Cleanliness of Manila Bay’s fish
THE CLEANUP in the aftermath of Supertyphoon “Mina” included the removal of a large amount of garbage from Manila Bay, but not all of the pollution are visible to the naked eye. Some contaminants have found their way to the bay through the Pasig and Pampanga rivers over time, and not all of it comes from industrial or agricultural sources.
In the Sept. 15 issue of the Journal of Hazardous Materials, a team of researchers from several Asian universities, including Fernando Siringan from the Marine Science Institute at the University of the Philippines Diliman, reported on the levels of chemical compounds from personal care products (PCPs) such as soap or cosmetics that have found their way into the fish caught in the bay.
“Manila Bay has been identified as one of the major hotspots of pollution in East Asia,” Siringan and his colleagues wrote in their paper. “The present investigation was aimed to study the occurrence and behavior of preservatives and antimicrobials in commercial fish species from Manila Bay and evaluate the dietary exposure of humans to these compounds.”
The researchers’ work is based on analyses of nearly 20 species of fish bought at various fish markets along Manila Bay back in 2008. Among the fish sampled were kalapato (yellowtail scad), kaltang or lapu-lapu (coral grouper), alumahan (Indian mackerel), galunggong (redtail scad) and samaral (spotted scat).
Almost all species of fish analyzed turned out to contain “measurable levels” of chemical preservatives called parabens and antimicrobial agents such as triclosan from personal care products. The results, the researchers said, “show prevalent contamination of Manila Bay by [these compounds].” Despite these words, they also found that the chemical levels do not exceed acceptable daily intake values.
For example, they noted that the preservative levels were found to be nearly 5,000-fold lower than the acceptable daily intake value, and, they added, “~500-fold lower than the reported daily exposure through body care products.” The researchers said the difference between the acceptable limit and the levels they found means that “the consumption of Manila Bay fish will not pose any health risk from parabens for consumers.”
However, the team also noted that the levels of antimicrobial agents are half of the acceptable daily intake value. The spread of the antimicrobial agents in Manila Bay was revealed when these compounds were identified inside fish that live close to the surface of the water and in fish that are found closer to the seabed.
“The obtained results will serve as vital baseline data for the environmental risk assessment associated with PCPs and coastal water management of Manila Bay and elsewhere,” Siringan and his colleagues wrote. “To our knowledge this is the first study on paraben preservatives and antimicrobials in fish from developing countries.”
The researchers also said that among other compounds they plan to check for in future studies involving Manila Bay are the active ingredients in sunscreens known as UV filters because of their involvement in coral bleaching.
Several of Siringan’s coauthors were also part of a paper on a different set of chemical pollutants found in Manila Bay fish that was published online Aug. 9 in the journal Environmental Pollution.
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