• The introduction of Ultra-Low Sulfur Diesel (ULSD) by fuel companies. This “clean” diesel has only 3 percent sulfur, compared to what is found in “normal” diesel. Hence, the soot amount is reduced without much impact on the vehicle’s peak power or on the vehicle’s fuel economy.
• Car manufacturers have succeeded in lowering DPM emissions into the atmosphere by building more efficient engines; new diesel engine models have been enhanced to burn their own emissions, effectively reducing carbon monoxide emissions.
• Newer diesel engine models are designed with a complex filtration system that filters larger particles when emissions do occur.
• Commercial diesel engines are fitted with a urea-injection system, which reacts urea with harmful nitrogen oxide gas to emit nitrogen and ammonia. (While ammonia is an environmental pollutant that is highly reactive and can be a fatally toxic gas if inhaled directly, it is a safer option than nitrogen oxide.)

These advances may be small steps, but in the whole scheme of things can save millions of lives across the world. Diesel pollution will, however, remain a hotbed issue that requires total commitment to resolving, with the goal of eradication, if possible.