  |
|
| BENZENE
IN AIR AND IT'S EFFECT ON HUMAN HEALTH |
Concentration of Benzene in Ambient Air in Delhi (CPCB
Measurement) :
· Active Sampling:
Benzene levels in Delhi’s air environment measured as per standard procedure for active sampling (2 hrly thrice a day ) using low flow personal pumps for sampling and analysis by using Automated Thermal Desorption (ATD) -capillary GC-FID. The results are summarized in following table.
Table 11 : Benzene Levels in Delhi’s Urban Environment, 1998
| S.No. |
Location |
Concentration ug/m3 | |
|
August, 1998 | November 1998 | ||
| 1. |
Residential Area | 110* (21-267) |
248+ (187-308) |
|
2. |
Traffic intersection | 116** (70-163) |
382** (271-540) |
|
3. |
Petrol Pump | 169** (83-238) |
428+ (294-456) |
Note 1) * Average of 4 values measured at three location
2) ** Average of 4 values measured at each of four locations
3) + Average of 4 values measured at each of five locations
7. Concentration of Benzene in Ambient Air in Delhi (CPCB
Measurement) :
· Active Sampling:
Benzene levels in Delhi’s air environment measured as per standard procedure for active sampling (2 hrly thrice a day ) using low flow personal pumps for sampling and analysis by using Automated Thermal Desorption (ATD) -capillary GC-FID. The results are summarized in following table.
Table 11 : Benzene Levels in Delhi’s Urban Environment, 1998
| S.No. |
Location |
Concentration ug/m3 | |
|
August, 1998 | November 1998 | ||
| 1. |
Residential Area | 110* (21-267) |
248+ (187-308) |
|
2. |
Traffic intersection | 116** (70-163) |
382** (271-540) |
|
3. |
Petrol Pump | 169** (83-238) |
428+ (294-456) |
Note 1) * Average of 4 values measured at three location
2) ** Average of 4 values measured at each of four locations
3) + Average of 4 values measured at each of five locations
Results clearly indicate increasing order from residential to Traffic intersection to Petrol pump.
· Passive Sampling:
Benzene levels in Delhi’s urban environment measured also as per M/S Drager’s (Germany) standard procedure for passive sampling (fortnightly basis) i.e. conventional CS2 desorption capillary GC-FID analytical techniques. The results are summarized in following table.
Table 12: Benzene Concentration (µg/m3of Air) in Delhi’s Urban
Environment.
| S. No. |
Area /Category |
Benzene Concentration (µg/m3of Air) | ||||||
|
Aug’ 98 | Nov’ 98 |
May’ 99 |
Jun’ 99 |
Jul’ 99 |
Aug’ 99 |
Sep’ 99 | ||
|
1. |
Residential and Mixed Use |
- | 88* (76-99) |
21** (11-29) | 12** (5-17) |
13** | 18** |
15** |
| 2. |
Traffic Intersection | 42* (39-45) |
195* (193-196) | 38* (32-43) |
20* (16-24) | 22* |
24* | 25* |
| 3. |
Petrol Pump | 164+ (61-365) |
182+ (91-414) | - |
- | - |
- | - |
Note 1) * Average of 4 values measured at one location
2) ** Average of 4 values measured at each of six locations
3) + Average of 4 values measured at each of three locations.
The levels of Benzene measured at ITO (B.S.Z. Marg) during Aug. 1998 & Aug. 1999 has shown a marked decrease of about 43% from 42 µg/m3 to 24 µg/m3 .
The results of active sampling were in higher side probably due to several factors i.e. adsorbent material used, moisture content & presence of other pollutants in the air which need to be standardized. Whereas results of passive sampling were found in tune with on-line BTEX analyzers & portable G.C.
· Routine Benzene Monitoring (Passive sampling) in Delhi :
CPCB has been monitoring Benzene in Delhi at seven locations from May 1999 to April 2000, comprising Residential, Industrial & Commercial areas. Monthly variations in Benzene levels have been shown in Figure-3 .
· The maximum Benzene concentration has been observed at Moti Nagar with 75 µg/m3 during December 2000.
· The minimum Benzene concentration observed at J.N.U. was 6 µg/m3 during June & July 1999.
· Benzene levels during winter season were observed higher & varies between 17 µg/m3 at JNU and 56 µg/m3 at ITO. Lower values were observed during summer and monsoon ranging between 12 µg/m3 at JNU (both season) and 29 µg/m3 and 24 µg/m3 during monsoon and summer respectively at ITO.
