It's easy to protect your children from what you can see -- but it's a much bigger challenge to keep them safe from what you can't.

Your home is almost certainly filled with invisible threats to you and your family -- and a new study shows how the chemicals in many common household objects can turn your child or grandchild into a physical and emotional wreck... before he even turns three!

The chemicals are called phthalates, and -- like the BPA used in many food containers -- they basically act as estrogen inside the human body, throwing the natural hormonal balance out of whack.

It's bad enough for adults -- but it can be positively disastrous for a child.

Researchers from Columbia University's Mailman School of Public Health measured phthalate levels in the urine of 319 pregnant women, then tracked their children from birth through their toddler years.

They found that the kids with the highest levels of prenatal exposure were battling serious mental issues by the age of 3, including anxiety, depression, withdrawal, and emotionally reactive behavior.

And it didn't stop there.

These children were also more likely to suffer from delays in motor skill development -- and the girls were even more likely to suffer delays in mental development.

This isn't the first time these chemicals have been linked to bad news. Other studies have found they can lead to breast development in boys, lower sperm counts and testicular atrophy in men, and early puberty and other problems in girls.

Amazingly, despite these and other alarming links, there are no real federal regulations on these chemicals -- so they're in pretty much everything, up to and including your floor and walls.

They're in raincoats... shower curtains... perfumes... shampoos... nail polish... detergents... and, until very recently, toys.

That makes phthalates nearly impossible to avoid, so this is a "do your best" situation. Do your best to keep these chemicals out of your home and away from your family -- before these chemicals do their worst to you and your children.