New Toxicology For Old

Nervous system is in the most cases a likely target for the untoward effects of chemicals. The harmful consequences affect primarily the individual but may also considerably strain the whole society. The consumption of ethanol is a glaring example (National Institute on Alcohol Abuse and Alcoholism 1978). As ethanol, many organic liquids have similar immediate effects on the nervous system. The rapidity of the response suggests the involvement of the neuronal communication. The nervous system is also vulnerable to the depletion of oxygen, another common cause for the rapid deterioration of the brain function. It is quite impossible to list all the effects produced by the very large number of the individual chemicals. It would be more fruitful to try to understand the characteristics of the nervous system and the biochemical toxic mechanisms in the evaluation of the neurotoxicity of chemicals. Transfer of Xenobiotics in the Brain The adult central nervous system displays a functional barrier toward the blood-borne chemicals so that water-soluble compounds with an approximate molecular weight above 100 are largely prevented from directly entering the brain (Bradbury 1979). The functional barrier has morphological features typical to it and has a very close association of adjacent capillary cells separated by clefts of 12 A wide (Jacobs 1978). The nervous system capillaries are enveloped by glial cell tongues, and these pericytes contain contractile elements (Le Beux and Willemot 1978a, b) so that the capillaries can be constricted.

Over 400 years ago, Swiss alchemist and physician Paracelsus (1493-1541) cited: "All substances are poisons; there is none that is not a poison. The right dose differentiates a poison from a remedy." This is often condensed to: "The dose makes the poison." So, why are we overtly anxious about intoxications?In fact, poisons became a global problem with the industrial revolution. Pesticides, asbestos, occupational chemicals, air pollution, and heavy metal toxicity maintain high priority worldwide, especially in developing countries. Children between 0 and 5 years old are the most vulnerable to both acute and chronic poisonings, while older adults suffer from the chronic effects of chemicals. This book aims to raise awareness about the challenges of poisons, to help clinicians understand current issues in toxicology.

Interest and information in the field of medical toxicology has grown rapidly, but there has never been a concise, authoritative reference focused on the subjects of natural substances, chemical and physical toxins, drugs of abuse, and pharmaceutical overdoses. Medical Toxicology of Natural Substances finally gives you an easily accessible resource for vital toxicological information on foods, plants, and animals in key areas in the natural environment.

Poisoning is a far more serious health problem in the U.S. than has generally been recognized. It is estimated that more than 4 million poisoning episodes occur annually, with approximately 300,000 cases leading to hospitalization. The field of poison prevention provides some of the most celebrated examples of successful public health interventions, yet surprisingly the current poison control "system" is little more than a loose network of poison control centers, poorly integrated into the larger spheres of public health. To increase their effectiveness, efforts to reduce poisoning need to be linked to a national agenda for public health promotion and injury prevention. Forging a Poison Prevention and Control System recommends a future poison control system with a strong public health infrastructure, a national system of regional poison control centers, federal funding to support core poison control activities, and a national poison information system to track major poisoning epidemics and possible acts of bioterrorism. This framework provides a complete "system" that could offer the best poison prevention and patient care services to meet the needs of the nation in the 21st century.

First multi-year cumulation covers six years: 1965-70.