Trace elements and polycyclic aromatic hydrocarbons in road gully sediments from different land uses, Hong Kong
- 53 Downloads
This study investigated the concentrations of cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), zinc (Zn), and polycyclic aromatic hydrocarbons (PAHs) in sediments collected from gully pots for road drainage in Hong Kong. The presence and intensity of anthropogenic contamination of road gully sediments were assessed. Identifications of potential sources of trace elements and PAHs were performed to help understand the situation for future control of pollution to the land and aquatic environments.
Materials and methods
Gully sediment samples were collected from gully pots of 18 roads that are potentially exposed to different pollution sources in Hong Kong. The selection of roads considered different road features, adjacent land uses, and traffic volumes. Composite samples were collected for the analysis of trace elements (Cd, Cr, Cu, Pb, Ni, and Zn) and PAHs by an accredited environmental testing laboratory. Geo-accumulation index (Igeo), contamination factor (Cf), modified degree of contamination (mCd), ecological risk factor (Er), and pollution load index (PLI) were used to assess the level of ecological risk of trace element contamination. Positive matrix factorization (PMF) and PAH diagnostic ratios were applied to identify the sources of trace elements and PAHs.
Results and discussion
Elevated trace element concentrations were commonly found in gully sediments. The concentrations of Zn (267–3700 mg kg−1) were the highest compared to the other trace elements. Noticeable high concentrations of Cu (27–1020 mg kg−1), Pb (21–332 mg kg−1), and Cr (14–439 mg kg−1) were found in all samples. The PAH contents were moderate to high (0.6 to 24.7 mg kg−1). Commercial/industrial emissions and road features that cause frequent acceleration-deceleration and turning events showed important influences on the contaminant levels. Strong correlations between the concentrations of Cd, Cr, Pb, and Zn were identified, implying that these trace elements are likely from common sources. The contamination assessment indices reflect significant sediment pollution. The ecological risk ranges from the considerable/moderate-risk class to over the high-risk class.
The collected gully sediments are identified as highly contaminated and need to be isolated from the environment upon final disposal. Through the comprehensive analysis of the collected data, this study provides a detailed insight into the contaminant levels of road gully sediments and potential sources of contamination. Disposal of gully sediments and potential impacts due to release of contaminants into the downstream aquatic environment during rainstorm events should receive attention and need further investigation.
KeywordsGully sediments Hong Kong PAHs Trace elements
Support for this project was provided by the Research Grant Council under the Inter-Institutional Development Scheme (IIDS), Ref. No. UGC/IIDS13/E02/14.
- Addo MA, Darko EO, Gordon C, Nyarko BJB, Gbadago JK (2012) Heavy metal concentrations in road deposited dust at Ketu-South District, Ghana. Int J Sci Technol 2:28–39Google Scholar
- Depree C (2008) Contaminant characterization and toxicity of road sweepings and catchpit sediments: towards more sustainable reuse options. Land Transport New Zealand Research Report 345. Available via http://www.nzta.govt.nz/assets/resources/research/reports/345/docs/345.pdf. Accessed 21 Feb 2016
- East-West Gateway Coordinating Council (2000) Highway runoff and water quality impacts. East-West Gateway Coordinating Council. Available via http://www.ewgateway.org/pdffiles/library/aq/wqhwywords.pdf. Accessed 22 June 2017
- EL-Bady MSM (2014) Road dust pollution by heavy metals along the sides of expressway between Benha and Cairo, Southern of Nile Delta. Egypt J Appl Environ Biol Sci 4:177–191Google Scholar
- Environment Canterbury (2012) Canterbury regional urban stream sediment and biofilm quality survey. Report prepared by Golder Associates (Report No. R12/5). Environment Canterbury. Available via https://www.ecan.govt.nz/data/document-library/?ids=2381830,2433534,2433544,2378551,2360316,1442859,476336,813553,932275,1597829,813561,1083689,1929584,1929055,2993014,927106,785522,1762968,1545732,1151106,2032464,1106929,1258844,1933404. Accessed 16 May 2017
