Rubber Automobile Tires
The United States has a very strong tendency to mass produce almost every product that has been in circulation. The United States auto industry is a multi-billion dollars a year industry; in 2015 there were 263.6 million registered vehicles in the United States. These vehicles include cars, trucks, semi-trucks, and motorcycles so to be generous let's say every vehicle uses 4 tires it doesn't account for the spare or the 18-wheeler semis. The number of tires in circulation for the number of vehicles is roughly 1.05 billion tires on United States roadways in 2015. However, this number could be much higher if we estimate that every car has a spare and that doesn’t include the 12 other tires that semi trucks have. Each tire has two main components the rubber and the wire mesh. The rubber could be natural or synthetic rubber and zinc covered steel wire for the wire mesh. The rubber is used for the car to get traction with the ground in different environmental conditions. The steel wire mesh is used for the reinforcement of the tire so that it can carry the load of an automobile. As you may know, most tires are filled with just air however they are starting to fill the air with nitrogen. For my object, I was concerned about the amount of hazard that we are putting up with on Earth in order to have this commodity from harvesting to manufacturing to disposal. And my second aspect to look at rubber tires is environmental justice there is a lot of injustice happening when it concerns the disposal and harvesting of material for tires.
Evolution of the Modern Vehicle Tire:
The first pneumatic tires were invented in 1888 by the company Mercedes Benz. Benz also invented the first gasoline powered car which came equipped with these tires. However, these tires aren’t what we might be used to the tires on the first gasoline car looked more like bike tires with spokes attached to a giant metal ring. The tire was completely framed in metal with a small layer of rubber around the edges filled with a small amount of air. Rubber tires became popular after they were used in a famous race in Paris, France called from Paris to Bordeaux in 1895 (Rajan et al). Since they were just like bike tires however they didn’t have any tread on them so on a wet day the tires would just skid off the road. It wasn’t until 1905 that tires started getting made with tread on them. This tread helped increase the friction coefficient that the tire makes with the ground so it allows for safer driving when turning and braking. 25 years later Du Pont an American company successfully developed synthetic rubber which now allows a tire to increase not only in quality but they became significantly cheaper, Henry Ford used this method to make cars more affordable for the average American family.
Modern tire structure was invented in 1940 and sought out to improve fuel efficiency. In 1940 in order to relieve the American public from skyrocketing oil prices car manufactures started to replace heavier exterior parts of the car along with this came changes to tires (Rajan et al). In order to help with fuel efficiency, they started to manufacture tires with the steel wire mesh to help with weight distribution and lifespan of the tire. 10 years later the first radial tire was invented which gives us a rotation of the tire (forward facing). These two technological advances are what gave us the modern tire that we see every day. Some recent technology advances are the airless tire by Hankook tire. Not only does this tire only use one type of synthetic rubber without steel wire they are made of recycled tire parts and the production cost and price for these tires are about half (Hankook).
Risk and Hazards (Harvesting & Manufacturing):
The two main components of car tires are rubber and steel wire mesh that is coated in zinc. The rubber can be one of two materials natural rubber or synthetic rubber, natural rubber comes from trees. Hevea brasiliensis or pará rubber tree is the Earths natural form of rubber. This tree produces a milky sap substance that contains rubber latex and produces every day for 20-25 years (Cain). 70% of Earths rubber manufacturers are the countries Malaysia, Indonesia and Thailand. A risk from harvesting is that these countries are all third world countries and have established minimal employment laws, the minimum wage in Thailand is about $10 a day and $93 per month in Indonesia and $244 per month in Malaysia (website). These trees are described as very laborious since they do need to be sapped every day. These countries have a history of extorting labor from their citizens without providing adequate living situations. The second and more popular tire is the synthetic rubber tire. These tires are much easier to produce because they come from petroleum by-products. Both of these methods helped produce about 33 billion pounds of rubber annually. The main hazard that comes with synthetic tires is the wearing down of and releasing hydrocarbons from the tires. Since petroleum is part of the carbon cycle, petroleum produces a high amount of hydrocarbons which are not great for the atmosphere. Along with being harmful to the atmosphere, a study done by K.E Day took three different types of tires, new, worn, and pieces of breakaway tires were submerged in 300 liters of water. The tests showed that all of these tires leached out toxic chemicals that are unsafe for animals and humans. However, there is some good, once the tires were removed from the water the toxic chemicals were non-volatile and slowly degraded. The last hazard is the steel wire mesh that reinforces the tire. Zinc and lead are among the most prevalent heavy metals found in urban city runoff. The steel wire mesh is coded in zinc and when a tire is worn down the steel comes into contact with the ground and the zinc washes into our sewer systems (Christensen et al.). Mining zinc comes with a huge environmental impact, along with zinc usually nickel and iron are found with it. Ways of purifying zinc for commercial use involves combustion and calcination which is superheating of elements to extract all other elements but zinc. This process fills the atmosphere with carbon dioxide and zinc which contributes to greenhouse gases and climate change.
