1961-1975 2004f-185 adverseeffects agentorange aircraft armedforces australian chemical diseases epidemiology etiology foreignservice healthaspects healthriskassessment herbicides history medical medicalcare medicine military militarymedicine occupationalexposure participation polychlorinateddibenzodioxins respiratorytractneoplasms toxicology veterans veteranshealth vietnamconflict vietnamwar vietnamwar(1961-1975) wa240 wa240i594v2004 warfare