Moog

I commute five miles each way per day in London, and am getting fed up of inhaling lung-fulls of sooty exhaust fumes from buses, lorries and other road vehicles. I'm thinking of getting a pollution filter mask, but have heard contradictory reviews, some saying they are great, others saying the masks don't filter out the smallest (most dangerous) particles, and restrict breathing.

What are peoples experience of these masks? Asthmatics who find they alleviate their problems? People who say their breathing is restricted? All sides of the story wanted!!

Moog

Nightshade

Suggest that you vist your local industrial supply house to
find the correct mask for your riding. Yes, the correct mask
as there are many types of filters for different applications.

I can understand why you would need one in London as diesel
is the fuel of choice for busses, lorries, etc. I also know
that breathing to much diesel exhust IS very bad for your
health so best of luck finding the correct mask,mate.

Joeagain

I've racked my brain on this one. The restriction of breathing is something of a problem for me because some of my riding involves a lot of rolling-hill type roads, right next to slower moving traffic.

If you come up with anything, or even a possibility, please post it.


Joe.

CdCf

Pressure ventilation...
A pump driven by pedal power, forcing air through the filter...

Konakazi

Try the "Breathe Smog" mask over at Nashbar. I've seen these elsewhere in the City. Probably a good idea to wear but I've got so many accessories as it is...

Breathe’s smog mask will protect the user from harmful effects of smog and pollution. It is made from hypo-allergenic neoprene, fastened at the back with Velcro and is equipped with 2 exhalation valves. The mask comes with a tightly woven carbon filter which is most often used in environmental and pharmaceutical industries and is designed to filter out a wide spectrum of pollutants. The filter is replaceable and is sold separately.

steveknight

I doubt it does much. it takes sore rpetty fine filtering to get most airborn gas pollutants.

John C. Ratliff

I am a commuting bicyclist, who has written on these forums for several years. My day job, however, is as on environmental health and safety engineer for a high-tech company. So I am going to make some comments here which may not endear me with the bicycle manufacturers.

The above respirator may, and may not, work. It has to my knowledge never been tested. All industrial respirators used in the United States must pass a "technical certification," receive a TC number, and are listed by the National Institute for Occupational Safety and Health for use in industrial environments. There are a number of different certifications, and types of respirators. Half-face, particulate respirators can be either disposable, or reusable. The reusable ones are generally made of rubber or silicone, and have cartridges for specific hazards. Once the hazard is known, then the respirator can be chosen to meet the hazard. In the occupational environment, the employer must set up a respirator program. This program consists of:

--Hazard evaluation and respirator selection.
--Training for the employee concerning how to use the respirator.
--A medical evaluation to ensure that the respirator user can use a respirator without medical problems.
--Fit testing of the respirator to ensure that the respirator will not leak.

To find out more about respirators, you can visit the following sites:

NIOSH Respirator Information

NIOSH Respirator User's Guide

So, knowing the above, what is the hazard. It is diesel exhaust, which has very small particulates, and some gases. The gases would be nitrous oxides and carbon monoxide. There are several ways to go here, but if you want a respirator only for the diesel particulates, then a HEPA (high efficiency particulate) respirator would do. These can be either disposable, or half-face chemical respirators with cartridges. If you don't care about the gases, then a disposable N-95 certified respirator (such as was used for the SARS outbreak last year) will do well. N-95 is a listing which means that the respirator will remove 95% of the particles greater than 0.5 microns in diameter. If you also want to get rid of the gases, you need a cartridge respirator which will absorb both CO and nitrous oxides.

The above respirator claims to do this, but it needs to be fit tested to ensure a fit. I would also like to see more information on its filtering capabilities. If they cannot provide data, assume that the respirator cannot filter what it claims it can.

Once you get the respirator, a fit test is vital to ensure that it works. Fit tests can be conducted by any occupational medicine clinic. A sweat or irritant aerosol is used to test the fit, and see whether it actually works. This would be a great way to test the above respirator.

Now, the question was brought up about a respirator which would not inhibit breathing, such as pumping up those long hills but in a highly polluted environment. Well, such a creature does exist, and is called a Powerd Air Purifying Respirator (PAPR). Basically, there is a small package you wear on your back, with a hood over your head and a tube for the filtered air to flow to the hood. It may not be the best for visibility in the less expensive models, but is used by farmers and others in high particulate environments.

