David W. Yeager

Lead in human tissues

Abstract Tissues from 46 white males from the Cincinnati area have been analyzed for lead content. Tissue sections and procedures were standardized and detailed information was obtained in order to account for variables such as age, postmortem changes, type of death and pathological conditions. This report focuses on the lead concentrations found in 29 tissues from each person deceased, including their changes with age, and compares the results with those found in the literature. Although lead concentrations in calcified tissues increased with age, in several tissues the lead concentrations decreased. Some of these decreases were associated with aging and pathological changes. Dense bone lead content increased steadily with age, while spongy bone lead leveled off or decreased in later years. The apparent body burden of lead of this population sample was less than that reported by others. Many of these individuals (70% or more) seemed to be in lead balance with their environment.

Total body burdens and tissue concentrations of lead, cadmium, copper, zinc, and ash in 55 human cadavers.

Trace metal contents of human tissues and total body burdens are useful for studies of nutrition and certain diseases. Data are summarized and analyzed for individuals exposed to the normal Cincinnati environment, for 29 tissues from 55 cadavers for lead and ash concentrations, and from 26 cadavers for cadmium, copper, and zinc concentrations. Total body burdens also were calculated and correlated against each other and age. The distributions for ash, copper, and zinc were close to normal, but those for lead and cadmium were closer to lognormal. Bone lead increased with age, whereas soft tissue lead did not. The calculated mean percentage of total body lead in the bones ranged from 78% at age 20 to 96% at age 80. Correlations of blood concentrations with total body burdens were negligible for cadmium and zinc. For copper the correlation coefficient was a poor 0.54. For lead in blood vs soft tissue burden it was a very poor 0.37, and vs total body lead it was negligible. Thus the use of blood samples as a convenient clinical measure of body burdens for these metals may be of limited value. These and other findings provide a useful bank of information for health studies.

Interference of Pb with essential brain tissue Cu, Fe, and Zn as main determinant in experimental tetraethyllead encephalopathy

Abstract After exposure of rabbits to tetraethyllead, each analyzed brain area (frontal cortex, cerebellum, hippocampus) contained approximately 33 μg of lead per gram dry weight. At the same time, there was a statistically significant loss in the same brain areas of the essential elements, copper, iron, and zinc. While the molar ratio between gain of lead and decrease of copper revealed an approximate proportionality of 1:1, the ratio between lead and iron was approximately 1:2. The decrease of zinc levels varied in these brain areas and was lowest in the inferior hippocampus. The potentiality of an interference of lead with essential trace metals of the brain, preferentially with the metal group of metalloenzymes, as the primary and dominant mechanism of the toxic action of lead in lead encephalopathy, is discussed.

Cadmium in liver, kidney, and hair of humans, fetal through old age

Cadmium concentrations were measured in the liver, kidney, and hair of 107 individuals from the Cincinnati area. The tissue samples were obtained from hospital and coroner autopsy cases and represent a cross-section of individuals from fetal to old age. The sections used were standardized and analyzed for cadmium by atomic absorption. Information obtained at the time of autopsy included the cause of death, the conditions of the tissues, the body height and weight, the amount of anthracosis in the lungs, as well as age, sex, and race. The liver concentrations increased steadily until the late decades. The kidney concentrations increased to the fourth decade, peaked, and decreased steadily from the sixth decade thereafter. The leveling effect in the liver may have been due to the increased presence of fatty livers, and the kidney decreases to nephrosclerosis. The kidney and liver were statistically well correlated. Hair, which achieved a surprisingly high Cd concentration in early infancy, tended to decrease throughout the rest of the age span and correlated poorly with the liver and kidney. There seemed to be no relationship between the amount of pulmonary anthracosis and the cadmium found in any of the tissues. The results obtained here for liver and kidney were in line with other reports in the literature; however, the hair results were somewhat different.

