I think that Brazil should be concerned because a space rock explosion is a concern for any country that is in the zone that the rock manner will fall in. The explosion can send giant chunks of space rock hurling toward infrastructure in Brazil and cause massive damage, not only to buildings, but also in the form of civilian deaths.
This is just the beginning and we should all be concerned. If you haven't found God yet you need to because this is serious stuff. This could very well be the beginning of the end of life on earth. We could very well be living in the end times and you should all accept Jesus as your lord and savior.
So, in fairness, it would be really unfortunate and probably quite disappointing to be showered by thousands of bits of fast moving space debris, but really, unless the Brazilian government is hiding the biggest beach umbrella of all time, what can they do about it? The rock has already exploded, the debris on a fixed course; stay indoors and enjoy the show.
There is no reason for Brazil to be concerned with the rock exploding over their airspace. If there was any dangerous substance in the rock and now in the air or ground, we would be able to measure it. Fear being an intial response has been a hindrance to humanity since our dawn.