Automobile Emission Information
There was no real concern for the pollution of automobile emissions didn’t arrive until the 1950’s and 1960’s. Essentially there was an exhaust pipe and a muffler at the end to reduce noise pollution, not air pollution. Although now common for a good fifty to sixty years, pollution wasn’t a worry.
One of the first emission control measures was the mass production of the PCV, or positive crankcase ventilation system for automobile engines. California grew rapidly in the 50’s and 60’s. Combined with their hazy, hot and humid weather, were thousands of vehicles, thus the man-made invention of smog. Since California recognized such a problem, it was the first state to mandate the use of the PCV system in 1961 and later vehicles. The process takes unburned caustic fuel fumes, and re-introduces them into the engines intake track, burning the fumes as opposed to releasing them untouched into the atmosphere. It was a fairly cost effective emission control, and soon most vehicles were manufactured with a PCV system. Again starting with California in 1966 came the first laws with regards to tailpipe, exhaust emission controls, the rest of the country followed suit in 1968. Up until the catalytic converter, once fumes were in the exhaust that’s how they were entered into the atmosphere. Vapors through the exhaust are converted to less harmful agents when introduced to the catalytic converter. There are high value minerals that help in the conversion of the toxins, such as platinum, so even they are a target of thieves. One common theme to reduce pollution is to burn any excess particulates. This is done through evaporative emissions control, and exhaust gas recirculation. With EVAP, air is drawn into a canister, pulling the vapor into the engine where it is burned off. Exhaust gas recirculation reintroduces exhaust into the engine compartment; it helps to reduce the amount of nitrogen oxide emissions. There are several other smaller components that go into the control of emissions. The onboard computer itself helps to control the efficiency of the engine to reduce waste and the creation of excess pollutants.
Since vehicle pollution is such a concern, all states have emission testing. Once more, emission testing standards were introduced in California in 1966. Tailpipe emissions are tested, with standards based on pollutants per parts per million. Emission testing is typically done once a year, standards vary from state to state, and most states do test. In Massachusetts for example it is part of the annual vehicle safety inspection.
With hybrids, ethanol powered vehicles, natural gas engines, and even nitrogen based engines, air pollution caused by automobiles may someday be a thing of the past. Fortunately gasoline powered vehicles are much cleaner than they were 40, 30, or even 20 years ago, but they still produce pollutants. As of 2007 there were 250 million vehicles on the road in the United States per the Department of Transportation, and the majority of them are gasoline powered. Until drastically low and zero emission vehicles become common, the key to less pollution is routine maintenance and the reduction of unnecessary driving, for example, don’t drive a half a mile to get a gallon of milk. It may not come in our lifetime, but automobile pollution should eventually be non-existent.