18th May 2022 (8 Topics)
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Cancer-causing benzene
Context
A new analysis found that in 2021, a dozen petroleum refineries in the United States reported average benzene emission levels that exceeded the federal threshold of 9 micrograms per cubic metre.
About
What is benzene?
- Benzene is a chemical that is a colorless or light yellow liquid at room temperature. It has a sweet odor and is highly flammable.
- Benzene evaporates into the air very quickly.
- Its vapor is heavier than air and may sink into low-lying areas.
- Benzene dissolves only slightly in water and will float on top of water.
Where benzene is found and how it is used?
- Benzene is formed from both natural processes and human activities.
- Natural sources of benzene include volcanoes and forest fires.
- Benzene is also a natural part of crude oil, gasoline, and cigarette smoke.
- Benzene is widely used in the United States. It ranks in the top 20 chemicals for production volume.
- Some industries use benzene to make other chemicals that are used to make plastics, resins, and nylon and synthetic fibers.
- Benzene is also used to make some types of lubricants, rubbers, dyes, detergents, drugs, and pesticides.
Health threat
- Proximity to an oil refinery was associated with a statistically significantly increased risk of incident cancer diagnosis across all cancer types.
- Breathing benzene at a concentration as low as 0.13 µg/m3 over a lifetime could result in up to one additional cancer diagnosis per one million people exposed.
- As benzene levels rise, those risks increase proportionately.
- Long-term exposure to relatively low (0.13 µg/m3) benzene levels can contribute to health effects like blood disorders, a weakened immune system and elevated risk of cancer.
- Exposure to higher benzene concentrations over a short period of time can trigger acute neurological symptoms like dizziness and headaches.
- It can also reduce blood cell counts, including during prenatal development and weaken the immune system, increasing susceptibility to diseases.
How benzene works?
- Benzene works by causing cells not to work correctly.
- For example, it can cause bone marrow not to produce enough red blood cells, which can lead to anemia.
- Also, it can damage the immune system by changing blood levels of antibodies and causing the loss of white blood cells.
- The seriousness of poisoning caused by benzene depends on the amount, route, and length of time of exposure, as well as the age and pre-existing medical condition of the exposed person.
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