,['j;
'
POFllUl
Deporfment Of Environment Mo loy
2000
A Guide To Air Pollutant lndex ln Malaysia
(API)
Department of Environment Ministry of Science, Technology and the Environment 12th & 13th Floor, Wisma Sime Darby Jalan Raja Laut
50662 KUATA TUMPUR MATAYSIA O3-294 7844
fel:
Homepage: www.jas.sains.my
F irst Edition 1993 Second Edition 1996 Third Edition 1997 Fourth Edition 2ooo
ACKNO\ LEDGMENT The Dâ‚Źpartrnent of Envircnment wishes to acknowledge the contributions by the following organisations in producing this publication:
(i) Universiti Putra Malaysia (ii) Alam Sekitar Malaysia Sdn Bhd
FOREWORD
The Air Pollutant lndex (APl) is established to provide easily understandable information about air pollution to the public. lts predecessor was the Malaysian Air Quality lndex (MAQI) which was developed after a study done by the University Pertanian Malaysia in 1993. In line with the need
for
regional harmonisation and
for
easy
comparison with the countries in ASEAN, the API was adopted in 1996. The API follows closely the Pollutant Standard lndex (PSl) developed by the United States Environmental Protection Agency (u5-EPA).
Air pollution levels are determined using internationally recognised ambient air quality measuring techniques. The pollutants measured which include sulphur dioxide, nitrogen dioxide, carbon monoxide, ozone and suspended particulate matters of less than ten microns in size are considered health related pollutants. API is then computed using the technique developed by US-EPA.
With the publication of this information booklet, I hope the public will have a better understanding of the APl. Last but not least, I would like to acknowledge with thanks the contributions by University Putra Malaysia, ASMA Sdn Bhd and all those who have contributed towards the publication of th is booklet.
WAM*:-: HAIAH ROSNANI IBARAHIM Director-Ceneral of Environment Malaysia.
A GUIDE TO AIR POLLUTANT INDEX IN MALAYSIA Introduction
In 1989, the Departrnent of Environment (DOE) formulated a set of air quality guidelines, termed Recommended Malaysian Air Quality Guidelines (RMG) for air pollutants, dehning the concenhation limits of selected air pollutants which might adversely affect the health and welfare of the general public. Based on the RMG, the Dâ‚Źparhnent subsequently developed its first air quality index system, known as the Malaysian Air Quality Index (MAQI) in 1993. An index system plays an important role in conveying to both decision-makers and tle general
public the status of ambient air quality, ranging fiom good to hazardous. Application of the hdex system, particularly in indusaialised countries, has demonshated its useful role in providing a sound basis for both the effective management of air quality, as well as the effective protection ofpublic health.
ln line with the need for regional harmonisation and for easy comparison with countries in the region, the Departrnent revised its index system in 1996, and the Air Pollutant Index (API) was adopted. The API system of Malaysia closely follows the Pollurant Standard lndex (PSI) systen ofthe United States. Air Pollutant Indâ‚Źx (AlI) Recommended Malaysian
Air Quality Guidelines
An air pollution index system normally includes the major air pollutants which could cause poteutial harm to human health should they reach unsafe levels. The air pollutants included in Malaysia's API are ozone (O3), carbon monoxide (CO), nitrogen dioxide (NO2), sulphur dioxide (SO2) and suspended particulate matter of less than l0 microns in size (PMl0). Generally, an air pollution index system is deyeloped in easily understood ranges of values, instead of using the actual concenhations of air pollutants, as a means for reporting the quality of aa or level ofair pollution. To reflect the status ofthe air quality and its effects on human health, the ranges of index values could then be categorised as follows: good, modemte, unlealthy, very unhealthy and
hazardous. The index values may also be categorised accordhg to episode or action criteria, such as air pollutant levels within stipulated standards, or levels signifying conditions for alert, waming, emergency aad significant harm. The key reference point in these air pollution index systems is the index value of 100
(the "safe" limit), which is based on the National Guidelines for the spâ‚Źcifrc air pollutants concemed.
