region of normal exposure
41Ozone depletion — Image of the largest Antarctic ozone hole ever recorded (September 2006) Ozone depletion describes two distinct but related phenomena observed since the late 1970s: a steady decline of about 4% per decade in the total volume of ozone in Earth s… …
42perception — perceptional, adj. /peuhr sep sheuhn/, n. 1. the act or faculty of apprehending by means of the senses or of the mind; cognition; understanding. 2. immediate or intuitive recognition or appreciation, as of moral, psychological, or aesthetic… …
43Attention deficit hyperactivity disorder — Attention deficit/hyperactivity disorder Classification and external resources Children with ADHD often find it difficult to do their schoolwork. ICD 10 F …
44Kryptonite — This article is about Kryptonite, the element from the Superman mythos. For other uses, see Kryptonite (disambiguation). Kryptonite Lex Luthor in front of a display of kryptonite and holding green kryptonite. From a panel in Action Comics Annual… …
45Poliomyelitis — Polio redirects here. For the virus, see Poliovirus. Not to be confused with poliosis, a condition of the hair being or becoming white or grey. Poliomyelitis Classification and external resources A man with an atrophie …
46AIDS — For other uses, see AIDS (disambiguation). Acquired immunodeficiency syndrome (AIDS) Classification and external resources …
47Ionizing radiation — consists of highly energetic particles or waves that can detach (ionize) at least one electron from an atom or molecule. Ionizing ability depends on the energy of the impinging individual particles or waves, and not on their number. A large flood …
48immune system — Anat. a diffuse, complex network of interacting cells, cell products, and cell forming tissues that protects the body from pathogens and other foreign substances, destroys infected and malignant cells, and removes cellular debris: the system… …
49immune system disorder — Introduction Disorders of the immune systemany of various failures in the body s defense mechanisms against infectious organisms (see table (Disorders of the immune system)). Disorders of immunity include immune deficiency diseases, such… …
50Cancer — For other uses, see Cancer (disambiguation). Cancer Classification and external resources …
