HUMAN HEALTH EFFECTS FROM CADMIUM EXPOSURE: COMPARISON BETWEEN PERSONS LIVING IN CADMIUM-CONTAMINATED AND NON-CONTAMINATED AREAS IN NORTHWESTERN THAILAND.

Environmental cadmium contamination is present in some rural villages of Mae Sot District, Tak Province, northwestern Thailand. We compared the health of 751 persons aged ≥ 35 years living in 3 contaminated villages with 682 people from 3 non-contaminated villages with similar socio-demographic and lifestyle characteristics in the same district. All the subjects were screened for urinary cadmium (a biomarker for long-term cadmium exposure), renal function, hypertension, diabetes, hypercholesterolemia, hypertriglyceridemia, urinary tract stone disease and bone mineral density in 2012. The study renal functions included urinary excretion of ß2-microglobulin (early tubular effect), total urine protein and glomerular filtration rate (glomerular effects). The geometric mean of urinary cadmium level was significantly higher among persons living in the contaminated areas (2.96 µg/g creatinine) than those in the non-contaminated areas (0.60 µg/g creatinine). Persons living in contaminated areas had a significantly higher prevalence of renal dysfunction, bone mineral loss, hypertension and urinary stones than those living in non-contaminated areas. There were no significant differences between the 2 groups in the prevalence of diabetes, hypercholesterolemia and hypertriglyceridemia. This study shows health effects due to environmental cadmium exposure. The prevalences of diabetes, hypercholesterolemia, and hypertriglyceridemia were not associated with cadmium exposure.

PERSONAL AND ENVIRONMENTAL RISK FACTORS SIGNIFICANTLY ASSOCIATED WITH ELEVATED BLOOD LEAD LEVELS IN RURAL THAI CHILDREN.

A community-based study was conducted to determine personal risk factors and environmental sources of lead exposure for elevated blood lead levels (≥ 10 µg/dl, EBLLs) among rural children living at the Thailand-Myanmar border in Tak Province, northwestern Thailand. Six hundred ninety-five children aged 1-14 years old were screened for BLLs. Environmental specimens for lead measurements included samples of water from the streams, taps, and household containers, house floor dust, and foods. Possible lead release from the cooking ware was determined using the leaching method with acetic acid. The overall prevalence of EBLLs was 47.1% and the geometric mean level of blood lead was 9.16 µg/dl. Personal risk factors significantly associated with EBLLs included being male, younger age, anemia, and low weight-for-age. Significant environmental risk factors were exposure to a lead-acid battery of solar energy system and use of a non-certified metal cooking pot. Some families whose children had high BLLs reported production of lead bullets from the used batteries at home. About one-third of the house dust samples taken near batteries contained lead content above the recommended value, compared with none of those taken from other areas and from the houses with no batteries. The metal pots were safe for cooking rice but might be unsafe for acidic food preparation. Both nutritional intervention and lead exposure prevention programs are essential to reduce EBLLs in this population.

Association of elevated urinary cadmium with urinary stone, hypercalciuria and renal tubular dysfunction in the population of cadmium-contaminated area.

Excessive urinary calcium is the major risk of renal tubular dysfunction and urinary stone formation. We examined the association of elevated urinary cadmium with urinary stones and chronic kidney disease (CKD) in 1,085 study residents of 13 cadmium-contaminated villages. Elevated urinary cadmium was significantly correlated with urinary stone and CKD. Elevated urinary cadmium appeared to increase risk of urinary stone and CKD; ORs and 95 % CIs were 2.73 (1.16, 6.42) and 3.73 (2.50, 5.57) after adjusting for other co-variables. This study revealed that elevated urinary stone and CKD induced by cadmium might increase the risk of urinary stone and CKD.