Air Quality
Standards or
The Recommended Malaysian An Quality Guidelines (RMG) which form the basis for calculating the API are presented in Table 1. These guidelines have been derived from available scientific and human health data, and basically represent "safe levels" below which no adverse health effects have been observed. The RMG are generally comparable to the conesponditg air quatity standards recommended by the World Health Organisation and other countries.
The averaging time, which varies ftom I to 24 hours for the different air pollutants in the RMG, represents the period of time over which measurements
is monitored and reported for the
assessment
of human health impacts of
specific air pollutants. As such, the air pollution indices are normally monitored and reported for the same averaging times as those employed for the air quality standards/guidelines.
A?I As mentioned earlier, the API system closely follows the PSI system of the United States. As such, the API breakpoints at 100 for the various air pollutants correspond to the respective RMG concenftations regarded as being "safe levels". In other words, air quality with API values exceeding 100 are considered likely to cause health effects to the general public. Further, a linear corelation is assumed from API 0 to API 100, with the breakpoint at API 50 conesponding to 50% of the RMG concentration standards for the various air pollutants. Breakpoints at API 200, 300, 400 and 500 directly mirror those of the PSI system of the United States. Figures I to 5 depict tle sub-index functions of the five API pollutants involved, which are used as the basis for calculating the APL The respective breakpoints and their corresponding episode category descriptors are also indicated. The relevant equations for the calculation ofAPI values for the various concenfration segmenls are also presented in Figures I to 5. The coresponding API values calculated as a firnction of the air pollutant
concentrations are listed in Table 3. Further, air quality in terms of human health impacts and implications are categorised as follows under the API system adopted in Malaysia:
API
DESCRIPTOR
0-50
good modemte
51 - 100 101 - 200 201 - 300
>300
unhealthy very unhealthy hazardous
Table 4 summarises additional information on general human health effects and cautionary statements within each ofthe API categories.
Followirg the requirements of the RMG from the standpoint of human health implications, the API values are reported for varying averaging tirne as follows: PMIO and SO, on 24-hour running averages, CO on 8-hour running averages and O3 and NO2 on l-hour running averages. The API for PM10 (based on a 24-hour period ruming average), reflects specifically levels of suspended particulate natter pollution and it may not be linked directly to visibility factors, as visibility is often determined by results of semi-quantitative observations over relatively shorter time periods.
How Is the Air Pollutant Index Calculated? To determine the API for a given tirne period, the sub-index values (sub-A?I) for all five air pollutants included in the API system are fust calculated using the above mentioned sub-index furctions for the air quality data collected ftom the Continuous Air Quality Monitoring Stations. The corresponding air quality clata are subjected lo the necessary quality control processes and quality assurance procedwes, prior to the sub-index calculations. The API value reported for a given time period represents the highest API value among all the sub-APIs calculated during that particular time period. The predominant parameter contributing towards a particular A?I value is normally indicated alongside the API value. For example, during the 1997 haze episode, the predominant air pollutant parameter was PMlo and heuce the API values reported were primarily based on the PMIO sub-index.
This approach is also adopted by the PSI system ofthe United States, and is also commonly followed by other countries in an effort to promote a uniform and comparable API system. Ideally, all sub-API yalues exceeding the API 100 threshold limit should also be reported in addition to the predominant API value per se.
The following is an outline of the procedures involved ia calculating the API values (process flow chart is shown in Figure 6):-
(r)
Collect continuous air quality data for the five air pollutants in the API system for sufficient averaging time periods;
(ii)
Conduct the necessary calibration, validation, quality control and quality assruance in the process ofdata collection;
(iii)
Calculate average concentration
of the specific air pollutants for
the
specified averaghg time periods;
(iu)
Calculate sub-hdex value for each of the five air pollutants based on the
average concentrations calculated and functions (Figures I -5): (u)
with the use of the sub-index
Report the API at a given time for the preceding averaging period (taking the common end point of l-hour, 8-hour or 24-hour for all hve pollutants) in temls ofthe highest sub-hdex value obtained; i.e. API = Max {sub-indices of all five air pollutants} State the specific air pollutant responsible predominant pammeter along with the index; State the relevant health effect category
Report also other sub-indices,
if
for the API value as the
ofthe API reported;
any, which exceed 100 (thereby
indicating violation of an RMG).
