Occupational lead nephropathy.

Among eight subjects suspected of excessive occupational exposure to lead, detailed examination of renal function identified abnormalities in four. Glomerular filtration rate was less than 87 ml/mim/1.73 m2 in one subject with asymptomatic renal failure, and in three subjects with preclinical renal dysfunction. In the subject with asymptomatic renal failure, chelation therapy increased the glomerular filtration rate, p-aminohippurate (PAH) extraction, the maximal PAH secretion rate (TmPAH) and improved proximal tubule ultrastructure, despite decreased renal plasma flow. This improvement in PAH transport was associated with correction of a proximal tubule defect in tritiated PAH uptake detected by section freeze-dry autoradiography of renal biopsy specimens. In three subjects, the etiologic diagnosis of lead-induced nephropathy was established by exclusion, but tubular dysfunction did not obviously exceed the reduction in blomerular filtration. Proximal tubule abnormalities were seen in each of the three patients who underwent biopsy. These studies suggest that lead nephropathy may be an important occupational hazard in the United States lead industry.

Effect of pulmonary tuberculosis on blood concentrations of copper and zinc.

An investigation of copper and zinc concentrations in active cases of pulmonary tuberculosis (TB) was undertaken. Whole-blood, plasma, and erythrocyte concentrations of copper and zinc were determined for TB patients and controls using atomic absorption spectrophotometry. Elevated whole-blood and plasma copper concentrations or depressed whole-blood and plasma zinc concentrations, or both, were characteristic of the TB patients. In most cases, however, the high copper concentrations and low zinc concentrations did not occur concurrently. The whole-blood and plasma copper/zinc concentration ratios were also significantly elevated in the TB patients.

Extraction of lead from printed matter at physiological values of pH.

In an in vitro laboratory study of the extractability of lead in printed matter it was found that dangerous quantities of lead, up to 200 mug, could be extracted from "small" pieces of printed paper at pH values in the range of human gastric fluid. Lead was not extracted at pH values in the range of human saliva. Children who chew printed matter may not be in danger of absorbing lead, but the pica-prone child who swallows printed material may be at risk of absorbing excessive amounts of this toxic metal. The use of printing inks containing high-lead levels should be discouraged.

Distribution of thallium and lead in children's blood.

Mean whole blood concentrations for lead and thallium were determined by atomic absorption spectrophotometric analysis for children residing in Newkark, NJ. Frequency distributions for the various concentration ranges for both metals were recorded. There is no noticeable correlation between the lead and thallium content of whole blood, which suggests that exposure to and/or absorption of these substances are different.

Application of the zinc protoporphyrin (ZP) test as a monitor of occupational exposure to lead.

Zinc protoporphyrin, the predominant abnormal metabolite that appears in whole blood as a result of chronic lead absorption, can be assayed fluorometrically in diluted whole blood with great sensitivity. An extremely simple and rapid test for the effects of lead absorption is described that is based on this assay. Results of a field trial show a characteristic dose-response relationship between zinc protoporphyrin and lead, and indicate that this test should be seriously considered as a monitor for the effects of chronic lead adsorption.

Comparison of zinc protoporphyrin and free erythrocyte protoporphyrin in whole blood.

The recent change in emphasis from blood lead to erythrocyte protoporphyrin as the primary diagnostic test for screening for childhood lead poisoning has made it desirable to develop the quantitative relationship between the two protoporphyrins, free erythrocyte protoporphyrin (FEP) and zinc protoporphyrin (ZP), that are now widely used for screening purposes. ZP was found to be equal to 1.4 EP, thus permitting the measurement of either parameter, and its conversion to the other.

Filter paper-disc method for the determination of zinc protoporphyrin in blood.

Zinc protoporphyrin, an abnormal metabolite resulting from undue lead absorption, can be quantitatively determined in blood that has been spotted and dried on filter paper. This procedure, which yields values that correlate well (r = 0.96) with those obtained by direct determination in whole blood, offers advantages in convenience of collection, storage, and transportation that recommend it for field use. The light sensitivity of the zinc protoporphyrin, however, mandates that the specimens be protected from excessive light exposure until analyzed.

Copper, zinc, magnesium, and calcium in plasma and cerebrospinal fluid of patients with neurological diseases.

We investigated whether information on concentrations of some trace-mental concentrations in blood plasma or cerebrospinal fluid, or both, could be of value in diagnosis or management of various neurological diseases, and whether concentrations in plasma could serve as a means of estimating the protein or metal concentrations in cerebropsinal fluid. Samples of both from 82 patients were analyzed for copper, zinc, magnesium, and calcium by atomic absorption spectrophotometry. Protein concentrations in cerebrospinal fluid were also determined. Metal and protein concentrations in plasma and in cerebrospinal fluid were not strongly enough correlated to permit the estimation of one from the other. However, the correlation coefficients between calcium in plasma and cerebrospinal fluid (r = 0.41), magnesium and protein in cerebrospinal fluid (r = 0.40), magnesium in plasma and calcium in cerebrospinal fluid (r = 0.36), and magnesium and calcium in cerebrospinal fluid (r = 0.66) were statistically significant (P less than .01). Patients with cerebral infarctions had abnormally high copper concentrations in their plasma and cerebrospinal fluid. The ratio of plasma copper to plasma zinc was also significantly higher in cases of cerebral infarction.

Manganese pollution in the city environment and its relationship to traffic density.

As lead is phased out of gasoline, other additives with anti-knock properties, particularly organic manganese compounds, are being substituted. Unavoidably, such compounds go through the combustion process, are eliminated in exhaust gases, and become part of the city environment. To obtain some indication of the extent of this new pollution street soils from various locations in a heavily trafficked city (Newark, NJ) were analyzed for manganese and lead by atomic absorption. Highly signigicant inverse relationships were found between the concentrations of both contaminants and distances from major traffic arteries. Strong circumstantial evidence is thus provided that: 1) manganese pollution is occurring, along with lead, in the city environment; 2) this new pollution is related to traffic density; and 3) the most likely sources are automobile exhausts. This suspicion is further strengthened by the significant correlations observed between manganese and lead contents in children's blood, suggesting a common source for both. Substantiation of the safety of this practice of adding manganese to gasoline is needed.

Copper/zinc ratios in whole blood, plasma, and erythrocytes in pulmonary tuberculosis.

Concentrations of copper and zinc in plasma, whole blood, and erythrocytes were determined in pulmonary tuberculosis (TB) patients and controls by atomic absorption spectrophotometry. The plasma and whole blood copper/zinc ratios were markedly higher in the TB patients. Eighty-seven percent of the TB patients had plasma copper/zinc ratios above 2.00, and 94% had whole blood copper/zinc ratios above 0.20. None of the controls had plasma copper/zinc ratios above 2.00, while 24% of the controls had whole blood ratios greater than 0.20. Whole blood and plasma copper/zinc ratios appear to be more sensitive indicators of the presence of pulmonary TB than the individual copper and zinc concentrations. Patients with conditions in which copper and zinc metabolism are altered might benefit from the monitoring of copper/zinc ratios.