A Study of The Air Quality in Underground Car Parks
A Study of The Air Quality in Underground Car Parks
A Study of The Air Quality in Underground Car Parks
.,
:-
0
u
40
10.00 am 12.00 noon
2.00 pm
Time
4.00 6.00
.....,\\ ./,l
\./
g,oopm
80
Fig. 5: Temporal variation of carbon monoxide and traffic flow at UCP 2
UCP 1. Hence the traffic flow was always on the
high side compared to UCP 1. Measurements of
the background carbon monoxide level in these
UCPs (i.e. before any vehicle has entered in the
morning) revealed that the CO values were
either close to or exceeded the proposed Malay-
sian Air Quality Standard of 9 ppm (UCP 1 = 8
ppm, UCP 2 = 19 ppm, and UCP 3 = 10 ppm).
DISCUSSION
More than 90% of the carbon monoxide
concentrations measured exceeded 10 ppm in all
the underground car parks studied. The mean
CO concentration in all the UCPs also exceeded
the proposed Malaysian Air Quality Standard of
9 ppm for an 8 hour average, and 35 ppm 1 hour
maximum value (except in UCP 1). The occur-
rence of intermittently high levels of carbon
monoxide exceeding 100 ppm in UCP 2 and
UCP 3 is of concern with respect to its implica-
tion for human health. From the relationship
between in the blood and
the carbon monoxide concentration in the air
(Anon., 1959), light to moderate symptoms of
carbon monoxide poisoning will be evident after
1 to 2 hours exposure in these car parks. The
relatively lower CO values in UCP 1 can be
accounted for by the smaller traffic volume since
the building is primarily used as an office
complex.
Lead is considered hazardous to human
health due to its cumulative effect in the body. A
comparison of all the sites revealed that UCP 3
has the greatest range of airborne lead. The
maximum value recorded (23.9 Jl.g/m 5) is very
much higher than the value in the proposed
Malaysian Air Quality Standard of 0.7 Jl g/m5
for all zones. The average individual breathes in
about 20 m 5of air per day, which is equivalent to
0.14 m 5per 10 minutes (Waldbott, 1978). Based
on the mean lead level of 16 p.g/m 5(in UCP 3),
a car park user or tenant who spends about 10
minutes in the car park each day would have
inhaled 1.2 Jlg of lead per day. Assuming
that he uses the car park for 250 days in a year,'
he would have taken in 300 Jlg lead per year.
The amount retained in the alveoli is about 10%
(Anon., 1972) Le. about 30 iLg lead per year.
Hence it would not take long for the lead con-
centration to accumulate to around 80 p.g lead
per 100 gm blood which could well manifest in
clinical symptoms.oflead poisoning.
The high readings of carbon monoxide and
airborne lead in all the underground car parks
studied pose a potentially serious threat to the
198
PERTANIKA VOL. 9 NO.2, 1986
A STUDY OF THE AIR QUALITY IN UNDERGROUND CAR PARKS
health of car park users or tenants. Especially at
risk are the security personnel and car park
attendants who patrol and manage the car parks
daily. To reduce these problems, the traffic flow
into the car parks should be strictly controlled to
avoid overcrowding which would eventually
produce excessively high levels of pollutants. In
addition, knowledge of the daily peak traffic
flow should be made available to the operating
personnel so that they can switch on additional
ventilation fans during peak hours.
The higher correlation of airborne lead
concentration with traffic flow compared to
carbon monoxide indicates that this approach to
determining the air quality in enclosed car parks
is more promising than using carbon monoxide
as the reference. Since carbon monoxide is
lighter than air, it tends to ascend and escape
detection by the CO tester unless this is carefully
sited. On the other hand, airborne lead, being
more dense, is confined to the car park. This
approach should be pursued until the lead
content in petrol has been reduced to very low
levels. Officially, the level of lead in petrol was
reduced from 0.8 gil to 0.4 gil in April 1985 and
it is anticipated that the government will initiate
further reductions in the future.
ACKNOWLEDGEMENTS
The expert advice and valuable assistance
of Mr. Abu Bakar Che Man from the Factory
and Machinery Department is gratefully
acknowledged.
REFERENCES
ANON., (1959): Ventilation of vehicular tunnels. The
Institute for Highway Construction of the Swiss
Institute of Technology. Report of the Com-
mittee on Tunnel Ventilation to the Swiss Depart-
ment of Highways. Bulletin No. 10.
ANON., (1972): Health Hazards of the Human Envi-
ronment. W.H.O. Publication. Geneva.
ANON., (1983): Carbon Monoxide Measurements At
Covered Car Parks and in Residential Areas.
Unpublished report by the Department of the
Environment, Malaysia.
ANON., (1985): Underground Car Park for Selangor
Padang. New Straits Times Press. 15 March
1985. Malaysia.
COLUCCI, J.M., BEGEMAN, C.R. and KUMLER, K.
(1968): Analysis of Exhaust Emissions. Sixty-first
Annual Meeting, Air Pollution Control Asso-
ciation. St. Paul, Minn. June 1968.
WALDBOl1, C.L. Ed. (1978): Health Effects of
Environmental Pollutants. The C.V. Mosby
Company, Missouri, U.S.A.
(Received 19 October, 1985)-
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