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. An example of such damage is the Red Forest, a victim of the Chernobyl accident. 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 exposure 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.
In addition to this, AvPD is more prevalent in people who have comorbid social anxiety disorder and generalised anxiety disorder than in those who have only one of the aforementioned conditions.Some studies report prevalence rates of up to 45% among people with generalized anxiety disorder and up to 56% of those with obsessive–compulsive disorder. Posttraumatic stress disorder is also commonly comorbid with avoidant personality disorder.Avoidants are prone to self-loathing and, in certain cases, self-harm. Substance use disorders are also common in individuals with AvPD—particularly in regard to alcohol, benzodiazepines, and opioids—and may significantly affect a patients prognosis.Earlier theorists proposed a personality disorder with a combination of features from borderline personality disorder and avoidant personality disorder, called "avoidant-borderline mixed personality" (AvPD/BPD). Causes
Causes of AvPD are not clearly defined, but appear to be influenced by a combination of social, genetic and psychological factors. The disorder may be related to temperamental factors that are inherited.Specifically, various anxiety disorders in childhood and adolescence have been associated with a temperament characterized by behavioral inhibition, including features of being shy, fearful and withdrawn in new situations. These inherited characteristics may give an individual a genetic predisposition towards AvPD.Childhood emotional neglect and peer group rejection are both associated with an increased risk for the development of AvPD. Some researchers believe a combination of high-sensory-processing sensitivity coupled with adverse childhood experiences may heighten the risk of an individual developing AvPD.