The number one toxicity is heavy metals. I myself was not felling well for a while. I went to many doctors, conventional, holistic, specialist, and even chiropractors. It didn't really help till I got a pre and post urine test for heavy metals, and my lead levels were through the roof. The doctor did chelation therapy to get it out. We can talk more about that another time. Just know this heavy metals especially at high amounts are detrimental to your health. Heavy metals include mercury, nickel, cadmium, tin, arsenic, uranium, aluminum and lead among others. Besides being to toxic your body, the metals also prevent many essential minerals from being absorbed in you. There is a study by Dr Andrea Frustaci MD about the link between heavy metals and heart disease. Mercury can get into us from dental silver fillings. Another source for mercury is from coal plants. Mercury vapor gets pumped into the air from the burning fuel and ends up in the air and water. We then breathe in that air and drink the water. If not us the fish drink it. Bigger fish being higher up on the food chain end up being prone to higher amounts of mercury. Tuna for example is known for having mercury. So cut down on heavy metals by eating organic when possible, eating smaller fish, getting an air filter for your home, get water filter for your water, and your on your way to wellness.