Cadmium Levels in the Lung, Liver, Kidney Cortex, and Urine Samples from Australians without Occupational Exposure to Metals

Abstract

The authors undertook this study to assess levels of cadmium exposure in the general population. Samples of lung, liver, and kidney were obtained from 61 cadavers (43 males, 18 females; 2-89 yr of age, mean age = 38.5 yr) who died from accidental causes and who were subject to postmortem examinations at the John Tonge Centre for Forensic Sciences, Queensland Health Scientific Services, Brisbane, Australia, in 1997 and 1998. Samples of bladder urine were also obtained from 22 cadavers. Tissue and urine samples were analyzed for cadmium, zinc, and copper with inductively coupled plasm (ICP) mass spectrometry. The overall mean values for cadmium in the lung, liver, and kidney cortex samples were 0.13, 0.95, and 15.45 microg/gm wet tissue weight. The average renal cadmium level in subjects with high lung-cadmium levels (n = 13) was 6 microg/gm wet tissue weight higher than that of similarly aged subjects who had medium lung-cadmium levels (n = 30). In females, the average level of cadmium in the liver was 74% greater than in males, and the average liver cadmium in females with high lung-cadmium levels was 100% higher than in males in the same age range who had the same high lung-cadmium levels. Renal cadmium accumulation tended to be greater in females than in males who were in the same age range and who had similar lung-cadmium levels, a result that suggested that there was a higher absorption rate of cadmium in females. The mean value for a urinary cadmium excretion of 2.30 microg/gm creatinine was found in a subset of samples that had a mean age of 39 yr and a renal cortex cadmium concentration of 18.6 microg/gm wet tissue weight. Urinary cadmium excretion rates were correlated more strongly with lung and kidney cadmium content than with age or liver cadmium levels. The results suggest that urinary cadmium excretion may be increased in smokers and could provide some estimate of body cadmium burdens in future Australian epidemiological studies.

Emerging Roles of Cadmium and Heme Oxygenase in Type-2 Diabetes and Cancer Susceptibility

“…Cadmium in liver plus kidney comprises one third of a total amount of cadmium in the body (body burden). Urinary cadmium concentrations correlate closely with levels of cadmium in kidney and lung (Satarug et al 2002). This allows for use of urinary cadmium concentration as a measure of cumulative lifetime exposure (Slob and Krajnc 1993;Choudhury et al 2001).…”

“…In consequence, extremely small amounts of cadmium are excreted -only about 0.001% of total body burden is excreted daily mostly in urine (Kjellström and Nordberg 1978;Slob and Krajnc 1993;Choudhury et al 2001;Satarug et al 2002). In a 20-yr Belgian population cohort, blood and urinary cadmium levels decreased slowly; a yearly decline rate at 1.8% and 3.4%, respectively (Nawrot et al 2008).…”

“…In a 20-yr Belgian population cohort, blood and urinary cadmium levels decreased slowly; a yearly decline rate at 1.8% and 3.4%, respectively (Nawrot et al 2008). Cadmium from diet and smoking deposit and accumulate in nearly all organs and tissues, including the retinal pigment epithelial (RPE) cells in eye tissue, thyroid, breast, lung, liver, pancreas and kidney (Satarug et al 2000b(Satarug et al , 2002(Satarug et al , 2003Uetani et al 2006;Satarug et al 2010). Cadmium causes distinct pathological changes in these tissues.…”

“…Another salient feature of cadmium is its long residence in tissues (half-life of 10-30 years, depending on tissue types) (Kjellström and Nordberg 1978;Satarug et al 2002). Accumulating human data indicate that cadmium toxicity occurs at exposure levels lower than previously estimated.…”

“…In chronic, low-dose exposure situations, kidney cortex cadmium concentrations are 10 to 20 times greater than liver cadmium concentrations (Satarug et al 2000b(Satarug et al , 2002(Satarug et al , 2003Satarug and Moore 2004). For example, in the study of 61 Australian autopsy cases, aged 2 to 89 years, mean cadmium content in lung, liver and kidney cortex was 0.13, 0.95 and 15.45 μg/g wet tissue weight, respectively.…”