There are four types of emissions which are generally tracked by groups like the EPA. Each can have an effect on your school bus maintenance. Understanding the different emissions will make it easier to decide which fuel system is right for you:
Nitrogen oxide is one of the most serious of the forms of air pollution created by buses and other vehicles. NOx contributes directly to acid rain. Additionally, it can react with ammonia and other compounds in the air to create particles which are harmful to human and animal lungs.
Generally, propane systems are best at eliminating NOx.
Carbon monoxide is a “greenhouse gas;” it’s one of the primary gases contributing to global climate change. Carbon monoxide is harmful to all oxygen-breathing creatures (humans included) in high enough doses because it can displace oxygen in the bloodstream and get absorbed by the body.
One of the less-discussed polluting emissions, NMHCs are a form of volatile organic compound which has a tendency to enter the atmosphere and stay there. For example, smog is partially made up of NMHCs. This is a broad class of pollutants, and individual compounds can be harmful to life, increase greenhouse effects or both.
Particulate matter covers all of the solids which are emitted by engines and is another major component of smog. PM can be particularly dangerous to life because PM particles are often nanoscopic – too small to be filtered – and so embed themselves deep inside a person or animal’s lungs. PM contamination can build up inside someone for many years, causing increasing health problems over time.
When investigating cleaner-burning fuels and other ways of reducing your school bus maintenance costs, be sure to take a look at the big picture. Compare all the different kinds of pollutants and how various fuels reduce those contaminants, and try to match your choice against what’s needed in your community.
If you’ve already invested in green fuels, how did your district pick a type? When you share, all of us learn. Let’s talk about it below!