While many of us are aware of the environmental damage done by plastic, fewer people know about the threat from the ubiquity of microplastics. Scientists first found them in our bodies more than a decade ago. Worryingly, researchers have now found them in the human heart. Scientists at the Beijing Anzhen Hospital in China collected cardiac tissue samples from 15 patients undergoing heart surgery. After analyzing the samples, they discovered tiny pieces of plastic, from a multitude of sources. They included a plastic commonly used as a shatter-proof alternative to glass, a polythene widely used in clothing and food containers, and a polyvinyl chloride used in construction.

The scientists reported finding, "tens to thousands of individual microplastic pieces in most tissue samples". Chemicals from microplastics are released into the body, potentially leading to allergic reactions, cancer, cell death, and chronic inflammation, among other complications. Scientists reckon the average person consumes around five grams of microplastics a week, or 52,000 particles a year. Microplastics are so prevalent that they make up 39 per cent of dust particles in our homes. Scientists say these tiny shards are near-impossible to remove from the body. They say it is becoming critical to limit the amount of plastic we breathe in, ingest, swallow or absorb.