The Fate of α-Pinene in Sediments of a Wetland Polluted by Bleached Pulp Mill Effluent: Is It a New Clue on the “Carlos Anwandter” Nature Sanctuary Wetland Case, Valdivia, South of Chile?

The volatile monoterpene alpha-pinene has been measured in sediments of a selected area at "Carlos Anwandter" Nature Sanctuary, a Ramsar protected wetland located at the northwest of Valdivia City, south-central Chile. The ecosystem was seriously damaged by an uncontrolled liquid emission of a pulp mill (CELCO-Arauco) located about 15 km upstream of Rio Cruces during 2004. Exploratory data analysis was applied to analytical data collected from sediment samples, having found alpha-pinene as a reiterative chemical at relatively high concentrations in some specific areas of the wetland. The decrease of the total concentration of alpha-pinene in the area under study is coincident with a point contamination that occurred during 2004 (12,240 ng g(-1)) showing a decay in 2005 (7,890 ng g(-1)) and middle of 2006 (4,060 ng g(-1)). The following years, last 2006, 2008, and 2009, show a relatively constant concentration with a clear tendency toward baseline levels (2,460-2,640 ng g(-1)). Since the decrease of concentrations of alpha-pinene in sediments in the period 2004-2009 shows an opposite trend as compared to the surface area increase of pine and eucalyptus plantation in Region de Los Rios, and not having found potential sources of alpha-pinene by anthropogenic activities other than the pulp mill in the area under study, it may be finally concluded that this compound did not enter the bodies of water from a gradual and natural process; instead there is a base to sustain anthropogenic input. alpha-Pinene in sediments may be a plausible chemical tracer capable of detecting pollution events over time and its impacts in aquatic ecosystems as well as changes in aquatic ecosystems produced by improperly treated pulp mill liquid emissions that use pine and eucalyptus species.