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CUHK Releases the Second Batch of Test Results on Campus Environment
The Chinese University of Hong Kong (CUHK) earlier appointed an independent accredited laboratory to collect air, water and soil samples at various locations and at different times on campus and sent them for testing. The University has just received the second batch of test results.
In addition, in response to the concerns of some University members over the level of CS (2-chlorobenzalmalononitrile) on CUHK campus, the University has arranged to conduct another round of tests. The results will be announced as soon as they are received in 2-3 weeks’ time.
Here is the summary of the second batch of test results including 13 soil samples (#1-#12 & S8) and 2 water samples (W9 & W10) compared with the guidance notes/international standards.
(1) Soil samples
Table 1: For soil samples (#1 – #12)
|
Contaminant |
Test results |
Reference Level |
Reference Document |
|
Dioxins |
0.0037-0.0059 ng/g |
1 ng/g |
Risk-Based Remediation Goals (RBRGs) for Soil – Public Parks, published by Hong Kong Environmental Protection Department |
|
Total PCBs |
< 0.2 mg/kg |
0.756 mg/kg |
|
|
PAHs |
< 0.500-2.05 mg/kg |
3.83-10,000 mg/kg |
Table 2﹕For soil sample (S8)
|
Contaminant |
Test results |
Reference Level |
Reference Document |
|
Dioxins |
0.12 ng/g |
1 ng/g |
Risk-Based Remediation Goals (RBRGs) for Soil – Public Parks, published by Hong Kong Environmental Protection Department |
|
Total Cyanide |
< 1 mg/kg |
4,900 mg/kg |
|
|
Total PCBs |
< 0.200 mg/kg |
0.756 mg/kg |
|
|
PAHs |
< 0.500 mg/kg |
3.83-10,000mg/kg |
(2) Water samples
Table 3: For water samples (W9 & W10)
|
Contaminant |
Test results |
Reference Level |
Reference Document |
|
Dioxins |
4.6-4.7 pg/L |
30 pg/L |
Drinking Water Standards from USEPA |
|
Total Cyanide |
< 0.05 mg/L |
0.2 mg/L |
|
|
Total PCBs |
< 0.50 µg/L |
0.5 µg/L |
|
|
PAHs |
< 0.1 µg/L |
0.1-0.4 µg/L |
Conclusion
(1) Soil samples
Among the 12 soil samples (#1-#12), the dioxins (I-TEQ) are well below the Risk-Based Remediation Goals (RBRGs) of dioxins in soil (I-TEQ) for public parks as quoted in the Guidance Manual for Use of Risk-Based Remediation Goals for Contaminated Land Management published by Hong Kong Environmental Protection Department (HKEPD) in 2007. This indicates that the dioxins (I-TEQ) levels in these soil samples (#1 – #12) are not significant, and the results are comparable to soil samples (S1-S7 & S9) collected in the more distant locations away from No. 2 Bridge (see table 1).
Based on the test results of Total Polychlorinated Biphenyls (PCBs), all soil samples (#1 – #12) are lower than the respective limits of PCBs level (0.756 mg/kg) for public parks cited in the aforementioned Guidance Manual from HKEPD (see table 1).
Regarding the Polycyclic Aromatic Hydrocarbons (PAHs) levels for these soil samples (#1 – #12), all of them are below the level as required by the reference document (see table 1). For the figures of individual PAH compounds, please click here.
A soil sample with black-smoked materials (S8) was collected in the vicinity of the burned mattress in Sir Philip Haddon-Cave Sports Field. The test result of the dioxins (I-TEQ) level is relatively higher than that of other soil samples though it is only about one tenth of the reference level cited in the Guidance Manual. The possible reason for the elevated result may be due to the burning of rubber or plastic components of the mattress. For the other testing parameters such as Total Cyanide, Total Polychlorinated Biphenyls (PCBs) and Polycyclic Aromatic Hydrocarbons (PAHs) for the sample (S8), they are all well lower than their respective limits as required by the related reference documents (see table 2).
(2) Water samples
Two water samples (W9 & W10) had been collected from Jockey Club Postgraduate Hall 1. The test results reveal that the dioxins (I-TEQ) levels for both samples (W9 & W10) are from 4.6 to 4.7 pg/L. In accordance with drinking water standards from United States Environmental Protection Agency (USEPA), the dioxins levels for these water samples (W9 & W10) are not significant. For the other testing parameters such as Total Cyanide, Total Polychlorinated Biphenyls (PCBs) and Polycyclic Aromatic Hydrocarbons (PAHs), they are all much below their respective limits as required by the related reference documents (see table 3).
In view of the aforementioned interpretation, the health hazards of these contaminants from the soil (#1 – #12 & S8) and water (W9 & W10) samples are negligible.
Other test results will be announced as soon as they are available. Related information may be viewed here.
