7-toxicity-science-consumer chemistry.pptx

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1. toxicity

2. WHAT IS TOXICITY?

3. What is toxicity? The action of poisons (including xenobiotics ) on biochemical reactions or processes in living organisms or ecological systems. A study of this action is the subject matter of toxicology. is the capacity of a substance to poison. is the ability of a chemical molecule or compound to damage susceptible sites or cells in the human body or in other living biological systems including plants, animals, or even ecosystems.

4. Types of toxicity Acute Toxicity. Subchronic  Toxicity. Chronic Toxicity. Carcinogenicity. Developmental Toxicity. Genetic Toxicity ( somatic cells )

5. Acute toxicity Any poisonous effect produced from a single or short exposure (24 to 96 hours) resulting in severe biological harm or death. For  example , hydrogen cyanide is a highly  toxic  substance;  acute  exposure at relatively low doses can result in death and many people die each year from inhaling carbon monoxide from faulty heaters.

6. Subchronic toxicity results from repeated exposure for several weeks or months. This is a common human exposure pattern for some pharmaceuticals and environmental agents. For example: Ingestion of warfarin (Coumadin) tablets (blood thinners) for several weeks as a treatment for venous thrombosis can cause internal bleeding and workplace exposure to lead over a period of several weeks can result anemia.

7. Chronic toxicity Represents cumulative damage to specific organ systems and takes many months or years to become a recognizable clinical disease. Damage due to subclinical individual exposures may go unnoticed. With repeated exposures or long-term continual exposure, the damage from this type of exposure slowly builds up until the damage the threshold for chronic toxicity. Ultimately, the damage becomes so severe that the organ can no longer function normally and a variety of chronic toxic effects may result. Chronic toxic effects include: Cirrhosis – alcoholics who have ingested ethanol for several years. Chronic kidney disease – workmen with several years of exposure to lead. Chronic bronchitis – long-term cigarette smokers. Pulmonary fibrosis – coal miners.

8. Carcinogenicity A complex multistage process of abnormal cell growth and differentiation that can lead to cancer. The two stages are: 1. Initiation – a normal cell undergoes irreversible changes. 2. Promotion – initiated cells are stimulated to progress to cancer.

9. Developmental toxicity Pertains to adverse toxic effects to the developing embryo or fetus . It can result from exposure to either parent before conception or to the mother and her developing embryo or fetus . Three basic types: 1. Embryolethality – failure to conceive, spontaneous abortion, or stillbirth. 2. Embryotoxicity – growth toxicity or delayed growth f specific organ systems. 3. Teratogenicity – irreversible conditions that leave permanent birth defects in live offspring.

10. Gene toxicity   Results from damage to DNA and altered genetic expression. This process is known as mutagenesis. The genetic change is referred to as a mutation and the agent causing the change is called a mutagen. There are three types of genetic changes: Gene mutation — change in DNA sequence within a gene. Chromosome aberration — changes in the chromosome structure. Aneuploidy or polyploidy — increase or decrease in number of chromosomes. If the mutation occurs in a germ cell, the effect is heritable. This means there is no effect on the exposed person; rather, the effect is passed on to future generations. If the mutation occurs in a somatic cell, it can cause altered cell growth (for example, cancer) or cell death (for example,  teratogenesis ) in the exposed person.

11. What are the symptoms of toxicity? Moderate poisoning symptoms, which usually are not life threatening or permanent, may include the following: Blurred vision. Confusion and disorientation. Difficulty breathing. Drooling. Excessive tearing. Fever. Low blood pressure (hypotension) Loss of muscle control and muscle twitching.

12. FOUR MAJOR ROUTES OF ENTRY CHEMICALS There are four major routes of entry chemicals can follow: Inhalation (breathing) Absorption (skin contact) Ingestion (eating) Injection.

13. Food toxicant Here is a list of 7 "toxins" in food that are actually concerning. Refined Vegetable and Seed Oils. Refined vegetable- and seed oils include corn , sunflower, safflower, soybean and cottonseed oils. ... BPA. ... Trans Fats. ... Polycyclic Aromatic Hydrocarbons (PAHs) ... Coumarin in Cassia Cinnamon. ... Added Sugar. ... Mercury in  Fish .