♻️ Lecture 8: Plastics and Health

What are microplastics?

Plastic particles <5mm, originating from cosmetics, fabrics, and plastic breakdown.

What are nanoplastics?

Nanoplastics = <100nm. Far more biologically active but harder to detect.

List three human exposure routes to microplastics.

Ingestion, inhalation, and skin contact.

Name two health effects linked to microplastics.

Mechanism	Effects
Physical	GI irritation, tissue damage, cellular stress
Chemical	Leaching of additives (BPA, phthalates) → hormone disruption
Immunological	Inflammation, oxidative stress
Endocrine Disruption	Alters reproductive/developmental processes

What is BPA and why is it concerning?

AND

What are other EDCs and why are they concerning?

• Bisphenol A (BPA): Affects hormone production & fetal development.

• EDCs (Endocrine Disrupting Compounds): DBP, DEHP, BPF etc.

  • Linked to infertility, cancer, metabolic disorders.

  • Effects persist transgenerationally via epigenetic changes.

How much plastic does an average person ingest per week?

Approximately 5 grams — about the size of a credit card.

• MPs pass through gut via endocytosis or dendritic cells.

• Can reach bloodstream, liver, spleen — especially if gut barrier impaired.

What are some environmental effects of MPs

• Ingestion by marine life → bioaccumulation in food web.

• Leads to:

  • Reproductive issues

  • Altered growth/metabolism

  • Biodiversity loss

How do plastics become present in the environment?

Enter through wastewater, textiles, abrasion, consumer products.