- Environmental Protection Department (2013) Water quality. Hong Kong Water Quality Resource Centre. Environmental Protection Department. Available via http://wqrc.epd.gov.hk/en/water-quality/dio_fur.aspx. Accessed 14 November 2015
- Environment, Transport and Works Bureau (2002) Technical Circular (Works) No. 34/2002 – Management of Dredged/Excavated Sediment, Hong Kong Special Administrative Region GovernmentGoogle Scholar
- Gadd J, Kennedy P (2000) Preliminary examination of organic compounds present in tyres, brake pads and road bitumen in New Zealand. Report prepared by Kingett Mitchell Ltd for Ministry of Transport. Ministry of Transport. Available via http://www.transport.govt.nz/assets/Import/Documents/stormwater-organics-2.pdf. Accessed 24 May 2016
- Ghaleno OR, Sayadi MH, Rezaei MR (2015) Potential ecological risk assessment of heavy metals in sediments of water reservoir case study: Chah Nimeh of Sistan. Proc Int Acad Ecol Environ Sci 5:89–96Google Scholar
- Goonetilleke A, Wijesiri B, Brandala ER (2017) Water and soil pollution implications of road traffic. In Hester RE, Harrison RM (ed) Environmental impacts of road vehicles: past, present and future (pp. 86–106). United Kingdom, The Royal Society of ChemistryGoogle Scholar
- Grigoratos T, Martini G (2014) Non-exhaust traffic related emission. Brake and tyre wear PM. JRC Science and Policy Reports (Report EUR 26648EN). Available via https://ec.europa.eu/jrc/en/publication/eur-scientific-and-technical-research-reports/non-exhaust-traffic-related-emissions-brake-and-tyre-wear-pm. Accessed 24 May 2016
- Kabata-Pendias A, Pendias H (2001) Trace elements in soils and plants. CRC Press, WashingtonGoogle Scholar
- Kennedy P, Gadd J (2000) Preliminary examination of trace elements in tyres, brake pads and road bitumen in New Zealand. Report prepared by Kingett Mitchell Limited for Ministry of Transport. Ministry of Transport. Available via http://www.transport.govt.nz/assets/Import/Documents/stormwater-inorganic3.pdf. Accessed 26 May 2016
- Likuku AS, Mmolawa KB, Gaboutloeloe GK (2013) Assessment of heavy metal enrichment and degree of contamination around the copper-nickel mine in the Selebi Phikwe Region, Eastern Botswana. Environ Ecol Res 1:32–40Google Scholar
- Muller G (1969) Index of geoaccumulation in sediments of the Rhine River. Geo J 2:108–118Google Scholar
- Nasser MA, Saleh IA (2012) Heavy metal contamination in roadside dust along major roads and correlation with urbanization activities in Cairo. Egypt J Am Sci 8:379–389Google Scholar
- Sivakumar S, Chandrasekaran A, Balaji G, Ravisankar R (2016) Assessment of heavy metal enrichment and the degree of contamination in coastal sediment from south east coast of Tamilnadu, India. J Heavy Met Toxic Dis 1:1Google Scholar
- The President and Fellows of Harvard College (2015) WorldMap. The President and Fellows of Harvard College. Available via http://worldmap.harvard.edu/maps/4849. Accessed on 27 July, 2016
- The Government of the Hong Kong Special Administrative Region (2015a) LCQ6: air pollution caused by container vessels LCQ6 Annex II. Press Releases. Available via http://www.info.gov.hk/gia/general/201506/17/P201506170559.htm
- The Government of the Hong Kong Special Administrative Region (2015b) Ocean-going vessels required to switch to clean fuel while at berth with effect from July 1. Press Releases. Available via http://www.info.gov.hk/gia/general/201504/15/P201504150324.htm
- Transport Department (2014) The annual traffic census 2014 (TTSD Publication No.15CAB1). Transport Department. Available via http://www.td.gov.hk/en/publications_and_press_releases/publications/free_publications/the_annual_traffic_census_2014/index.html. Accessed 15 Aug 2016
- U.S. Environmental Protection Agency Office of Research and Development (2014) EPA positive matrix factorization (PMF) 5.0 fundamentals and user guide (Report No. EPA/600/R-14/108). Washington. Available via https://www.epa.gov/air-research/epa-positive-matrix-factorization-50-fundamentals-and-user-guide
- Yim WWS, Nau PS (1987) Distribution of lead, zinc, copper and cadmium in dust from selected urban areas of Hong Kong. Hong Kong Eng 7–14Google Scholar