A solid majority, 71 percent of Americans, believe the country “should do whatever it takes to protect the environment,” according to a 2014 poll by the Pew Research Center.
This strong public interest in our environment extends to urban living, prompting NerdWallet’s curiosity: Even though we all know that the city we live in influences our transportation and energy choices, how do environmental impacts differ across the U.S.?
We explored the data for the nation’s 150 largest cities to shed light on the best places for those seeking a green lifestyle and a healthy environment.
Photo credit: Shutterstock
Environmental quality: To uncover the impact of pollution on residents’ health, we looked at each city’s 2014 median of the U.S. Environmental Protection Agency’s daily Air Quality Index—a measure of sulfur dioxide, carbon monoxide, nitrogen dioxide and ozone levels that guide the assessment of acute health effects. The higher the index number, the more polluted an area. In most cases, air quality in U.S. cities has a median index score under 100, which falls into the EPA’s “moderate” range.
Transportation: To understand how cities might influence lifestyle choices, we looked at data from the U.S. Census Bureau’s American Community Survey on commuting methods to find out how many workers are walking, biking, carpooling and taking public transit.
Energy sources: To gain insight into the fuels people are using in each city, we looked at data from the American Community Survey on heating in homes. We were specifically interested in the number of homes using coal and wood because these fuels are particularly harmful. We also examined the use of solar energy because of its sustainability.
Housing density: Urban sprawl increases transportation needs and resource use, so we looked at data from the American Community Survey on the percentage of residential buildings with 10 or more residences in each city.
What we learned
Bigger is better: We might associate larger cities with polluting industries, but bigger cities tend to be denser, which reduces urban sprawl and energy needs for transportation per capita.
Air quality is fairly uniform: Many of the cities we examined fall within a narrow range of the EPA’s Air Quality Index, sitting between the classification of “good,” an index number under 51, and “moderate,” a number under 101. Of course, there are notable outliers, like Riverside, California, where the air quality about 30 days in 2014 reached “unhealthy” levels over 150.
Traditional fuels remain: While solar power is part of mainstream energy conversations, the data suggest adoption is lagging. Nationwide, out of 116 million homes, only 72,707 houses use solar heating, up from 2005 when the number was 36,682. While the use of traditional heating methods—including coal and wood burning—have remained stable.
America’s top 10 greenest cities
1. Honolulu, Hawaii
This city in the nation’s 50th state tops our list with its air quality, the best of all the cities we analyzed, and for residents’ widespread use of solar energy. In 2014, the city received the EPA’s highest classification of “good” for 351 of the 360 days measured, giving it a median Air Quality Index of 27 for the year.
2. Washington, DC
The national’s capital lands near the top of our list probably because of its excellent public transit, which carries 38 percent of commuters to work. Other highlights include the city’s low levels of pollution from heating fuels, such as coal and wood, in the dense city.
3. Arlington, Virginia
With a slightly higher number of dense residential buildings, but fewer commuters who walk or take public transportation, Arlington comes in just below its neighbor. Given their proximity, it isn’t surprising that Washington, DC and Arlington share a median Air Quality Index of 48, which is just within the EPA’s “good” classification.
4. San Francisco, California
San Francisco, long known as a center of activism around sustainability, scores well in terms of transportation, with 10 percent of commuters walking in the hilly city to work. The city also shines in terms of solar energy use, with slightly over 13.8 of every 10,000 homes using the sun’s energy for heat. In comparison, 6.25 of every 10,000 homes use solar heating nationwide.
5. Miami, Florida
When it comes to healthy air quality and the number of residents who carpool, Miami shines. But in this city, fewer commuters use public transportation. Only 11 percent of residents commute on transit, one of the lowest public transportation figures in our top 10.
6. New York City, New York
It’s big and a lot of people live here, but New York City’s density is why it made our list. Many of the city’s over 8 million residents walk to work while still more use the city’s comprehensive public transit system. However, 7.2 of every 10,000 homes still use coal for heat.
7. Boston, Massachusetts
More of Boston’s residents walk to work than in any other city on our top 10 list: 15 percent of Bostonians brave the seasons, including the harsh winter, on foot.
8. Orlando, Florida
Like Miami, Orlando does well when it comes to air quality, with only one day in 2014 with unhealthful air. The quality of air here isn’t surprising, since residents don’t use coal and they burn little wood for heat.
9. Seattle, Washington
While the city’s gray skies limit use of solar energy, Seattle makes our list for its air quality, high residential density and commuters who walk and use public transit at above-average rates. In the Emerald City, nine percent of workers walk to their jobs and four percent commute on a bike.
