How Bad is Idling Your Car REALLY?


We have all heard it plenty of times. Don’t idle your car! Children are breathing that exhaust! YOU are breathing that exhaust! But yet, when you show up to school or to the airport and you are just sitting there, surrounded by all the other people idling their cars… it becomes pretty darn hard to turn off the engine! So, how does idling REALLY affect air pollution, and what difference does turning off the engine really make?

Well, let’s take a quick look at the EPA statistics on driving versus idling to see how much pollution you can emit while idling your car. We will use NOx (nitrogen oxides) as the key pollutant to measure, since it is a major component of car exhaust. We will also only be looking at personal vehicles, or light duty passenger vehicles in EPA language. Two key facts: For every mile driven in a passenger vehicle, your car emits 0.69 grams of NOx. And for every minute of idling, your car emits about 0.059 grams of NOx.

Put more clearly:

1 mile driven in car = 0.69 g of NOx emitted

1 minute idling in car = 0.059 g of NOx emitted

So where the heck are we going with this? Let’s look at how the two compare. 1 mile of driving puts out about 12 times as much pollution as idling for a minute. So, if you sit there idling for 12 minutes, it is like driving 1 mile in your car!

Let’s paint a picture of this real quick. Another school day has ended, and there are a bunch of cars lined up waiting to pick up kids after finishing classes. BUT, instead of sitting still, they slowly circle the school at 5 miles per hour for 12 minutes, spewing out pollution from their tailpipes as they go. Of course, they do not want to turn their engines off, so they must keep circling and putting out pollutants. No parent would willingly circle a school for 12 minutes at a 5 MPH pace waiting for their child, because that would be a ridiculous waste when you could just be sitting still. Can you imagine running into parents at a school and having them wave at you as they go by, saying “Just doing my laps before the kids get out!” Furthermore, school administrators would be outraged that parents had gotten there early just to drive in a circle and put pollution into their school’s environment for kids to breathe!

The bottom line: it may not feel like anything is happening when you are sitting there, hanging out in an idling car, but the reality is that sitting in an idling car is just like driving around slowly and putting out pollution needlessly as you wait for the person you want to pick up. And all you have to do is take out the key when you are waiting for 30 seconds or longer, and the problem is solved!

(or buy an electric car) 🙂

This one feels like it is going to need a video to accompany it. Look out for one in the next couple weeks!


Image credit:

–The Vivergy Team


UK Countries Ban Smoking In Car With Children, But No Action On Air Pollution (Yet!)


Yesterday, England and Wales banned smoking in a car containing children under 18 years old, regardless of whether windows are opened or not. The crime is punishable by a fine of 50 pounds. The news follows studies that showed that smoking in a car leads to concentrations of particulate matter that could be 10 times higher than concentrations in bars which allow smoking.

Following the lead of California, as well as some parts of Australia and Canada, the law is meant to protect children, whose developing lungs are especially sensitive to airborne particulates and can experience asthma attacks due to acute exposure, and stunted development due to chronic exposure. The law is also meant to reinforce the social unacceptability of smoking while around children. Secondhand smoke sends almost 10,000 children to the hospital each year in the UK.

While this is an excellent step for the 400,000+ children in the UK that currently spend time in a car with a smoker once a week, the UK government should also consider the particulates that 100% of British children are exposed to 24 hours a day due to ambient air pollution. Let’s examine London. Approximately 2.15 million people under the age of 18 live in the city. The average particulate matter level for the year 2014 was 14 ug/m3, which is equal to spending 40 minutes each day in a sealed car with a smoker. This means that 2 million plus children are inhaling that much pollution every day, even after the smoking legislation! And we are simply talking about London, where 9,500 people die per year due to air pollution. Want to learn how to do these calculations yourself? This resource will teach you.

Now, air pollution is not quite as easy to solve as simply banning smoking in a car – it is a complex system that requires leadership from government, industry and individuals. But, if smoking in a car is so offensive that legislators deem that it should be banned, they should also consider laws which lessen dirty fuel use, because 100% of children under 18 are forced to inhale the pollutants that come from these sources.

–The Vivergy Team

Which Live Pollution Map is Better For You? Vivergy’s Share My Air vs. World Air Quality Index

A couple weeks back, we launched the Share My Air tool to make air pollution understandable in every community across the United States. Of course, we must recognize the authority in live air pollution mapping – the World Air Quality Index. So which is better for your purposes?

Map of air pollution in Northern U.S.

Share My Air tool

The Basics: Share My Air is a live map of air pollution monitors in the United States and some of Canada. It takes PM2.5 readings updated every hour, and converts them to an equivalent amount of secondhand smoke exposure.

Main Features: Clickable map of every official PM2.5 monitor in US and some of Canada, graphs of exposure in every area for last 24 hours, 1 month and 6 months. Can share any particular monitor instantly on Twitter/Facebook.

The Goal: Help people understand air pollution in their community, make it clear that it is in their best interest to take action.

