 In 1869, a patent was taken out for a new substance to replace elephant ivory in the production of billiard balls, and the plastics industry was born. Ironically, what started out as a conservation-minded measure has turned into an environmental problem. Hundreds of thousands of tons of trillions of tiny plastic particles are now floating on the surface of the sea. This is how it works, either from plastic objects like water bottles that get worn down into tinier and tinier pieces, or plastic microbeads flowing down into the sewers from our sinks. Plastic microbeads are often used as a scrubbing agent in personal care and cosmetic products, such as facial cleansers, shower gels, and toothpaste. And up to 94,000 microbeads could go down the drain in a single wash. Then when you trawl the oceans, you can find the same beads you find in the facial scrubs. Plastics are emitted into aquatic habitats every day in the United States. Late end to end, the United States emits enough microbeads to wrap around the planet more than seven times. The reason this may be a problem is that the plastic then accumulates toxic compounds from the water and then shuttles them, along with any chemicals originally in the plastic, into marine organisms, concentrating up the food chain and eventually ending up on our plates. The potential hazardous effects on humans then evidently includes alterations in chromosomes which lead to infertility, obesity, and cancer. Wait, wait, let's take a step back and review the evidence. Plastic gets into the oceans, but does it even get into the fish? Yes, microplastics have been shown to be ingested by fish and other seafood. But are we then actually eating plastic-ingesting fish? Yes, we are eating plastic-ingesting fish. Don't we just poop the plastic out? Small enough microparticles may actually be able to get absorbed through the intestinal wall and into our bloodstream. This uptake of ingested microparticles into small intestinal tissues and onto secondary organs has moved from being an anecdotal phenomenon to a recognized and quantifiable process. But that's in rodents. I mean, just because it's been demonstrated across a variety of lab animals, you don't know if it happens in people until you put it to the test. The closest we have is working with human placentas after a childbirth. And what they found is that plastic microparticles could indeed cross the placental barrier from the maternal bloodstream. So if it could get into a pregnant woman's circulation, it might get into her baby's circulation as well. The reason this is concerning is that plastic debris can be a source of toxic chemicals, both chemical additives in the plastic itself, and then pollutants the plastic sucks up from the water that can then be later released into the body. BPA is one of the chemical additives that can originate from the plastic itself. Given that BPA concentrations have been measured in plastic debris, microplastics may be a major source of BPA in seafood, but no one's really looked into it until now. BPA levels in the edible parts of seafood. Yes, fish and seafood present one of the highest BPA contamination levels, but is that just because they were looking at canned fish products, like tuna and sardines? Manufacturers may use BPA in the lining of food cans directly. Yes, BPA may also leach from the plastic in the oceans, causing a direct contamination of the fish. In fact, some argue that this BPA environmental contamination fish could be worse than the BPA from the cans themselves, but you don't know until you put it to the test. Here are the BPA levels found in canned seafood. You can see the highest levels were found in like tuna, cockles, sardines, and blue crab, but these were all canned, so you don't know how much is from the can versus the seafood itself, until you look at non-canned seafood and sometimes found even higher levels in some fresh mollusks, clams, flounder, and cod. That's not good, since plastics chemicals such as BPA are known endocrine disruptors, meaning known hormone disruptors. And besides that, fat soluble pollutants from the seawater can glom onto the microplastic surfaces and potentially present additional risk, which we'll cover next.