17-Estradiol and Organochlorine Pesticide Levels in the East and West Sites of

The present study was conducted to determine contamination of Laguna de Bay with the hormone 17�-estradiol (E2) and organochlorine pesticides. Water samples were collected from the east and west bay of the lake particularly in sites adjacent to land-uses associated with the discharge of these compounds either through diffuse or point sources. While organochlorines were not detected at the limit of 0.05 ppb, E2 concentrations ranged from 0.29 ± 0.07 �g l -1 to 0.40 ± 0.16 �g l -1 in both sites. No inter-site difference (west vs. east) in E2 concentration was noted. The obtained E2 levels exceeded the reported threshold in literature for the induction of the yolk precursor vitellogenin and ovotestis formation in male � sh. Whether or not the measured E2 concentrations could elicit biologic effects that