(vi)
An example of graphically presenting the air quality in terms ofthe API, that can be used for reporting in the TV media, is shown in Figure 7. The shaded segments may be represented by successive colours of the specfium: "good" (blue); "moderate" (green); "unhealthy" (yellow); "very unhealthy" (orange); "hazardous" (red). This would give a subjective impression of a gradual worsening of the air pollution problem with each descriptor category. 7
Table
1
:
Recommended Malaysia Air euality Cuidelines (at 25" Celsius and 101 .1 3 kPa) adopted in Air Pollutant lndex calculation
POTTUTANT
AND MTTHOD
AVERACINC TIME
OZONE
l
AS 2524
8 HOUR
CARBON #
l
(u/m')
0.10 0.06
200
30
120
9
35 10
l HOUR 24 HOUR
o.'17
320
0.04
AS 2695
SUTFER
HOUR
(pp'n)
B HOUR
MONOXIDE NITROCEN DIOXIDE AS 2447
HOUR
MALAYSIA CUIDETI NES
1O
MINUTE
l
0.19 0.13 0.04
500 350
DIOXIDE AS 2523
HOUR 24 HOUR
PMl
24 HOUR
150
1 YEAR
50
O
AS 2724.6
105
#mg/m3
Table
2:
Significant Harm Level to Apl value of 5o0 Pollutant and Averaging Time
Concentration (!rglm')
(ppml
57,500
50
3,750
2.O
Carbon Monoxide (CO)
thr
Nitrogen Dioxide (NO')
thr
Ozone t hr
(Ot 1,200
0.6
Particulate Matter (PMl 0)
24 ht Sulfer Dioxide (SO) 24 hr
600
2,620
1.0
Table 3: API vaLues, llt st€ps of 5, fron 5 to Fglml
15 20
150
200
29 30 35
30
50
al 350 8o
45 50
r00
55
550
60 65
650
124
70 75
130 150
80
a5
avJ
9m 95
140
954 200
r015
2r0
1r5 1m r25
rr05
224 230
130
l2
10
260
135
12
45
2lo
r2 80
2AO
145 150
13 15
t350
290 3L0
155 160
13
85 20 14 55
310 32A 330
105
165
250
14
175
1525
1&
t5 60
350
!g/ml
15 21 26
75 00 25
f9ln3
OO
15 00
64 00
20 00 25 00
aO O0
3l 75 42 0o 47 25 52 50
96 00 11244 128 00 144 00 160 00
57 15 63 m 6a 25 73 50 78 75
00 00 00 22100 240 00
31 16
a4 3B 94 99 105
m 25 50 75 00
/5 50 24925 244 00 27475 139 174
50 25 00 41175 452 50 313 348 343
1/6
192 206
256 00 272 23a 304 320
0A 00 00 00
50 00 AAl5A {42 00 52250
r9
15
95
16 30
360 370 360 390 400
,15
!0
135 ra0 225
o
o1o
?70 315 360 405
so 00 60 00 TAAA 30 00 90 00 100 0n
495
120 00 iro 00
765
r40 0! r50 J0
oTt
- a-l-
0015 -o0006 00m 0oo8 0025 0010
o 055
0026 003,1
C043
0
012
0 051
0
016
0 068
0
020
0@5
oo22 o 024
0 094 0 102
0
0f2
o 136
0 0
036 03a
!
