Plastic was invented about 150 years ago. Its invention was closely connected with the game of billiards. In the middle of the 19th century, billiards was very popular in the U.S. Originally, the billiard balls were made from ivory and this material was difficult to get. As a result, people searched for a new material for billiard balls and invented the first example of plastic.
　Now plastic is used in a wide variety of products because it is light, strong, and cheap to produce. About 36% is used for packaging, 16% in construction, and 15% for man-made fibers such as polyester. The rest is used in a variety of products. In many ways, plastic has changed our lives for the better.
　The problem with plastic is that much of it is soon thrown away. Only 9% of plastic is recycled and 12% burned. The remaining 79% either goes into landfills or is left as trash in the environment. The human race produced 8.3 billion tons of plastic items between 1950 and 2015, and of that about 5.5 billion tons ended up as waste. Unfortunately, a huge amount of plastic gets into rivers and then flows into the oceans.