Monitoring of cadmium toxicity in a Thai population with high-level environmental exposure.
This study evaluated the utility of single and combined measurements of cadmium toxicity markers for surveillance purposes, using a sample of 224 individuals, 30-87 years of age, who were residents of cadmium polluted area in Mae Sot District, Tak Province, Thailand. Urinary cadmium levels excreted by them ranged between 1 and 58 microg/g creatinine with geometric mean of 8.2 microg/g creatinine which was 16-fold greater than the average for the general Thai population of 0.5 microg/g creatinine. The urinary markers evaluated were total protein, albumin, N-acetyl-beta-D-glucosaminidase (NAG), lysozyme, beta2-microglobulin (beta2-MG) and alpha1-microglobulin (alpha1-MG). Among these markers, only NAG showed a positive correlation with urinary cadmium in both male and female subjects with and without disease (r=0.43-0.71). Further, the prevalence rates for urinary NAG above 8 units/g creatinine (NAG-uria) increased with exposure levels in a dose dependent manner (p=0.05) among subjects with disease. In contrast, however, increased prevalence of beta2-MG above 0.4 mg/g creatinine (beta2-MG-uria) was associated with cadmium above 5 microg/g creatinine only in those without disease (POR=10.6 and 7.8 for 6-10 and >10 microg/g creatinine). Prevalence rates for abnormal excretion of all other markers, except albumin, were markedly increased among those having beta2-MG-uria with and without disease (chi2-test, p<or=0.001-0.02). Thus, urinary beta2-MG and NAG should be used together with urinary cadmium in the monitoring of renal toxicity in a population exposed to high-level cadmium coupled with high prevalence of chronic diseases.
Teeyakasem
Wimonrat
W
Division of Toxicology, Department of Forensic Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand.
Nishijo
Muneko
M
Honda
Ryumond
R
Satarug
Soisungwan
S
Swaddiwudhipong
Witaya
W
Ruangyuttikarn
Werawan
W
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000652:urine; D002104:Cadmium / Q000633:toxicity* / Q000652:urine; D003404:Creatinine / Q000652:urine; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis*; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000633:toxicity* / Q000652:urine; D062665:Epidemiological Monitoring; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000139:chemically induced* / Q000453:epidemiology / Q000652:urine; D008297:Male; D008875:Middle Aged; D013785:Thailand
D015415:Biomarkers; D004785:Environmental Pollutants; D002104:Cadmium; D003404:Creatinine