· The monthly average values observed at all locations during monitoring period varies between 15 µg/m3 at JNU and 35µg/m3 at ITO.
· Overall (all seven locations) annual mean Benzene concentration has been calculated 26 µg/m3 during May 1999 to April 2000, which is 1.6 times higher than United Kingdom’s annual running mean standard i.e. 16 µg/m3 ( 5 ppb).
Fig.3 : Benzene Level By Passive Sampling in Delhi During May 1999
-2000. 
· Routine Benzene Monitoring (Passive sampling) in Kanpur :
CPCB has been monitoring Benzene in Kanpur city at five locations from June 1999 to May 2000, comprising Residential, Industrial & Commercial areas. Monthly variations in Benzene levels have been shown in Figure: 4.
· The maximum Benzene concentration has been observed at Dada Nagar with 90 µg/m3 during November 1999.
· The minimum Benzene concentration observed at I.I.T. Campus with 3 µg/m3 during September1999.
· Benzene levels during winter season were observed higher & varies between 8 µg/m3 at IIT Campus and 54 µg/m3 at Dada Nagar. Lower values were observed during summer and monsoon ranging between 6 µg/m3 and 5 µg/m3 at IIT Campus both season and 35 µg/m3 and 33 µg/m3 during summer and monsoon respectively at Parade.
· The monthly average values observed at all locations during monitoring period varies between 7 µg/m3 at IIT Campus and 41 µg/m3 at Parade.
· Overall (all five locations) annual mean Benzene concentration has been calculated 22 µg/m3 during June 1999 to May 2000, which is 1.4 times higher than United Kingdom’s annual running mean standard i.e. 16 µg/m3 (5 ppb).
BTX Monitoring in Ambient Air
CPCB initiated Benzene monitoring in ambient air at selected locations with a view to collect background Benzene levels in ambient air, their seasonal & diurnal variations. Passive monitoring & Benzene is being conducted at 7 locations in Delhi (with effect from May1999) and 5 locations in Kanpur (with effect from June 1999) using Orsa 5 Drager tubes (German make) containing coconut charcoal on fortnightly basis. Samples thus collected are extracted using Carbon –di-Sulphide and analysed using Capillary Gas Chromatography with Flame Ionisation Detector.
During one year study period (1999-2000), Benzene concentration range between 6 µg/m3 and 75 µg/m3 in Delhi with overall average annual average of 26 µg/m3 while Benzene concentration range between 3 µg/m3 and 90 µg/m3 in Kanpur with overall average annual average of 22 µg/m3 .
CPCB also initiated On-line BTX monitoring at selected locations in Delhi. Benzene levels monitored using on-line BTX analyser (GC-PID based model MLU-950) varies 2.3µg/m3 and 38.1 µg/m3 with overall average of 12.5 µg/m3 average values for Toluene , m,p- Xylene, o- Xylene & Ethyl Benzene were recorded as 40.90, 17.30, 7.0 & 5.6 µg/m3 respectively. BTX analyser has been used to assess half an hourly values round the clock during sampling period.
On line Active BTX monitoring in Delhi :
CPCB initiated On-line BTX monitoring at ITO during Nov. 2000 subsequently at CPCB premises at East Arjun Nagar During Nov. 2000, Feb.2001 & March 2001.
The monitoring of BTX in ambient air was conducted using continuous online instrument (MLU 950 of Synspec) from 28th March to 31st March and from 01st April to 04th April 2001 under foot over bridge at BSZ Marg, I.T.O., from 12th April to 18th April 2001 in Jhilmil Industrial Area, G.T.Road, Shahdara , from 09th May to 16th May 2001 at National Physical laboratory, Pusa Road, from 13th to 16th Sept 2001 at Hotal Taj Palace, Dhaula Kuan, from 17th to 21st Sept 2001 at Safdarjung Hospital, from 22nd Sept. to 5th Oct. 2001 at ITO and from 9th to 12th Oct.,2001 at Britannia Chowk, Ring Road.
Results of monitoring of BTEX in µg/m3 are shown in Table-13 and figure 5-8 which shows-
· That average Benzene levels were highest at I.T.O. (BSZ Marg) during winter (Nov. 2000) i.e. 38.1µg/m3 and lowest at National Physical Laboratory (Pusa Road) during summer (May, 2001) i.e. 2.3 µg/m3 .
· Overall average Benzene conc. for Delhi was calculated 12.5 µg/m3 with 16.5µg/m3 & 7.0 µg/m3 during winter and summer season respectively.
