The old Buchans mine has been closed for nearly three decades. (CBC)

Residents in the small central Newfoundland community of Buchans are at risk of lead poisoning after tests showed a nearby abandoned mine has dangerously high levels of toxic substances.

Residents have been advised they've been breathing in pollutants from the old mine site for decades.

Ten toxic substances showed up in the tests. Here's a look at the dangers of each:

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Lead

A metallic pollutant that is toxic to numerous bodily organs and tissues, including the heart, bones, intestines, kidneys, reproductive system and nervous system. It's especially toxic to children and may cause permanent learning and behavioural disorders. Symptoms include abdominal pain, headaches, anemia and irritability. Extreme or prolonged exposure could cause seizures, coma and death.

Arsenic

Naturally found in the environment, but can also be released from certain human activities, such as mining. Human exposure usually happens through food and water. Toxic levels of arsenic affect the brain by causing neurological disturbances and could also cause organ failures and death. Symptoms include severe stomach pain, excess saliva, vomiting, diarrhea, hoarseness and speech difficulty.

Copper

Although it is found in the human body and is essential for physical and mental health, high levels of copper can be dangerous. Symptoms of copper poisoning are similar to those produced by arsenic. Extreme levels could cause convulsions and palsy.

Uranium

Excess exposure could affect the normal bodily functions of the kidneys, brain, liver and heart. Symptoms include vomiting, diarrhea, chronic fatigue, rashes, recurring ear and eye infections, weight loss and cough.

Zinc

Although an essential component of a healthy body, excess amounts of zinc can be harmful because they prevent copper and iron absorption, as well as reduce body immune functions and good cholesterol levels.

Antimony

Naturally found at low levels in the environment. Humans are usually exposed to it through air, water and contaminated foods. Prolonged exposure to high levels of antimony can cause eye, skin and lung irritations. Exposure could also cause heart problems, vomiting, diarrhea, stomach pain and ulcers.

Barium

Barium levels in the environment are naturally low. However, barium waste can be released into the air during mining and industrial operations. Studies on the effects of barium have shown that exposure to large amounts of the metal for even a short period could lead to paralysis or death. Those who swallow or drink barium in smaller amounts could experience difficulty breathing, increased blood pressure, stomach irritation and a change in nerve reflexes. Exposure could also cause damage to the liver, kidneys, heart and spleen.

Molybdenum

Prolonged exposure to molybdenum can cause eye and skin irritations. Symptoms of chronic exposure include headaches, joint pain and fatigue.

Thallium

Highly toxic metal that is often used in rat poisons and insecticides. People often experience abdominal pain, nausea and vomiting within a few hours of an acute exposure. Chronic exposure can cause fatigue, headaches, depression, loss of appetite, leg pain and vision disturbances.

Selenium

At healthy levels, selenium plays an important role in the production of certain bodily enzymes. However, higher than normal levels could cause hair loss, vomiting, fatigue, mood swings and "garlic breath," as well as neurological problems.