Emission, speciation, and evaluation of impacts of non-methane volatile organic compounds from open dump site

Figures & data

Figure 1. Sampling sites in Dhapa Dumping ground showing sampling points.

Table 1. Emission rate of nonmethane VOCs (in m³/year) estimated using flux box

	Winter				Summer				F value *
	Site A		Site B		Site A		Site B
	Mean	SD	Mean	SD	Mean	SD	Mean	SD		Significance level (P)
Benzene	55.3	66.4	91.4	185.9	59.5	91.6	151.6	215.9	1.38	0.24
Benzene dichloro-	32.4	44.8	13.9	44.2	31.7	46.7	48.5	71.4	3.97	0.05
Benzene, butyl-	14.3	23.9	32.6	90.2	21.0	39.3	55.9	66.3	1.66	0.20
Benzene, propyl-	25.3	41.5	8.4	19.0	30.1	48.8	35.4	28.0	8.15	0.01
Benzene, 1-chloro-2-methy	4.6	18.3	19.5	41.8	28.7	61.0	36.0	49.9	4.47	0.04
Chloroform	4.4	17.7	2.9	16.3	19.7	21.8	42.7	44.7	26.14	0.00
1,1,1-Trichloroethane	2.1	5.0	4.1	10.7	6.1	8.4	13.1	15.8	9.51	0.00
1,2-Dibromoethane	22.1	53.4	6.1	16.8	23.0	36.6	0.8	1.3	0.26	0.61
1,1,2,2-Tetrachloethane	5.0	7.3	2.0	4.9	9.3	10.5	6.2	8.0	7.66	0.01
2-Bromo1,3,5 trichlorobenzene	8.7	15.7	3.3	9.1	8.4	14.6	20.5	23.7	9.83	0.00
Ethylbenzene	22.5	33.5	35.9	88.7	30.8	40.3	65.9	102.9	1.91	0.17
Bromodichloromethane	10.6	18.2	8.5	24.4	9.3	17.6	14.6	42.6	0.33	0.56
Carbon tetrachloride	5.0	14.5	8.2	28.6	30.6	42.3	34.5	41.4	14.77	0.00
Propane, 1,2-dichloro-	16.5	52.4	9.7	41.7	11.4	14.8	15.0	16.3	0.05	0.82
Xylenes	26.0	39.1	26.9	62.8	52.8	62.9	70.3	74.9	8.73	0.00
Tetrachloroethylene	7.9	21.4	12.3	33.5	26.7	44.6	4.0	6.5	0.06	0.81
Toluene	38.9	56.0	55.9	103.2	53.6	81.0	138.3	145.1	6.70	0.01
Trichloroethylene	11.9	16.8	5.1	14.0	30.4	80.1	4.2	4.1	0.70	0.41
Formaldehyde	184.5	134.3	261.3	293.6	133.8	109.9	324.4	405.3	0.07	0.79
Acetaldehyde	262.2	319.1	765.7	1229.3	976.8	687.1	1188.6	1093.1	3.43	0.04
Acetone	9.9	21.7	177.9	245.5	36.9	44.2	291.9	358.5	1.21	0.28
Acrolein	47.0	61.3	7.8	9.7	111.1	228.0	120.2	154.8	6.64	0.01
Propanal	10.1	25.1	83.3	213.6	112.0	185.8	110.7	149.8	1.32	0.26
Butanal	9.1	7.3	50.9	137.8	11.7	14.3	28.0	28.9	0.36	0.55
Crotonaldehyde	143.3	239.7	197.3	556.1	1301.8	921.0	1160.3	1041.5	22.84	0.00
Benzaldehyde	12.3	16.1	29.7	36.5	5.6	3.2	11.8	12.1	4.37	0.04
Isovalaraldehyde	25.7	15.0	35.7	65.3	32.3	19.9	58.2	61.0	1.30	0.26
Valaraldehyde	63.0	56.8	32.0	32.6	376.9	183.0	235.3	265.5	23.82	0.00
o-Tolualdehyde	1.0	1.1	1.7	1.9	5.9	3.6	6.8	4.7	30.50	0.00
m,p-Tolualdehyde	4.4	2.5	4.9	5.8	3.1	2.9	13.5	35.4	0.77	0.39
Hexanal	68.4	63.6	36.8	35.2	499.7	186.8	521.8	412.3	45.04	0.00
2,5-Dimethylbenzaldehyde	11.8	9.7	2.8	2.8	12.0	10.3	8.8	9.7	2.50	0.12

Notes: Highlighted data indicate significant difference at P < 0.05.

*F values corresponding to one way ANOVA test between seasons.

Figure 2. Box–whisker plot showing seasonal variation of various NMVOC species in flux box.