· Toluene level was observed much high than Benzene and other parameter (i.e. Xylene and Ethyl Benzene) which range between 5.1 µg/m3 at NPL Pusa Road (summer) and 152.0 µg/m3 at ITO, (winter) with overall average of 40.90 µg/m3 . Overall Toluene level was approximately more than 3 times, when compared with Benzene level.
· Overall average levels of m,p Xylene, o-Xylene and Ethyl Benzene were observed 17.3, 7.0 & 5.6 µg/m3 respectively.
· Vehicular pollution seems to be the major contributor of high level at ITO during Nov. 2000 due to higher Benzene content in petrol as compared to Oct. 2001. Benzene content in petrol in National Capital Territory (NCT) and Mumbai has been reduced from 3% to 1% after Nov. 2000.
| Table 13: BTX levels observed in Delhi during Nov. 2000 to Oct. 2001. | ||||||
|
Concentrations in µg/m3 at 25°C | ||||||
|
Locations |
Period |
Benzene |
Toluene |
m,p-Xylene |
o-Xylene |
Ethyl-Benzene |
|
ITO, BSZ Marg |
Nov. 2000 |
38.1 |
152.0 |
68.4 |
26.9 |
21.9 |
|
East Arjun Nagar |
Nov. 2000 |
18.2 |
73.5 |
22.1 |
8.2 |
7.6 |
|
East Arjun Nagar |
Feb. 2001 |
18.2 |
41.2 |
16.7 |
6.4 |
5.4 |
|
East Arjun Nagar |
Mar. 2001 |
12.2 |
30.9 |
11.5 |
4.6 |
4.1 |
|
ITO, BSZ Marg |
Mar. 2001 |
7.4 |
24.6 |
14.9 |
6.4 |
4.8 |
|
ITO, BSZ Marg |
Apr. 2001 |
7.5 |
24.0 |
14.9 |
6.6 |
4.8 |
|
Jhilmil Ind.Area |
Apr. 2001 |
5.6 |
14.5 |
9.6 |
4.2 |
3.1 |
|
NPL, Pusa Road |
May. 2001 |
2.3 |
5.1 |
1.4 |
0.7 |
0.6 |
|
Hotel Taj Palace |
Sept.2001 |
6.0 |
16.3 |
6.3 |
2.6 |
1.8 |
|
SafdarJang Hospita |
Sept.2001 |
9.5 |
27.5 |
11.2 |
4.5 |
3.4 |
|
ITO, BSZ Marg |
Sep-Oct.2001 |
10.1 |
31.4 |
15.1 |
6.0 |
4.4 |
|
Britania Industry chowk |
Oct.2001 |
15.5 |
50.2 |
15.9 |
6.8 |
5.0 |
| Delhi (Nov.2k-Oct.2k1) |
Minimum |
2.3 |
5.1 |
1.4 |
0.7 |
0.6 |
| Average |
12.5 |
40.9 |
17.3 |
7.0 |
5.6 | |
| Maximum |
38.1 |
152.0 |
68.4 |
26.9 |
21.9 | |
| Winter |
16.5 |
56.0 |
22.2 |
8.8 |
7.1 | |
| Summer |
7.0 |
19.8 |
10.5 |
4.5 |
3.5 | |
Half hourly observations show (Figure:9) that concentration of all measured components remain prevalent since evening time till midnight which reflect that BTEX compounds do not dissipate into the environment immediately after release. They persist in the lower atmosphere during dark and comparative cooler temperature in the night until oxidised during daylight. It is observed that BTX level build up in high conc. for a longer duration at Traffic intersection as compared to residential & Institutional area.
Fig. 9 : Half Hourly Reading of MLU Analyser on Nov. 16th 2000 at ITO.
Table 14 : Benzene Emission from Vehicular Monitoring during 1999 in
Delhi. (By Using CS2-Method GC-FID, during January, 1999).