Now, about the risk itself. My wife receives The New England Journal of Medicine, and in it's October 21, 204 issue there is an article about "Exposure to Traffic and the Onset of Myocardial Infarction." This is a very interesting article, with several references I want to read. This is a study of heart attacks by 691 people exposed to traffic in Augsburg, Germany. The exposure could be either by being in a car in traffic, a bicycle, or public transportation. Here is an interesting quote:

In short, it appears we cyclists have less exposure to these pollutants than do people in cars and buses. Remember, the particles they are talking about are very, very tiny, and cannot be seen for the most part.

My strategy is to try actively to avoid these exhausts. I use some of the principles for protection from radiation: time, distance and shielding.

Time: pick the time of day to avoid the highest traffic. Limit time in high traffic areas to a minimum. You can see that 100 m can remove a lot of the pollutants. At times, I've seen a truck blow a bunch of exhaust garbage into the air, and I have stopped. I waited for a full minute (its a long time to look at a watch's second hand ), then proceeded. The air was clear by then. I also hold my breath through some real bad areas.

Distance: that 100 meters can be gained by going a different route, using back roads that are quieter.

Shielding: Trees, houses, etc. can provide breaks and shield you from pollutants. I have a bike path that goes beside a freeway, and recently I have been taking a different route in front of stores in their parking lots. These are parallel routes, which are about 100 m apart (maybe a bit less), with building between.

There are three types of controls used by the safety and industrial hygiene professionals to protect employees. They can also be used by cyclists. These are engineering controls, administrative controls and the use of personal protective equipment. Engineering and administrative controls are always preferable to PPE, as they are more sure and not as subject to malfunction. Usually, we don't have much control of engineering, but taking a bike path (not bike lane, which is right on the road) rather than riding the road is an engineering control for diesel exhaust. But PPE (in this case respirators) can also be used in combination with administrative controls (time, distance and shielding) to achieve greater protection from diesel exhaust. I hope this helps.

John

steveknight

you filled in where I left off (G)
if a guy you also have to be clean shaven too. it's a pain to get a good seal and I sure would not want to ride with any mask on. it woudl be so uncomfertable.
I think scoba gear would be the only practical method (G)

bpave777

WOW! thanks John. that was really great reading.

Konakazi

That was interesting but isn't there something a little closer to the consumer level that would help? I mean I can't imagine anybody wearing a bag on their head with a tube attached to a backpack while riding their bike. Some things just aren't practical, and unless you're really paranoid about pollution, I doubt a casual commuter is going to go get their products tested etc.

Seeker

John did an excellent job. I've worked as an industrial x-ray tech in the petro chemical industry where I had to have evaluation and fit test for resperators and yes you would have to be really paranoid about pollutants (or eviromentally sensitive) to go that route but it is likely the most effective way. You do have to be clean shaven for the resperator to be effective and leak free and one fit test is not for a lifetime. You need to do fit tests over because your face changes.

SCBA (self contained breathing apperatus) is in practical due to smaller (known as escape units) only hold 5 minutes of air while larger units are heavy and with higher levels of physical work (like riding a bicycle) you will find the air tank empty sooner.

As for the commercial units sold to the general public I don't think they will be too effective because they don't take some of the above conciderations into account

fatbat

Apparently, the respro series of masks is the only sport-filter mask to do a decent job of filtering small pollutants.

fatbat

steveknight

it was a joke (G) but hey mabye we can make bicycle tubes into the compressed air tanks. then if you get hit by a car mabye you can take them out too (G)

John C. Ratliff

Today, I rode home wearing my half-face respirator. I used a North respirator with a N-100 HEPA filter on it (two cartridges). It was not difficult at all. There was a bit more breathing resistance, but not that much more. I did notice several things. I stopped to turn on a light in my work parking lot, and one of my workmates stopped his car to see whether I needed help. But it was very difficult to talk with him. It's well known that communications is inhibited by a respirator, and this simply confirmed it. Also, I noticed that even in the cold air, my safety glasses did not fog up. That's because the exhalation valve is below my chin, and so no warm, moist air from my breath got to the glasses. Finally, I did not smell the car exhausts. All in all, I will be using the respirator again.

