Time to Protect Earth: Safe Life from Plastic Pollution Dioxin is just one of hundreds of Contaminants stored in the human fat - Hossain Shahriar, Ph.D. The history of plastics goes back more than 100 years - however, compared to other materials, plastics are relatively modern. Their usage over the past century has enabled society to make huge technological advances to take us towards the new Millennium. Pre-20th Century although we think of plastic as a modern invention, there have always been "natural polymers" such as amber, tortoiseshell and horn. These materials behaved very much like manufactured plastics and were often put to similar uses to today's materials - for example, horn, which becomes transparent and pale yellow when heated, was used to replace glass in the 18th century. The original breakthrough for the first semi-synthetic plastics material – cellulose nitrate occurred in the late 1850s and involved the modification of cellulose fibers with nitric acid. Cellulose nitrate had many false starts and financial failures following its invention by a Briton, Alexander Parkes, who exhibited it as the world's first plastic in 1862. Firstly known as Parkesine, then Xylonite, it began to find success in the production of objects such as ornaments, knife handles, boxes and more flexible products such as cuffs and collars. The American Hyatt brothers were attempting to develop a substitute for the ivory billiard ball and in so doing came up with a process for manufacturers using a nitrate cellulose composition. Celluloid was thus born and was patented in 1870 - its early commercial success lay in dental plates for false teeth. In 1912, German chemist Fritz Klatte at Greisheim Electron unknowingly made the first PVC in an attempt to create uses for large quantities of acetylene gas fuel lamps just before the new technology of electric lights made them obsolete. He had reacted acetylene with hydrochloric acid (HCl). Not knowing what to do with the new material, it was stored for some time, and polymerization took place. Their patent expired in 1925 without them ever knowing what to do with it. Independently, in 1926, chemist Waldo Semon at the American company B.F. Goodrich invented PVC. And again, it was patented. One of the first uses for PVC was insulation on electric cables in 1930. Mass production, facilitated by improved injection molding, and automation, greatly reduced its price. PVC has been commercially available since 1942. By 1950, there were five companies producing PVC. And by 1980, there were twenty. Today, vinyl is the second largest-selling plastic in the world, and the industry employs more than 100,000 people in just the US. PVC is the second largest volume thermoplastic only to polyethylene. Production capacity has almost doubled over the last 20 years, currently 27 million tons/year worldwide. Current worldwide uses of PVC by percent are as follows: Building 56%; Packaging 15%; Consumer goods 10%; Electronics industries 9%; Agriculture 5%; others 5%. Health Hazard Dioxin is created during all phases of PVC production, as well as in its disposal by incineration or accidental fire. There is no "threshold" dose, meaning that the lowest dose that has hormonal action has not been found yet. Researchers have been unable to find the threshold using the most up-to-date advanced systems.
© Copyright Hossain Shahriar,Ph.D.2000-2006
PVC plastic is the largest single use of chlorine in the U.S., accounting for about 34 percent of all chlorine production. In 1996, the US and Canada alone produced 6.61 million tons of PVC and copolymers. A large body of evidence suggests that the greatest share of the nation's dioxin burden stems from the manufacture, use, recycling, and disposal of this enormous quantity of PVC plastic. The US Environmental Protection Agency (EPA) has known since the 1980's, that dioxin is an unavoidable by product created during the production and heating or incineration of many...
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