I Heard That Breastmilk Is More Polluted Than Formula Milk. Is That True?

It's possibly true, but it's probably not a sound reason to give formula rather than to breastfeed.

Most formula milks are based on cow's milk.  That means that whatever the cow has been exposed to so would the infant.  That would include, in most of the world, high doses of antibiotics or growth hormones.  In Europe most cows have little if any exposure to those things, but no doubt some other pollutants do get into cow's milk here, too.

At the top of the food chain and in our increasingly polluted world, it perhaps shouldn't be surprising that we humans get exposed to a lot of different chemicals, including whatever gets into our food, the perfumes in the shampoo we use or in the detergent we use, plastic fumes, etc.  So of course, these things can get into a mother's milk, too.

The thing to remember is that this pollution problem, although not something to be happy about, isn't new.    When past studies compared how breastfed and forumla fed infants fared, and found an advantage for mother's milk, that still applies even though the milk had some contaminents in it then, and does now, too.  The mother's milk was better, in spite of the pollution.