Changing The effect of Motion Blur based on damage?

I am looking to have Motion Blur Effect change (public float blurAmount = 0.8f as the damage level increases for the player.

What would be the best approach? Modify the Motion Blur effect with function to respond to a broadcast message?

Can I use the Shader.blurAmout to change the value via Javascript, or am I going to run into performance problems?

Thanks in Advance.

 

In my experience there's no performance hit modifing this value in JS. I'd recommend, when it falls to an imperceptible value, switching off the component for better efficiency.