wo Sh eentpe Aigreund Information idkFLevels of thermal radiation that can produce skin burns arTae SP ttieerd te the immediate testing site nrenw Fools on th: s geyes, however, may extend for much greater dixtatves. These effects may be either permanent damage tu part « eat ee eye ora temporary flash “blindness.” The latter ip ont’ adiscomfurting effect but can be potentially laigzirdous in Ghat 2 eee of automobile drivers and aircraft pilots. ‘This is one'e ey ana age Teanune why certain areae of highways huve been ciused fi ae aans epwch fied periods of time around the Nevada Test Sis and als @ aaahSoguhy the same precautions have been taken for the air lane a x : a und the Nevada and Pacific testing sites. Bee ae rhaps surprisingly. the amount of heat (calories) received ag “ay per. nit aren on the rear portion of the eyeball (retinn) dot me . Nat decrense with increasing distance from the point of burst-- vote Bee meen ro ee Aeemeeent SOM TE nue —- eeealLehn eA omSais) ihei 22S oa . ~ Be es ; Ls aa) oan ae - A *, NSTae _a Sand ; . > if ean ae rower . i : Figure 7.- A downtown Los Vega winds. showing how the glass wae wi kee out by the rarefaction wate, tather than pushed in by the com pression wave resulting from the Novembgr 4. MAL nuclear tras at the Nevada Test Site. been no significant structural damages from refracted blist waves since good predictive methods have been developed. There has been no known case cf direct injury to man or animals from the refracted blast waves. Evaluation The predictive procedures developed resulted ino greativ Miaindaing off site damage from blast effects. Tn fact. there have been only incidents of single windows being déenaged gineo ES. Pwo oceurred in lief and a third in (Ma? 22 ) ~geneept for the absorption (attenuation) effect in tiv utmond “.. phere. While the expected decrease in energy por unit areal ‘does occur outside the eye (the inverse square law), the ima ie Fy- formed on the retina correspondingly decrenses in aise in thom ge eame proportion. The result ia that the thermal dose, in cp 2 < gyles per unit area, remains constant but it covers « smalley i aM ayeaon the retina. Vhis reduction in image size on Loe retin , ‘-with increasing distance from the burat continues until . °*spegches approctimately O,Q001N inch (7 aicrons) in diamates "which is generally taken ag about the Hmit for the maximus ve focusing effect of the human eve. Of course s diiution of v) S -, pupil of the eye, such as at nighttime, will permit more lighee "enter and, although the retinal image size dues net -leange, ‘dae can be relatively more hagardous. Also, ois aesuined Chitg " gny light gathering devices such as binucwlir also wow! ae “ Ineroase the hazard. “Any damage to the retina probably would not be detected b an eye examination if it were lesa than 60 microns io diamete: Actual functional impairment of visian probably sould not | i noted if the lesiona were mild and less than 80 nucesis in digg efer on the foven—the most sensitive portion of the selina, Thera may te lese injury te the retina of the eye if a giver total amount of thermal energy le received ul a slower rats ie. there is mure opportunity for the adjacent colts in ti a retina to counchict away some of the Heat. Hirh victd dete: ae Hone in the lower atmosphere exhibit a slower rate cf deliver yi than low yields (say, uo million tons vernun Qe thsi top dg At very hivh platuder, say above gi0 qnde ooiv abo Re Yooow af the totat yield from a tnegaton dete vie uppen a