Chất độc hại, hoặc độc tố, hóa chất ảnh hưởng xấu đến các sinh vật sống đó. Chất độc này là nghiên cứu về Tác động. Các chất hóa học gắng sức một loạt các hiệu ứng, tùy thuộc vào lượng ăn vào, hít vào, hoặc hấp thụ. TOXICYTOSIS Toxicytosis là loại và cường độ của các phản ứng gợi bởi một hóa chất. Để xác định phản ứng với hóa chất, độc chất học các hành kiểm soát liều lượng cho động vật thử nghiệm trong phòng thí nghiệm và sử dụng thông tin để gần đúng các mối nguy hiểm. | Toxicity of Metals GENERAL DISCUSSION OF TOXICITY Toxic substances or toxins are chemicals that adversely affect living organisms. Toxicology is the study of these effects. Chemical substances exert a wide range of effects depending on the amount ingested inhaled or absorbed. Toxicytosis Toxicytosis is the type and intensity of response evoked by a chemical. To determine the response to chemicals the toxicologist administers controlled doses to laboratory test animals and uses the information to approximate the hazards for humans. Toxic Effects The toxic effects of chemicals are various. Some chemicals interfere with the function of an organ . kidneys lung or liver and others disrupt the blood-formation mechanism enzyme activities the central nervous system or the immune system. For example dioxin an extremely toxic compound affects DNA and ultimately the immune system. Acute Effects Acute effects are symptoms that appear right after exposure. These effects are generally caused by fairly high concentrations of chemicals during a short exposure period. Chronic Effects Chronic effects are delayed but long-lasting responses to toxic agents. They may occur months to years after exposure and usually persist for years. They are generally the result of low-level exposure over a long period. Lethal Effects Lethal effects can be defined as responses that occur when physical or chemical agents interfere with cellular and subcellular processes in the organism to such an extent that death directly follows. Examples are suffocation and interference with movement to obtain food or escape predators. SUBLETHAL Effects Sublethal effects disrupt physiological or behavioral activities but do not cause immediate mortality although death may follow. Examples include interference with feeding growth retardation alteration in blood chemistry changes in the number and type of blood cells and tumor formation. 39 2002 by CRC Press LLC 40 .
