CO poisoning in traffic jams

Why aren’t we all dead from CO poisoning when stuck in traffic among thousands of cars not going anywhere?

Wild guess - even with all those cars packed together, there’s enough circulation to keep CO from reaching dangerous levels. Remember, even in a fairly dense traffic jam, you’re still going to have plenty of exposure to the wind.

Couple the above with the fact that modern car engines are very efficient and don’t emit much CO to begin with.

I dunno. Totally anecdotal, but when I used to get stuck in gridlocked traffic in Washington, D.C., I would often arrive at my destination feeling a bit light-headed and stoned. Which is part of why I avoided D.C. like the plague and stayed in Virginia as much as possible.

Wouldn’t the CO start to rise as soon as it hits atmosphere? (CO is lighter than air, right?) Wouldn’t this help reduce the concentration at breathing level?

I have experienced nausea and lightheadedness in dense non-moving traffic while other passengers did not. Perhaps some people are more sensitive to the gas?

In Afghanistan, the Salang tunnel has been the scene of several deaths during traffic jams because of fumes:

true story about an ironic place to get CO2 poisoning–the clear mountain air of a national Park.

At Lassen National Park in California (on Mount Lassen ), there was a ticket booth at the entrance to park where a Ranger sat for 8 hour shifts. The booth was set at a narrow spot on the road, between 2 cliff faces. On busy days, the cars lined up with engines running, and —yes, a Ranger collapsed from carbon monoxide poisoning, in the semi-enclosed area shaped by two cliffs and lack of wind. They stopped using the booth in 1983.

Per NIOSH, the relative gas density of CO is .97, so with air being 1.0, it’s almost neutral.

I’d lean towards radiated heat from the vehicles causing a thermal updraft from the traffic jam, carrying away the CO and permitting cleaner air to replace it at ground level.

There have been many times I’ve sat in 2-3 hour traffic jams at the Tijuana-San Diego border, inhaling the exhaust of thousands of vehicles with dubious emissions systems without noticeable ill effects on my physical health (it can take a toll on your emotional state though.). I feel for the street vendors, panhandlers, and others who work the border everyday to scratch out a living. I noticed the border patrol agents have ventilated booths to help catch a fresh breath every now and then, but breathing that air has to take a physical toll over time.

While not the same as “modern emissions controlled engines,” NASCAR drivers on many tracks suffer greatly from CO poisioning. While it’s gotten better in the past few years, many drivers ended their race with pounding headaches, and light headedness, unrelated to hydration. CO tests performed on drivers showed very unhealthy levels.

Is it something I’m going to worry about on a daily basis? Nope… not even on 128 during rush hour.