Scientific American New Technologies Could Protect Against Arsenic Toxicity in Water Filters in household faucets and genetic technology could help reduce this public health threat, biologist Rebecca Fry says Advertisement Arsenic’s potent effect on humans has been known since at least the Roman Empire. For centuries, it was a popular poison for murderers because it can’t be seen, smelled or tasted in food or water. That made it difficult to detect. As chemical detection methods improved, its use as a poison declined. But arsenic, a naturally occurring chemical element in the Earth’s crust, remains a threat to human health. Regular, long-term exposure increases the risk of chronic disorders such as cancer, diabetes and heart disease for millions of people around the world.