OBJECTIVE: This paper examines the potential carcinogenic risk to human health associated with arsenic levels in five commercially important fish products from Laguna de Bay.
METHODS: Fish samples were collected in eight sampling stations in three major areas of the lake during the dry and wet seasons.  Coordinates of sampling locations were recorded using Global Positioning System and plotted in Geographic Information System digital maps. Analysis of arsenic was conducted using Atomic Absorption Spectrophotometer.
RESULTS: The highest life time cancer risk for arsenic was computed for tilapia from sampling station 2B during the dry season with risk value of 8.51x10-5 or about 85 excess cancer cases per 1,000,000 populations. Calculated cancer risks showed seasonal variations that were distinct among the five fish species. Excess life time cancer risks associated with fish consumption during dry season showed the following order of magnitude: Tilapia > Bighead carp > Kanduli >Bangus > Dalag. For wet season, the order of magnitude was: Bighead carp > Bangus > Kanduli >Tilapia > Dalag. Correlation analyses showed that fish mean standard size do not have significant effect on the levels of arsenic in fish samples for both dry and wet seasons.
CONCLUSION: This study concludes from the point of view of disease prevention that long-term consumption of five commercially important fish species from Laguna de Bay may cause significant carcinogenic health risk.