The five common heavy metals are lead, mercury, cadmium, arsenic, and chromium. These elements can accumulate in the body and cause harmful effects — neurological damage, kidney and liver injury, cancer, and developmental problems — especially with chronic exposure. Avoid contamination in food, water, and workplace, and seek medical testing if exposure is suspected.

The eight commonly referenced heavy metals are lead, mercury, arsenic, cadmium, chromium, nickel, copper, and zinc. These metals can accumulate in the body and environment; some are toxic even at low levels (lead, mercury, arsenic, cadmium, certain chromium forms), while others (copper, zinc) are essential in small amounts but harmful in excess.

The 23 heavy metals commonly listed (alphabetical): Aluminum, Antimony, Arsenic, Barium, Beryllium, Cadmium, Chromium, Cobalt, Copper, Iron, Lead, Manganese, Mercury, Molybdenum, Nickel, Platinum, Selenium, Silver, Thallium, Tin, Titanium, Vanadium, Zinc. These elements are frequently monitored in clinical, environmental and consumer-product toxicology panels because of their potential health and ecological effects.

Top three heavy metals are lead, mercury, and cadmium. Lead causes neurotoxicity and developmental delays, especially in children, and affects blood and kidneys. Mercury damages the nervous system and kidneys; main exposure is contaminated fish and occupational sources. Cadmium harms kidneys and bones, raises osteoporosis risk, and accumulates from smoking and contaminated food. All three are toxic even at low chronic exposures.

The "big four" heavy metals are lead, mercury, arsenic, and cadmium. These metals are highly toxic even at low exposures: lead and mercury mainly harm the nervous system and development; arsenic is a known carcinogen affecting skin, lungs, and bladder; cadmium damages kidneys and bones. Common exposure sources include contaminated water, food, industrial emissions, batteries, and certain consumer products.

Tin is a post‑transition (poor) metal and is not generally classified as a heavy metal. Elemental tin and common inorganic tin salts have low toxicity; however, some organotin compounds (for example, tributyltin) are highly toxic, environmentally harmful, and often regulated. Health risk depends on chemical form, dose, and exposure route.