Potentially poisonous substances are everywhere — in the air, the water and even inside our own bodies.

But don’t panic.

“Everything is poisonous,” said Martin Ronis, a professor at the LSU Health Sciences Center in New Orleans “The only thing that matters is the dose.”

From water to alcohol, everyday substances can be toxic, and possibly deadly, in the wrong amount, Ronis said during a lecture sponsored by the Toxicology Education Foundation at the Bluebonnet Branch of the East Baton Rouge Parish Library.

“The dose makes the poison” is a maxim that summarizes the basic principles of toxicology, which is the study of negative effects of chemicals on the human body. It means a substance can only have a toxic effect if it reaches a certain dosage, and it’s the message Ronis and other speakers want to get across.

In the age of abundant information easily found online and passed along through social media, some scientists and medical professionals see a need to educate the public on what toxins should be feared — and when.

For example, ignorance has led some people to fear sunscreen more than skin cancer and others to believe that vaccines are deadly or can cause life-altering diseases, Ronis said.

Many Americans fear genetically modified foods, he said, even though scientists have not found any evidence they are harmful.

Americans also overreact to substances they learn about through news reports, Ronis said, fearing lead levels in water supplies and dioxin in food. But you really shouldn’t be afraid, he said.

He blames the fear, in part, on a lack of science education and a media focused on negative stories.

“This is exaggerated by social media,” Ronis said. “That social media essentially gives equal weight to things that are evidence-based and things that are not evidence-based. Therefore, the public gets very confused about what is and what is not true.”

Philip Wexler, a toxicologist with the National Library of Medicine and a member of the Toxicology Education Foundation, wants the public to learn to think critically and determine what is truly harmful.

“We have to take each on a case-by-case basis and see what the situation is, what the circumstances are, and make reasoned decisions the best we can,” he said.

Misconceptions abound, Wexler said.

Here are some examples of confusion set straight by the speakers of the Toxicology Education Foundation:

Silica: Poison control centers routinely receive calls from panicked parents whose kids ingest silica gel. Those little packets of the desiccant — a substance that keeps things dry — are found in shoes, clothing, beef jerky and countless other items.

Printed on the package is the ominous warning: “THROW AWAY. DO NOT EAT.”

“There is absolutely nothing toxic about silica gels,” said Kelli Baker, a nurse at the Louisiana Poison Center in Shreveport. “They just pass right on through.”

It’s likely the paper and ink on the packet are more toxic than the silica gels inside, Baker said.

Botulinim: These toxins are among the most potent poisions known to man. But they can also smooth wrinkles and treat chronic migraines.

C. Botulinum is the toxin responsible for botulism food poisoning, which can cause muscle weaknesses and even death. Cans of food that bulge out can be contaminated with it, according to the Toxicology Education Foundation.

But some of those same properties make botulinum type A useful for Botox, a medical treatment first used to stop wrinkles and is now used to help migraine sufferers.

Ethanol: Alcohol has more negative effects than many substances Americans fear, including illegal drugs, Ronis said.

“Drugs of abuse pale in comparison to the effects of alcohol,” he said, citing the risks of alcohol abuse.

But it has been proven that a glass of red wine each day positively affects your health.

“It’s all about dose,” he said. “Consumption of a small amount actually reduces your risk of heart disease.”

Dihydrogen monoxide: It’s clear, has zero calories and it makes up 70 percent of the human body. But water (dihydrogen monoxide is its chemical name) can kill you.

“Water is the stuff of life, but water can kill you at a high enough level,” Ronis said.

Drinking too much water can cause a sodium imbalance and swelling of the brain.

For most healthy people, this is rare, doctors say. You would have to drink gallons and gallons of water to become intoxicated.

Those who are most at risk include endurance athletes, such as marathon runners, who drink water but do not replenish the electrolytes — sodium, potassium and other minerals lost through sweat — they lose while exercising.

The real danger, especially in the hot, humid Southern summer, is dehydration from not drinking enough water.