Chemical components and health implications of Bitumen
Bitumen is a very thick and sludgy material in its pure form. In order to increase its viscosity, solvents are added and when Bitumen and the solvents are released into the environment, they do not stay together and the volatile portions are released into the atmosphere.
While exposure to pure Bitumen can cause mild to severe skin burns depending on the concentration, it is the additives that once released cause the most significant health effects.
One of the solvents comes from the chemical family known as Naptha which includes Napthalene (coal tar). The Material Safety Data Sheet (MSDS) lists that it is toxic to blood, kidneys, the nervous system, the reproductive system, liver, mucous membranes, gastrointestinal tract, upper respiratory tract and the central nervous system Symptoms of exposure to high levels include fatigue, lack of appetite, confusion, nausea, vomiting, diarrhea, blood in urine. Some research has shown that prolonged high exposure to Napthalene may destroy red blood cells and result in hemolytic anemia.
Rats exposed repeatedly to Napthalene vapors developed abdominal and nasal cancers. Female rats were more susceptible to cancer in the bronchi and lungs.
Benzene, another solvent is known to cause cancer most commonly leukemia and other blood related cancers such as non-Hodgkin lymphoma. Inhalation of high doses of benzene may affect the central nervous system with can lead to drowsiness, dizziness, headache, tremors, confusion and/or unconsciousness. Consuming benzene can cause vomiting, stomach irritation, dizziness sleepiness convulsions and rapid heart rate. Swallowing very high levels can lead to death. Long term exposure affects the bone marrow and the production of new blood cells.
Toluene is a known human carcinogen and has a distinct odor associated with paint thinners, fingernail polish and rubber adhesives. Exposure can cause mild to moderate skin irritations and can be absorbed to some extent through the skin. Inhalation of the vapour affects the repiratory tract causing coughing, wheezing and nasal discharge. Inhalation of high levels cause central nervous system effects such as nausea, headache, dizziness, tremors, restlessness, light-headedness, memory loss, insomnia, impaired reaction time, hallucinations, ataxia and loss of motor control. It can also cause heart palpitations, increased or decreased blood pressure, respiratory depression vision disturbance and loss of appetite. Chronic exposure can lead to brain, kidney and liver failure.
Hydrogen sulphide with its distinctive smell of rotten eggs can also be a concern from Bitumen and oil wells. Just a few breaths of high levels can cause death. Short term exposures at low levels can cause coughing, changes in blood pressure, vomiting, difficulty breathing, headache, drowsiness, brain damage and nerve damage.
Each of these components has Material Safety Data Sheets which outline not only the health effects but also exposure control, storage and handling, and what measure to take in the event of an exposure. Members would be advised to participate in Emergency Preparedness committees to create plans to prevent, control and react to exposures.
BCTF, Health and Safety Committee