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Journal Articles - UP - MSI

Permanent URI for this collectionhttps://repository.unesco.gov.ph/handle/123456789/50

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1995 - 199912000 - 20101

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    Heavy metal fluxes in Bang Pakong River Estuary, Thailand: Sedimentary vs diffusive fluxes
    Cheevaporn, V.; Jacinto, G. S.; San Diego-McGlone, M. L. (Elsevier BV, 1995-04)
    Estimates of the flux of heavy metals into the sediments (sedimentary flux) of Bang Pakong River Estuary and the diffusive flux of these metals across the sediment-water interface provide quantitative approximations on the movement of heavy metals from the water column into the sediments, and vice versa. Results showed higher sedimentary flux of Cu, Pb, Zn, Cd, Cr and Ni (0.1–16.8 μg cm−2 yr−1) relative to the diffusive flux of these metals (0.01–4.8 μg cm−2 yr−1). The percentage diagenetic contribution (ratio of diffusive flux to sedimentary flux) of these metals ranged from 10–91%. This suggests that diagenetic remobilization and release of these metals from the sediments into the overlying water may contribute to the subsequent redeposition of these metals into the sediments. Metal enrichment at the surface sediments when compared with deeper sections of the sediment may not necessarily be interpreted as evidence of recent natural, anthropogenic inputs alone, but may also be a consequence of the deposition of metals previously released from the sediments through diagenesis.
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    Effects of environmental regulations on heavy metal pollution decline in core sediments from Manila Bay
    Hosono, Takahiro; Su, Chih-Chieh; Siringan, Fernando; Amano, Atsuko; Onodera, Shin-ichi (Elsevier, 2010)
    We investigated the high-resolution heavy metal pollution history of Manila Bay using heavy metal concentrations and Pb isotope ratios together with 210Pb dating to find out the effects of environmental regulations after the 1990s. Our results suggested that the rate of decline in heavy metal pollution increased dramatically from the end of the 1990s due to stricter environmental regulations, Administrative Order No. 42, being enforced by the Philippines government. The presented data and methodology should form the basis for future monitoring, leading to pollution control, and to the generation of preventive measures at the pollution source for the maintenance of environmental quality in the coastal metropolitan city of Manila. Although this is the first report of a reduction in pollution in Asian developing country, our results suggest that we can expect to find similar signs of pollution decline in other parts of the world as well.