Certo mi chiedo per averne trovato tracce addirittura nella polvere quanta roba c'era in ballo(?)

Fifteen small chips having a total mass of 1.74 mg were extracted from a 1.6 g sample of dust from which readily identifiable glass and concrete fragments had been removed by hand. Thus the fraction of red/gray chips was approximately 0.1% by weight in the separated dust Another sampling showed 69 small red/gray chips in a 4.9 g sample of sepa- rated dust. Further samples are being analyzed to refine this estimate. The fall of the WTC Towers produced enormous clouds of dust whose total mass is difficult to ascertain; but clearly the total mass of red/gray chips in the WTC dust must be substantial given the fraction observed in these sam- plings.