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Guest Editorial The Perception and Practice of Toxicology in South Africa The evolving nature of the science of toxicology is exemplified by its definition. Over the years, the definition of toxicology has emerged from the more traditional view of “the science of poisons” to a more advanced exercise of “the study of the adverse effects of chemical, physical or biological agents on living organisms and the ecosystem, including the prevention and amelioration of such adverse effects” that was proposed by the Society of Toxicology in 2005, as requested by the National Library of Medicine (NLM). Therefore, the task of toxicologists over the years has progressed from mere identification of poisons/toxic compounds to developing methodologies for their identification and quantification in biological and environmental media, to studying their mechanisms of action, to producing antidotes, to, finally, predicting their adverse effects and thus assisting in prevention and amelioration of such adverse effects. The current perception of toxicology in South Africa conforms more to the traditional definition of toxicology. South Africa, similar to other countries on the African continent, possesses a wealth of knowledge on the healing and poisonous properties of indigenous plants. A recent review of the economically important poisonous plants affecting livestock as well as those used ethnobotanically for the treatment of disease in humans and animals is a good example of such descriptive toxicology practiced in the country (1). Other examples are studies describing the importance of poisoning from plant materials (2) and those identifying and isolating their cytotoxic active ingredients using different analytical methods (3-8). There is also an abundance of information on the venoms of insects and animals endemic in the area. The earliest recorded descriptive study of snake venoms dates back to 1946 (9) with others following (10, 11). Later studies have also described the isolation of novel components of snake venom and have elucidated their mechanisms of action (12-16). Similar studies on the composition of scorpion venoms and the elucidation of their mechanisms of toxicity have also been reported (17-24), including a recent review on the subject published in 2008 (25). Investigations on venoms from other insects and animals including ants (26) and frogs (27) have also been published. Treatments offered against insect and animal venoms have also been the subject of toxicological investigations (28) where specific antibodies to neutralize most snake venom coagulant enzymes were tested (29). Similar studies of scorpion venom aimed at designing specific antibodies that would be useful for clinical applications have also been published (30). The availability of such antivenoms at poison centers has been strongly recommended (31). Consultations held in a major poison center in South Africa have also been analyzed with the indication that 75% of the consultations were of a toxicological nature and 16% of these were attributed to poisoning from plants and animals (32-34). The antibacterial properties of local snake venoms have been ascertained (35) along with guidelines for the treatment and management of snake bites (36, 37). Environmental pollutants have also been studied, but once again, the studies have been descriptive in nature. For example,
a number of pesticides were determined in drinking, ground, surface, and marine waters from the Eastern Cape Province of South Africa (38). Copper pollution associated with smelting operations at a nearby mine within the Phalaborwa area in Kruger National Park was quantified by measuring its concentration in airborne dust, topsoil, and impala (Aepyceros melampus) liver (39, 40). The association between exposure to environmental pollutants and disease was also investigated. A link between exposure to pesticides and certain birth defects among the children of rural South African women who worked on the land (41) and between the levels of particulate matter and upper respiratory tract illnesses in children (42) was observed. Moreover, specific recommendations were also made for the sitting of future preschool facilities but falling short in generating South African standards for environmental lead exposure in children (43). This perception and practice of toxicology emanates from the manner in which toxicology is taught in South Africa (44). Basic introductory and advanced courses in toxicology are available in forensic, clinical, ecological, veterinary, and pharmacology disciplines. There are also excellent undergraduate and postgraduate programs for many scientific disciplines including chemistry, biology, biochemistry, physiology, anatomy, genetics, molecular biology, microbiology, histopathology, hematology, pharmacology, genetic toxicology, reproductive toxicology, carcinogenicity, immunology, general toxicology, law, and regulations. Therefore, because there are no dedicated toxicology departments at universities in South Africa, the onus has been on individuals trained in other disciplines to make contributions to the field of toxicology and hence the focus on types of studies exemplified in the previous paragraphs. There is, however, a dire need to train toxicologists in South Africa to contribute to the regulation, protection, and safety evaluation of newly manufactured compounds and those polluting the general or the working environments. These disciplines are part of regulatory toxicology, which sets standards to protect the public and the environment against potential risks of harmful substances including chemicals, pesticides, food additives, cosmetics, and pharmaceuticals (45). It is surprising that similar arguments as these were presented by Hayes (46) three and a half decades ago, justifying the establishment of dedicated university departments to train toxicologists, especially in the field of risk assessment, to contribute to the legal structure of safety evaluation. It is hoped that South Africa will not wait to evolve in its perception and practice of toxicology. Presently, most of the standards or limit values of chemicals approved by local governmental agencies in South Africa are those copied from Australian, European, or American standards. There are currently no limit values that have been ratified as a result of risk assessments based on local toxicological research and epidemiologic data applicable to the local conditions in South Africa.
The Way Forward What can be done to “modernize” toxicology in South Africa?
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First, the importance of the discipline of regulatory toxicology needs to be recognized by different governmental departments as well as by industry in the country. This is in line with the notion that the public sector is a source of rewarding and varied career opportunities for toxicologists, including regulatory toxicologists (47). This, in turn, will create the need for training toxicologists in risk assessment who will be able to quantitatively estimate toxicological risk. The establishment of the Institute of Water Research at Rhodes University in Grahamstown, South Africa, is an example of such a demand and supply scenario in the field of ecotoxicology. With its close association with the Department of Water Affairs and Forestry (DWAF), the necessary platform for a shift toward a perception of toxicology as a more advanced discipline was created. For example, this institute recently reported on its investigation of the suitability of internationally accepted protocols that are dominated by nonindigenous test organisms to set guidelines for anthropogenically induced salinization to protect aquatic ecosystems in South Africa. Subsequently, a wide range of South African freshwater invertebrate species were tested for their use in the development of salinity guidelines and recommendations for water quality managers and those responsible for deriving water quality guidelines for South Africa (48). The refinement of the protective salinity guidelines for South African freshwater resources has also been proposed (49). Moreover, a study on the application of ecological risk assessment to water resource management and to the draft guidelines for local application in South Africa was proposed (50) and completed (51). Second, with the establishment of the Toxicology Society of South Africa (TOXSA) in 2001, it is now possible to create the correct environment for the acceptance of toxicology as a distinct scientific discipline. It is also possible to direct efforts toward the registration of toxicologists as such with the South African Council for Natural Scientific Professions (SACNASP). Moreover, with the support from the International Union of Toxicology (IUTOX), it is now feasible to provide training opportunities in the much needed field of risk assessment. It is also possible to provide continuing education toxicology courses at international congresses held in South Africa, such as the upcoming seventh Congress of Toxicology in Developing Countries (7CTDC) to be held in South Africa in 2009. Finally, it is hoped that with the introduction of the globally harmonized risk assessment methodology by WHO/IPCS (52), it will be much easier to understand and therefore implement risk assessment as it should be in South Africa. Mary Gulumian National Institute for Occupational Health and Department of Haematology and Molecular Medicine Faculty of Health Sciences UniVersity of the Witwatersrand P.O. Box 4788 Johannesburg 2000, South Africa Tel: +27117126428 E-mail:
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