Renal tubular dysfunction in children living in the Aral Sea Region

Background: The Aral Sea region is a natural area seriously polluted by human activities. Recent surveillance revealed the increased prevalence of diverse chronic diseases in children. Aims: To investigate the function of renal tubules, which are most at risk of damage as a result of heavy metal intoxication, in children of the Aral Sea region. Methods: A group of 205 children living in Kazalinsk, close to the Aral Sea, and a group of 187 children living in Zhanakorgan, far from the Aral Sea, were examined by means of random urine samples. Both urinary N-acetyl-ß-D-glucosaminidase (NAG; U/mmol Cr) and ß₂ microglobulin (BMG; µg/mmol Cr) were calculated for each subject. Results: Mean urinary NAG and BMG were both significantly higher in Kazalinsk than in Zhanakorgan (NAG: 0.77 (0.58) and 0.62 (0.37) U/mmol Cr; BMG: 41.8 (54.8) and 22.5 (20.4) µg/mmol Cr, respectively; mean (SD), p < 0.01). The number of children with abnormal values of NAG (>1.5 U/mmol Cr) was significantly more prevalent in Kazalinsk than in Zhanakorgan (7.9% and 2.6%, respectively, p < 0.05). Conclusion: Renal tubular function of children around the Aral Sea region is profoundly impaired. This should be taken into account when considering the health problems of this area.