585
a l0
r53
a 162
3tio
1Al 00
0
0l
0
053 066
0 r92
J70
130m 1ql 0l
0
092
0 255
01ta 0 13J
0299
1a3 r95 0 209 a 222 0 235
a {al 0 42e 0 450
?4a 251 0271 0 2at
0 0 0 0
563
603 54tl @4 725
00 50 00 50 00
447.25 765 50 AA &6 00 7s 8,t6 50 50 8a7 00 25 527 aA
522 556 591 626 661 695
30 00 35 00 .0 00
'd-a
aor
00 968 00 75 1006 50 730.50 1019@ 195 16.65 76525 1069 50 26 400 o0 1130 @ CO is h..sur.d rs d I br.vcr.s., Ol a.d NO2 ft I 145
r./mj 10 00
4€
500
;4m
-1000 20 00 23O 00 240 00 250 00
12
2@ @
12 30
0 155
270 @
2& m
60 12 90
0 165
29
@ 3@ @
1320
3r0 @
13 80
320 330
0l
0 213
0 3?1
0 145 00
12
13
1,1
6
3,rO.O)
50
10
0 175
o 185 0 191 0 196
0 0
0 0
350 m br evd.8cs. SO2
r.d pNllo
arc 24
br.vc,ag.s
0 471 0 493 514
536 557
579
(
mg/m3 [9/n] 210 215 220 225 230 235 240 245
2g 2@ 265 270 275 240
2q 295 300
cont. inued
Fgln3 pslnl
)
gglml
1243
0.220
1300 1356
357.00 360.50 354.00
16 50
480
840 920 960
17.25 18.00
0.230 0.240
500
1000
1413
Q57.50
18.75
0.250
505 540 560 sao 600
,005 l080
1469
372.5
1526 1542
374.50 378 00 381.50 385.00
23.75 20 25 21.00
o 274
26.35 27.20
620
1240
640
1240
1808
2A.05
6S 6ao 700
1320 1360
1865
24.90 29.75 30.@ 31.45 32.30 33.15 34.00
724 744 Td)
18.70
1955
460
20.40 21.25 26 25 23 a0
24.65 25.50
'1120 1160 1200
1400
1639 1695
0.24o 0.290 0.300
392.00 395.50 399.00
24.AO
0.310 0 320
24.75 25.50
0.340
4O2.4,0
2625
0.350
406.00 409.50 413 o0 416.50 420.00
27.gJ 27.75 24.50 29.25 30.00
0 370 0.380 0 390 0.400
30.50 31.00 31.50 32.00 32.50
0405
38A.50
1921 1978
2031 1480 1520
2091 2147
800
1560 1600
2204 2260
780
2175 22.&
810
1625
2297
424.O0
820
1650
2334
42800
1675 1700
2371
36.40 37.00
630 840 850
432.00 436.00 440.00
330
37.60
860
'17fi
335
34.20
E70
'tT75
340
3E.60
840
345
39.40
690
350
.10.00
900
r800 1425 r850
305 310
34.60 35.20
315
35.4O
320
1725
355
40.60
910
360
41.20
365
41.E0
370
4210
375
a3.00
920 930 940 950
1075 1900
360 3a5 390 395
,t3.60
9€O
20oo
4.20
m25
11_@
970 9@
45.,()
99
ll
I
2556
2593 2630
266f
1925 195,0
2T7A
1975
2E15
2050 2075 hr
2442 2519
270d 2741
46@ CO is mc.lurcd .s
2404 2445
rvaag., 03 nd
2a52 28a9 ?326 2963 30m
0 330
0 360
0.410
0415 0.420 0.425
3.00
0.430
444.00 452.00 456.00 460.00
33.50 34.00 34.50 35.00
0435
464.00 464.00
35.50 36.00 36.50
0.455 0:160 0.465 0.470 o.175
472_OO
476.00 440 00
37.0O
:16.4.00
34.00 34.50 39.00 39.50 40.00
4!6.00 a92.00 496.00 500 00
NO2 ar! I -hr
l0
tvcntcsi
37.&
0.440 0.445 0.450
0.4E0
0.4a5 0.a90 0.495
SO2 ard PM l0
0.330 0.345 0.360 0.375 5.375 0.405 0.420 0.435 0.450 0.465 0 4a0 0 495 0 510 0.525 0.540 0.555 0 570 0.585 0.600 0.610 0.620 0.630 0.640 0.650 0 660 0.670 0.6€0 0.690 0.700 0.710 0.720 0 730 0 740 0.750
0.660 0.690 0.724
0.760 0.770
1.520
0.7E0 o 790
1.560
0 750
575 0.810 0.840 0.870 0.900 0.930 0.960 0 990 1.020 1.050 1.080
1110 1.140 1 174 1.200
1220 1.240 1260 1.280 1.300
t.320 1.3,10
1.360 1 360
1.400
1.424 1.4,{0
