Case based review: Toxicology on the Acute Medical Unit.

Accidental and intentional poisoning from prescribed, illicit and organic substances remains a major cause of morbidity and mortality worldwide and accounts for just under 1% of the total number of NHS hospital admissions, or around 170,000, a year in the UK1. A knowledge of the constellation of signs and symptoms that constitute specific poisonings (referred to as toxidromes) may enable early empirical decontamination, antidote administration, enhanced elimination and supportive care, and may also help to predict the clinical course. This paper presents a series of clinical vignettes to demonstrate emerging presentations in toxicology to help inform the practice of Acute Physicians, who alongside colleagues in Emergency Medicine and Critical Care, are at the front line of diagnosing and treating poisoned patients.

Transformation products and reaction pathways of carbamazepine during photocatalytic and sonophotocatalytic treatment.

This study examines the degradation of the antiepileptic carbamazepine (CBZ) by sonolysis, TiO2-based heterogeneous photocatalysis under UV-A and simulated solar irradiation, and by the combined use of UV-A and ultrasound irradiation (i.e. sonophotocatalysis) in demineralized water, ground water and effluent wastewater. The processes were compared with respect to substrate conversion rate and the extent of DOC reduction as a measure of mineralization. CBZ was degraded following a pseudo-first order kinetics. Sonophotocatalysis provided the highest rate of CBZ transformation over the time-course of the experiment while the degree of DOC removal in pure water was similar for all the studied treatments (around 40%), and always lower than CBZ conversion. This indicated that a considerable organic load remained in the treated solutions that could also be attributed to the presence of persistent oxidation products. UPLC-(+ESI)-QToF-MS was employed to determine major CBZ-related transformation products. Several recalcitrant hydroxy- and keto-derivatives of CBZ were tentatively identified. A Daphnia magna bioassay was used to evaluate the potential toxicity of the samples collected at different time points showing that the mixtures were highly toxic to D. magna.

Sonochemical degradation of ofloxacin in aqueous solutions.

The use of low frequency (20 kHz), high energy ultrasound for the degradation of the antibiotic ofloxacin in water was investigated. Experiments were performed with a horn-type ultrasound generator at varying applied power densities (130-640 W/L), drug concentrations (5-20 mg/L), hydrogen peroxide concentrations (0-100 mM) and sparging gases (air, oxygen, nitrogen and argon). In general, conversion (which was assessed following sample absorbance at 288 nm) increased with increasing ultrasound energy and peroxide concentration and decreasing initial drug concentration. Moreover, reactions under an argon atmosphere were faster than with diatomic gases, possibly due to argon's physical properties (e.g. solubility, thermal conductivity and specific heat ratio) favoring sonochemical activity. Overall, low to moderate levels of ofloxacin degradation were achieved (i.e. it never exceeded 50%), thus indicating that radical reactions in the liquid bulk rather than thermal reactions in the vicinity of the cavitation bubble are responsible for ofloxacin degradation.

Drugs degrading photocatalytically: Kinetics and mechanisms of ofloxacin and atenolol removal on titania suspensions.

The conversion of the antibiotic ofloxacin and the beta-blocker atenolol by means of TiO(2) photocatalysis was investigated. Irradiation was provided by a UVA lamp at 3.37x10(-6)einstein/s photon flux, while emphasis was given on the effect of catalyst type and loading (50-1500mg/L), initial substrate concentration (5-20mg/L), initial pH (3-10) and the effect of H(2)O(2) (0.07-1.4mM) as an additional oxidant on substrate conversion and mineralization in various matrices (i.e. pure water, groundwater and treated municipal effluent). Conversion was assessed measuring sample absorbance at 288 and 224nm for ofloxacin and atenolol, respectively, while mineralization measuring the dissolved organic carbon. Degussa P25 TiO(2) was found to be more active than other TiO(2) samples for either substrate degradation, with ofloxacin being more reactive than atenolol. Conversion generally increased with increasing catalyst loading, decreasing initial substrate concentration and adding H(2)O(2), while the effect of solution pH was substrate-specific. Reaction rates, following a Langmuir-Hinshelwood kinetic expression, were maximized at a catalyst to substrate concentration ratio (w/w) of 50 and 15 for ofloxacin and atenolol, respectively, while higher ratios led to reduced efficiency. Likewise, high concentrations of H(2)O(2) had an adverse effect on reaction, presumably due to excessive oxidant scavenging radicals and other reactive species. The ecotoxicity of ofloxacin and atenolol to freshwater species Daphnia magna was found to increase with increasing substrate concentration (1-10mg/L) and exposure time (24-48h), with atenolol being more toxic than ofloxacin. Photocatalytic treatment eliminated nearly completely toxicity and this was more pronounced for atenolol.

Organochlorine and organophosphoric insecticides, herbicides and heavy metals residue in industrial wastewaters in Cyprus.

Most industries in Cyprus possess permits either for disposal at central wastewater treatment plants (the treated effluent of which is reused or disposed into the sea), or discharge on soil, or reuse either for irrigation or groundwater recharge or discharge into the sea. A preliminary investigation undertaken by the University of Cyprus in regards to dangerous substances was the first step towards establishing a new licensing and monitoring system. Liquid-liquid extraction was used for the extraction of the selected pesticides from wastewaters. Gas chromatography with two different detection methods (ECD and FTD) was applied for the determination of 17 pesticides (12 organochlorine insecticides, 3 organophosphoric insecticides and 2 herbicides). In addition ICP and a mercury evaporation unit were used to determine the concentrations of heavy metals in the samples. The results revealed the presence of several priority substances in wastewaters, in most cases at concentrations well below the regulatory limits. Non-compliance was observed for a limited number of metals. Sixteen out of 17 organic substances that were monitored for 1-year period time were traced in different wastewater streams. What was found out is that there is a need to expand the analytical determinations and the monitoring to more wastewater streams and more priority substances, in order to safeguard the water resources in Cyprus.