Terrorist attacks are growing in complexity, increasing concerns around the use of chemical, biological, radiation, and nuclear (CBRN) agents. This has led to increasing interest in Counter-Terrorism Medicine (CTM) as a Disaster Medicine (DM) sub-specialty. This study aims to provide the epidemiology of CBRN use in terrorism, to detail specific agents used, and to develop training programs for responders.

The open-source Global Terrorism Database (GTD) was searched for all CBRN attacks from January 1, 1970 through December 31, 2018. Attacks were included if they fulfilled the terrorism-related criteria as set by the GTD’s Codebook. Ambiguous events or those meeting only partial criteria were excluded. The database does not include acts of state terrorism.

There were 390 total CBRN incidents, causing 930 total fatal injuries (FI) and 14,167 total non-fatal injuries (NFI). A total of 347 chemical attacks (88.9% of total) caused 921 FI (99.0%) and 13,361 NFI (94.3%). Thirty-one biological attacks (8.0%) caused nine FI (1.0%) and 806 NFI (5.7%). Twelve radiation attacks (3.1%) caused zero FI and zero NFI. There were no nuclear attacks. The use of CBRN accounted for less than 0.3% of all terrorist attacks and is a high-risk, low-frequency attack methodology.

The Taliban was implicated in 40 of the 347 chemical events, utilizing a mixture of agents including unconfirmed chemical gases (grey literature suggests white phosphorous and chlorine), contaminating water sources with pesticides, and the use of corrosive acid. The Sarin gas attack in Tokyo contributed to 5,500 NFI. Biological attacks accounted for 8.0% of CBRN attacks. Anthrax was used or suspected in 20 of the 31 events, followed by salmonella (5), ricin (3), fecal matter (1), botulinum toxin (1), and HIV (1). Radiation attacks accounted for 3.1% of CBRN attacks. Monazite was used in 10 of the 12 events, followed by iodine 131 (1) and undetermined irradiated plates (1).

Currently, CBRN are low-frequency, high-impact attack modalities and remain a concern given the rising rate of terrorist events. Counter-Terrorism Medicine is a developing DM sub-specialty focusing on the mitigation of health care risks from such events. First responders and health care workers should be aware of historic use of CBRN weapons regionally and globally, and should train and prepare to respond appropriately.