L460 1.480 1.500
1.540 1.580 1
rr. z+ht lvcntcs
600
{
mdm3 yg/rt 410 a15
1m
47.15 47.73 4E.30
'1@O
t8.88
1050
1G0 t0/t0
F9ln3 !g/m3 2152 2174 2201
160
1Q
49.45 50.03 50.60
4,15
5i-18
1090
4aa
5r.75
1100
2308 233,. 2360
430 :135
455 460 465 170 175
4& a6 a9 495 5m
1070
160
continued)
2256 2242
!g/m3
3113 3150 31a8
515.q)
41.50
520.@ 525.00
12.0O
0.515 0.520
42.50
055
Q25
59.@
,*1.00
0_5$
3253 3300 3334
535.@ 5:lO.@ 545.00 550.@
â‚Ź.50
0_535
:!1.00
0.5ro
44-50 ,t5.00
0.545 0.550
555.@
:15.50
5@.@
16.00 46.50 47.00 17 _50
0.555 0.560 0 565 0.570 0.575
0.830 0.440 0.850 0.860 0.870 0.840 0.890 0.900 0.910 0.920 0.930 0.940 0.950
5&.@
44.00 ,ts_50 49.00 ,t9.50 $.00
0.5& 0.545 0.590 0.596 0_6@
0.960 0.970 0.940 0.990 1.000
1110
2386
52.90 53.48
1120
2412 2434
5:1.05 5:1.53
11:t0 1150
2161
2490
3413 3450 3488 3525 3563
55.20 55.7a 56.35 56.93 s7 50
1160 1170 1180 1190 lUtO
25t6 2512 2566 2594 2620
$00 638 $75 3713 3750
I h rvcng..
O.] asd NO2 ar. I -lu !vcra86: SO: ard PM l0
CO rs nl.asurd ar
1130
d
565.@ 570.@ 575.@
ll
5E5.00
5$.m 595.@
6d).O
aI. 2+hr avcns.s
1.650 1.640 1.700
1.720 1.740 1.760
r.780
1.o0 1.820 1.6,10
I
60
r.880
1.$0 1.920 1.910 1.960
1.$0 2.@0
Table 4i Comparison
ofAPlval!6s with levalof pollution and haalth measur€s'
Status
Level of Pollution
Good
Pollution low and has no ill oflscts on health.
Health l\,leasures
+ 0-50
5.1
-
1oo
101-2OO
Moderate
Unhealthy
Moderate poltution and has no eff€cts on
health
r'
ill
symptoms e disease
Mild aggravation of among high risk persons, i thos€ with heart or lung
No r€slriction of aclivilios for all groups of people. To practice h€althy lifestylo e.g. not to smoke, exercise regularly and to obssN€ prop€r nulrition.
4r No rostriction of activities for all groups
+
rt +
of P€ople' To Practice healthy lifeslyle e-g. nol to smok€, exercis€ regularly and to obs6rvo prop€r nutrition.
Restriclion ofoutdoor activitiss for high risk persons G6neral population should reducs
vigorous outdoor activily.
Table 4: continued
Status
201 -
300
Vgry Unhoallhy
Level oI Pollution
Heallh M€ast/res
of
Significant aggravation symptoms and d€croased toleranco in person vvith or lung
dis€ase.
exerciso heart
s 4
4
301 -
500
Hazardous
symptoms health.
S€vere aggravation of and endang€rs
+
a Abovs
5O0
Emerygncy
symploms health.
Severe agglavation of anc, endang€rs
Sourco: Minislry ot He3lth, Malaysia.
a
Elderly and persons with known heart or lung disease should stay indoors and r€duc€ physical activity. Gene€l populaiion should avoid vigorous outdoor aclivity Those with any health problems to consult doclor
Elderiy end psrsons with exislin€ h€art or lung disoase should stay indoors and reduce physical activity. General population should avoid vigorous outdoor activily
c€neral population advis€d to follow th6 orders ot tho National Securi9 Council and always to follow the announcaments through the mass rnedia.