10. Jersey City, New Jersey
The city shares a mediocre air quality index with its neighbor New York City. However, Jersey City also shares a positive trend: residents use public transit at far above-average rates. At least 46 percent of workers living in Jersey City commute on public transit, second only to New York City’s 56 percent.
Top 25 greenest cities in America
The score for each city was calculated from the following measures:
1. The 2014 Median Air Quality Index from the U.S. Environmental Protection Agency. This is 25 percent of a city’s score.
2. The percentage of workers who carpool, bike, walk or use public transit to commute to work from the U.S. Census Bureau’s 2013 American Community Survey. Together the transportation variables are 25 percent of a city’s score.
3. The percentage of occupied buildings with 10 or more residents is from the 2013 American Community Survey, this was 25 percent of a city’s score.
4. The number of residential buildings with a primary heat source of solar, coal or wood per 10,000 buildings is from the 2013 American Community Survey. Solar was taken as a positive variable and accounted for 8.33 percent of the final score while coal and wood heat sources were treated as negative and were 16.67 percent of a city’s final score.
Note: Newark, New Jersey, was originally ranked 24th, but because of environmental hazards outside the scope of the study, the city was omitted from the final list.
YOU MIGHT ALSO LIKE
In 2010, world leaders agreed to 20 targets to protect Earth's biodiversity over the next decade. By 2020, none of them had been met. Now, the question is whether the world can do any better once new targets are set during the meeting of the UN Convention on Biodiversity in Kunming, China later this year.
- Ocean Scientists Create Global Network to Help Save Biodiversity ... ›
- 5 Reasons Why Biodiversity Matters - EcoWatch ›
- 26 Organizations Working to Conserve Seed Biodiversity - EcoWatch ›
- The Top 10 Ocean Biodiversity Hotspots to Protect - EcoWatch ›
- New Platform Shows How to Protect Biodiversity and Save Planet ... ›
- These Scientists Are Listening to the Borneo Rainforest to Protect ... ›
EcoWatch Daily Newsletter
By Andrew Rosenberg
The first 24 hours of the administration of President Joe Biden were filled not only with ceremony, but also with real action. Executive orders and other directives were quickly signed. More actions have followed. All consequential. Many provide a basis for not just undoing actions of the previous administration, but also making real advances in public policy to protect public health, safety, and the environment.
- Here Are Biden's Day One Actions on Climate and Environment ... ›
- UCS Offers Science Advice for Biden Administration - EcoWatch ›
A first-of-its-kind study has examined the satellite record to see how the climate crisis is impacting all of the planet's ice.
- 'Ghost Forests' Are an Eerie Sign of Sea-Level Rise - EcoWatch ›
- Sea-Level Rise Takes Business Toll in North Carolina's Outer Banks ... ›
- Sea Level Rise Is Locked in Even If We Meet Paris Agreement ... ›
By Ana Maldonado-Contreras
- Your gut is home to trillions of bacteria that are vital for keeping you healthy.
- Some of these microbes help to regulate the immune system.
- New research, which has not yet been peer-reviewed, shows the presence of certain bacteria in the gut may reveal which people are more vulnerable to a more severe case of COVID-19.
You may not know it, but you have an army of microbes living inside of you that are essential for fighting off threats, including the virus that causes COVID-19.
How Do Resident Bacteria Keep You Healthy?<p>Our immune defense is part of a complex biological response against harmful pathogens, such as viruses or bacteria. However, because our bodies are inhabited by trillions of mostly beneficial bacteria, virus and fungi, activation of our immune response is tightly regulated to distinguish between harmful and helpful microbes.</p><p>Our bacteria are spectacular companions diligently helping prime our immune system defenses to combat infections. A seminal study found that mice treated with antibiotics that eliminate bacteria in the gut exhibited an impaired immune response. These animals had low counts of virus-fighting white blood cells, weak antibody responses and poor production of a protein that is vital for <a href="https://doi.org/10.1073/pnas.1019378108" target="_blank">combating viral infection and modulating the immune response</a>.</p><p><a href="https://doi.org/10.1371/journal.pone.0184976" target="_blank" rel="noopener noreferrer">In another study</a>, mice were fed <em>Lactobacillus</em> bacteria, commonly used as probiotic in fermented food. These microbes reduced the severity of influenza infection. The <em>Lactobacillus</em>-treated mice did not lose weight and had only mild lung damage compared with untreated mice. Similarly, others have found that treatment of mice with <em>Lactobacillus</em> protects against different <a href="https://doi.org/10.1038/srep04638" target="_blank" rel="noopener noreferrer">subtypes of</a> <a href="https://doi.org/10.1038/s41598-017-17487-8" target="_blank" rel="noopener noreferrer">influenza</a> <a href="https://doi.org/10.1371/journal.ppat.1008072" target="_blank" rel="noopener noreferrer">virus</a> and human respiratory syncytial virus – the <a href="https://doi.org/10.1038/s41598-019-39602-7" target="_blank" rel="noopener noreferrer">major cause of viral bronchiolitis and pneumonia in children</a>.</p>