Audience: US and Canadian citizens casually interested in air pollution and knowledgeable of the dangers of secondhand smoke

Potential Applications: Explaining the dangers of air pollution in every community, making air pollution more emotional for everybody, from normal citizens to scientists


World Air Quality Index

The Basics: World Air Quality Index includes over 8000 live-streaming monitors from around the world. It includes air quality measurements in particulate matter 2.5, particulate matter 10, ozone and nitrogen dioxide as well as weather metrics such as temperature, pressure, humidity, wind speed and wind direction.

Main Features: Clickable map of every live-streaming air quality monitor across the world, graphs of exposure for each pollutant measured by that particular monitor for past 48 hours. Can share via many social networks, and read up on the meaning of different AQI values easily.

The Goal: Put air pollution in communities across the world on one comparative measure (EPA’s AQI). Give a full explanation of what AQI means, and what negative health consequences can result from a poor AQI.

Audience: Anyone with an internet connection that would like to compare air pollution around them to air pollution in any community across the world.

Potential Applications: Helping individuals understand if their air pollution is better or worse than similar cities. Comparing air pollution regulations across different countries.


World Air Quality Index and Share My Air work well for different audiences. World Air Quality Index, with its comprehensive monitoring network and multiple pollutant measurements, satisfies those who have above average knowledge of atmospheric science and air pollution formation. Share My Air’s focus on one pollutant, a universally understandable metric and limited range means that it would work best for American and Canadian users who are casually interested in air pollution (or, perhaps that interest might increase after seeing the map!).

–The Vivergy Team

Vivergy Pollution Stats Update: Suspending the PM2.5 to Cigarettes Smoked Calculation

Three weeks ago, we covered the difficulty of comparing air pollution exposure to cigarette smoking, mainly due to challenges associated with doing a controlled study and a non-linear dose response curve. You can also read up on our original documentation on this conversion based on the work of Arden Pope at Brigham Young University.

After further conversation with Dr. Pope himself, we have decided to suspend the air pollution to cigarettes smoked calculation this week due to the challenges of doing this calculation in a fair way. Since the current literature shows a large gap between raw exposure and health impacts, we decided it was not fair to put a hard number on this for the moment. Having said that,  Dr. Pope bolstered our confidence in the secondhand smoke-oriented conversions (pollution to time in a car with a smoker and pollution to months living with a smoker) so we will be focusing on those for the time being. Secondhand smoke is much easier to compare to air pollution since children are exposed to both, allowing for a controlled study. The literature shows very similar longitudinal health impacts of exposure to secondhand smoke versus air pollution on a per unit basis.

Bottom Line: Until new evidence comes out that fairly compares air pollution to smoking cigarettes in a longitudinal way, we are going to stick to the secondhand smoke oriented conversions.

–The Vivergy Team

Latest Evidence From Lead Air Pollution Researcher Shows That Vivergy Air Pollution to Cigarettes Conversion Is An Underestimate

A new review by C. Arden Pope of Brigham Young University, the leading voice on the health impacts of air pollution, calls into question the relevance of his previous work of converting air pollution exposure to cigarette inhalation based on raw exposure statistics.

In one of our previous blogs, we walked through the method we use to convert air pollution exposure to an equivalent number of cigarettes inhaled. This was based on published work of Dr. C. Arden Pope of BYU. But this week, on the MyHealth Beijing blog, Dr. Pope pointed out that under further review, this exposure-based calculation is insufficient for describing the incrementally larger health problems that people who inhale air pollution experience compared to health issues that they would expect to experience when inhaling an equivalent amount of fine particulates from cigarettes.

This all started a few weeks ago when Dr. Richard Muller at the University of California, Berkeley published a study that showed an estimated 4000 Chinese die per day due to outdoor air pollution. Dr. Muller observed that the deaths measured in his study went far beyond the expected number of deaths that these Chinese citizens would experience if they inhaled an equivalent amount of cigarette smoke. In fact, his study showed that based strictly on the health impacts, a Beijing resident inhaled about 40 cigarettes of air pollution every day. This stands in stark contrast to Pope’s estimate, which was around 1/6 of a cigarette a day. A difference by a factor of over 200!

After a discussion, Pope wrote the response posted on MyHealth Beijing which points out the challenges of the strictly exposure-based model versus calculating the exposure based on the resulting health impacts (a chicken or the egg problem). One thing is certain: Pope’s original cigarette calculation is not accurate based on the actual health issues that people experience from outdoor air pollution. The original calculation is an underestimate of the number of cigarettes, but by how much is unclear. Which means the Vivergy air pollution to cigarettes conversion is too low!

A few factors make this calculation complex. First of all, children inhale air pollution 24 hours a day, 365 days a year while their lungs and heart are still developing and have weakened defenses. But you are not going to find any children that smoke cigarettes, so it is challenging to design a controlled experiment since air pollution has a head start by getting into children’s lungs at a more vulnerable point. Also, making the assumption that every unit of air pollution or cigarettes inhaled leads to a directly related increase risk for death may be unfair. It may be more of a logarithmic relationship, where air pollution or cigarettes inhaled at lower levels leads to exponential increases in risk, but as you inhale more of each, the health risks become less per unit of pollution inhaled since your body is already overwhelmed by the pollutants entering the heart and lungs.

