Radiation Burn - Beta Burns

Beta Burns

"Beta burns" are shallow surface burns, usually of skin and less often of lungs or gastrointestinal tract, caused by beta particles, typically from hot particles or dissolved radionuclides that came to direct contact with or close proximity to the body. They can appear similar to sunburn. Unlike gamma rays, beta emissions are stopped much more effectively by materials and therefore deposit all their energy in only a shallow layer of tissue, causing more intense but more localized damage. On cellular level, the changes in skin are similar to radiodermatitis.

High doses of radiation can cause rapid browning of skin, known as "nuclear tan".

The dose is influenced by relatively low penetration of beta emissions through materials. The cornified keratine layer of epidermis has enough stopping power to absorb beta radiation with energies lower than 70 keV. Further protection is provided by clothing, especially shoes. The dose is further reduced by limited retention of radioactive particles on skin; a 1 millimeter particle is typically released in 2 hours, while a 50 micrometer particle usually does not adhere for more than 7 hours. Beta emissions are also severely attenuated by air; their range generally does not exceed 6 feet (1.8 m) and intensity rapidly diminishes with distance.

The eye lens seems to be the most sensitive organ to beta radiation, even in doses far below maximum permissible dose. Safety goggles are recommended to attenuate strong beta.

Beta burns can occur also to plants.

Careful washing of exposed body surface, removing the radioactive particles, may provide significant dose reduction. Exchanging or at least brushing off clothes also provides a degree of protection.

If the exposition to beta radiation is intense, the beta burns may first manifest in 24–48 hours by itching and/or burning sensation that last for one or two days, sometimes accompanied by hyperaemia. After 1–3 weeks burn symptoms appear; erythema, increased skin pigmentation (dark colored patches and raised areas), followed by epilation and skin lesions. Erythema occurs after 5–15 Gy, dry desquamation after 17 Gy, and bullous epidermitis after 72 Gy. Chronic radiation keratosis may develop after higher doses. Primary erythema lasting more than 72 hours is an indication of injury severe enough to cause chronic radiation dermatitis. Edema of dermal papillae, if present within 48 hours since the exposition, is followed by transepidermal necrosis. After higher doses, the malpighian layer cells die within 24 hours; lower doses may take 10–14 days to show dead cells. Inhalation of beta radioactive isotopes may cause beta burns of lungs and nasopharyngeal region, ingestion may lead to burns of gastrointestinal tract; the latter being a risk especially for grazing animals.

• In first degree beta burns the damage is largely limited to epidermis. Dry or wet desquamation occurs; dry scabs are formed, then heal rapidly, leaving a depigmented area surrounded with irregular area of increased pigmentation. The skin pigmentation returns to normal within several weeks.
• Second degree beta burns lead to formation of blisters.
• Third and fourth degree beta burns result in deeper, wet ulcerated lesions, which heal with routine medical care after covering themselves with dry scab. In case of heavy tissue damage, ulcerated necrotic dermatitis may occur. Pigmentation may return to normal within several months after wound healing.

Lost hair begins regrowing in 9 weeks and is completely restored in about half a year.

The acute dose-dependent effects of beta radiation on skin are as follows:

According to other source:

As shown, the dose thresholds for symptoms vary by source and even individually. In practice, determining the exact dose tends to be difficult.

Similar effects apply to animals, with fur acting as additional factor for both increased particle retention and partial skin shielding. Unshorn thickly wooled sheep are well protected; while the epilation threshold for sheared sheep is between 23–47 Gy (2500–5000 rep) and the threshold for normally wooled face is 47–93 Gy (5000–10000 rep), for thickly wooled (33mm hair length) sheep it is 93–140 Gy (10000–15000 rep). To produce skin lesions comparable with contagious pustular dermatitis, the estimated dose is between 465–1395 Gy.