A Guide to Pollutant Index (API) in Malaysia

,['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,