Under the study project titled "Post-Wastewater Treatment Determination of Endocrine Disrupting Compounds for Interventions" conducted in the rivers of Mega Manila, researchers identified endocrine-disrupting compounds (EDCs) that can potentially harm aquatic organisms and humans.

"Even in nanogram per liter to microgram per liter concentrations, these contaminants of emerging concern may have harmful effects on aquatic organisms and humans," researchers explained.

"The findings are critical evidence of contamination because there are no regulatory guidelines yet on these contaminants in the waterways and water systems," they added.

Meanwhile, based on the study, E1, commonly known as estrone, is a hormone capable of triggering endocrine-disrupting effects, even at low concentrations and with prolonged exposure. This includes potential fertility issues in aquatic organisms.

"It had been the only hormone detected to date in this study of the rivers, and its presence was attributed to municipal wastewater since this type of hormone can come from human and animal waste," UPD-CS said in a statement.

The study was conducted under the Department of Science and Technology (DOST) project and facilitated by researchers from the University of the Philippines (UP) College of Science, specifically the Institute of Chemistry (UPD-CS IC).

EDCs are combinations of substances that can imitate hormones, disrupting hormone regulation within the human body.

Prolonged exposure to these compounds may result in various health-related complications, specifically in the endocrine system, including respiratory and neurodevelopmental problems, infertility, diabetes, obesity, and potentially prostate or breast cancer.

"In the Philippines, it is important to know the presence and concentrations of EDCs in aquatic systems because many Filipinos depend on aquaculture and fishing for livelihood and subsistence," researchers said in their study.

Consequently, EDCs are classified as water Contaminants of Emerging Concern (CEC).

The research was led by Dr. Maria Pythias Espino and assisted by Kate Galera and Katrina Sta. Ana was conducted in the Marikina, Pasig, Angat, and Pampanga rivers.

This study marks the first documentation of the presence and levels of EDCs in these rivers and provided valuable baseline data for the DOST's ongoing research program, titled "Removal of Excess Nitrogen and Endocrine Disruptors from Wastewater' (RENEW)."

Other chemicals detected

Furthermore, besides the mentioned chemicals, experts also emphasized the discovery of industrial chemicals bisphenol A, nonylphenol, and octylphenol in the rivers.

"The researchers surmised that this was due to their extensive use in manufacturing various products such as detergents, textiles, plastics, and many more, but clarified that the concentrations are still below international guideline values," UPD-CS said.

Due to this finding, researchers noted that the said rivers need "more cleanup efforts, effective regulations in wastewater treatment, and sustainable water resource management policies are needed to improve the water quality of the rivers in Mega Manila."

The Marikina and Pasig rivers, as well as the Angat and Pampanga rivers, all flow into Manila Bay, significantly impacting one of the Philippines' economically and socially significant water bodies.

The United States, Canada, and the European Union have established guidelines for certain EDCs in their environmental waters.

Unfortunately, the Philippines currently lacks guidelines for regulating these compounds, and there are inadequate wastewater treatment facilities to mitigate CECs.

The research team anticipates that these findings will accelerate the development of national guidelines for monitoring and controlling these contaminants.

Furthermore, samples collected from the four rivers underwent solid-phase extraction and were subsequently analyzed using liquid chromatography with tandem mass spectrometry.

This analytical method allows for separating and identifying compounds present in ultra-trace concentrations.