This article has originally been written in Norwegian. You can read a machine translated version here.
 

Against the background of an (again) increasing threat of the use of weapons of mass destruction, I would like to share a decision-making tool for evacuation from a contaminated area.

The abbreviation CBRNE is a collective term for chemical, biological, radioactive, nuclear and explosive threats and weapons. In this HOW-TO, we focus on radioactive and nuclear threats, but the tool also works for chemical and biological warfare agents.

This method is intended as a basic approach and the problem is much more complex in reality. Reminder that it is not a scientific (tested) method. The model also makes a number of assumptions, so the tool has its limitations.

It should only be used when protection where you are (shelter) is NOT available and in the absence of a public recommendation (in Norway via NRK broadcasting on DAB+ and online). The information is shared as is - i.e. without any form of guarantee. Feel free to provide input and feedback.

At Rohrmüller Medical, we call this tool the "Stay-or-Go" method. It is a mixture of a number of methods from specialist literature and practical procedures, but due to its special nature, no specific sources are given here. As easy-to-read, overarching documents (recommendations), the following can be mentioned:

Nuclear War Survival Skills by Cresson Kearny (2001)

Nuclear Contamination Avoidance, US Army Manual FM 3-3-1 (1994)

STAY-OR-GO method:

1. We start from a nuclear, local incident in the form of an ICBM, dirty bomb, etc. This is verified visually (remember "duck and cover", don't look at flash, wait for pressure wave) or with the help of media information. It is also very useful to have a dosimeter available.
2. Find a large map / overview map. Best in paper form in terms of signing in and to be independent of electricity / mobile and data.
3. Draw a rectangle on the lee side (opposite where the wind blows from) of the epicenter of the event with a size of 5km x 2.5km (CDC recommendation: 11km x 5km). The long side is along the wind direction. This is usable for the first 4 hours.
4. Expand the rectangle by 600m every 4 hours .
5. Draw a new rectangle every time the wind direction changes (the ENTIRE area must be considered contaminated).

If you are inside the rectangles: Protect yourself on the spot immediately. Outside rectangle: Move further away / do not enter rectangle. Experience has shown that the rectangle model gives a better assessment than the cloud/drop shape.

Special cases:

• Wind speed: over 20 km/h (6 m/s or 13 mph): Rectangle must be adjusted after 2 hours, not 4. Rectangle must be adjusted: 6km in length, reduce width to 2km. Below 20 km/h wind speed, the model does not need to be adapted.
• Temperature (both high and low): Has an impact on the effect of various agents (BC) as well as the decision to evacuate (e.g. increased sweating). Not elaborated here further.
• Terrain: Urban terrain: Draw a 5km x 5km block around the displayed area, i.e. square instead of rectangle. However, use the original rectangle at wind speeds above 32km/h (9 m/s). Open landscape: No adaptations of original rectangle. Forest terrain : It is safer to navigate closer to the rectangle since forests absorb a lot.
• Inversion : "Perfect" weather for using C combat agents since the agent will be pushed down to the ground! Accordingly, the rectangle must be extended/followed over a longer period of time, i.e. a larger area will be displayed.

The aim of the article is an avoidance of contamination (contamination avoidance), NOT action routines In, for example, a radioactively contaminated environment. This requires special equipment in the form of dosimeters and knowledge of interpretation. An automated, personal, very small measuring device that can show dangerous radiation levels is e.g. K8 Nuke Safeguard. 

As always: The article is to be considered a personal opinion with no guarantee of completeness or correctness. I will always make sure to use the best possible sources. The use of the recommendations is the responsibility of the reader. Read the disclaimer here and use common sense. Thanks.