As a father of five daughters – involving five pregnancies — I know how to clean up cat poop.

A task I continue daily.

So do others.

Each year in the United States, cats deposit about 1.2 million metric tons of feces into the environment, and that poop is carrying with it what may be a vast and underappreciated public health problem, say scientists July 9 in the journal Trends in Parasitology, a Cell Press publication.

Some of that poop is laden with an infectious parasite known as Toxoplasma gondii, a protozoan that has recently caused toxoplasmosis epidemics in otherwise healthy people, not just in pregnant women or people with immune deficiencies. Additional concerns have been raised by studies linking T. gondii to schizophrenia, obsessive-compulsive disorder, rheumatoid arthritis, brain cancer, and even to kids’ trouble in school.

“The accumulation of Toxoplasma gondii oocysts, found in cat feces, may be a much bigger problem than we realize because of their apparent long life and their association with some diseases,” said E. Fuller Torrey, who directs the Stanley Medical Research Institute.

He calls for better control of the cat population, especially feral cats, and more research. Surveys have shown that our backyards and communities may harbor three to 400 oocysts per square foot or more in places where cats frequently leave deposits. Each and every one of those oocysts has the potential to cause an infection.

My kids wouldn’t go in the sandbox; said it was a giant kitty litter.