That being said, there is one way that we may be able to draw similarities between the two: second-hand smoke. Since there are plenty of children who have inhaled second-hand smoke, scientists can easily study the health effects compared to outdoor air pollution. Pope notes, “In fact, the elevated fine PM [particulate matter] exposures and excess mortality risks for SHS [second-hand smoke] and air pollution are remarkably similar”. Secondhand smoke may be a much more accurate tool for comparison than cigarette smoking itself.

Be on the lookout for an announcement in the coming weeks when we decide how to fairly update our air pollution to cigarettes calculation to reflect this new knowledge. We are very glad to see that an unprecedented level of research is going into this field, and we are happy to be transparent as we try to stay up to date with the latest science.

–The Vivergy Team

What Is Causing Air Pollution Levels To Go Through The Roof in the Northern U.S.?

Map of air pollution in Northern U.S.

After the release of the Share My Air live pollution map last week, processing air quality data instantly and “seeing” trends has become far easier for those of us who don’t know how to query an air pollution database! As we checked out the live map over the past two days, we noticed a distinct trend. Monitors across the Midwest and Northeast were getting more red in a hurry, meaning their pollution levels were spiking. This was not just a few monitors, it seemed to be every monitor. We looked for an explanation in national or local news, but we could not find any reports on the phenomenon. Are we crazy?

To test whether this is an actual pollution wave hitting many states across the northern U.S., we decided to do a little investigation. We took a random sample of 50 monitors across 10 states (5 per state). States sampled include: MN, WI, IL, IN, MI, OH, PA, NY, NJ, and KY. We looked at daily averages for the past two days (Aug 30, 2015 and Aug 31, 2015) and compared them to daily averages for every other day of the month. What we found was startling, to say the least.

Out of 50 monitors sampled, 40 (80%) experienced their highest daily pollution value for the month over the past 2 days. Considering that this study sampled 10 states, this a quite a land area for pollution to spike simultaneously. This is not a local pollution event in any one place – it is a blanket of pollution covering many communities within these 10 states.

Two questions followed: is anybody reporting on this across the Midwest, Northeast and Mid-Atlantic? We could not find any definitive articles. Also, where is the pollution coming from?

Here is our theory: the wildfires in the Northwest and California release tons of fine particulates into the air. The West experienced their air pollution event last week, but these tiny particulates can stay in the air for weeks. They likely entered the jetstream and began a journey across the rest of the U.S., getting deposited into communities along the way.

What do you think? Is this caused by the wildfires, or something else? Is anybody experiencing the effects of this pollution right now? Has anybody else done a report on this? Let us know! Shoot an email to, tweet @vivergy and talk to us on Facebook at Would love to hear your thoughts!

-The Vivergy Team

One Of These Filters Is Full Of The Pollutants We Breathe Every Day


We talk to a lot of parents on a daily basis. I mean A LOT. One of the most common reactions that we get from Ann Arbor parents is the utter shock that their outdoor air has the same amount of pollutants as living with a smoker for 3 months of the year (see how we calculate that here). So, we did a simple little experiment to show that you are breathing air pollution even if you cannot see it. Try it yourself if you want! The results are the picture above. Which do you think comes from outdoor air?

Materials Needed

-Coffee Filters

-Rubber Bands

-Vacuum with hose attachment

-Power Source



For each treatment group, you must use a coffee filter to cover the open end of the hose attachment on your vacuum, and use the rubber bands to keep it in place. This simulates the function of a lung – the vacuum “inhales” air when it is turned on, and the white coffee filter shows any impurities in the air that it is sucking in.

Treatment 1

Attach a coffee filter to your vacuum in the manner described above. Bring your vacuum cleaner outside (if you will be present for the entire experiment), or open a window and put the hose attachment out the window (if you will not be present). Turn on the vacuum. Ensure that it is not running at full power so that it does not destroy the coffee filter. Let the vacuum run for 16 hours in this manner (or for any time of your choice). Make sure that the vacuum does not overheat by checking on it a few times through out the experiment.

Treatment 2

Attach a coffee filter to your vacuum in the manner described above. Bring your vacuum cleaner outside and turn it on. Ensure that it is not running at full power so that it does not destroy the coffee filter. Light one end of your cigarette to simulate smoking, and hold the hose 2-3 feet from the burning end. You may need to relight the cigarette intermittently to keep it burning. Continue to do this until the cigarette has burned down to the filter.


Inspect each coffee filter afterwards. Did your filters change colors like ours did? In the picture above, the first filter resulted from running the vacuum outdoors in Ann Arbor for 16 hours at an average outdoor particulate matter concentration of 9 micrograms per cubic meter. The second filter resulted from “inhaling” a cigarette that burned all the way down to the filter. Makes the pollutants entering your lungs a little more visible, eh?


Air pollution becomes pretty darn visible once you are able to trap it on a medium visible to the human eye! You can run this easy, low-cost experiment if you want to see air quality for yourself. Try this experiment on days with average PM2.5 levels of 5ug/m3, 10ug/m3 and 15 ug/m3 or greater and see how the results differ. And that filter changes color after only 16 hours! Imagine what happens when you breathe that stuff every single day…

–The Vivergy Team