[Study of contents of nitrates, fluorides, aluminium in dialysis water in Tunisia]. / Etude des teneurs en nitrates, aluminium, et fluorures dans les eaux de dialyse en Tunisie.

Nitrates, fluorides and aluminum have often been incriminated in cases of poisoning sometimes life threatening such as methaemoglobinaemia, dental and skeletal fluorosis, and myoclonal encephalopathy in patients undergoing haemodialysis. The three elements mentioned have something in common: their water origin (drinking water and dialysis water). To study the situation in Tunisia in this respect we propose to determinate the contents of nitrates, fluorides, and aluminum in drinking water and dialysis water supplied by the water board (SONEDE). 540 samples of drinking water and dialysis water were taken from 95 centers of haemodialysis scattered all over the country, between January 2000 and December 2001. These samples are divided in three parts (drinking water, soften water, and dialysis water ). Results show levels of fluorides < 1.5 ppm in most areas with the exception of zones rich in phosphate where the mean level is 1.61 +/- 1.22. the levels of nitrates are in most regions < 50mg/l and those of aluminum < 100microg/l. The levels of fluorides, nitrates and aluminum in dialysis water were within acceptable national and international limits excepting a few centers where the levels of the these contaminants are high, exposing patients on haemodialysis to acute and chronic intoxication. This contamination is caused in majority of cases by a dysfunction of water dialysis treatment chain, therefore caution is necessary and strict measures of control should be introduced.

Estimation of Ochratoxin A in human blood of healthy Tunisian population.

Human exposure to Ochratoxin A (OTA) has been investigated in many Mediterranean countries, where OTA was found with a higher frequency in foodstuffs and blood samples. The aim of this study was to assess OTA concentrations in human blood serum in Tunisia and to evaluate the impact of several factors (age, origin, sex) on these prevalence reference values. One hundred and seven blood serum samples from healthy subjects were analyzed using a solid-phase extraction linked to a high-performance liquid chromatography (HPLC) method. OTA values ranged from 0 to 3.43 ng/mL with a mean value of 0.49+/-0.67 ng/mL. OTA levels were higher in the Sahal group. Our results reflect OTA concentration previously detected for human blood in Tunisia. Origin, but not age and sex, may affect the OTA reference values.