracted by an ammonium pyrrolidino dithiocarbamate/methyl/isobutyl ketone (APDC/MIBK) system and the MIBK extract is evaporated on a tantalum boat. The mercury is detected by an atomic absorption spectrophotometer. Measurement of the absorption peak height is used to determine the quantity of mercury present. A 50 ml urine sample is required, which allows for many replicate runs.

Determination of Mercury in Urine by Atomic Absorption

A discussion of the application of plastic bags is presented along with results of an experiment in which two plastic film materials were used to contain the vapors of four different chemicals at concentrations bracketing the current (1969) TLV. The four chemicals—benzene, methyl alcohol, methyl isobutyl ketone, and methylene chloride—are members of classes of important compounds used in many industrial applications. Additional studies using reactive mixtures under various environmental conditions are needed to determine retention characteristics under conditions similar to the conditions under which the samples are collected or standards prepared.

James O. Pierce

Papers

Effect of dietary cadmium on growth, cadmium absorption and cadmium tissue levels in growing lambs.

The determination of part-per-billion levels of citric and nitrilotriacetic acids in tap water and sewage effluents.

Toxic heavy metals in vegetables and forage grasses in Missouri's lead belt.

Determination of Mercury in Urine by Atomic Absorption

The Use of Plastic Bags for Industrial Air Sampling