A researcher from the National Research Council of the Philippines revealed recently that environmental pollutants in form of xenoestrogens are the direct cause of the observed reproductive abnormalities in male common carp in Laguna de Bay.
Dr. Michelle Grace V. Paraso, the NRCP researcher affiliated to the College of Veterinary Medicine at the University of the Philippines Los Baños, said that Laguna de Bay is receiving untreated domestic waste from an estimated 1.47 million households. Water lake samples from Laguna de Bay were found to contain 17?-estradiol (E2), a hormone excreted by humans or animals that disrupts the endocrine and reproductive system of animals exposed in E2-contaminated aquatic environment. The levels of E2 in 2014 are in elevated amounts compared to those obtained in 2010, Dr. Paraso added.
Dr. Paraso examined the blood samples and male reproductive organ of both caged and feral fish and the results are rather striking. Caged male fish are found to have higher level of vitellogenin (which is normally expressed in egg-laying animals) presumably because caged fish are confined in one site unlike feral fish that get exposed to different dilutions of estrogenic contaminants in the lake. Both caged and feral fish have delayed growth and maturation of their testis and some have serious reproductive abnormality such as testicular degeneration which can cause male infertility. “The findings of this study are a cause for concern and may have important implications on the sustainability of fish populations,” remarked Dr. Paraso.
Among the important policy recommendations raised are (1) strict implementation of environmental laws, standards and regulations, especially provisions for proper waste management; (2) control and regulation of xenoestrogen emissions through strict enforcement of discharge permits particularly among large commercial establishments such as hotels, malls, etc; (3) establishment of basic sewage treatment facility in each home and the establishment of sewage treatment plant at the municipal level; and (4) incorporation of xenoestrogen testing an assessment of exposure impacts on aquatic organisms in environmental monitoring programs.
Dr. Paraso’s study is one of the six completed studies supported by NRCP that were presented during the Environmental Protection and Food Safety Policy Recommendations and Scientific Forum last 09 December 2015 at the Acacia Hotel, Alabang Mutinlupa City. The forum was intended to come up with policy recommendations that could be used by various stakeholders such as policy makers in the local and national governments in crafting of laws and ordinances for the protection of the environment and attainment of food safety.