| S.No. |
Type of Vehicle | Sampling Code | Benzene Conc. (mg/m3) |
| 1. |
Maruti Car (without catalytic converter |
S-39 S-40 | 53 235 |
| TOTAL |
288 | ||
| 2. |
Maruti gipsy (with catalytic converter |
S-43 S-44 | 53 94 |
| TOTAL |
147 | ||
| 3. |
Ambrassoder (with catalytic converter) |
S-37 S-38 | 21 145 |
| TOTAL |
165 | ||
| 4. |
Three Wheeler (Petrol) | S-33 S-34 |
330 24 |
|
TOTAL | 354 | ||
| 5. |
Three Wheeler (Petrol) | S-41 S-42 |
882 280 |
|
TOTAL | 1162 | ||
| 6. |
Two Wheeler Two stroke | S-35 S-36 |
1574 666 |
|
TOTAL | 2240 | ||
| 7. |
Two Wheeler Two stroke | S-31 S-32 |
1528 222 |
|
TOTAL | 1750 |
Table 15 : Benzene Emission from Vehicular Monitoring during August
1998 in Delhi. (By Using CS2-Method GC-FID During August 1998).
| S.No. |
Type of Vehicle | Sampling Code | Benzene Conc. (mg/m3) |
| 1. |
Two Wheeler with Lead Petrol |
LP1 LP2 | 1133 176 |
| TOTAL |
1309 | ||
| 2. |
Two wheeler with unlead petrol |
ULP1 ULP2 | 226 138 |
| TOTAL |
364 |
esults clearly indicate increasing order from residential to Traffic intersection to Petrol pump.
· Passive Sampling:
Benzene levels in Delhi’s urban environment measured also as per M/S Drager’s (Germany) standard procedure for passive sampling (fortnightly basis) i.e. conventional CS2 desorption capillary GC-FID analytical techniques. The results are summarized in following table.
Table 12: Benzene Concentration (µg/m3of Air) in Delhi’s Urban
Environment.
| S. No. |
Area /Category |
Benzene Concentration (µg/m3of Air) | ||||||
|
Aug’ 98 | Nov’ 98 |
May’ 99 |
Jun’ 99 |
Jul’ 99 |
Aug’ 99 |
Sep’ 99 | ||
|
1. |
Residential and Mixed Use |
- | 88* (76-99) |
21** (11-29) | 12** (5-17) |
13** | 18** |
15** |
| 2. |
Traffic Intersection | 42* (39-45) |
195* (193-196) | 38* (32-43) |
20* (16-24) | 22* |
24* | 25* |
| 3. |
Petrol Pump | 164+ (61-365) |
182+ (91-414) | - |
- | - |
- | - |
Note 1) * Average of 4 values measured at one location
2) ** Average of 4 values measured at each of six locations
3) + Average of 4 values measured at each of three locations.
The levels of Benzene measured at ITO (B.S.Z. Marg) during Aug. 1998 & Aug. 1999 has shown a marked decrease of about 43% from 42 µg/m3 to 24 µg/m3 .
The results of active sampling were in higher side probably due to several factors i.e. adsorbent material used, moisture content & presence of other pollutants in the air which need to be standardized. Whereas results of passive sampling were found in tune with on-line BTEX analyzers & portable G.C.
· Routine Benzene Monitoring (Passive sampling) in Delhi :
CPCB has been monitoring Benzene in Delhi at seven locations from May 1999 to April 2000, comprising Residential, Industrial & Commercial areas. Monthly variations in Benzene levels have been shown in Figure-3 .
· The maximum Benzene concentration has been observed at Moti Nagar with 75 µg/m3 during December 2000.
· The minimum Benzene concentration observed at J.N.U. was 6 µg/m3 during June & July 1999.
· Benzene levels during winter season were observed higher & varies between 17 µg/m3 at JNU and 56 µg/m3 at ITO. Lower values were observed during summer and monsoon ranging between 12 µg/m3 at JNU (both season) and 29 µg/m3 and 24 µg/m3 during monsoon and summer respectively at ITO.
· The monthly average values observed at all locations during monitoring period varies between 15 µg/m3 at JNU and 35µg/m3 at ITO.
· Overall (all seven locations) annual mean Benzene concentration has been calculated 26 µg/m3 during May 1999 to April 2000, which is 1.6 times higher than United Kingdom’s annual running mean standard i.e. 16 µg/m3 ( 5 ppb).
Fig.3 : Benzene Level By Passive Sampling in Delhi During May 1999
-2000. 
· Routine Benzene Monitoring (Passive sampling) in Kanpur :
CPCB has been monitoring Benzene in Kanpur city at five locations from June 1999 to May 2000, comprising Residential, Industrial & Commercial areas. Monthly variations in Benzene levels have been shown in Figure: 4.
· The maximum Benzene concentration has been observed at Dada Nagar with 90 µg/m3 during November 1999.
· The minimum Benzene concentration observed at I.I.T. Campus with 3 µg/m3 during September1999.
