Even though heavy metals are the oldest known toxins harmful to humans, heavy metal toxicity is still a topic that requires further investigation. This paper aims το provid an overview on the most dangerous heavy metals and their negative effects on the human health.Arsenic (As) contaminated underground water and arsenic based agricultural products have generated a worldwide increase of illnesses and deaths that are mainly due to various types of cancer and skin disorders. Industrialization and manufacturing made ead (Pb) poisoning a common occurrence, forcing governments to take measures to decrease lead usage. Mercury (Hg), being highly bioaccumulative and with an increasing presence in the environment, when consumed through food is proven to be especially harmful to lactating mothers, fetuses and children. The vast use of admium (Cd) for technological and agricultural purposes poses a high risk of occupational and non-occupational exposure of humans to that element, since it has been confirmed to cause carcinogenesis. Public awareness of the topic is necessary in order to prevent future increase of heavy metal related human diseases and deaths