Chronic Disease and Microbes<p>Patients with chronic illnesses including Type 2 diabetes, obesity and cardiovascular disease exhibit a hyperactive immune system that fails to recognize a harmless stimulus and is linked to an altered gut microbiome.</p><p>In these chronic diseases, the gut microbiome lacks bacteria that activate <a href="https://doi.org/10.1126/science.1198469" target="_blank" rel="noopener noreferrer">immune cells</a> that block the response against harmless bacteria in our guts. Such alteration of the gut microbiome is also observed in <a href="https://doi.org/10.1073/pnas.1002601107" target="_blank" rel="noopener noreferrer">babies delivered by cesarean section</a>, individuals consuming a poor <a href="https://doi.org/10.1038/nature12820" target="_blank" rel="noopener noreferrer">diet</a> and the <a href="https://doi.org/10.1038/nature11053" target="_blank" rel="noopener noreferrer">elderly</a>.</p><p>In the U.S., 117 million individuals – about half the adult population – <a href="https://health.gov/our-work/food-nutrition/2015-2020-dietary-guidelines/guidelines/" target="_blank" rel="noopener noreferrer">suffer from Type 2 diabetes, obesity, cardiovascular disease or a combination of them</a>. That suggests that half of American adults carry a faulty microbiome army.</p><p>Research in my laboratory focuses on identifying gut bacteria that are critical for creating a balanced immune system, which fights life-threatening bacterial and viral infections, while tolerating the beneficial bacteria in and on us.</p><p>Given that diet affects the diversity of bacteria in the gut, <a href="https://www.umassmed.edu/nutrition/melody-trial-info/" target="_blank" rel="noopener noreferrer">my lab studies show how diet can be used</a> as a therapy for chronic diseases. Using different foods, people can shift their gut microbiome to one that boosts a healthy immune response.</p><p>A fraction of patients infected with SARS-CoV-2, the virus that causes COVID-19 disease, develop severe complications that require hospitalization in intensive care units. What do many of those patients have in common? <a href="https://www.cdc.gov/mmwr/volumes/69/wr/mm6912e2.htm" target="_blank" rel="noopener noreferrer">Old age</a> and chronic diet-related diseases like obesity, Type 2 diabetes and cardiovascular disease.</p><p><a href="http://doi.org/10.1016/j.jada.2008.12.019" target="_blank" rel="noopener noreferrer">Black and Latinx people are disproportionately affected by obesity, Type 2 diabetes and cardiovascular disease</a>, all of which are linked to poor nutrition. Thus, it is not a coincidence that <a href="https://www.cdc.gov/mmwr/volumes/69/wr/mm6933e1.htm" target="_blank" rel="noopener noreferrer">these groups have suffered more deaths from COVID-19</a> compared with whites. This is the case not only in the U.S. but also <a href="https://www.washingtonpost.com/world/europe/blacks-in-britain-are-four-times-as-likely-to-die-of-coronavirus-as-whites-data-show/2020/05/07/2dc76710-9067-11ea-9322-a29e75effc93_story.html" target="_blank" rel="noopener noreferrer">in Britain</a>.</p>
Discovering Microbes That Predict COVID-19 Severity<p>The COVID-19 pandemic has inspired me to shift my research and explore the role of the gut microbiome in the overly aggressive immune response against SARS-CoV-2 infection.</p><p>My colleagues and I have hypothesized that critically ill SARS-CoV-2 patients with conditions like obesity, Type 2 diabetes and cardiovascular disease exhibit an altered gut microbiome that aggravates <a href="https://theconversation.com/exercise-may-help-reduce-risk-of-deadly-covid-19-complication-ards-136922" target="_blank" rel="noopener noreferrer">acute respiratory distress syndrome</a>.</p><p>Acute respiratory distress syndrome, a life-threatening lung injury, in SARS-CoV-2 patients is thought to develop from a <a href="http://doi.org/10.1016/j.cytogfr.2020.05.003" target="_blank" rel="noopener noreferrer">fatal overreaction of the immune response</a> called a <a href="https://theconversation.com/blocking-the-deadly-cytokine-storm-is-a-vital-weapon-for-treating-covid-19-137690" target="_blank" rel="noopener noreferrer">cytokine storm</a> <a href="http://doi.org/10.1016/S2213-2600(20)30216-2" target="_blank" rel="noopener noreferrer">that causes an uncontrolled flood</a> <a href="http://doi.org/10.1016/S2213-2600(20)30216-2" target="_blank" rel="noopener noreferrer">of immune cells into the lungs</a>. In these patients, their own uncontrolled inflammatory immune response, rather than the virus itself, causes the <a href="http://doi.org/10.1007/s00134-020-05991-x" target="_blank" rel="noopener noreferrer">severe lung injury and multiorgan failures</a> that lead to death.