Plastic pollution is when we use too much plastic and don't throw it away properly. You know how you love toys and playing with them? Well, plastic is like a toy, and we grown-ups use it all the time. We use plastic to make things like water bottles, toys, and even our foods come in packages made of plastic. The plastic is made to last a long time, more than even 1,000 years!
But the problem is, when we finish using the plastic, we often don't put it in the trash. Instead, we just leave it on the street or in the ocean. This is bad because plastic doesn't break down like other materials do. You know how when you leave a banana peel outside, it turns brown and eventually disappears? Well, plastic doesn't break down in the same way. It just breaks up into smaller and smaller pieces, but it never really goes away.
So, when we leave plastic on the street or in the ocean, it goes into the soil and water, and hurts animals and the planet. Animals sometimes eat the plastic, which can make them very sick or even die. And when plastic goes into the ocean, it can float around and hurt sea creatures. This is why we need to make sure to always throw our plastic trash away in the trash can, so it doesn't hurt the planet and wildlife!