What is this black sooty material on the inside of my roller shutter?
Looks like fungus of some sort. It grows on many surfaces. Try household cleaners and a sponge. 

There are many types of mold, and the hysteria surrounding them is often unwarranted. Mold spores are everywhere, and only a very specific type is potentially dangerous, and only in significant quantities. 


  The term “toxic mold” is not accurate. While certain molds are toxigenic, meaning they can produce toxins (specifically mycotoxins), the molds themselves are not toxic, or poisonous. Hazards presented by molds that may produce mycotoxins should be considered the same as other common molds which can grow in your house. There is always a little mold everywhere – in the air and on many surfaces. There are very few reports that toxigenic molds found inside homes can cause unique or rare health conditions such as pulmonary hemorrhage or memory loss. These case reports are rare, and a causal link between the presence of the toxigenic mold and these conditions has not been proven.


Basically, if it can be cleaned up it's not a serious issue. You wouldn't throw away an item that can be wiped clean.