Toxins are substances that produce serious health problems or death when introduced to a living thing. In this activity, you will learn about different types of toxins.

Another word for a toxin is poison. If something is poisonous, it is toxic. You know that everyone is different. What may be a toxic amount for you may not be toxic to your friends. An example of how different levels of exposure affect people differently involves asthma. This chronic respiratory disease often arises from allergies, and it usually involves sudden recurring attacks of difficulty with breathing, chest constriction, and coughing. If you are severely asthmatic, a low level of exposure to something such as cigarette smoke might trigger an attack that may be very harmful. If you are only mildly asthmatic, a greater level of exposure to cigarette smoke might be tolerated before an asthma attack occurs.

 

Exhaust from a car, chlorine from a pool, fumes from certain chemicals, the wrong medicine, spoiled food, or even too much alcohol can be toxic to certain individuals.

You may be eating something that is toxic and not know it. A natural process called biomagnification can cause some of the foods you eat to cause a buildup of toxic substances in your body. In an earlier lesson, you learned about bioaccumulation. You may remember that this refers to how pollutants enter a food chain. Biomagnification, on the other hand, refers to how pollutants can concentrate as they move across the food chain.

Biomagnification works like this (please note that fish is only an example — this is not true for all fish!):

If:

• 1 plankton has 1 part per million (ppm) of mercury in it, and
• 1 small fish eats 10 plankton, it now has 10 ppm of mercury in it, then
• 1 medium fish eats 10 small fish, it now has 100 ppm of mercury in it, then
• 1 large fish eats 10 medium fish, it now has 1,000 ppm of mercury in it, then
• you eat 10 large fish, you now have 10,000 ppm of mercury in you!

Over time, if you continue to eat fish with mercury in them, your level of mercury may reach a toxic level. This may cause you to become very sick or even die. To know where the food you are eating is coming from is very important. As humans continue to pollute the environment, the sad fact is that more toxins are getting into the ground that we grow our food on and into the water from which we get seafood.

Some people dismiss many news reports and videos because they feel that they over exaggerate the problem. It may be wise, however, to consider them as a way to educate ourselves about the toxins that surround us. Being aware that such toxins are in our environment allows us to take steps to reduce our exposure.