Forensic investigations are often a combination of both scientific techniques and historical background studies. One example that is often used is the background to leaded gasoline. Gasoline service stations can be found on many street corners and, in fact, there were many more service stations in the United States in the 1960s than there are today. This means that potential sources of contamination criss-cross the country and can be found in just about every neighbourhood.
Today, the United States uses more than 300 million gallons of gasoline per day. No other country comes close to this number. Between the 1920s and the late 1980s, this gasoline contained lead. Because many of these underground tanks had been in the ground for decades, the leakage of leaded gasoline was a common occurrence. We are still finding leaded gasoline in the ground today, almost 10 years after it was banned.
Tetraethyl lead (TEL) was first introduced as a gasoline additive in 1923. After many years of research, TEL was discovered by researchers at General Motors in Dayton, Ohio. Credit for its discovery is normally given to Thomas Midgley, Jr., who later went on to discovery chlorofluorocarbons (CFCs). However, the research work was headed by Charles F. Kettering, who was the discoverer of many automotive inventions, such as the electric starter.
In the late 1800s and the early part of the 20th Century, automobiles were run on many different types of fuel, such as steam, alcohol, diesel fuel and natural gas. Gasoline was also used, but it was limited by a drawback known as “knock”. As the motor engines became more powerful and the compression ratios increased, a knocking or pinging would occur in the cylinders. This was caused by detonation of the fuel. TEL was introduced as a way of reducing that knock and it allowed engines to be produced of greater power.
Many may claim that TEL paved the way for the great industrial expansion of the early 20th Century.
At the time, many believed that TEL would only be used for a few years. Petroleum reserves were believed to be small and it was anticipated that alternative fuels would need to be found. At the time, Henry Ford believed that ethanol would be the fuel of the future. However, ethanol was not a fuel that could be patented (unlike lead gasoline) and, therefore, it was in the interest of industry that leaded gasoline be used.
In 1924, workers at Jersey Standard’s (today’s ExxonMobil), DuPont’s and GM’s TEL manufacturing facilities began to develop lead poisoning and about 15 died. A large outcry developed from the public and leaded gasoline was subsequently banned. GM and Jersey Standard petitioned the government, the Surgeon General reviewed the situation and eventually leaded gasoline went back on the market. However, research into the adverse health impacts of leaded exhausts was not investigated at that time in much detail. It was not until the 1960s that researchers began to realize the full impact of leaded gasoline on the environment. Despite the impact to the environment and the known ill effects on children, it took another 30 years before leaded gasoline was fully banned in the United States.
In 1960, a new type of lead additive was introduced: tetramethyl lead and several of its reaction products. These lead additives have helped forensic investigators because their use was limited from 1960 to generally the early 1980s.
In the late 1960s, people began to understand the impact of leaded exhausts was having on human health and the environment. Studies were completed and it was shown that, in particular, children were being adversely impacted by elevated concentrations of lead in the air, in the food and throughout the environment. Requests to ban leaded gasoline were put before the government, but the lead and petroleum industries fought vigilantly to keep lead in gasoline.
Despite the science, lead was not banned in gasoline until 1996. Many believe that the United States was on the forefront of the lead ban, but here are some interesting pieces of information:
Q: What country first banned leaded gasoline? A: Switzerland in 1925. They eventually allowed the sale of leaded gasoline in 1947.
Q: What country first banned leaded gasoline for environmental or health reasons? A: The Soviet Union. Leaded gasoline was banned in cities such as Moscow and Leningrad in the 1950s. However, in the rest of the country, it was vigorously used and not banned in Russia until 2003.
Q: What country first completed a total ban on leaded gasoline? A: Japan. The ban went into effect in 1980. By the mid-1970s, many parts of Japan were completely lead free.
Q: What country first banned leaded gasoline in the western hemisphere? A: Brazil in 1988. Brazil has plenty of ethanol and never used lead to the extent that other countries did.
The history of leaded gasoline is an important subject because it allows us to see where this country has been as far as our past energy choices and possibly through these mistakes, it will help to better guide us in the future.