My kids started school last week. Normally, this is the week we would see school buses filling our streets carrying children every morning and afternoon. These are not normal times in September of 2020, with COVID19 keeping in person schools closed and wildfires burning across the West and all of us inside our homes with hazardous particulate matter levels outside. Sometimes it is hard to hope for healthier air, but I want to focus today on a very hopeful topic- the massive benefit of cleaning up old diesel school buses. While meeting with legislators in our state capitol and trying to convey the importance of decreasing diesel exhaust, I frequently cite a particular study on children in school buses by Dr. Sara Adar, my guest on the podcast today. Professor Adar joins me from the University of Michigan where she studies the impact of particulate matter, diesel and ozone on our health.
Washington State invested in cleaner diesel technology for its school buses between 2005 and 2009, and Dr. Adar conducted a study to evaluate what happened to the air the children breathed after retrofits were done and what happened to the childrens’ health. They followed 275 children from primarily college-educated white families over 4 years while the state worked to clean up the diesel school bus fleet and change to ULSD (ultra low sulfur diesel). They monitored the air pollution inside and outside the buses and followed as the school buses were upgraded with cleaner air technologies such as diesel oxidation catalysts (DOCs) to reduce tailpipe emissions and crankcase ventilation systems (CCVs) to reduce the engine emissions. They monitored the number of sick days the children missed as well as tested their lung function over time. They found that the clean engine technologies significantly decreased the pollution exposure in the buses and had significant health and absenteeism benefits.
As a lung doctor who looks at lung function tests on a regular basis, I was particularly excited to see the improvements in lung function that occurred in children as the clean technology was implemented. The FVC is the Forced Vital Capacity- a measurement of the kids’ lung size. Growing lungs are healthier lungs. California has demonstrated that as they decreased air pollution around schools, kids’ lungs started to grow again. This effect is seen in this study as well, with lung function improving as DOCs improved the air quality and the use of ULSD.
Fuels also seemed to make a difference in lowering the FeNO (exhaled nitric oxide) with the change to ultra low sulfur diesel (ULSD), which is also heartening for policy related to cleaning up the fuels we use as well. This is a particularly important measure for people with asthma.
Since most vehicles in the US have changed to ULSD, this study concluded that there are likely 14 million fewer missed school days across the country with this change. They found a similar effect with the decrease in tailpipe emissions with DOC technology. What if we could change all the school buses across the country to cleaner buses, and save another 14 million fewer sick days for kids? Think about all the parents that have to stay home with those sick kids, costing their employers sick days (if they’re lucky enough to have paid sick leave) or costing their families a days’ wages. Think of the healthcare expenditures for inhalers, hospitalizations, etc. Wouldn’t you like lower healthcare premiums or lower Medicare and Medicaid expenditures?
I love this study, because it gives me hope. We can use intelligent policy and invest in cleaner transportation technologies to improve the health of our communities and decrease our healthcare expenditures. Dr Adar and I also discussed studies in Georgia, where changes to cleaner buses led to better educational achievement in students. We know there are cognitive changes in children from traffic related air pollution, and missed school days also put children farther behind. I am particularly defensive of my “Twitchy Airways Club” members, since asthma and COPD can run in families, and there can be generational effects of missed sick days from school and work for those with asthma, who are more sensitive to diesel exhaust and other forms of traffic-related air pollution. It’s also important to note that this study was done with a predominantly white, college-educated population of children in Washington State that suffers less from the public health crisis of racial disparities in air pollution exposure. I imagine the benefit is likely even greater among groups of more historically disadvantaged children. Black children are more likely to suffer and die from asthma than white children, and cleaning up traffic related air pollution is a significant opportunity to address racial disparities in our communities.
Right now with the particulate matter levels in the West at astronomical levels, it might seem odd to be thinking about the smaller levels emitted from buses. However, they have real chronic effects that we can see in our kids. If we can decrease our chronic, daily particulate matter exposure, it makes all of us more resilient to these catastrophic events, like the wildfires that climate change is brining.
We also discussed the many studies that have shown additional healthy life expectancy from intelligent air pollution policy and investing in healthy air. This has never been more timely and obvious while wildfire smoke is choking the West Coast. It’s a win-win. Let’s clean up the air.
Take Action-
1- Find out the age of the school buses or other public diesel engines in your area. If they have not been retrofitted or do not have engines from after 2007, find out what your school district or municipality is planning to do and whether they have applied for DERA funding or help from the National Clean Diesel Rebate Program to help improve health and decrease absenteeism. Find out if your local area can obtain funding from the Volkswagen Settlement for cleaning up the fleet.
2- Call or write your Members of Congress and tell them you support a Clean School Bus Act in the next Congress- it’s an investment in the futures of our kids and a future strong economy.
3- Make sure your bus drivers have good health insurance and working conditions.
4- Talk to your local town or city council, your state legislature, and your federal elected representatives about your concerns about unhealthy air and traffic related air pollution, and share your thoughts about the economic benefits of healthy air.
- Make sure you let your representatives know that you and your children are particularly vulnerable to unhealthy air.
- Make sure your own work commute involves healthier transportation options.
- Find out rules there are for engines that drive by where you live and work.
- You have the right to breathe healthy air!
References:
Asthma Facts from AAFI– including information on disparities for black Americans
Austin W, Heutel G, Kreisman D. School bus emissions, student health and academic performance. Econ Educ Rev. 2019. 70: 109-126.
Clean School Bus Act- https://www.congress.gov/bill/116th-congress/senate-bill/1750
WA state and electric school bus purchase – STN article (source of image)