Environmental Justice (Time for a Change):
Once upon a time in the United States, we had over 2 billion old used tires littered throughout the country (Motavalli). From these pile up came Colorado's tire mountain which was the largest of the stockpile of tires with an estimated 89 million tires. These tires like I mentioned before release hydrocarbons and leach the water systems with a toxic amount of chemicals that are harmful to humans, animals, and plant life. In 1983, a tire dumb with about 7 million tires caught fire in Rhinehart Virginia sending a plume of smoke 3000 feet high and 50 miles long into the atmosphere and over three states. However, in an effort to reverse the environmental injustice that we created by stockpiling tires throughout the United States we started to re-purpose tires. Today we have broken down the estimated 2 billion tires by 90% by simply repurposing them. In 2009, more than 500,000 tons became ground rubber and playground walkways, mulch, animal bedding, sports surfacing, molded products and auto parts (such as floor mats). Efforts to stop the growing tire piles scatters throughout the United States is been very successful, large companies like Bridgestone sponsored an event to help clean up abandoned tires by waterways and lakes. In 2014 this event cleaned up 802 tires from Del Rio, Texas. After all the efforts were done States started to make it illegal to dumb whole tires in landfills a total of 38 states past this law (Nash). Since we know the hazards of tire runoff and having them as an eyesore what does the United States do? They start to export old worn tires to different Asian counties. China and Vietnam realized that it is cheaper to burn tires as fuel in different factories rather than fossil fuels. However, this environmental injustice affects not only the local region that must deal with the pollution of these factories. Western states started to see an increase in pollutant emissions from the years 2005-2010 when the study was done by Nasa Jet Propulsion Laboratory (Nash). Even though old worn tires have become an eyesore and were made illegal to dump in landfills and have a hazardous runoff, the United States didn't fix the problem we just moved it elsewhere, but still, all of us suffer from this environmental injustice.
The United States at one point or another had an estimated 2 billion old or worn tires stockpiled in different locations. The largest pile being in Colorado where the pile of tires exceeded 89 million. From studies done we figured out that tires leach harmful runoff that is toxic for living things including hydrocarbons, zinc, and lead. The history of the tire is fairly recent with the start date of the modern tire in the 1940s. It is astonishing to see that only in 70 years be manufactured enough tires to have 2 billion old ones. With this rapid manufacturing, there are bound to be some risk and hazards. Some risks are exploiting of labor in third world counties that have minimal employment laws. These citizens will work 9-11 hours out in the fields doing back breaking labor. Some hazards are the increase in carbon dioxide, zinc, and lead in urban areas. With all these tires being created there is bound to environmental injustice, we see this in the form of pollutants that travel across the Pacific Ocean and into the air of the western state. The increase carbon dioxide creates a larger greenhouse effect that doesn't allow all reflected sunlight to escape Earth back to space causing Earth to heat up. According to our textbook when looking at the carbon cycle we see that carbon dioxide takes thousands of years to make its way to the atmosphere and in some cases, it takes millions of years. What humans are doing is accelerating the process of filling the atmosphere with carbon dioxide, burning tires because they are an eyesore or we just don't want them in our country is not the answer. We cannot just export our used tires to other counties because we all live under the same atmosphere we must do a better effort of recycling our tires.
Cain, Patrick (2014). How tire company Bridgestone is solving a tricky natural-resource issue. Retrieved from https://www.fastcompany.com/3033390/how-tire-company-firestone-is-solving-a-tricky-natural-resource-issue
Christensen, R. Erick, Guinn, P. Vincent. (1979) Zinc from automobile tires in urban runoff. Retrieved from Civil Engineering Database
Day, K.E. (1994) Toxicity of leachate from automobiles tires to aquatic biota. Retrieved from Google Scholar.
Motavalli, Jim (2014). Americas Tire mountains: 90% are gone thanks to recycling programs. Retrieved from https://www.mnn.com/lifestyle/recycling/blogs/americas-tire-mountains-90-percent-are-gone-thanks-to-recycling-programs
Nash, Leah (2016). California’s old tires cross the ocean and come back as smog. Retrieved from http://www.takepart.com/feature/2016/02/12/tire-recycling-california-smog
Rajan, Raghuram, & Volpin, Paolo, & Zingales, Luigi (1997). The eclipse of the U.S tire industry. Retrieved from http://gsblgz.uchicago.edu
Robbins, P., Hintz, J., & Moore, S. A. (2013). Environment and society: a critical introduction. Retrieved from https://ebookcentral.proquest.com
S. H. Cadle and R. L. Williams (1979) Gas and Particle Emissions from Automobile Tires in Laboratory and Field Studies. Rubber Chemistry and Technology: March 1979, Vol. 52, No. 1, pp. 146-158.