</p><p>Several studies <a href="https://doi.org/10.1016/j.trsl.2020.08.004" target="_blank" rel="noopener noreferrer">described in one recent review</a> have identified an altered gut microbiome in patients with COVID-19. However, identification of specific bacteria within the microbiome that could predict COVID-19 severity is lacking.</p><p>To address this question, my colleagues and I recruited COVID-19 hospitalized patients with severe and moderate symptoms. We collected stool and saliva samples to determine whether bacteria within the gut and oral microbiome could predict COVID-19 severity. The identification of microbiome markers that can predict the clinical outcomes of COVID-19 disease is key to help prioritize patients needing urgent treatment.</p><p><a href="https://doi.org/10.1101/2021.01.05.20249061" target="_blank" rel="noopener noreferrer">We demonstrated</a>, in a paper which has not yet been peer reviewed, that the composition of the gut microbiome is the strongest predictor of COVID-19 severity compared to patient's clinical characteristics commonly used to do so. Specifically, we identified that the presence of a bacterium in the stool – called <em>Enterococcus faecalis</em>– was a robust predictor of COVID-19 severity. Not surprisingly, <em>Enterococcus faecalis</em> has been associated with <a href="https://doi.org/10.1053/j.gastro.2011.05.035" target="_blank" rel="noopener noreferrer">chronic</a> <a href="https://doi.org/10.1016/S0002-9440(10)61172-8" target="_blank" rel="noopener noreferrer">inflammation</a>.</p><p><em>Enterococcus faecalis</em> collected from feces can be grown outside of the body in clinical laboratories. Thus, an <em>E. faecalis</em> test might be a cost-effective, rapid and relatively easy way to identify patients who are likely to require more supportive care and therapeutic interventions to improve their chances of survival.</p><p>But it is not yet clear from our research what is the contribution of the altered microbiome in the immune response to SARS-CoV-2 infection. A recent study has shown that <a href="https://doi.org/10.1101/2020.12.11.416180" target="_blank" rel="noopener noreferrer">SARS-CoV-2 infection triggers an imbalance in immune cells</a> called <a href="https://doi.org/10.1111/imr.12170" target="_blank" rel="noopener noreferrer">T regulatory cells that are critical to immune balance</a>.</p><p>Bacteria from the gut microbiome are responsible for the <a href="https://doi.org/10.7554/eLife.30916.001" target="_blank" rel="noopener noreferrer">proper activation</a> <a href="https://doi.org/10.1126/science.1198469" target="_blank" rel="noopener noreferrer">of those T-regulatory</a> <a href="https://doi.org/10.1038/nri.2016.36" target="_blank" rel="noopener noreferrer">cells</a>. Thus, researchers like me need to take repeated patient stool, saliva and blood samples over a longer time frame to learn how the altered microbiome observed in COVID-19 patients can modulate COVID-19 disease severity, perhaps by altering the development of the T-regulatory cells.</p><p>As a Latina scientist investigating interactions between diet, microbiome and immunity, I must stress the importance of better policies to improve access to healthy foods, which lead to a healthier microbiome. It is also important to design culturally sensitive dietary interventions for Black and Latinx communities. While a good-quality diet might not prevent SARS-CoV-2 infection, it can treat the underlying conditions related to its severity.</p><p><em><a href="https://theconversation.com/profiles/ana-maldonado-contreras-1152969" target="_blank">Ana Maldonado-Contreras</a> is an assistant professor of Microbiology and Physiological Systems at the University of Massachusetts Medical School.</em></p><p><em>Disclosure statement: Ana Maldonado-Contreras receives funding from The Helmsley Charitable Trust and her work has been supported by the American Gastroenterological Association. She received The Charles A. King Trust Postdoctoral Research Fellowship. She is also member of the Diversity Committee of the American Gastroenterological Association.</em></p><p><em style="">Reposted with permission from <a href="https://theconversation.com/a-healthy-microbiome-builds-a-strong-immune-system-that-could-help-defeat-covid-19-145668" target="_blank" rel="noopener noreferrer" style="">The Conversation</a>. </em></p>
By Jeff Masters, Ph.D.
The New Climate War: the fight to take back our planet is the latest must-read book by leading climate change scientist and communicator Michael Mann of Penn State University.
- 12 New Books Explore Fresh Approaches to Act on Climate Change ... ›
- Dr. Michael Mann on Climate Denial: 'It's Impaired Our Ability to ... ›