Chapter 14 Toxicology Objectives: Know what the endocrine system is. Know what hormones are. Know the four major types of chemical toxins. Know what endocrine disruptors are. Understand the problem of BPA

Toxins There are many different types of toxins that found in the environment.

Types of Toxins Carcinogens – substances or types of radiation that cause cancer Mutagens – substances that cause genetic mutations in an organisms DNA (Damage DNA) Mutagens may cause cancer or birth defects Teratogens – substances that affect the development of embryos

Types of Toxins Endocrine disruptors – substances that interfere with the endocrine system

Polycyclic Aromatic Hydrocarbons (PAH) PAHs are carcinogens PAHs are a concern because they are persistent. (They do not leave the environment easily) Individual PAHs vary in behavior. Some can turn into a vapor in the air very easily. Most do not break down easily in the water.

PAHs

Mutagens

Teratogens Thalidomide– prescribed to pregnant women in the 1950s as a sleeping pill and to help with morning sickness

Endocrine Disruptors Endocrine disruptors are becoming the most important and potentially frightening type of toxin They can affect the body at the most minute amounts. They hi-jack the body’s most powerful signaling system 93% of Americans have detectable levels in their urine.

BPA Bisphenol A - pronounced BIS phee nawl Bisphenol A (BPA) is a chemical that has found almost universal uses. BPA has allowed for the production of strong and clear plastics.

These are made with BPA

BPA is Ubiquitous

What does BPA do? Bisphenol A at the molecular level looks like estrogen. Estrogen is primarily a female sex hormone, though males do have it though it much smaller amounts. BPA has been linked to cancers of the breast, prostate, and testicles to name a few. Studies have linked it to obesity, drug addiction, and thyroid problems. Reproductive capacity may also be affected.

BPA and Lab Animals

Endocrine Disruptors

The Endocrine System The endocrine system is a group of organs and associated structures that regulate bodily functions such as cell growth. The major organs of the endocrine system are: hypothalamus pituitary gland thyroid parathyroid adrenal glands pineal body reproductive glands (ovaries and testes) pancreas

Hormones Hormones are the chemical messengers that are released from one cell and affect a different cell in another area of the body. Examples of hormones include ADH (antidiuretic hormone) growth hormone Insulin Testosterone Estrogen Adrenaline

How Endocrine Disruption Works

What is being done Canada has banned the sale of BPA containing products The US has only banned it from baby bottles It can still be found in bowls for toddlers, cans of infant formula, and other food packages. Endocrine disruptors are also found in the clothing of infants and toddlers Flame retardants are known endocrine disruptors