Streams of Babel — Carol Plum-Ucci

In a New Jersey suburb, two women die of brain aneurysms within twenty-four hours--events that cause the government to suspect that a terrorist cell has unleashed a deadly biochemical agent. With each glass of water they drink, the people of Trinity Falls are poisoning themselves.
A world away in Pakistan, a sixteen-year-old computer genius working as a virtual spy for the United States sees an influx of chatter from extremists about a substance they call Red Vinegar that will lead to many deaths in Colony One. Can he warn the victims before it's too late?