Table 2. Correlation among rate of emissions of carbonyl compounds from dump site

	Formalde- hyde	Acetalde- hyde	Acetone	Acrolein	Propanal	Butanal	Crotonaldehyde	Benzaldehyde	Isovalaraldehyde	Valaraldehyde	o-Tolualdehyde	m,p-Tolualdehyde	Hexanal
Acetaldehyde	0.40
Acetone	0.54	0.47
Acrolein	0.04	0.16	−0.14
Propanal	0.28	0.72	0.50	−0.06
Butanal	0.10	0.44	0.34	−0.01	0.71
Crotonaldehyde	0.13	0.65	0.18	0.41	0.61	0.29
Benzaldehyde	0.51	0.46	0.32	−0.16	0.30	0.36	−0.06
Isovalaraldehyde	0.34	0.48	0.50	0.33	0.65	0.64	0.41	0.40
Valaraldehyde	0.13	0.40	0.01	0.30	0.34	0.00	0.83	−0.12	0.18
o-Tolualdehyde	0.10	0.19	0.11	0.32	0.26	0.09	0.39	0.03	0.56	0.33
m,p-Tolualdehyde	0.67	0.06	0.09	0.23	0.16	−0.01	0.17	0.21	0.31	0.24	0.38
Hexanal	0.08	0.34	0.16	0.33	0.29	−0.02	0.78	−0.19	0.29	0.89	0.51	0.16
2,5- Dimethylbenzaldehyde	0.17	0.27	0.00	0.15	0.29	−0.04	0.53	0.04	0.21	0.61	0.21	0.19	0.59

Note: Significant co-relations are denoted with boldface.

Figure 3. Flux emission from landfill: LandGEM model predicted vs. flux box measurement: (a) noncarbonyl VOCs and (b) carbonyl VOCs.

Figure 4. Contribution of different VOC species toward ozone-forming potential of Dhapa dumping ground.

Table 3. Estimated occupational exposure of dump-site workers, noncancer hazard and cancer risk

	IRAC classification	Chronic inhalation RfC (mg/m^3)	Chronic orel RfD (mg/kg-day)	Inhalation unit risk (μg/m^3)^−1	Concentration (μg/m^3)	Daily exposure (mg/kg-day)	HQ	Risk
Benzene	1	3.00E-02		7.80E-06	22.66	2.1E-03	7.55E-01	1.77E-04
Butylbenzene^$	—		5.00E-02		11.03	1.0E-03	2.09E-05
Propylbenzene	—	1.00E+00	1.00E-01		2.74	2.6E-04	2.74E-03
Chloroform	2B	9.77E-02		2.30E-05	13.83	1.3E-03	1.42E-01	3.18E-04
Ethane, 1,1,1-trichloro-	3	5.00E+00			3.10	2.9E-04	6.19E-04
Ethane, 1,2-dibromo-	—	9.00E-03		6.00E-04	3.08	2.9E-04	3.42E-01	1.85E-03
Ethane, 1,1,2,2-tetrachlo^$	2B		3.00E-02	7.40E-06	1.39	1.3E-04	4.39E-06	1.03E-05
Ethylbenzene	2B	1.00E+00		2.50E-06	14.11	1.3E-03	1.41E-02	3.53E-05
Bromodichloromethane^$	2B		2.00E-02	3.70E-05	1.24	1.2E-04	5.89E-06	4.59E-05
Carbon tetrachloride	2B	1.00E-01	4.00E-03	6.00E-06	3.12	3.0E-04	3.12E-02	1.87E-05
Propane, 1,2-dichloro-	3	4.00E-03		1.00E-05	1.29	1.2E-04	3.22E-01	1.29E-05
Xylene	3	1.00E-01			11.69	1.1E-03	1.17E-01
Tetrachloroethylene	2A	4.00E-02		2.60E-07	1.61	1.5E-04	4.03E-02	4.19E-07
Toluene	3	5.00E+00			21.24	2.0E-03	4.25E-03
Trichloroethylene	1	2.00E-03		4.10E-06	1.50	1.4E-04	7.48E-01	6.13E-06
Formaldehyde	1	9.83E-03		1.30E-05	21.15	2.0E-03	2.15E+00	2.75E-04
Acetaldehyde	2B	9.00E-03		2.20E-06	20.17	1.9E-03	2.24E+00	4.44E-05
Acetone	—	3.09E+01			6.60	6.3E-04	2.14E-04
Acrolein	3	2.00E-05			4.77	4.5E-04	2.39E+02
Propionaldehyde	—	8.00E-03			1.47	1.4E-04	1.83E-01
Benzaldehyde^$	—		1.00E-01		4.63	4.4E-04	4.39E-06

Notes: ^$HQ calculated from daily exposure and chronic oral RfD value.