True or false: A poison in any amount will cause harm. False. Many people believe that a poisonous substance will always cause illness or even death no matter what the amount, or dose. This is not the case. The truth is that a person may not become ill from an encounter with a toxic substance. Why is this? The dosage of the material is not high enough to cause symptoms.

What kinds of things determine a dose? Questions like, how intense was the exposure, how long did the exposure last and at what concentration was the toxin during contact, help solve this problem. Did the exposure occur all at one time in just a few minutes, or has this problem been happening for months? While some toxins can cause significant health risks to people following long-term low intensity exposures this is not a common occurrence.

The concept of dosage is easy to understand with medicines. For instance, we all know that taking one teaspoon of cough medicine stops coughs. We also know that drinking 4 ounces, a much larger dose, will cause serious side effects. In these instances, the doses of the medication are the direct causes of both the desired effect and the hazardous effect.

Try to imagine this. There are two glasses filled with the same amount of water. Now add a drop of red food coloring to one glass but to the second glass add 10 drops. The intensity of color in this case is similar to the intensity of a possible exposure. One drop of food coloring in one glass only turns the water a light pink while the water in the other glass, signifying an intense exposure, now has a deep red color to it. Now think of the water as a person, the food coloring as a poison. The person who had the higher intensity exposure is more likely to have ill effects than the person who had only a minimal exposure from the same.

Let’s look at another example. Carbon monoxide (CO) is a well-known poison. A high dose exposure, whether short or long, is likely to cause serious health effects, while low levels, even following a long-term exposure, are not likely to cause serious symptoms. For instance, people who smoke cigarettes expose themselves to low levels of CO routinely but do not show signs of toxicity from the CO in their bodies. The low levels that they frequently expose themselves to do not cause the lethal effects of CO poisoning that the public fears.

Dosage is a key factor in determining the severity of poisonings therefore it is one that is important to understand. Following contact with a poison, a person should call their local poison control center. By sharing accurate information specialists can determine if the contact was severe or mild and what the likelihood is of a person developing side effects from the exposure. From anywhere in the country dial 1-800-222-1222 to talk to a specialist in poison information.