Agent Orange Footprint Still Visible in Rural Areas of Central Vietnam

Table 1

Overview of international interlaboratory studies—determination of PCDD/F-TEQ in environmental matrices.

Name of study	Implementer	Lab code	Matrix	TEQ	ALS value (ng/g) or (pg/uL)	Refer. value (ng/g) or (pg/uL)	Z-score for TEQ*
International Interlaboratory Study IIS-01 on sludge samples, 2006	Luc Levert, M.Sc. Chimiste Chef de division Matériaux de Reference, Centre d'expertise en analyse environnementale du Québec, Canada	425	Sludge 1	Lower bound	0.0197	0.0179	NA
				Upper bound	0.0197	0.0179
			Sludge 2	Lower bound	0.0103	0.0101
				Upper bound	0.0103	0.0101
			Solution	Lower bound	86.5	85.8
				Upper bound	86.5	85.8
International sediment exchange for tests on organic contaminants, Exchange Programme (SETOC), 2006, I.Q	SETOC-Wepal; P.O. Box 8005; NL-6700 EC Wageningen; The Netherlands	ECCM (841)	Sediment 1	Lower bound	0.0233	0.0216	NA
				Upper bound	0.0233	0.0216
			Sediment 2	Lower bound	0.0430	0.0312
				Upper bound	0.0430	0.0312
			Sludge 3	Lower bound	0.0450	0.0424
				Upper bound	0.0450	0.0424
			Soil 4	Lower bound	0.0864	0.142
				Upper bound	0.105	0.142
11th round of the International Intercalibration Study, 2006 (in cooperation with Wepal-SETOC)	Profesor Bert van Bavel, Chairman and Coordinator of International Intercalibration Studies, Dyltabruk, Sweden	153	Ash A	Lower bound	0.179	0.151	0.74
				Upper bound	0.179	0.151
			Ash B	Lower bound	0.343	0.333	0.32
				Upper bound	0.343	0.333
			Ash C	Lower bound	0.196	0.192	0.21
				Upper bound	0.196	0.192
			Sediment A	Lower bound	0.0233	0.0233	−0.03
				Upper bound	0.0233	0.0233
			Sediment B	Lower bound	0.0356	0.0340	0.45
				Upper bound	0.0356	0.0340
			Sludge C	Lower bound	0.0450	0.0445	−0.04
				Upper bound	0.0450	0.0445
			Soil D	Lower bound	0.162	0.151	0.69
				Upper bound	0.162	0.151
			Solution R	Lower bound	83.7	82.2	0.17
				Upper bound	83.7	82.2
12th round of the International Intercalibration Study, 2007 (in cooperation with Wepal-SETOC)	Profesor Bert van Bavel, Chairman and Coordinator of International Intercalibration Studies, Dyltabruk, Sweden	153	Ash A	Lower bound	2.97	2.90	0.24
				Upper bound	2.97	2.90
			Ash B	Lower bound	1.06	1.07	0.04
				Upper bound	1.06	1.08
			Ash C	Lower bound	0.257	0.268	−0.18
				Upper bound	0.257	0.269
			Sediment A	Lower bound	0.0526	0.0600	−0.94
				Upper bound	0.0526	0.0600
			Sediment B	Lower bound	0.0229	0.0270	−0.78
				Upper bound	0.0239	0.0270
			Sediment C	Lower bound	8.67	9.05	−0.09
				Upper bound	8.67	9.05
			Sludge D	Lower bound	0.00192	0.0029	−0.72
				Upper bound	0.00279	0.0032
			Solution	Lower bound	25.1	22.1	1.78
				Upper bound	25.1	22.1
Cambridge Isotope Laboratories, 2007 International Interlaboratory Study on Fly Ash Reference Material	Jay Grazio, Study Coordinator,; Cambridge Isotope Laboratories, Inc.,; USA	ALS Czech Rep.	Fly ash	Lower bound; Upper bound	0.112; 0.112	0.133; 0.133	NA
13th round of the International Intercalibration Study, 2008 (in cooperation with Wepal-SETOC)	Profesor Bert van Bavel, Chairman and Coordinator of International Intercalibration Studies, Dyltabruk, Sweden	153	Ash A	Lower bound	0.162	0.165	0.08
				Upper bound	0.162	0.165
			Ash B	Lower bound	1.01	1.00	0.25
				Upper bound	1.01	1.00
			Ash C	Lower bound	0.186	0.167	0.50
				Upper bound	0.186	0.167
			Sediment A	Lower bound	0.0283	0.0373	−1.27
				Upper bound	0.0285	0.0380
			Sediment B	Lower bound	0.0360	0.0345	0.22
				Upper bound	0.0360	0.0350
			Sediment C	Lower bound	0.726	0.723	0.17
				Upper bound	0.726	0.721
			Sediment D	Lower bound	0.00183	0.00328	−1.03
				Upper bound	0.00312	0.00363
			Solution	Lower bound	319	312	0.39
				Upper bound	319	312
14th round of the International Intercalibration Study, 2009 (in cooperation with Wepal-SETOC)	Profesor Bert van Bavel, Chairman and Coordinator of International Intercalibration Studies, Dyltabruk, Sweden	153	Ash A	Lower bound	0.167	0.179	NA
				Upper bound	0.167	0.180
			Ash B	Lower bound	0.995	0.995
				Upper bound	0.995	0.995
			Ash C	Lower bound	0.941	0.915
				Upper bound	0.941	0.915
			Sediment A	Lower bound	0.00331	0.00940
				Upper bound	0.00385	0.00961
			Sediment B	Lower bound	0.0664	0.0781
				Upper bound	0.0664	0.0782
			Sediment C	Lower bound	0.203	0.213
				Upper bound	0.203	0.214
			Sediment D	Lower bound	0.148	0.150
				Upper bound	0.148	0.150
			Solution	Lower bound	152	158
				Upper bound	152	158

∗Acceptable 𝑍-score is between: (−2.0 and +2.0); NA: 𝑍-scores not available.