Nearly one of every four children under 6 in the nation is poor, the study found.
Earlier studies have found similar results for men, they said.
Other studies have found no such effect on heart rate.
However, another study at the same time found a rate of 1 per 10,000.
On the other hand, at least one study found no effect.
Earlier studies had found a rate of less than 4%.
A recent study of day care found the same thing.
The current study found the total rate to be nearly 9 percent.
Much of this money, the study found, went to just a few people.
The public hospital was 115.6 percent below the national average, the study found.
