The 9/11 first responders suffer from a range of different illnesses, some of which are rare in the general population. Some of the illnesses can be attributed to the high pH of the WTC dust. Less understood, and requiring further study, are unusual illnesses of the immune system commonly observed in the WTC first responders. [5] Additionally, aluminum and silicates – potential causes of the observed illnesses of the immune system – are components of nanothermite formulations. In 2009, an international team of researchers discovered what appear to be sol-gel nanothermite formulations in every WTC dust sample tested.