· Benzene levels during winter season were observed higher & varies between 8 µg/m3 at IIT Campus and 54 µg/m3 at Dada Nagar. Lower values were observed during summer and monsoon ranging between 6 µg/m3 and 5 µg/m3 at IIT Campus both season and 35 µg/m3 and 33 µg/m3 during summer and monsoon respectively at Parade.
· The monthly average values observed at all locations during monitoring period varies between 7 µg/m3 at IIT Campus and 41 µg/m3 at Parade.
· Overall (all five locations) annual mean Benzene concentration has been calculated 22 µg/m3 during June 1999 to May 2000, which is 1.4 times higher than United Kingdom’s annual running mean standard i.e. 16 µg/m3 (5 ppb).
BTX Monitoring in Ambient Air
CPCB initiated Benzene monitoring in ambient air at selected locations with a view to collect background Benzene levels in ambient air, their seasonal & diurnal variations. Passive monitoring & Benzene is being conducted at 7 locations in Delhi (with effect from May1999) and 5 locations in Kanpur (with effect from June 1999) using Orsa 5 Drager tubes (German make) containing coconut charcoal on fortnightly basis. Samples thus collected are extracted using Carbon –di-Sulphide and analysed using Capillary Gas Chromatography with Flame Ionisation Detector.
During one year study period (1999-2000), Benzene concentration range between 6 µg/m3 and 75 µg/m3 in Delhi with overall average annual average of 26 µg/m3 while Benzene concentration range between 3 µg/m3 and 90 µg/m3 in Kanpur with overall average annual average of 22 µg/m3 .
CPCB also initiated On-line BTX monitoring at selected locations in Delhi. Benzene levels monitored using on-line BTX analyser (GC-PID based model MLU-950) varies 2.3µg/m3 and 38.1 µg/m3 with overall average of 12.5 µg/m3 average values for Toluene , m,p- Xylene, o- Xylene & Ethyl Benzene were recorded as 40.90, 17.30, 7.0 & 5.6 µg/m3 respectively. BTX analyser has been used to assess half an hourly values round the clock during sampling period.
On line Active BTX monitoring in Delhi :
CPCB initiated On-line BTX monitoring at ITO during Nov. 2000 subsequently at CPCB premises at East Arjun Nagar During Nov. 2000, Feb.2001 & March 2001.
The monitoring of BTX in ambient air was conducted using continuous online instrument (MLU 950 of Synspec) from 28th March to 31st March and from 01st April to 04th April 2001 under foot over bridge at BSZ Marg, I.T.O., from 12th April to 18th April 2001 in Jhilmil Industrial Area, G.T.Road, Shahdara , from 09th May to 16th May 2001 at National Physical laboratory, Pusa Road, from 13th to 16th Sept 2001 at Hotal Taj Palace, Dhaula Kuan, from 17th to 21st Sept 2001 at Safdarjung Hospital, from 22nd Sept. to 5th Oct. 2001 at ITO and from 9th to 12th Oct.,2001 at Britannia Chowk, Ring Road.
Results of monitoring of BTEX in µg/m3 are shown in Table-13 and figure 5-8 which shows-
· That average Benzene levels were highest at I.T.O. (BSZ Marg) during winter (Nov. 2000) i.e. 38.1µg/m3 and lowest at National Physical Laboratory (Pusa Road) during summer (May, 2001) i.e. 2.3 µg/m3 .
· Overall average Benzene conc. for Delhi was calculated 12.5 µg/m3 with 16.5µg/m3 & 7.0 µg/m3 during winter and summer season respectively.
· Toluene level was observed much high than Benzene and other parameter (i.e. Xylene and Ethyl Benzene) which range between 5.1 µg/m3 at NPL Pusa Road (summer) and 152.0 µg/m3 at ITO, (winter) with overall average of 40.90 µg/m3 . Overall Toluene level was approximately more than 3 times, when compared with Benzene level.
· Overall average levels of m,p Xylene, o-Xylene and Ethyl Benzene were observed 17.3, 7.0 & 5.6 µg/m3 respectively.
