There’s nothing like sitting behind a truck or bus belching out noxious fumes at a set of traffic lights to ruin your morning ride to work. Well maybe having to sit behind a rubbish truck but at least that’s not an entirely toxic smell.

There’s been a few times where I’ve stopped a few metres behind a vehicle and actively noticed the fumes coming out of the rear of the vehicle. When in this situation it’s hard not wonder if you’re actually doing massive damage to your lungs. I mean people breath in concentrated car fumes to commit suicide right?

So what are the effects of the much more diluted common urban road pollution to cyclists?

Thankfully here in Australia we’re a far cry from the haze that can be seen in a lot of Asian cities and Traffic on our roads generally moves pretty well outside of the peak hours.

Carbon monoxide seems to be the main culprit we need to watch out for in motor vehicle emissions. It binds to our blood stronger then oxygen and if levels get too high you effectively become oxygen starved and pass out. If levels continue to rise the end result is death.

The good news is as cyclists we’re in a pretty good position on the roads for carbon monoxide absorption. Sure we’re out in the open but with atmospheric dispersion and the height the average cyclist sits at, unless you’re in the drops forcibly sitting behind someone’s exhaust – the good news is that the carbon monoxide levels in your blood shouldn’t reach toxic levels.

The even better news is that for the most part we’re in a much better vantage point then motorists.

As cyclists, especially in Melbourne we’re off to the side of the vehicles and except for some buses most vehicles pump out their emissions directly to the rear. Cyclists on average also sit higher then their driver counterparts and distance plays an important role in how much pollution you are taking in.

As just 10m from traffic pollution levels in the air have dropped approximately 90%.

For the poor motorist stuck in a traffic jam not going anywhere with the airconditioning on, that air is being pumped in from the outside and worse still it’s not dispersing. Infact the air inside motor vehicle can be up to three times as pollutant concentrated as the immediate air outside.

Worse still the average motorist is in a rest state when driving so their lungs and respiratory system aren’t as active in expelling pollutants so carbon monoxide is taken up at a higher rate then cyclists.

I watched an interesting video shot by Channel Nine’s Health program in which they conducted a road test to measure carbon monoxide levels in a cyclists blood. Interestingly enough they found that after 27km’s of riding in Sydney peak hour traffic, carbon monoxide levels rose from just over 2% to a high of 2.5%.

To give some perspective, a high value is considered 10% or above.

They also tested a bicycle courier and despite riding 50-70km a day in the traffic all day long he only had a peak value of 2.7%.

You can watch the full report below:


Keep in mind these tests were conducted in Sydney too which with a lack of street bicycle lanes and planning is arguably the worst Australian city to cycle in during peak hour congestion wise.

For now, in Australia at least I’d say we don’t really have to worry about vehicle pollution as we ride around the streets. I know I feel a lot more comfortable with the thought of having a 7-8% healthy levels buffer.  If a bicycle courier still falls under 3% then my 10-12km commute and weekend shopping trips must be pretty negligible.

For the paranoid out there though there are pollution masks available. Although not common I’ve seen everything from the ‘bandana mask’ to the full on Darth Vader’esque face mask. Usually it’s the Asians wearing them and I guess coming from some of the air pollution levels found over there it’s probably a bigger deal to them.

Personally after doing a bit of poking around it seems most of these pollution masks rely on a activated carbon/pad filtration system of some sort. Coming from the goldfish keeping hobby I know all to well that activated carbon has a limited life span and in the fish tank it’s not all that long.

Given this I can only wonder about the effectiveness of a bicycle pollution mask over a few months or even weeks once that carbon has filled up. To be honest I’m not sure how quickly activated carbon absorbs air pollutants but I know it fills up pretty quickly (a matter of weeks) in the aquarium.

Whether you go the face mask route or prefer to keep things simple the more important thing is that you’re still out there cycling. The next time you’re whizzing past a ‘going nowhere fast’ traffic jam take a moment to think about how bad some of those pollution levels must be with all those aircons directly sucking up the exhausts of the vehicle in front of them.

Feel healthier yet? I sure do.

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