1994f-702 2000h-898 2003e-957 adverseeffects asphyxiatingandpoisonous braindamage braininjuries clinicalneuropsychology cognitiondisorders complications control ecologicalsystems etiology gases hazardoussubstances headinjuries maximumallowableconcentration movementdisorders occupationalexposure patients physiopathology prevention rehabilitation safetymeasures standards submarinemedicine submarines(ships) toxicology wd650r4542002 we706r523c2000 wl354d257s1994