Science
What Are Alpha Particles? A Simple Guide
Discover what alpha particles are, why they are trending in science, and how this unique form of radiation affects people, from health risks to medicine.
What is it?
An alpha particle (α) is a positively charged particle consisting of two protons and two neutrons, making it identical to the nucleus of a helium-4 atom. It is emitted by certain radioactive elements, like uranium and radium, during a process called alpha decay. Alpha particles are a form of ionizing radiation but have distinct properties. They are relatively heavy and slow-moving compared to other types of radiation. Due to their large mass and +2 charge, they are highly ionizing, meaning they can easily knock electrons off other atoms. However, they have very low penetration power and can be stopped by a simple sheet of paper or the outer layer of human skin.
Why is it trending?
Alpha particles are gaining significant attention in the medical field, particularly in oncology. The key trend is their use in an advanced cancer treatment called Targeted Alpha Therapy (TAT). This innovative therapy attaches alpha-emitting radionuclides to molecules that specifically target and bind to cancer cells. Once delivered, the alpha particles release their high energy over a very short distance—less than 100 micrometers—killing the cancer cells while minimizing damage to surrounding healthy tissue. The high effectiveness and precision of TAT have led to promising results in clinical trials for various cancers, including prostate cancer and leukemia, fueling a resurgence of interest and research into alpha-emitting radiopharmaceuticals.
How does it affect people?
The effect of alpha particles on people depends heavily on the type of exposure. Externally, alpha radiation is not considered a significant health risk because the particles cannot penetrate the skin's dead outer layers. The primary danger arises from internal exposure. If a substance that emits alpha particles is inhaled, ingested, or enters the body through a wound, it becomes extremely hazardous. Inside the body, the highly ionizing nature of alpha particles can cause severe damage to living cells and DNA in their immediate vicinity. This cellular damage can lead to radiation sickness or increase the long-term risk of developing cancer.