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Pharmaceutically active substances (PhACs) and drugs of abuse (DAs) are two classes of contaminants of emerging concern that have attracted great concern and interest by the scientific community during the last two decades. Numerous studies have revealed their presence in treated urban wastewaters. This is mainly due to the fact that some compounds are not efficiently removed during wastewater treatment processes, and are thus able to reach the aquatic environment through wastewater discharge and reuse practices. The application of an optimized multi-residue method for the simultaneous confirmation and quantification of licit and illicit drugs has been investigated in influent and effluent wastewater samples from seven wastewater treatment plants (WWTPs) located in north-eastern Tunisia. Analysis was performed through ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Out of 12 pharmaceutical compounds analyzed, 11 of them were detected mainly in effluent wastewaters. In both matrices, antibiotics and β-blockers were the most detected groups. This suggests that these compounds show noticeable resistance against biological treatment in WWTPs. The estimated concentrations of antibiotics in effluents ranged from ca. 35 ng/L to 1.2 μg/L. However, all five studied illicit drugs were detected, mainly in influent wastewaters. Forensic investigation performed on people suspected to be drug abusers covering all Tunisian cities was conducted by monitoring an epidemiological study of human urine samples surveying rate of consumption for illicit drugs. Hence, these preliminary results confirmed the presence of illicit drugs in the influent wastewater samples. For example, quantification ranges for cocaine were found to be 25-450 ng/L in influent wastewater samples. Significant differences for cocaine consumption across the two sampling methods were observed. Consequently, we conclude that the analyses in wastewater are more reflective of the real levels of illicit drug consumption. Moreover, the cost for chromatographic analysis is lower than the screening test methods for human biological specimen, particularly staffing, which are likely to be much lower.

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Methanol poisoning continues to be a public health problem in Tunisia in spite of the different legislative measures. We report a series of 16 cases of methanol poisoning admitted to our Intensive Care Unit between December 2003 and April 2004. The patients' median age was 21.5 years (range 16 to 53 years) with a median SAPS II of 14 (range 12 to 84) and an APACHE II of 8 (range 6 to 36). The median latent period was 9.5 hours (range 4 to 24 hours) with a delay to medical consultation of 36 hours (range 6 to 48 hours), and a median serum methanol concentration of 1.4 g/L (range 0.19 to 3.62 g/L). Clinical signs included central nervous system symptoms (69%), gastrointestinal complaints (87%), visual disturbances (69%) and metabolic acidosis (94%). Three patients (19%) required mechanical ventilation because of deep coma or shock and died within 6 hours. Hemodialysis was performed in eleven patients (69%) because of visual disturbances and/or metabolic acidosis. One patient developed irreversible bilateral blindness and another unilateral blindness secondary to optic neuropathy. Statistical significant risk factors for the developing of visual disturbances were found to be the ingested quantity of methanol, the latent period, acidosis and serum methanol concentration on admission.

Under normal environmental conditions, many plants synthesize cyanogenic glycosides, which are able to release hydrogen cyanide upon hydrolysis. Each year, there are frequent livestock and occasional human victims of cyanogenic plants consumption. The present work aims to determine the hydrocyanic acid content in different samples of cyanogenic plants, selected from the Tunisian flora, and in the almond syrup. In order to evaluate their toxicity and their impact on the consumer health in the short term as well as in the long term, using the ISO 2164-1975 NT standard, relating to the determination of cyanogenic heterosides in leguminous plants.