It's no wonder - typical of lead poisoning. 

The article gives more info than that though. Lead levels in children have dropped over the last twenty years and

"he says that shifts in how the state measures educational assessment -- and a district that has struggled for decades -- are both significant factors in the recent test scores."

The district needs help regardless, but knowing your child's lead levels are lower than your own may have been at that age is probably something of a relief.

Horrible story!