STUDIES IN LEAD POISONING: Comparison between different Laboratory Tests

Abstract

The urinary output of a-aminolaevulic acid (ALA), coproporphyrins, and lead in 15 leadintoxicated workers was determined and correlated with the degree of intoxication. Raised levels of ALA in the urine show the best agreement with clinical evidence of intoxication.In addition these values were correlated with the amount of lead excreted after treatment with a total dosage of 9 g. penicillamine. Weak correlations were found between therapeutically excreted lead and initial values for lead and coproporphyrin in urine. In contrast the initial values for ALA correlate very closely (P < 0 001). It is concluded that determinations of the output of ALA are to be preferred in the evaluation of lead intoxication and that they point directly to the amount of metabolically active lead in the organism.

Parameters indicative of absorption and biological effect in new lead exposure: a prospective study

“…Most authors recommend the former by reason of its greater sensitivity and specificity (Cramer and Selander, 1965;Haeger-Aronsen, 1971) but some prefer the latter (Williams, King, and Walford, 1969;Waldron, 1971). However, all of these opinions are based upon cross-sectional 134 studies.…”

Method for estimating objectively the comparative merits of biological tests of lead exposure.

“…To determine the comparative merits of the tests for estimating lead absorption, or lead-poisoning, surveys could be made in which these factors were measured together with the biological tests. For example, the symptoms of lead-poisoning can be assessed on a numerical scale to obtain a "score" as shown by Cramer and Selander (1965). " Absorption " is difficult to define-and therefore difficult to measure.…”

“…The punctate basophil count and haemoglobin (Legge and Goadby, 1912), urinary lead (Belknap, 1935), blood lead (American Public Health Association, 1943), urinary coproporphyrin (de Langen and Ten Berg, 1948), and urinary 8-aminolaevulinic acid (ALA) (Haeger-Aronsen, 1960) have been recommended, and are still used (Zielhuis, 1961 ;Ministry of Labour, 1964;Moncrieff et al, 1964 ;Dagg et al, 1965 ;Cramer and Selander, 1965 ;Williams, 1966).…”

Quantitative determination of urinary delta-aminolevulinic acid as an index of lead exposure by high-performance liquid chromatography.

“…Inhibition of delta-aminolevulinic acid (ALA) dehydratase produces an accumulation of ALA in tissues and consequently causes its excretion in urine. 1) Previous colorimetric methods for the determination of urinary ALA2) depended on purification of ALA by ion-exchange chromatography, which was timeconsuming when applied to many urine specimens.…”