· Vehicular pollution seems to be the major contributor of high level at ITO during Nov. 2000 due to higher Benzene content in petrol as compared to Oct. 2001. Benzene content in petrol in National Capital Territory (NCT) and Mumbai has been reduced from 3% to 1% after Nov. 2000.
| Table 13: BTX levels observed in Delhi during Nov. 2000 to Oct. 2001. | ||||||
|
Concentrations in µg/m3 at 25°C | ||||||
|
Locations |
Period |
Benzene |
Toluene |
m,p-Xylene |
o-Xylene |
Ethyl-Benzene |
|
ITO, BSZ Marg |
Nov. 2000 |
38.1 |
152.0 |
68.4 |
26.9 |
21.9 |
|
East Arjun Nagar |
Nov. 2000 |
18.2 |
73.5 |
22.1 |
8.2 |
7.6 |
|
East Arjun Nagar |
Feb. 2001 |
18.2 |
41.2 |
16.7 |
6.4 |
5.4 |
|
East Arjun Nagar |
Mar. 2001 |
12.2 |
30.9 |
11.5 |
4.6 |
4.1 |
|
ITO, BSZ Marg |
Mar. 2001 |
7.4 |
24.6 |
14.9 |
6.4 |
4.8 |
|
ITO, BSZ Marg |
Apr. 2001 |
7.5 |
24.0 |
14.9 |
6.6 |
4.8 |
|
Jhilmil Ind.Area |
Apr. 2001 |
5.6 |
14.5 |
9.6 |
4.2 |
3.1 |
|
NPL, Pusa Road |
May. 2001 |
2.3 |
5.1 |
1.4 |
0.7 |
0.6 |
|
Hotel Taj Palace |
Sept.2001 |
6.0 |
16.3 |
6.3 |
2.6 |
1.8 |
|
SafdarJang Hospita |
Sept.2001 |
9.5 |
27.5 |
11.2 |
4.5 |
3.4 |
|
ITO, BSZ Marg |
Sep-Oct.2001 |
10.1 |
31.4 |
15.1 |
6.0 |
4.4 |
|
Britania Industry chowk |
Oct.2001 |
15.5 |
50.2 |
15.9 |
6.8 |
5.0 |
| Delhi (Nov.2k-Oct.2k1) |
Minimum |
2.3 |
5.1 |
1.4 |
0.7 |
0.6 |
| Average |
12.5 |
40.9 |
17.3 |
7.0 |
5.6 | |
| Maximum |
38.1 |
152.0 |
68.4 |
26.9 |
21.9 | |
| Winter |
16.5 |
56.0 |
22.2 |
8.8 |
7.1 | |
| Summer |
7.0 |
19.8 |
10.5 |
4.5 |
3.5 | |
Half hourly observations show (Figure:9) that concentration of all measured components remain prevalent since evening time till midnight which reflect that BTEX compounds do not dissipate into the environment immediately after release. They persist in the lower atmosphere during dark and comparative cooler temperature in the night until oxidised during daylight. It is observed that BTX level build up in high conc. for a longer duration at Traffic intersection as compared to residential & Institutional area.
Fig. 9 : Half Hourly Reading of MLU Analyser on Nov. 16th 2000 at ITO.
Table 14 : Benzene Emission from Vehicular Monitoring during 1999 in
Delhi. (By Using CS2-Method GC-FID, during January, 1999).
| S.No. |
Type of Vehicle | Sampling Code | Benzene Conc. (mg/m3) |
| 1. |
Maruti Car (without catalytic converter |
S-39 S-40 | 53 235 |
| TOTAL |
288 | ||
| 2. |
Maruti gipsy (with catalytic converter |
S-43 S-44 | 53 94 |
| TOTAL |
147 | ||
| 3. |
Ambrassoder (with catalytic converter) |
S-37 S-38 | 21 145 |
| TOTAL |
165 | ||
| 4. |
Three Wheeler (Petrol) | S-33 S-34 |
330 24 |
|
TOTAL | 354 | ||
| 5. |
Three Wheeler (Petrol) | S-41 S-42 |
882 280 |
|
TOTAL | 1162 | ||
| 6. |
Two Wheeler Two stroke | S-35 S-36 |
1574 666 |
|
TOTAL | 2240 | ||
| 7. |
Two Wheeler Two stroke | S-31 S-32 |
1528 222 |
|
TOTAL | 1750 |
Table 15 : Benzene Emission from Vehicular Monitoring during August
1998 in Delhi. (By Using CS2-Method GC-FID During August 1998).
| S.No. |
Type of Vehicle | Sampling Code | Benzene Conc. (mg/m3) |
| 1. |
Two Wheeler with Lead Petrol |
LP1 LP2 | 1133 176 |
| TOTAL |
1309 | ||
| 2. |
Two wheeler with unlead petrol |
ULP1 ULP2 | 226 138 |
| TOTAL |
364 |
 |
|  |