A couple of other points:

--Respirators need attention. They cannot just be used over and over again. The filters need changing once they become clogged (or for those with activated charcoal, when gases are smelled through them). The mask needs to be cleaned after each use to prevent the development of bmacterial buildup inside it.

--Fit testing for the general public is not necessary, but is highly desireable (it's the law for workers). You can test the fit of the half-face non-disposable cartridge respirators by covering the filters, and breathing in. If the respirator collapses onto your face, the fit is good. If air leaks around the seals, it is not. Then blow out while plugging the exhaust valve. It should inflate slightly before air leaks around the seals. This is a test that workers must perform each time they put on a respirator, even after they have been fit tested.

--If you have asthma, clausterphobia, or any other thing that could affect wearing a respirator, get a respirator physical first. Tell the doc why you want to wear one, and bring it with you (many who do respirator physicals can do the fit testing). Since there is increased breathing resistance, and you are bicycling, be very careful here. If you even have the question, get a physical.

John

Dane

While you're at it, increase your vitamin C intake...it increases your lung's defenses against air pollution.

andygates

Consumer-level urban commute cycling experience: None of the filters are worth it when the tradeoff of heavier breathing, icky moistness, steaming-up glasses, etc, is all taken into account. Instead, get in the habit of nose-breathing. Snot is a damn good filter and it's self-changing when spent.

Mind you, fume filters do look cool.

John C. Ratliff

I rode my bike, and wore the same mask as yesterday, this morning. I have some more interesting observations. This morning's commute was cold; it froze on the ground for the first time this Fall. Here's my experience from this morning.

The respirator does work to keep moisture off the glasses. I didn't have the usual fogging problems this morning. I had one hill to climb, and found that even with the respirator it was not difficult. Then it got interesting. As I said, today started out clear and cold. Well, when it's cold, I get the runny-nose syndrome. But with a respirator on, it cannot be "self-changing" as is noted above. It must either stay in the respirator, go out the exhalation valve, or be incorporated some other way. I chose to incorporate some of it, actually a good bit of it. So my mention of washing out the respirator each day is vital when it is used for bicycling.

Now, there is another part of the above quote I would like to discuss--the notion that snot is a good filter. For large particles, it is. Stuff in the air will settle onto the hairs and mucus, and be expelled. This actually happens throughout the respiratory tract, except if you smoker. The reason is something called the "muco-cilliary escalator." The cells of the respiratory tract have hair-like structures called cillia. These beat in a specific direction, out. A constant blanket of mucus is being beat out of our lungs, taking these large particles out with it. We then either spit them out, or swallow them (as above). But this applies only to fairly large particles.

Diesel exhaust particles are very small; they don't settle out. Instead, they stay with the air flow, and penetrate very deep into the lungs, actually into the alveoli themselves (air sacs). They are less than a micron in diameter (0.5 microns = 1.96850394 x 10-05 inches = 0.00002 inches). This means they are deposited deep in the lungs, and a significant number end up in the air sacs themselves. They cannot settle because the motion of the molecules in the air keeps them suspended (Brownian motion). But they go to the places the molecules go. They deposite deep in the lung, and can diffuse into the cells in the air sacs. Breathing through the nose does not significantly affect this deposition. Here's a PubMed Reference Article

So the effects of diesel are real, and respiratory protection can be helpful. But so can the time/distance/shielding principles I discussed earlier. You will need extra maintenance time if you use a respirator, though, unless it is a disposable one. More on that later.

John

kurremkarm

Wow, you should combine all this **** and put it in a FAQ and they should lock it here. Very informative stuff, John. Thanks very much.

I notice irritants in heavy traffic here in Wichita during rush hour, but if i take one way streets and avoid the main ones it's a lot better.

I think i will use ur tiime, distance, and shielding thing-- avoiding the busy streets, keeping distance from trucks and buses, and etc.

oboeguy

Wow, great thread. From my commuting experience, I'd be concerned with the inability to get drivers' attention (i.e. can't yell). In any case, this thread has certainly made me more interested in a Car-Free Central Park. (yes, non-NYC-people, we have cars in CP!)

karenaurora

Can I ask John C Ratcliff what his North respirator is made of? Does it slip off your nose if your get hot and sweaty? I've been painting some windows recently with a respirator and (in the summer) if my face got too sweaty the mask slipped off. Do you still think these are the best to get? I need to do something - I am allergic to the fumes I think; I get so tired and miserable after less 15 mins of rush hour traffic. Just an ordinary commercial cycle fume mask will not help I don't think, and theya re very expensive. Its good that youve posted that stuff, thanks.

