RESUMEN
A number of dumpsites occur on the island of Saipan and in the surrounding coastal waters. Many of these sites date back to the immediate post WWII clean-up period and contain a variety of wartime wastes. Metallic debris is generally the most visible waste material and commonly includes bomb fragments, artillery shells, bullets, and other military hardware. In this investigation, we examined the heavy metal status of soils from around several of these dumpsites and in any obvious drainage pathways leading from them to the coast. Sediments were also taken for analysis from a number of coastal discharge points and three submerged sites. Metal enrichment was evident for one or more elements in deposits from two of the three submerged sites and 24 of the 32 land-based sites visited. Copper, Pb, and Zn were the most commonly encountered contaminant metals with levels well in excess of 1000 µg/g(-1) in several instances. Elevated Hg and Cd concentrations were also relatively widespread throughout the study area although levels of each element seldom exceeded 1.0 and 10.0 µg/g(-1), respectively. Silver, another element of toxicological concern, was only occasionally detected despite registering a high of 42 µg/g(-1) at one particular site. The metal data were weighed against established benchmarks formulated for the protection of human and ecological health. Implications of the findings and issues of primary concern are briefly addressed.
Asunto(s)
Monitoreo del Ambiente/métodos , Sedimentos Geológicos/química , Metales Pesados/análisis , Contaminantes del Suelo/análisis , Suelo/química , Instalaciones de Eliminación de Residuos , Cobre/análisis , Humanos , Mercurio/análisis , Micronesia , Segunda Guerra MundialRESUMEN
Heavy metals were examined in sediments from the southern half of Saipan Lagoon. These waters provided tactical access for US troops during WWII and were heavily shelled at the time. Mercury profiles in sediments were, to some extent, reflective of this event. Samples from the southern end of the lagoon, where an old post-war dumpsite once existed, were found to be substantially enriched with Pb, Cu and Zn. Further north, the lagoon was primarily impacted by urban runoff. Metal enrichment in sediments from this region was generally highest at storm drain outlets and attenuated seawards. Moderate enrichment was rarely exceeded for any element other than Hg beyond the 50 m mark. Sediment quality guidelines used to flag potentially adverse ecological health effects revealed no PEL exceedances. TEL exceedances for Pb and Cu were identified in sediments near the former dumpsite. The public health implications of the data are briefly addressed.
Asunto(s)
Sedimentos Geológicos/química , Metales Pesados/química , Eliminación de Residuos/métodos , Segunda Guerra Mundial , Micronesia , Océano Pacífico , Contaminantes Químicos del Agua/análisisRESUMEN
In 2004-2005, several species of marine fish were collected for mercury (Hg) analysis from Saipan Lagoon, Saipan, Commonwealth of the Northern Mariana Islands. Relatively high concentrations were found in representatives from the Hafa Adai Beach area located some distance from known sources of Hg contamination. A follow-up investigation aimed at identifying additional land-based sources of Hg in the area was launched in early 2007. The study identified a medical waste incinerator as the primary source of Hg enrichment. The incinerator was operational for about 20 years before it was closed down by the U.S. Environmental Protection Agency (EPA) in January 2006, for multiple violations of the Clean Air Act. Stormwater runoff from this facility entered a drainage network that discharged into the ocean at the southern end of Hafa Adai Beach, about 1 km away. At the time of this investigation storm drain sediments at the coast were only marginally enriched with mercury although values some 50x above background were detected in drainage deposits a few meters down-gradient of the incinerator site. Mercury concentrations in fish from the Hafa Adai Beach area were also significantly lower than those determined in similar species 3 yr earlier. The implications of the data are briefly discussed.
Asunto(s)
Peces/metabolismo , Incineración , Eliminación de Residuos Sanitarios , Mercurio/análisis , Animales , Agua Dulce/análisis , MicronesiaRESUMEN
Extremely high levels of manganese (Mn) were encountered in foliar tissue of the monocot tree Pandanus tectorius from southern Guam with values exceeding 10,000 microg/g dry weight in some wetland representatives. Historically, dried Pandanus leaves were used extensively as a source of domestic fiber in the local Chamorro culture. A possible link between the use of this plant and a neurodegenerative disease complex that once plagued the island and is symptomatically similar to the occupational disease "manganism" poses an intriguing question that merits further investigation.