From the Sunday Times in Perth Western Australia, April 17, 1994, page 25
Smog above danger mark
Dangerously high levels of photochemical smog plagues Perth and readings
this week again were above the recommended health levels.
Photochemical smog - a dangerous mix of hydrocarbons and oxides of
nitrogen which results in a filthy brown haze - hung over the city on
Smog causes severe respiratory problems and continued exposure will
damage the lungs.
At Swanbourne, one of the Department of Environmental Protection's nine
air-monitoring stations, the unofficial reading on Thursday was 95 parts
of ozone per billion parts of air.
The recommended World Health Organisation level is 80ppb.
Thursday's reading came after hot, still conditions all week with
maximum temperatures of 30.6C (Monday) 35.1C (Tuesday) 27C (Wednesday)
and 30.6C (Thursday).
Since October 1, the DEP has recorded 24 separate "incidents" when the
ozone level has been above 80ppb for at least one hour.
January 22-23 and Mark 16-18 were the worst days, with widespread
recordings above acceptable levels.
The highest individual recording was 110ppb at Cullacabardee on March
18, after 91ppb and 88ppb the previous days.
On January 22-23, Caversham had six hours where the readings were above
Surprisingly, Rolling Green, near Toodyay, was the worst affected, with
five days of unsafe readings.
According to Murdoch University associate professor of city policy,
Peter Newman, the smog problem will get worse if Perth continues its
reliance on the car.
DEP smog expert Iain Cameron said photochemical smog, not to be confused
with haze, was a summertime complaint fuelled mainly by the fumes from
"Smog is a photochemical reaction; the ingredients being oxides of
nitrogen and hydrocarbons", Mr Cameron said.
"Most of those come from the back end of your motor car.
"The activity starts about the end of September and goes through until
about April. By May it starts to settle down again.
"The industry at Kwinana does contribute to it but all the studies that
are done anywhere in the world indicate motor vehicles are the main
"We have got to get out of our cars and into public transport."