Petroleum hydrocarbon contamination in seawater along the Western Coast of the Philippines

A study on petroleum hydrocarbon concentrations in seawater from the South China Sea off the western coast of the Philippines was conducted during April to May 1998. The concentrations of dissolved/dispersed petroleum hydrocarbons (DDPH) in seawater samples were measured at 31 stations, using Ultraviolet Fluorescence (UVF) Spectroscopy technique. The DDPH concentrations were found to be in the range of 0.02 - 1.47 µg/l as chrysene equivalent, with an average of 0.25 µg/l. An attempt was made to compare between petroleum hydrocarbons in seawater samples from the near-shore area (8 stations) and the offshore area (23 stations). It was found that the DDPH concentrations of the near-shore stations were in the range of 0.03 - 0.47 µg/l, with an average of 0.12 µg/l, whereas the DDPH concentrations of the offshore stations were in the range of 0.02- 1.47 µg/l, with an average of 0.29 µg/l. However, the student’s t-test of the two data groups indicated that the two means were not significantly different at a = 0.05