Aluminium is contained in most antiperspirants. The worrying thing about it, along with many other heavy metals and compounds, is the lack of research conducted on it. The effect of chronic long-term exposure to the majority of the countless chemicals you encounter everyday in the form of food additives, cosmetics, cleaning products, pesticides etc has never been established. That’s without taking into account the synergistic effects of multiple chemicals. Even if we could say aluminium is safe at X amount per day, what about when it’s mixed with fluoride? Together they’ve been shown to be able to pass the blood-brain barrier.
When you think of how many ingredients some products have, it seems hopeless that we’ll be able to fathom the kind of damage we’re doing to ourselves. How on Earth do you study the effects of thousands of chemical combinations on humans over decades? The government seems happy to allow companies to create and use whatever their chemical imaginations allow though, and we have no choice but to be their guinea pigs.