1 / 8

Beneficial Thresholds and Harmful Limits: Understanding LD50 and Risk Assessments in Environmental Health

Explore the concept of beneficial limits and harmful thresholds in toxicology through LD50 assessments. Understand how LD50 - the dose at which 50% of the population dies - is determined, and its significance in risk assessments for environmental health. Learn to differentiate between beneficial and harmful doses of toxic substances, and gain insights into threshold effects where no harmful responses are observed up to a certain dosage. Discover the importance of dosage indicators and how to determine optimal dosages versus harmful ones.

orsin
Télécharger la présentation

Beneficial Thresholds and Harmful Limits: Understanding LD50 and Risk Assessments in Environmental Health

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. LD-50 Lab Introduction earthref.org Scripps Classroom Connection

  2. “Everything is poisonous yet nothing is poisonous.”Paracelsus earthref.org Scripps Classroom Connection

  3. Max Benefit Beneficial Increasing Amount Harmful Everything can be beneficial up to a certain point, and then might be harmful. • earthref.org Scripps Classroom Connection

  4. Example: Watching TV Max Benefit Beneficial 0.5 1 2 3 4 5 6 7 Increasing Hours Harmful • earthref.org Scripps Classroom Connection

  5. Dose Response Curves • How can you decide what is the optimal dose? A harmful dose? • Important dose “indicator” • LD50-lethal dose, where 50% of the population dies • earthref.org Scripps Classroom Connection

  6. A Closer Look: LD 50 Examples Toxic Substance A 100 100 Toxic Substance B 50 50 % Showing A Response 0 0 Dose of toxicant • earthref.org Scripps Classroom Connection

  7. Threshold Effects Threshold:no effects are seen to occur in response to the dose 100 Which substance, A or B has a higher threshold for toxicity? A B 50 Response % 0 • earthref.org Scripps Classroom Connection

  8. Risk Assessments • Determining potential adverse environmental health effects on people exposed to pollutants • LD50 and threshold effects • Includes many steps and processing • Eventually incorporated into regulations • earthref.org Scripps Classroom Connection

More Related