Figure 1 : API subindex function for carbon monoxide SIGMFICANT HARM I-EVFJ-
500 450 400
400
EMERGENCY
350
x
300
WARNING LEVEL
Lt.l
o
a l
250
d
200
I50 ALERT LEIEL
150 100
50
MAQG
50
% MAQG
20.0 25.0 30.0 35.0 0.00 5.0 10.0 15.0(8-hOUT RUNNING AVERAGE )
CARBON MONOXIDE
,
40
0
45
0
PPM
Equation for the calculation ofAPI based on 8- hour average concentation:
conc<9ppm 9 < conc. <
15
15 < conc. <
conc. > 30
30
ppm
API=conc.x
ll.l1lll
API = 100 + {[conc.
-
9] x 16.66667\
A?I = 200 + {[conc.
-
15] x 6.66667]
-
30] x 10]
API
:
t4
300 + {[conc.
50.
Figure 2 : API subindex function for ozone SENIFTCaNT
500
tI{ Mr5tsL
450 400 350
Iz
300
o
250
I
zoo
D
150
100 50 0
0.00
0.10
0.20
0.30
0.40
0.50
OZONE (1 -hour AVERAGE), ppm
Equation for the calculation ofAPI based on *conc < 0.2
ppm
0.4 conc. > 0.4 ppm 0.2 < conc. <
l-
hour average concentsation:
A?I = conc. x 1000 ApI = 200 + {[conc. _ 0.2] x 500] API :300 + {[conc.
15
-
0.4] x 1000]
0.60
Figure 3 : API subindex function for nihogen dioxide
500 450 400 350
x 300 6
Azso 5
d 200 150 100 50 0 NITROGEN DIOXDE
(l
nour A\/ERAGE), ppm
Equation for the calculation ofAPI based on
l-
hour average concentration:
iconc < 0.17 ppm
API=conc.x588.23529
*0.17<conc.<0.6
API = 100 + {[conc.
-
0.17] x 232.56]
0.6<conc.<1.2
API = 200 + {[conc.
-
0.6] x 166.667]
conc. > 1.2 ppm
API=300+ {[conc.
-
1.2]
16
x250]
Figure 4 : API subindex fimction for sulfur dioxide
5@ 450
4m 350
x
300
a
82fi
t26 't
50
1m 50 0
0.00 0.10
0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 SULFUR DIOXIDE (24 - hollls RUNNIIIG AVERAGE)pFtr
Equation for the calculation ofAPI based on 24
-
hour average concentration:
.conc < 0.04 ppm
API=conc.x2500
*0.04<conc.<0.3
API = 100 + {[conc.
0.3<conc.<0.6
API=200+ {[conc. - 0.3] x333.333]
conc. > 0.6 ppm
API=300+ {[conc. - 0.6] x 500]
l7
-
0.04] x 384.61]
1.00
Figure 5
:
API subindex function for PMl0
SI@{IFCANT
N
RM LEIEI
500
450
4@ 350
X
300 B z E 250
a
tr
200 '150
100
50
o.o0 Equation for the
l(x) 400 200 500 PM lo (2lldr RI-NNING AvERACE). !9ml calculation ofAPI bascd on 24 - hour average concentration: 100
50pg/m3 50 < conc. < 150 150 < conc. < 350 350<conc.<420 420 < conc. < 500 conc. > 500pg/m3 conc <
API: API
conc.
:50
+ {[conc.
-
APt = 100 + {[conc.
50] x 0.5]
-
150] x 0.5]
API =200+ {[conc -350] x 14286] API = 300 + {[conc. API = 400 + [conc.
18
-
-
420] x 1.25]
500]
600
Figure 6: Air Pollutant Index Process Flowchart
I Indivi{nal Pollutants
t Individiual
Indei _! A
Select l\.[ax.
Indei _t
i
Air Pollutant Indei V
t
Figure 7: Examplc of possible API report fi)r {clevision.
I]NHEALTHY
%***
200
o
7-
'4
o,
O/
tr 7^
luz API = 150
POLLUTANT: Ozone TODAY'S HEALTH IMPLICATION: Mild aggravation of symptoms among high risk persons, i.e. those with heart or lung disease,