Exposure in Low Doses of Melamine is Not Associated in Children's Kidney Problems

Overall, only a small percentage (0.2%) of children exposed to relatively low dose melamine were affected. And none of the children developed acute kidney failure, urinary tract obstruction, or needed treatment.

02/01/09 Exposure to low dose melamine in contaminated food products is not associated with severe kidney problems such as acute renal failure, concludes a study published on bmj.com.

Large scale screening programmes for populations exposed to low dose melamine, such as those undertaken in Hong Kong after the recent tainted milk scandal in China, may not be worthwhile and are unlikely to lead to any health benefits, say the authors.

By late September, at least four babies in China died and thousands more became ill after consuming milk containing high doses of melamine. Melamine was added to a wide range of food products to make them appear to have a higher protein content and to pass food quality tests.

Contaminated milk and other food products were also sold in Hong Kong, although they contained much lower concentrations of melamine. For example, milk products in China were found to contain up to 2563mg/kg of melamine, compared to up to 68mg/kg in Hong Kong*.

Little is known about the consequences of exposure to low dose melamine in humans.

Professor Hugh Lam and colleagues from the Chinese University of Hong Kong examined 3170 children aged 12 years or less, referred from a Hong Kong government initiated territory wide screening programme for renal complications in response to the contaminated milk scandal.

All children who had consumed milk products tainted with melamine for one month or more underwent renal ultrasonography and tests on their urine.

The researchers report that one child had a renal stone and seven had possible melamine related renal deposits. In addition, 208 (6.6%) children were positive for blood in their urine, although only 7.4% of these were confirmed by microscopy, suggesting an overall prevalence of less than 1% for haematuria (red blood cells in the urine, a sign of possible kidney problems).

The authors suggest that the considerable differences in outcomes for the children in China and Hong Kong is likely to be due to the large differences in levels of exposure to melamine in the milk products consumed.

The authors conclude by saying that the severe complications observed in the Chinese mainland are unlikely to occur elsewhere, but call for research to assess the long term public health impact of consuming melamine contaminated products.