Industrial Development of Hong Kong and its Environmental Impacts as Recorded by Sediment Pb Variation in Shenzhen Bay, South China

Lead (Pb) is a carcinogenic metal in environment mainly related to industry. To investigate the environmental impacts of Hong Kong economic development, we measured the Pb concentration in a sediment core from Shenzhen Bay with direct freshwater discharge from the city. The sediment chronological framework was established through comparing the variation pattern of Pb concentration between sediment core and instrumental data from a nearby monitoring station initiated in 1980s and was extrapolated to pre-1980 sediment record. The results show that the Pb concentrations in the sediment core fall between 40.0 and 109.8mg/kg. More importantly, the sediment Pb content shows a rapid increase from Year 1968 to 1987, then a continuous reduction until 2005 and leveled concentrations afterwards. This temporal variation coincides with Hong Kong’s industrial progress during 1950s through 1980s and strict enforcement of environmental protection policy issued in 1985, while is seemingly unrelated to Shenzhen’s urbanization soared after 1985, suggesting that the sediment Pb in Shenzhen Bay is mainly sourced from the industrial development in Hong Kong.

Keywords: Lead; Sediment; X-ray fluorescence (XRF); Grain size; Hong kong; Shenzhen bay