A short-term cross-over study on oral administration of soluble and insoluble cobalt compounds: sex differences in biological levels

Abstract

This paper describes a blind cross-over study on the gastrointestinal uptake of soluble and insoluble cobalt compounds (8.5 mumol/day) in 12 male and 11 female volunteers. In a controlled study it was found that the gastrointestinal uptake of the soluble cobalt compound cobalt chloride was considerably higher than the uptake of the insoluble cobalt compound cobalt oxide (urine ranges: < 0.17-4373 and < 0.17-14.6 nmol/mmol creatinine, respectively). Surprisingly, it was shown that ingestion of controlled amounts of soluble cobalt compound resulted in significantly higher urinary cobalt levels (P < 0.01) in females (median: 109.7 nmol/mmol creatinine) than in males (median: 38.4 nmol/mmol creatinine). The results suggest that the gastrointestinal uptake of cobalt is higher for females than males. The present study shows that the normal levels of cobalt in blood and urine in a non-random-selected group of Danes are low. As the fraction of values below the detection limit of the analytical method was 0.19 and 0.33 for urinary cobalt in females and males, respectively, distribution-free one-sided tolerance intervals were chosen to describe the values. The precision of the estimate of the tolerance intervals was expressed as coverage intervals. In females the 95% one-sided tolerance limit calculated for cobalt in blood and urine was 8.48 and 55.10 nmol/l with coverage intervals of 90% +/- 6.5% and 95% +/- 4.2% at a probability of 0.95, respectively. Even though the studied groups of males and females were not representative for the general population, the study indicates that oral exposure may be important in occupational settings.(ABSTRACT TRUNCATED AT 250 WORDS)

Hair concentration of essential trace elements in adult non-exposed Russian population

“…The observed gender difference in Cr values is caused by higher intake of the metal in men (Anderson and Kozlovsky 1985). At the same time, higher hair concentration of Mn and Co in women may result from higher intensity of intestinal absorption (Christensen et al 1993;Finley et al 1994). Hypothetically, increased V content in men may also have dietary origin.…”

Metal passivity as mechanism of metal carcinogenesis: Chromium, nickel, iron, copper, cobalt, platinum, molybdenum

“…The absorption of Cr(VI) or Cr(III) is known as influenced by disease state [39,40]. Gender-specific patterns of metal absorption, as for cobalt [41,42], iron [43], and smoking-related chromium and nickel [32], exist.…”

“…In a blind crossover study, oral exposure to cobalt chloride, CoCl 2 , led to significantly higher blood and urinary levels in nonoccupationally exposed females than males; gastrointestinal uptake was considerably higher for soluble CoCl 2 than insoluble Co(II,III) oxide, Co 3 O 4 , in males and females [41,42]. The data were to help assess absorption of cobalt blue dyes (soluble cobalt-zinc-silicate and insoluble cobalt-aluminate) at two Danish pottery factories [42].…”

Speciation of Cobalt

“…The respective gastrointestinal absorption rates of inorganic cobalt forms have, however, not been very well characterized. In the hamster, less than 0.5% of CoO is absorbed by the digestive route, whereas 9-45% of cobalt chloride is absorbed in humans by the same route [15]. In human volunteers, depletion of iron stores was associated with a significantly increased gastrointestinal absorption of the element administered as cobalt chloride [16].…”