Microplastics are everywhere, but are they harming us?

NEW YORK - Microplastics have been found in the ocean and the air, in our food and water. They have been found in a wide range of body tissues, including the heart, liver, kidneys and even testicles. But are they actually harming you? Evidence suggests they might, but it's limited in scope.

Some researchers are worried, but acknowledge there are lots of unanswered questions. The information you need to know, sent directly to you: Download the CTV News App Dr. Marya Zlatnik, a San Francisco-based obstetrician who has studied environmental toxins and pregnancy, has seen studies raising concerns about microplastics' impact on the health of babies and adults.

But it's a young research field, and it's not something she generally discusses with patients. "I'm not entirely sure what to say yet," Zlatnik said. Here's a look at what's known so far: What are microplastics? Plastics are man-made materials -- many of them derived from oil or other petroleum products.

They can break down into smaller particles, through exposure to heat and weather and even animal digestion. Researchers have increasingly been interested in microplastics, which can be as wide as a pencil eraser or as small as a fraction of the width of a human hair. Nanoplastics, another area of study, are even smaller.

These miniscule plastics have been detected in air, water and soil, in milk, and in bottled and tap drinking water. They also have been found in a variety of foods, including salt, sugar, honey, rice and sea.