Would a moist cloth wrapped around the nose be reasonably effective as compared to an anti-pollution mask? On looking at the prices of masks and filters, I figured that it could eventually get rather expensive for me. Moreover, there's an article in a newspaper that these masks don't really help:


  Don't be fooled by safety masks (Sep 30, 2001)
  According to a
  two-year painstaking study conducted by a group of researchers in the
  department of chemical engineering, Indian Institute of Science, no
  mask being sold in Bangalore is effective against the most common and
  harmful pollutants: carbon monoxide (co), sulphur dioxide (so2),
  suspended particulate matter (spm), oxides of nitrogen (nox). The
  study, commissioned by the council for scientific and industrial
  research (csir), has been examining all the material used in the
  filters inside the plastic masks. To their utter dismay, researchers
  found that people using these masks are being fooled beyond
  imagination. says senior scientific officer Mr.J.R. Mudakavi: "we have
  tested more than a dozen such masks available in the city's markets. I
  am sorry to see that none of them informs the buyer what it is
  effective against, what load it can take, if the filter is recyclable,
  et al". The most injurious of all, CO, is not filtered by any mask.
  sulphur dioxide is absorbed by some filters to some extent, but given
  its concentration in the atmosphere, these masks are effective only
  for 2-3 hours. no user is told that if the filter is washed it can be
  used efficaciously a few more times. one of the dreaded pollutants is
  spm (small particles from industry, stone crushing, construction
  materials, exhaust, etc) which when inhaled in large quantity gets
  deposited in the lungs and can cause silicosis.


Ok, so if even the anti-pollution masks can't filter out CO or SO2 properly, then that leaves the danger of the particulate matter which in my opinion, could be prevented with just a cloth wrapped around the nose and mouth.  

Not a thin layer of cloth. A cloth where the folds form a couple of layers over your face and nose. If this cloth is moistened a bit, shouldn't it be effective against particulate matter.  

For a short ride of maybe 30 minutes, won't a simple cloth be more cost effective and offer a reasonable amount of protection against pollutants?
that leaves the danger of the particulate matter which in my opinion, could be prevented with just a cloth wrapped around the nose and mouth.


Diesel particulates are mostly in the 3-30 nanometre range of sizes. This is very fine and will not be stopped by normal cloth.

3M say a P2 (EU rating) filter should reduce exposure to diesel particulates. A P3 mask should remove a higher proportion of particles. I suspect these filters might not remove the finer diesel particulates.

Most of these masks are not intended to supply a large volume of air, they are workplace masks not sports masks.

Some cycling mask makers write about PM10 filtering. Note that PM10 are coarse dust particles 2500 to 10000 nanometers in size. That's a lot larger than most diesel particulates.

The key to an effective filter is a good air-tight closure against the skin around the entire perimeter of the filter. You cannot obtain the necessary fit using cloth alone.

If anecdotal stories have anything to teach it is that you should expect a white filter to become blackened even on short rides and that you therefore need to replace the filter every ride.