John C. Ratliff

Karenaurora,

First, let me say that you need to get a physical. Something is not right--getting tired and miserable after less than 15 minutes in rush hour traffic. I don't think you are allergic to fumes; the allergic reactions to substances are not simply getting tired and miserable. It may not be the atmosphere, but something within that is not right. Saying that, schedule the physical right after your commute, and have them take a blood carboxyhemoglobin test. It could be that the problem is carbon monoxide poisoning, and not diesel particles (carbon monoxide is a component of all internal combustion engines). It would also be good to get a stress EKG, to make sure the ol' ticker is ticking properly. And make sure to tell the doc that you plan to ride with a respirator, and therefore should get the one you buy fitted correctly.

Now, having gotten the physical out of the way. there are other points to discuss. A good, half-face respirator has two straps, and one goes over the top of the head. If it is adjusted correctly, there is no way it should become dislodged by a sweaty face. It sounds like your respirator did not fit correctly. There are a number of reputable manufacturers of respirators, and these include Wilson, North and MSA. Go to a safety supply house (or look up Lab Safety on the web) to get some.

I mentioned carbon monoxide above (CO is the chemical abbreviation) because I know of one study of drunk driving accidents in the Seattle, WA area some years ago. In the study, researchers found high levels of CO in the drivers who were arrested for drunk driving accidents. They hypothesized that the CO caused further deterioration in the driving ability of the drivers, who had also been drinking. Carbon monoxide adheres to hemoglobin in our red blood cells better than oxygen. It therefore displaces the oxygen, and when breathed in very large quantities, can cause death. The condition is called carbon monoxide poisoning. Before that, it can cause the tiredness and headaches you previously described. But, you cannot automatically assume that it is the CO; it needs to be checked out--15 minutes is probably too short a time period for this effect to occur.

Now, if it is CO, how do you protect against it. The respirator I described in earlier threads was for diesel particles, not for gases. To remove gases, a filter with an agent which removes the CO. These are color coded (and the color escapes me right now). Organic vapor cartridges will remove the paint vapors, but may not work well for CO. The other problem is that CO does not have any "warning properties." It cannot be smelled. Therefore, there is no way to know when a cartridge no longer works. These cartridges only work of a limited time before becoming exhausted. Therefore, they cannot be relied upon for long, and must be changed. At my company, these cartridges are changed with each use (usually daily). That also becomes very expensive.

So what to do? Well, again let me state that the concept of time/distance/shielding is important. Pick a time when fewer cars are on the road. Keep a distance away from them if possible. Keep material (walls, trees, etc.) between you and the cars. Keep on the upwind side (not really too possible, but if there is a choice...).

I hope this helps.

John

Anthony King

I just have to chime in and say the obvious--something is very, very wrong when we have to wear masks to breathe decent air.

Move to the country and learn to farm.

John C. Ratliff

Anthony,

We have to do more than move to the country; we have to improve the air quality by getting more people to bicycle! We have made some improvements over the years. By removing lead from gasoline, we don't poison inner city kids anymore with that heavy metal. Lead can reduce IQ in small quantities in children, even if it is not observed to be doing other damage. The fact that we now burn unleaded gasoline shows that improvements can be made.

But, on a more serious note, respirators are a viable alternative for some problems. I thought a bit about that at an intersection on my way to work, that if more people wore air purifying HEPA filtered respirators, it may send a message to those people in the "metal boxes" about what they are directly doing to the environment (and we too--I also drive on occasion). We have a lot of people who do not believe in the concepts behind "global warming," and that burning fossil fuels causes a rise in CO2 (and CO--see above) is contributing to that.

John

karenaurora

John, Ratcliff, Thanks for your reply, I think I've been feeling a little under the weather last week or so - so it makes my tolerance lower - but I definately get these effects from my half an hour and then return journey across the city trips. Thanks for your info, I am going to start finding out about masks today, and will talk to doctor!

AndrewP

Since the North mask and filters costs about $20, which is less than the cost of a pair of panniers, I suggest getting one and trying it. Only you know how sensitive you are and other peoples traffic conditions may not be the same as yours. When I was in England last year I certainly noticed the diesel smell, and not just in London.