 Think about it. The fact that you're alive and watching this video really is quite amazing. Every minute of every day you're being exposed to potentially lethal chemicals and I'm not just talking about the man-made stuff here. Oxygen, water, carbon dioxide, the chemicals that are in your food, get too much of them inside you and you have a problem. To make matters worse, our bodies are constantly making and using incredibly potent chemicals as they go about their daily business. Our cells and organs are in a constant frenzy of activity as vital but potentially lethal chemicals are inhaled, ingested, created, processed and eventually got rid of. Of course, this is the very essence of what it is to be alive. Cut out the chemicals and the seemingly crazy mad processes that they're part of and you'll be, well, dead. To stay alive and thrive, our bodies pull off an incredible balancing act between making use of the stuff we breathe and eat and are otherwise exposed to and making sure it doesn't kill us. The trouble is, it's a balancing act that can too easily be disrupted, too much or too little of something and the whole system begins to get out of whack. Because of this, staying healthy sometimes takes more than good intentions over what we put into our bodies and what we don't. It depends on knowing something about the science of how substances interact with our bodies and potentially cause harm. And this is where toxicology comes in. Toxicologists study what happens to stuff when it gets into your body, where it goes, what it does and how it leaves. They investigate the harm that can be caused when too much or too little stuff interferes with your internal balance and they help devise ways to avoid harm or to fight back when things get messed up. Not to put too fine a point on it, but toxicologists are the Sherlock's of the health world, using science and evidence to understand and protect our bodies down to the very DNA that makes us what we are. Toxicologists know that we can't escape from potentially harmful chemicals. We need them to remain healthy and to ensure the environment we live in is safe and good for us. But they also know that if enough of the wrong stuff gets to the wrong place at the wrong time, things can get messed up fast. As a result, this is a powerful science because it gives us the key to staying alive and thriving in a world that could otherwise be an awfully dangerous place. So whether you're wondering if your shampoo is as good for your body as it is for your hair or you're concerned about what's in your veggie burger and fries, or even if you're trying to work out how much chocolate a reasonable person can eat, a toxicologist might just turn out to be your best friend.