Concentrations of six metals in the air of eight cities

During 1968-1971, 8763 samples were collected at 59 sites in US cities for a study of particulate lead concentrations in air. Each site was sampled continuously for a full year. These samples have been analyzed for total suspended particulate matter and for cadmium, chromium, lead, manganese, nickel, and zinc. Results of over 42,000 analyses are summarized in convenient graphical form, showing geometric means, geometric standard deviations, maxima, and minima. Supplementary tables present these data and cumulative frequency distributions. This historical data base should be a useful reference to determine effects of changes in fuel consumption patterns and trends. It presents a uniquely extensive cross-sectional picture of trace metal concentrations determined by a single highly experienced laboratory. Results were compared with available recent data for 17 identical sites. Recent lead concentrations averaged 35% of the older values, and some reductions occurred in concentrations of other metals.

The Air Transport of Lead Compounds Present in Automobile Exhaust Gases

Abstract The movement of particulate lead compounds from the exhausts of gasoline-driven motor vehicles on a heavily travelled high-speed roadway (120,000 vehicles/24 hours) is under investigation in the Cincinnati area. The findings for the first year of the investigation indicate an average concentration of 7.8 micrograms/m3 at the roadway, 1.7 micrograms/m3 1300 feet to the leeward, and 1.1 micrograms/m3 at the station, 11000 feet leeward of the source of the lead. The concentration of lead in the air at the latter station is approximately the same as that of six years ago, as reported in the Public Health Service Publication No. 999-AP-12. The mass median equivalent diameter of the lead particles was found to be approximately 0.30 micron, with 70% of the lead being in the particles below 1 micron in diameter. Diurnal patterns reflected rush hour traffic as well as climatic conditions. Concentrations of lead in soils and grasses varied according to the distance from the roadway, with most of the contam...

The Determination of Cadmium in Biological and Related Material by Atomic Absorption

The extraction AAS procedure used for the determination of lead in biological and related material has been adapted with only a minor modification to the determination of cadmium in body tissues and in fluids, water, foods, and airborne dusts. The modification involved an adjustment of volume to decrease the concentration effect, noted when a relatively large volume of distilled water was used to bring the MIBK layer into the neck of the volumetric flasks. A sensitivity of 0.010 ppm can be attained, and accuracies of analysis range from ±10% for fractions of a microgram of cadmium to about ±4% for microgram quantities of cadmium. Because of the known association of cadmium with some lead ores, one hundred samples of blood from workers in various lead industries were analyzed. No relationship between the concentrations of lead and cadmium was found. Further, after deletion of ten obviously aberrant results, a mean concentration of 0.2 μg of cadmium per 100 ml of blood was obtained for the remaining ninety ...

Reproducibility and Quality Control in the Analysis of Biological Samples for Lead and Mercury

A simple statistical calculation was applied to 8 years of data on routine control sample and duplicate analyses from a laboratory quality control program. This provided standard deviations truly representative of this laboratory at no additional analytical expense, and accurate information on how they varied with concentrations. From these, the detection limit of the method, upper warning limits, and upper control limits for differences between duplicate analyses were calculated. These values were conveniently used for quality control in determinations of lead in blood and of mercury in urine.

Exposures to Beryllium in a Beryllium Alloying Plant

Abstract Continuous monitoring of the air at seven representative work locations in a beryllium alloying plant during a five-day period in 1960 showed that concentrations of beryllium in the air at all locations greatly exceeded the TLV of 2 micrograms per cubic meter of air. A similar survey during 1966 also yielded concentrations which exceeded the TLV for the greater portion of the time. Studies of the range of sizes of particles present in the air indicated that the particles were principally below 2 microns in size and that the particles in the so-called “respirable” range of sizes contained approximately 30% of the total beryllium present in the air. Concentrations of beryllium fluctuated widely from hour to hour at each location. Average concentrations observed during the two surveys are considered representative of concentrations which have existed in this plant during the last 13 years of operation. No cases of chronic berylliosis disease have been reported among workmen who have been under close...