"When researchers sampled playgrounds, they found blood, mucus, saliva and urine," reports Today.com. And we're not just talking about outdoor playgrounds. In 2011, mother Erin Carr-Jordan spent thousands of her own dollars to collected samples from the indoor play areas of nine fast food restaurants in seven states. The lab found fecal matter – human waste – in nearly 90 percent of the samples. Ball pits are even worse.