Diesel particulate matter (DPM) emissions not only contribute significantly to climate change but also have detrimental effects on public health. However, comprehending the exact impact of DPM can be challenging due to its complex composition. Let’s take a moment to explore the critical connection between DPM and both climate change and public health. By shedding light on this issue, we aim to raise awareness and inspire action towards reducing DPM emissions.
DPM’s climate impact — a short-lived climate (SLCP) pollutant
DPM acts as a short-lived climate super pollutant, delivering a rapid surge of heat to the atmosphere upon its release. According to the CCA Coalition, black carbon has a warming impact on the climate that is 460—1,500x stronger than CO2 per unit of mass. If left unchecked, DPM emissions could drive us towards climate tipping points, accelerating global temperature rise and its adverse consequences. Consequently, reducing DPM emissions becomes a crucial parallel path to decarbonization, helping us prevent such tipping points and mitigate the negative impact on our society.
Unveiling the components of DPM
DPM is comprised of various elements, including black carbon (soot) and several organic compounds. Additionally, diesel exhaust contains gaseous pollutants like volatile organic compounds (VOCs) and nitrogen oxides (NOx). The presence of NOx emissions is particularly significant as they can undergo chemical reactions in the atmosphere, leading to the formation of ozone — a potent greenhouse gas.
The serious health consequences of DPM
According to the California Air Resources Board (CARB), diesel engines emit a complex mixture of pollutants, including very small carbon
particles, or “soot” coated with numerous organic compounds. Diesel exhaust has been classified as a Group 1 carcinogen by the International Agency for Research on Cancer (IARC), and contains more than 40 cancer-causing substances, most of which are readily adsorbed onto the particles of soot.
Diesel PM contributes to numerous health impacts that have been attributed to particulate matter exposure, including increased hospital admissions, particularly for heart disease, but also for respiratory illnesses, and even premature death. Diesel PM is often emitted close to people so high exposures occur, and it is in a size range that readily deposits in the lung. Additional health impacts can result from exposure to secondary diesel PM that is formed in the atmosphere from oxides of nitrogen, emitted from diesel engines.
DPM and at-risk communities
Communities residing near distribution centers, rail yards, ports and other areas with high diesel engine activity are disproportionately affected by the negative health consequences of DPM. Fine particulate matter (PM2.5) pollution, a significant component of DPM, is responsible for a staggering 63% of deaths from environmental causes and 3% of all deaths. Moreover, black carbon — the largest component of DPM — is a known carcinogen that increases the risk of strokes, heart attacks and chronic respiratory diseases.
Children are particularly vulnerable to the health effects of DPM. Exposure to diesel exhaust can negatively impact lung development in children, leading to reduced lung function and increased respiratory problems throughout their lives. It may also contribute to the development of conditions such as childhood asthma. And a 2022 study even links low-level exposure to particulate matter to behavior issues and lower IQ scores in 2- to 4-year-olds.
The urgency behind the need for decarbonization
In today’s rapidly evolving world, the urgency for electrification and decarbonization cannot be overstated. It is no longer a matter of choice or convenience but a pressing necessity. Daimler Truck North America president John O’Leary aptly described this imperative as the “Speed of Right” during the Advanced Clean Transportation Expo.
The pace at which we adopt electrification and decarbonization measures must align with the urgency of the environmental challenges we face. It is crucial to tackle both long-term and short-lived pollutants to truly improve air quality and mitigate their detrimental impact on the environment and public health.
The impact of SLCPs explained
If our society had the ability to miraculously switch to 100% electric power by renewable energy tomorrow, global temperatures would continue to rise. CO2 lasts between 300 and 1000 years in the atmosphere. Think of this CO2 like water in a filling bathtub — if you slow the tap, the water level will rise more slowly. The water is always evaporating, but it is a slow process. Reducing SLCPs like black carbon and methane are like cracking the drain a little on the tub. Their reduction creates a negative rate of increase. Since the tap is always on, hopefully at a slower rate than before, it is critical to open the drain a little or the tub will overflow.
What you can do today
Now that we understand the critical impact of DPM emissions, it’s time to take action. If your organization utilizes onsite diesel generators or refrigerated transport units (TRUs), here are three steps you can take today to make a difference:
- Conduct an energy audit: Assess your facilities and/or transportation operations to identify areas where you can reduce both energy consumption and emissions.
- Update your stationary diesel generators and/or your TRU fleet: Evaluate and introduce low-emission or electric TRUs to your fleet. Just because it is new, does not mean it has lower emissions. Selecting the lower emissions option or adding an active diesel particulate filter to the diesel engine can have a significant effect on local air quality and global climate change.
- Highlight the environmental benefits of implementing these measures in your ESG reporting: Even if you don’t plan on keeping the asset for a long time, it will likely continue to have a useful life somewhere else. Reducing future emissions outside of your facility has the same global impact as reducing them at your facility.
By implementing these three steps, your organization can make a positive environmental impact while simultaneously improving its commitment to sustainability. Reducing DPM emissions can play a substantial, immediate role in limiting global warming and preventing multiple climate tipping points that make avoiding climate catastrophes difficult. It can also improve the health and well-being of communities affected by diesel engine operations.
