In a statement on Monday, the British Heart Foundation - - thirty years a supporter of cycling thanks to its London to Brighton bike ride - said "the research is not bad news for cyclists in cities. For most cyclists, the benefits to their heart health from regular exercise far outweighs risk from pollution, which has yet to be directly proven."
There's no BHF comment on the efficacy of anti-pollution masks.
The Sunday Times had reported: "Diesel exhaust includes nanoparticles of carbon and a range of metals. The particles are so tiny that experts say that it is pointless for cyclists to wear masks, because the mesh cannot be fine enough to block them."
The "experts" were not named.
Respro of London, the main UK manufacturer of cycle face masks, has now issued a rebuttal statement, included here in full.
The effectiveness of pollution masks
In order to consider the question of how protective masks are, the first distinction is how particulates are grouped into 'Inhalable' and 'Respirable'. Inhalable particulates: are the particles big enough to be trapped within the nasal hairs and the mucous membranes at the back of the throat: size is greater than one micron. Respirable particulates: are the particles that pass beyond the nasal hairs and the mucous membranes of the throat and pass into the lung sacs and subsequent blood barrier: size is less than one micron. These particulates can carry carcinogenic chemicals used in petrol (benzene, pyrene, etc) to the blood barrier. The performance test data for our particulate filter media has been recorded as follows: 99% of all particles over 0.3 micron in size will be trapped in the filter media (1mm is equal to 1,000 microns; 0.1 micron is one thousandth of a millimetre in size, therefore 0.3 is a third of one thousandth of a millimetre in size). It is believed that most airborne particulates are in the range of 0.1 - 10 microns in size. The filtration performance for particulates less than 0.3 microns would reduce at a linear rate which suggests that effective filtration greater that 50% would still occur at sizes well below 0.3 microns. When particles reduce to the molecular (nano size) level they then get trapped by the attractive forces of the pore structure of the Dynamic Activated Charcoal Cloth element that is situated behind the particle filter. The combination of particle and activated charcoal filters in some of Respro's masks really does afford effective filtration at all levels of particulate size. To say that wearing a mask is useless and suggest that people should not bother is irresponsible advice. Several Respro® masks exceed EN149 FFP1, which is an industrial standard for working in environments where exposure to potentially hazardous dust levels exists. Reasons to wear a mask would include: Lung irritation: many different pollutants - when mixed together - can cause irritation to respiratory systems.
Helps to prevent cancer: there are known carcinogenic agents such as pyrene and benzene present in petrol.
No gender: as the mask covers part of the face, people feel their gender isn’t so evident. This can be an issue for cyclists. Right image: the masks are an awareness statement to the other road users in cleaning up the environment. Respro would advise any cyclist to wear a mask in the following situations: Certainly if your are commuting daily in or out of rush hour periods
When there is low air velocity i.e. still air and not much wind
When the sun is shining. Photochemical smog produces Low Level O-zone which can cause irritation to those with asthmatic tendencies or susceptible lungs A simple scarf will filter large grit particles and nothing more, whereas a proper filter does a lot more and provides more complete protection. The main difference is the filter media. D.A.C.C. (Dynamic Activated Charcoal Cloth) combined with a hepa type particulate filter afford effective filtration at all levels of particulate size. Dynamic Activated Charcoal Cloth is the filter media laminated into the Bandit Scarf. The same filter media plus micron level particle filter is in the City Mask and Dynamic Activated Charcoal Cloth media plus Hepa-type particle filter is used in the Techno mask. DACC was originally developed by the U.K. Ministry of Defence for use in the protection against chemical and bacteria warfare situations. We use D.A.C.C. to effectively filter out Primary pollutants associated with vehicle exhaust emissions such as gases and vapours:
Low level Ozone
BRITISH HEART FOUNDATION'S PRO-BICYCLING PRESS RELEASE ISSUED AFTER REPORT IN THE SUNDAY TIMES: