driving a cab through the ground-level chemical soup

I've always wondered why nobody publishes regular ground level
ozone and other airborne chemicals in major cities of
the world, especially in the summer. This is an issue of health.

Here's some of the proof I've been waiting for. It says that
cabbies are literally swimming it. It being the airborne
particles.

Check this: Guardian

Cab users run highest risk of exposure to dirty air
By James Randerson

of all the usual forms of city transport taxis appear to be
the worst for exposing passengers to airborne particles,
finds research by Imperial College London. Using a
device that counts particles measuring 0.02 to 1
micrometre in diameter, Surbjit Kaur tracked 31
central London journeys, synchronising the readings
with recordings made of the journeys with a hidden
video camera. The experiment found that, on average,
taxi rides clocked up 107 000 particles per cubic
centimetre, compared with 92 000 for buses, 80 000
for bikes, 45 000 for walking and 36 000 for cars.